Microbiology Exam Iii

Front 1

Orthomyxoviruses

Back 1

3 types:
-Influenza A: infects humans and other species
--can cause pandemics
--Most common type of influenza
-Influenza B: restricted to humans
-Influenza C: Mostly restricted to humans
--less common

Front 2

Human Influenza Pandemics in the 20th century

Back 2

-1918: Spanish Flu, 20-40 million deaths
--H1N1
-1957: Asian Flu 1-4 million deaths
--H1N2
-1968: Hong Kong Flu 1-4 million deaths
--H3N2
-Swine Flu, 18,000 deaths
--H1N1
--young people wit weaker immune systems

Front 3

Spanish Influenza

Back 3

-Orthomyxovirus
-H1N1 type virus
-Affected middle aged and younger people
-over 30 million deaths
-War contributed to close contact and easy transmission of disease

Front 4

Influenza Virus Nomenclature

Back 4

Type / Species / Location / Number of isolate / year isolated

-Serotypes are based on surface proteins

Front 5

Influenza Virus microscopy

Back 5

-Can see proteins on surface of the virus

Front 6

Influenza A virus Key features

Back 6

- 100nm large
- Enveloped virus, carries part of cell membrane
-Genome is segmented negative strand RNA
-8 genomic segments
-10 genes total
--not the smallest virus, but pretty darn small
-Each genome segment forms a ribonucleoprotein (RNP)
-Transcription and replication occur in the nucleus
-Translation and protein synthesis occurs in the cytoplasm

Front 7

Influenza Virus eclipse period

Back 7

1. Virus binds to cell surface receptors
2. Endosome is formed around enveloped virus
3. Virus membrane/envelope and endosome fuse
--viral negative sense RNA is released into the cytosol
4. Viral RNA enters the nucleus and is replicated
-mRNA synthesis and RNA replication occurs in the nucleus
-Proteins are translated and synthesized in cytoplasm
5. Viral genome buds with late proteins to form enveloped virus

Front 8

Ribonucleoprotein
RNP

Back 8

-Negative-sense single-stranded RNA with 3 polymerase subunits
-Genomic organization of influenza virus
-Influenza RNA is ALWAYS part of complex with ribonucleoproteins
--unstable as RNA alone

Front 9

Influenza A virus genome shuffling

Back 9

-Segmented genome allows for reassortment of genomic segments
-Can cause major changes in subtype
-Form of antigenic shift
-Allows influenza virus to change and jump from species to species
-All segmented viruses undergo antigenic shift
--8 segments of orthomyxoviruses allows for increased antigenic shift

Front 10

Antigenic Shift and Orthomyxoviruses

Back 10

-Segmented genome allows for genomic shuffling/rearrangement
-Causes major changes in viral sub type
-Allows virus to change and jump from species to species
-Gives minor changes that change the virus and how a body interacts with the virus

Front 11

Influenza A mutation frequency

Back 11

-HIGH mutation frequency
-Single AA changes occur over time due to selective pressure and mistakes made by error-prone viral polymerase
-Cause antigenic drift
-Mutations occasionally make virus more pathogenic
-Minor changes that change virus and how abody interacts with the virus

Front 12

Antigenic Shift

Back 12

-Promotes fast evolution of viruses
-Gives virus means to jump from one species to another
-generates reassortment viruses
-Changes ability of the virus to interact with the host
-Can combine different strains to give new highly pathogenic strains with different viral proteins on the surface

Front 13

Swine flu and antigenic shift

Back 13

-Originated in March/April 2009 in Mexico
-Reassortment genome containing gene segments from avian, human, and swine influenza strains
-Transmitted to humans from pigs
--inhalation of viral particles
-Transmitted from human to human by inhaling viral particles
-Symptoms: high fever, coughing, sneezing, breathing difficulties, loss of appetite

Front 14

Antigenic Drift

Back 14

-Small mutations in key proteins
-Alter antigenicity and/or virulence
-Changes ability of virus ti infect, replicate, bud from the cells, etc.

Front 15

Influenza virus binding

Back 15

-Binds by HA protein
-Hemagglutinin
-Beinds sialic acid residues on cell surface
-Required for virus penetration and fusion
-HA mutations can directly affect pathogenesis

Front 16

Hemagglutinin

Back 16

-Surface protein on orthomyxoviruses/influenza viruses
-Allows virus to be infectious
-Binds sialic acid residues on the cell surface
-Mutations can directly affect pathogenesis
--can become much more efficient at binding
--can alter ability of virus to function
-Does not put the virus into the cell
--allows virus to attach
-HA0: non-infectious
-HA1 and HA2: infectious

Front 17

Forms of Hemagglutinin

Back 17

-HA0: non-infectious
--HA0 is cleaved by a host protein into HA1 and HA2
--Cleavage is required for viral penetration and fusion
-HA1 and HA2: infectious
--HA1: globular domain
--HA2: fusion peptide, linear form
-Allows virus to fuse with endosomal membrane

Front 18

hemagglutinin Cleavage

Back 18

-Cleaved from HA0 to HA1 and HA2
-Cleavage is required for viral penetration and fusion
-More cleavable HA leads to a more virulent virus
-Proteins have to change and become activated to fuse with endosomal membrane
-Cleavage exposes peptide and allows it to bind to the host membrane
-Host proteases cleave HA protein

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Less Virulent Hemagglutinin

Back 19

-Few basic residues at cleavage site
-Not cleaved easily
-No cleavage, no exposure, no fusion
-Only host proteases in the respiratory tract recognize and cleave protein
-Leads to respiratory tract infections

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More virulent Hemagglutinin

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-Many basic residues at cleavage site
-HA0 is cleaved easily
-Host proteases exist in many different cell types, can recognize and cleave HA protein
-Potentially deadly systemic infection

Front 21

Influenza virus Fusion into Endosome

Back 21

-Fusion is facilitated by cleavage of HA0 protein by host proteases
-Mediated by viral HA and M2 proteins
-M2 channel must be active for fusion
-Endosomal pH is key for viral fusion

Front 22

Low pH and influenza virus Fusion

Back 22

-low pH allows for activated M2 channel
-Ion enters the virion
-Viral protein interactions are altered
-HA conformational change occurs
-HA fusion peptide translocate 100Ao
-Fusion occurs and viral RNA segments are released into the cytoplasm

Front 23

Influenza Virus Replication

Back 23

-Replicates in the nucleus
-Assembly and packaging occurs in the cytoplasm
-Negative sense Viral RNA is transcribed into positive sense cRNA and mRNA

Front 24

Influenza Virus Budding

Back 24

-Due to Neuraminidase (NA)
-Temporary cleavage of Sialic acid, prevents HA from interacting with sialic acid
-Local disruption of Sialic Acid interaction with HA

Front 25

Neuraminidase

Back 25

-Component of influenza virus
-Allows virus to bud off of the host cell
-Cleaves Sialic acid from the cell surface, allowing release of infectious viruses
-Prevents HA from interacting with Sialic acid
-Local phenomenon near surface of the viral particle

Front 26

Neuraminidase inhibitors

Back 26

-Antivirals
-limit virus spread
-Reduce transmissibility

Front 27

Drugs against influenza virus

Back 27

-Symmetrel Fulmadine: M2 channel inhibitor
-Relenza Tamiflu: Neuraminidase inhibitor

Front 28

Hemagglutinin and Neuraminidase subtypes

Back 28

-16 hemagglutinin subtypes
-9 Neuraminidase subtypes

-Subtypes allow for different strains

Front 29

Infection of animals by Influenza virus

Back 29

1. Aerosol
-sneezing
-breathing
2. Fomites
-direct contact
-fecal matter

Enveloped virus, dies on dry surfaces
Influenza viruses infect many different species
-transfer between species via poultry, wild birds, and swine

Front 30

Emergence of new Influenza Viruses

Back 30

-Reassortment and mutations
-Modern pig and poultry production creates conditions for mass animal influenza outbreaks
-Proximity of humans and animals
--farms and markets
--creates potential for new viruses to emerge

Facilitates antigenic shift

Front 31

HA and spread of influenza

Back 31

-HA is a critical virulence factor
-HA restricts virus host range
--specific to host
-No prior immunity against new HA molecules
--new host is not protected, virus can go wild

Front 32

NS1

Back 32

-Internal protein of influenza virus
-Immune antagonist
--distracts the immune system and allows virus growth

Front 33

Avian influenza virus

Back 33

-Worldwide distribution
-Most important natural reservoir for influenza virus
--wild ducks, migratory birds
-Virus replicates in the lungs and cell lining the intestinal tract
-Fecal-oral transmission
-Tissue/organ specific proteases allows targeting of specific organs
-highly pathogenic avian strains H5 and H7 cause "Fowl Plague"
--systemic disease and CNS involvement
-Dx: virus isolation from cloacal swabs and serological typing or PCR
-Control with quarrantine, hygiene, and depopulation of infected flocks

Front 34

Avian Influenza virus worldwide distribution

Back 34

-Lots out bird flu in the world
-Lots of outbreaks

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Avian Influenza Virus in PA

Back 35

-May 1983, less than 10% mortality
-October 1983, more than 80% mortality
-Both were H5N2 strains
-2 key differences:
--Glycosylation site removed from HA from virulent strain, made one more virulent
--Multiple basic AA inserted at protease cleavage site

Front 36

More cleavable HA

Back 36

More virulent virus

Front 37

Hong Kong outbreak of Avian Flu

Back 37

-H5N1 virus transmitted directly to humans from birds
--Not human to human transmission
-New glycosylation site and additional basic AA present in H5 due to antigenic drift
-H5 HA is more readily cleaved by host proteases
--leads to systemic disease and high pathogenicity

Front 38

Equine Influenza Virus

Back 38

-2 subtypes
--A/Equine/Prague/1/56 (H7N7)
--A/Equine/Miami/1/63 (H3N8)
-Highly contagious via aerosol droplets
-Induces fever, dry cough, increased nasal exudate, secondary bacterial infections
-Infectious for at least 5 days
-3 weeks for complete recovery
-Vaccine is not effective, short-lived immunity only
-Control with quarantine, disinfection, and vaccination
-REPORT

Front 39

Equine Influenza Virus Dx

Back 39

-Virus isolation from nasopharyngeal swabs
-Influenza A antigen detection
-Paired serology
-PCR

Front 40

Canine Influenza Virus

Back 40

-Originates from Equine influenza virus
-First detected in racing greyhounds in 2004
--new dog-specific lineage H3N8
-2005: declared newly emerging pathogen in dog population in US
-Outbreaks in many states in 2013
-No evidence of transmission from dogs to humans
-Respiratory tract disease with secondary bacterial infections
--often mistaken for kennel cough
-Treatment is supportive
-1-5% mortality rate
-Vaccine exists

Front 41

Pigs and Influenza Virus

Back 41

-Pigs are "mixing vessels"
-Have cell surface receptors for both human and avian viruses
-Can support binding of viruses from many different species
-Over time, avian viruses in swine developed ability to recognize other receptors

Front 42

Properties of Rhabdoviruses

Back 42

-Enveloped
-Bullet shaped
-Have single external peplomer (G-protein)
-Helical nucleocapsid with linear negative-sense ssRNA genome
--11-15 kb
--encodes 5 structural proteins
-Replicates in cytoplasm

Front 43

Structural Proteins encoded by Rhabdovirus genome

Back 43

1. N: Nucleocapsid protein
2. P: Phosphoprotein (component of polymerase)
--interacts with L-protein
3. M: Matrix protein (assembly and budding)
4. G: Glycoprotein (attachment)
5. L: Large protein ( RN-dependent RNA polymerase)
--Interacts with P-protein

ONLY structural proteins encoded, no other proteins

Front 44

Negri bodies

Back 44

-Replicating rhabdoviruses in cytoplasm
-Focal areas of viral RNA
-Appear as red or dark bodies
-Diagnostic for rabies infection

Front 45

-Replicating rhabdoviruses in cytoplasm
-Focal areas of viral RNA
-Appear as red or dark bodies
-Diagnostic for rabies infection

Back 45

1. Vesicular Stomatitis Virus
-Vesiculovirus genus
2. Rabies virus
-Lyssavirus genus

Front 46

Rabies Virus Tanscription and Replication

Back 46

-Transcription occurs first
-Genome is organized so that most-needed protein is transcribed first
--allows for most about of protein to be made
--N-P-M-G-L
-mRNA transcripts are translated into viral proteins
-Replication gives +sense RNA, need replicative intermediate with +/- sense RNA to give –sense progeny RNA

Front 47

Animal Rhabdoviruses

Back 47

-Many different types
-Rabies is most important
--exists on all continents except Antarctica

Front 48

Rabies incidence and distribution in USA

Back 48

-Increasing since 19555!
-East coast: raccoon rabies
-Midwest: skunk rabies
-Texas: grey fox, coyote, dog rabies
-California: skunk rabies
-Canada and Alaska: Arctic Fox rabies

Front 49

Oral Rabies Vaccine Project

Back 49

-Recombinant Vaccinia virus expressing rabies virus G-glycoprotein
--live virus
-2ml of vaccine encased in wax layer with dog food or fish meal
-Vaccine is given in food, different recipes for different species
-Currently successful use in Texas and along east coast

Front 50

Raboral
V-RG

Back 50

-Oral Rabies Vaccine
-Cloned G-glycoprotein from rabies put onto vaccinia virus
-Dropped in various wildlife areas to provide vaccination to wildlife reservoir

Front 51

Rabies vaccine bait

Back 51

-Contains Raboral/V-RG vaccine
-Packet of liquid medicine within bait
-Tetracycline is also included
--animal inoculates self when biting into bait
--causes yellow markings on teeth, can identify animal as vaccinated
-NOT harmful to pets

Front 52

Infectious path of Rabies Virus

Back 52

1. Raccoon is bitten by rabid animal
2. Rabies virus enters raccoon through infected saliva
-virus may replicate a little in muscle tissue
3. Virus spreads through peripheral nerves to spinal cord and brain
4. Incubation in raccoon body for 3-12 weeks
-HIGHLY variable incubation period
-no signs of illness during incubation
5. virus replicates rapidly once it reaches the brain
-passes to salivary glands
-animal begins to show signs of disease
6. Infected animal dies within 10 days of showing signs

Front 53

Rabies incidence in domestic animals

Back 53

-Has dropped consistently since 1955
-Cats currently have highest incidence
-Conversely, cases in wild animals has increased since 1955

Front 54

Rabies Pathogenesis

Back 54

Zoonotic disease of wild and domestic animals
--can be transmitted to anyone and everyone!
-Entry via bite wound or skin abrasion
-Primary replication occurs locally in muscle tissue, low level replication
-Incubation period is highly variable
--usually 3-8 weeks, but can be more than a year
-Eventually infects peripheral nerves, travels to CNS and produces severe and fatal encephalitis
-Vaccine must be given EARLY for protection
-Dx: immunofluorescence of skin biopsies and presence of Negri bodies

Front 55

Rabies Virus progression

Back 55

1. Virus inoculated via saliva from bite or abrasion
2. Viral replication in muscle at site of wound
3. Virion enters PNS, ascends retrograde slowly, passive ascent via sensory fibers
4. Replication in dorsal ganglion
5. Rapid ascent towards spinal cord
6. Infection of the spinal cord, brainstem, cerebellum, ALL parts of brain are affected
7. Affects aggression areas of the brain, coincides with time when virus particles in saliva is high
8. Descending infection via nervous system to eye, salivary glands, skin, and other organs

Front 56

Rabies virus in the Salivary Glands

Back 56

-Formed by budding on the apical plasma membranes
-Virus is free to enter saliva
-Easily transmitted to the next host

Front 57

Rabies Virus in the Brain

Back 57

-Virus particles formed by budding on internal cellular membranes
-Virus is trapped
-Infects neighboring cells slowly
-Virus remains cell-associated

Front 58

Location of Rabies Bite

Back 58

-Determines incubation period
-Closer to the CNS, shorter incubation period

Front 59

Clinical picture Classical/Furious of Rabies in Humans

Back 59

-More common (80%)
-Prodronal phase
-Sensory excitation phase
-Coma and paralysis phase

Front 60

Clinical picture of Dumb/Paralytic Rabies in Humans

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-20% of cases, less common
-Prodromal symptoms, then directly to paralysis phase
-No sensory excitation phase

Front 61

Prodromal Phase of Rabies infection

Back 61

-Lasts 2-10 days
-Fever, headache, malaise, fatigue, anorexia
-Very general symptoms

Front 62

Sensory Excitation Phase of Rabies Infection

Back 62

-Lasts 2-7 days
-Neurologic symptoms develop
-Agitation
-Thrashing, convulsions, muscle spasms
-Virus has entered neurologic system
-not present in dumb/paralytic rabies

Front 63

Coma and Paralysis phase of Rabies infection

Back 63

-Mental status of patient deteriorates
-Sudden cardiac or respiratory arrest
-Coma
-All body systems deteriorate

Front 64

Rabies Treatment Triad

Back 64

1. Prompt, aggressive, first aid
-enveloped virus, easily inactivated
-tends to remain localized initially
2. Rabies vaccine for humans
-Killed vaccine, administered intramuscularly
-5 1.0 ml doses
3. Human rabies Immune Globulin
-Human hyperimmune serum is administered both systemically and locally
-Purified antibody, directed to G-protein

Front 65

Dog and cat bite post-exposure Rabies prophylaxis

Back 65

-Observe animal for 10 days
-No treatment for humans until animal develops signs of rabies

Front 66

Bat bite post-exposure Rabies prophylaxis

Back 66

-Regard as rabid
-Suspect exposure even if a bite wound is not clearly evident
-Unless proved negative by laboratory tests

Front 67

Wild animal bite post-exposure Rabies prophylaxis

Back 67

-Skunk, fox, coyote, raccoon, bobcat, woodchuck, other carnivores
-Regard as rabid unless proved negative by laboratory tests

Front 68

Bat rabies

Back 68

-700-800 cases of rabies in bats reported annually in US and Canada
-Most human cases of rabies in recent years have been bat-related
-Silver-haired bat by harbor highly virulent form of rabies virus
-Vampire bats feed on livestock

Front 69

Case Study of Rabies in 4-year old girl

Back 69

-Bat bites can be superficial and not easily noticed
-Bats behaving abnormally are always cause for concern
-Submit animal for rabies testing
-Consider bats to be rabid!
--low percentage are actually rabid, but better safe than sorry

Front 70

Vesicular Stomatitis Virus

Back 70

-Rhabdovirus
-Economically important disease in bovine and equine species
-2 serotypes in US and Canada
-Signs: excessive salivation, lameness, vesicular lesions on tongue, oral mucosa, and coronary band
--looks like FMD
-Outbreaks are often seen in western US in horses and cattle
-Enters animal through breaks in the skin or mucosa
--Lesions are NOT diagnostic
-May be transmitted by arthropods (sandflies)
-Zoonotic, gives influenxa-like illness in humans

Front 71

Vesicular Stomatitis virion genome

Back 71

-G
-P
-M
-N
-L

Front 72

Rhabdoviruses in Fish

Back 72

-Viral hemorrhagic septicemia virus (ebola virus of fish)
-Infectious hematopoietic necrosis viruses

Front 73

Category A diseases/Agents

Back 73

-High-priority agents
-Pose a risk to national security, potential bioterrorism agents
-Can be easily disseminated or transmitted from person to person
-Result in high mortality rates
-have potential to have major public health impact
-No specific treatment or vaccines
-Might cause public panic and social disruption
-Require special action for public health preparedness

Front 74

Category A agents

Back 74

-Anthrax (Bacillus anthracis)
-Botulism (Clostridium botulinum toxin)
-Plague (Yersinia pestis)
-Smallpox (variola major)
-Tularemia (Francisella tularensis)
-Viral hemorrhagic fevers
--ebola, marburg, arenaviruses

Front 75

Hemorrhagic Fever Viruses

Back 75

-Flaviviridae
--dengue, yellow fever, TBE group
-Arenaviridae
--lassa, junin, machupo, guanarito
-Filoviridae
--Ebola, marburg
-Bunyaviridae
--hantavirus

Front 76

Ebola Virus

Back 76

-Hemorrhagic Fever Virus
-First outbreak in 1976
-5 known strains
-EBOZ strain had highest mortality (88%)
-Ebola Reston is only in monkeys, not humans
-Last known strain in 2007

Front 77

Key properties of Filoviruses

Back 77

-Pleomorphic, have long filamentous forms and other shapes
-Uniform diameter of 80nm
-Vary greatly in length
-Composed of lipid envelope covered with peplomers surrounding helically wound nucleocapsid
-Single molecule of –sense ssRNA, 19.1kb
--largest of all –sense RNA viruses
-Infection is cytopathic in cultured cells and in target organs of host
-Cytoplasmic replication with large inclusion bodies
-Buds from the plasma membrane

Front 78

Ebola virus Infection

Back 78

1. Virus enters body via mucosal surfaces, skin abrasions, or parenteral introduction
2. Macrophages are infected, virus is amplified
3. Infection of macrophages can lead to immunosuppression in humans and non-human primates
-Cytokine storm disrupts cells
4. Dissemination via lymphatic and vascular systems
-endothelial cells are targets for replication
-Infection leads to vascular injury and increased permeability
--leads to hemorrhage and other circulatory dysfunctions
-Virus infects kidneys, adrenal glands, intestines, skin, and reproductive system

Front 79

Ebola in the Respiratory system

Back 79

-Alveolar macrophages are heavily affected
-Pulmonary endothelial cells are also affected

Front 80

Ebola in the Spleen

Back 80

-Deterioration of spleen functions
-Lymphoid cell depletion and generalized necrosis

Front 81

Ebola in the Liver

Back 81

-Liver functions eroded as hepatocytes, endothelial cells, monocytes, and kupffer cells are infected
-Large cytoplasmic inclusions can be detected in hepatocytes

Front 82

Paramyxoviruses

Back 82

-Important animal pathogens
-Canine Distemper Virus
-Newcastle disease Virus
-Bovine Respiratory Syncytial Virus
-Rinderpest virus
-Human Respiratory Syncytial Virus
-Parainfluenza virus

Front 83

Properties of Paramyxoviruses

Back 83

-Enveloped virus
-Has surface proteins
-150nm
-Negative sense single-stranded RNA genome
-1 genome segment that encodes all 7 genes
--No genetic reassortment, only 1 segment

Front 84

Paramyxovirus proteins

Back 84

-F: Fusion protein
-G: Attachment protein
-N: Nucleocapsid
-L: Large protein
-P: Phosphoprotein
-M: Matrix Protein

Front 85

Types of Paramyxoviruses

Back 85

-Respirovirus
-Rubulavirus
-Morbillivirus
-Pneumovirus

All have different proteins except for Fusion protein

Front 86

Paramyxovirus attachment protein

Back 86

-Hemagglutinin, glycoprotein, or hemagglutinin AND neuroaminidase
-Specific type depends on type of paramyxovirus

Front 87

Paramyxovirus Replication Steps

Back 87

1. Adsorption
2. Fusion with Sialic acid receptors on cell surface
-direct fusion, virus RNA is empties right into the cytoplasm
3. Uncoating
4. -Sense RNA is transcribed into mRNA and translated in cytoplasm
5. Antigenome is transcribed and replicated in the cytoplasm
6. -Sense genome fuses with plasma membrane and buds

Replication occurs in the Cytoplasm!

Front 88

Key features of Paramyxoviruses

Back 88

-Genome forms a ribonucleoprotein (RNP)
-Replication occurs exclusively in the Cytoplasm of the cell
-Envelope is derived from plasma membrane of the cell via budding
-Infection can result in:
1. Syncythia formation (giant cells)
2. Intracytoplasmic inclusion bodies
3. Intranuclear Inclusion Bodies

Front 89

Syncytia

Back 89

-Characteristic of Paramyxoviruses
-Cells fuse and form HUGE structures

Front 90

Paramyxoviruses Inclusion bodies

Back 90

-Inclusion body in astrocytic nucleus
-Accumulation of proteins

Front 91

Paramyxovirus nucleocapsid

Back 91

-Ribonucleoprotein
-Gives Herring-bone appearance to genome
-Well-protected RNA

Front 92

Paramyxovirus vs. Orthomyxovirus

Back 92

-Non-segmented genome vs. segmented genome
-Fuses with cytoplasmic membrane vs. fuses with endosome
-Replicates in cytoplasm vs. nucleus
-Endogenous capping vs. no endogenous capping
-Does not require a cellular primer for transcription vs. does require primer
-No genetic reassortment vs. lots of genetic reassortment
-Both need cleavage of surface glycoprotein
--paramyxovirus has own protease
-Both have single-stranded negative sense RNA helical nucleocapsid
-Sialic acid acts as receptor on cell surface (except in morbiliviruses)
-Both are enveloped
-

Front 93

Paramyxovirus Adrosption and Fusion

Back 93

1. HN or H or G binds to cellular receptor (sialic acid)
2. Binding causes conformational change in F-protein
3. F-protein is cleaved for activation
4. Viral and cellular membranes fuse when receptors engage

Front 94

Properties of Paramyxovirus Adsorption and Fusion

Back 94

-Basic AA at F-protein cleavage site increases virulence
-Alters ability of protease to cleave, promotes cleavage and leads to a more virulent virus
-Difference in a few AA can make a non-virulent strain into a virulent strain

Front 95

Viral Transcriptase Proteins

Back 95

-P and L proteins
-Allows for production of viral proteins from mRNA
-P and L proteins join with N protein for viral replication
--P,L,N forms viral replicase and generates viral genomes

Front 96

Polarity of viral RNA transcription

Back 96

-3' end has proteins that are needed in larger amounts
--end up undergoing more replication
-Gradient of proteins, and proteins accumulate in a gradient of concentration
-Always have more of the 1st protein
-Proteins are produced in the order they are needed for viral replication and assembly
-Replication can start with enough of 1st proteins have accumulated

Front 97

Viral genomic replication

Back 97

-Starts when enough NP protein has accumulated
-Transcriptase of PL becomes PLN and turns into replicase

Front 98

Canine Distemper Virus

Back 98

-Paramyxovirus, morbillivirus
-Polymorphic virus
-Important viral disease in canines
--80% mortality in unvaccinated animals
-Found in all fluids/secretions
-Spread via aerosol droplets
-Generalized infection with respiratory, intestinal, and urogenital tract complications
-CNS disorders, persistent infections, hard-pad disease on foot pads and nose
-Raccoon reservoir in PA

Front 99

Canine Distemper Virus Treatment

Back 99

-Vaccinate!
--formalin-inactivated and live-attenuated vaccines
-Exposed animals receive immune IgG
-Antibiotics can prevent secondary infections
-Expensive therapy and disease needs to be caught early

Front 100

Newcastle Disease Virus

Back 100

-Highly contagious
-Causes severe generalized infection in many avian species
--exotic pet birds, smuggled birds, etc.
-Transmission via airborne route, feed and water, transovarial infection
-Has caused many epidemics
-Results in big economic losses in poultry industry
-3 forms: lentigenic, mesogenic, and velogenic
-Cleavability of F-protein correlates to virulence
-Controlled through vaccination

Front 101

Newcastle Disease Virus Disease forms

Back 101

-Lentogenic
-Mesogenic
-Velogenic

-Different forms have different speed of disease
-Cleavability of F protein correlates with virulence

Front 102

Newcastle Disease Virus Signs

Back 102

-Depression and neurological signs
-Wing drooping
-Abnormal head and neck position
-Muscle tremors
-Legs dragging
-Paralysis
-Loss of appetite

Front 103

Newcastle Disease Virus Treatment

Back 103

-No specific treatment
-Live and killed vaccines are available
--administered in drinking water or by spray

Front 104

Rinderpest Virus

Back 104

-Acute, contagious disease
-Affects ruminants: cattle, buffalo, water buffalo
-"Bovine plague"
-Severe hemorrhagic inflammation of mucus membranes
-Severe gastroenteritis
-Severe stomatitis
-Greatest risk of spread is through transport of live animals

Front 105

Rinderpest history

Back 105

-Most important animal virus in history
-Reason for the start of veterinary medicine!
-Targeted for global eradication
--cell-culture adapted vaccines provide life-long immunity
-Declared eradicated in 2011

Front 106

Morbilliviruses in Dolphins, Seals, Lions

Back 106

-Dolphin Morbillivirus
-Porpoise Morbillivirus
-Phocine Distemper Virus
-Important pathogens, have caused a few outbreaks
-Clinical symptoms, RNA sequence, and antigenic profile mimic canine distemper virus
--also have inclusion bodies

Front 107

Hendra Virus

Back 107

-Emerging virus
-Natural reservoir in fruit bats
-Explosive outbreak of respiratory disease in Australia
--14 horses and 2 humans dead
-Causes severe interstitial pneumonia in horses
-Incubation period of 8-11 days in horses
-Causes acute febrile respiratory or neurologic illness
--results in death in 1-3 days

Front 108

Hendra Virus outbreaks

Back 108

-All in Australia
-39 outbreaks so far
-76 horses have died
-60% fatality in humans
-75% fatality in horses

Front 109

Nipah Virus Spread

Back 109

-Started in Ipoh in 1997
-Spread in Selangor as farmers sold pigs
-Human cases started in september 1998

Front 110

Nipah Virus

Back 110

-Causes encephalitis
-Natural reservoir in fruit bats
-Caused severe encephalitis outbreak in people with close contact exposure to pigs in malaysia and singapore
-265 cases and 105 deaths
--40% fatality
--10% relapse or late-onset encephalitis

Front 111

Nipah Virus Infection of Pigs

Back 111

-Predominantly a respiratory disease (upper respiratory tract)
--"barking pig disease"
-Low mortality with high infection rate
-Clinical signs are a mild to severe cough
-Occasional neurological signs
-Systemic endothelial cell tropism
-1.1 million pigs culled
-Transmission most likely from eating contaminated fruit
--close proximity of pig pens to mango trees

Front 112

Nipah Virus and "Flying Foxes"

Back 112

-Antibodies have been found in 5 malaysian species of bats
--4 fruit bats
--1 insectivorous bat
-Isolated in 2000 from bat urine
-Hendra Virus and Nipah Virus are closely related
--70-88% NT and 92% AA sequence identity

Front 113

Borna Disease Virus

Back 113

-Bornaviridae family of paramyxoviruses
-1st isolated in Germany
-Fatal, neurological disease of horses
--also affects sheep, cats, cattle
-Excitability, loss of coordination, abnormal positioning of the fore and hind legs, stands motionless with head down
-Causes bipolar disorder in humans?
-3-20 day disease course
-Virus enters intranasally, enters olfactory bulbs of the brain

Front 114

Virus Goals

Back 114

-Replication!!
-Dissemination, local or systemic
-Infection of more animals

Front 115

Immune system goals

Back 115

-Detection of pathogens
-Elimination and control of pathogens
-Prevention of tissue destruction
-Prevention of reinfection
-Cells:
--neutrophils
--eosinophils
--basophils
--lymphocytes
--monocytes
--platelets
--RBCs

Front 116

Types of virus infections

Back 116

1. Acute infection (influenza)
-High initial infection with resolution
2. Persistent infection (BVD)
-high initial infection that stays high, eventually leads to death
3. Latent infection (herpesviruses)
-repeated infections that may or may not produce signs
4. Lentivirus infection (SIV)
-virus is latent for LONG periods of time

Front 117

Factors determining type of viral infection

Back 117

-Strategies of the specific virus
-Viral adaptation to host species
-Immune response of the individual host
--Stress
--genetic factors
--co-infection
--environmental factors

Strategies of the virus
Adaptation to the host
Immune response of the host

Front 118

Innate immunity overview

Back 118

-Onset in 0-4 hours
-Response if by preformed, non-specific, or broadly specific effectors
-Effectors are able to remove the infectious agents
-Not hist-adapted
-Usually non-pathogenic

Front 119

Early Induced Innate immune Response overview

Back 119

-Response occurs in 4-96 hours
-Microbial-associated molecular patterns are recognized
-Inflammation and activation of effector cells by host immune system
-Infectious agent is removed
-No serum conversion, no adaptive immune response or clonal expansion

Front 120

Adaptive Immune Response overview

Back 120

-Late response, occurs after 96 hours of infection
-Antigen is transported into lymphoid organs and recognized by naive B and T cells
-Clonal expansion occurs and differentiation of naive cells to effector cells
-Antibodies are produced
-Infectious agent is removed

Front 121

Inflammatory cytokines

Back 121

-Induced by recognition of the virus
-Early response

Front 122

Steps in Immune Response

Back 122

1. Pathogen enters cell
2. Dendritic cells take up antigen and present on surface
3. Travel to lymph nodes and germinal centers via afferent lymph
4. Class switching occurs in germinal center
5. T cells and B-cells are activated, exit via efferent lymph

Front 123

Time After Viral Infection

Back 123

1-2 days: profuction of IFN-a, IFN-b, TNF-a, IL-12
2-4 days: NK-cell mediated killing of infected cells
6-9 days: T-cell mediated killing of infected cells

Front 124

Host Innate Immune Response

Back 124

-Invading virus triggers innate immune response (early response)
--NK cells arrive hours after infection
--Natural antibody occurs hours after infection (antibodies are already present)
--Complement activation hours after infection
--virus-induced interferon occurs a few hours to 4-5 days after infection
-Innate responses decrease viral load
-Innate responses eventually lead to stimulation of adaptive immune response

Front 125

Alternative Complement Pathway

Back 125

-Part of innate immune response
-Responds to viral particles and viral antigens (proteins)
-Antibody is not involved in the alternative pathway
-Complex sequence of events
-Opsonization leads to phagocytosis of virus
-Membrane attack complex lyses virus infected cells and enveloped viruses
-Activated complement contributes to inflammatory response

Front 126

Opsonization of virus particles

Back 126

-"Decorating" virus with C3b
-Makes virus more susceptible to phagocytosis

Front 127

Virus inhibiting host complement factors

Back 127

-Astrovirus and Influenza A virus inhibit C1
-Dengue virus inhibits C4b
-Vaccinia, variola, cowpox, HSV-1 and 2, and KHSV inhibit C3b
--do not allow complement pathway
-Prevent membrane from rupturing and cell dying

Front 128

NK cells

Back 128

-Recognize cells infected with the virus
-Help control the extent of the initial infection
-Receive activating signals from infected target cells
-Inhibitory receptor on KN cell interacts with loaded MHC-I on target cell
-Reduced/altered expression of MHC-I on virus-infected cells precents inhibitory signal, leads to lysis of infected target cells
-KN cells produce IFN-gamma
--leads to chemokine and adhesion molecule up-regulation
-Activated T-cells are recruited to tissue site
-Enhave the adaptive immune response
-BOTH MHC-I interaction and Activating receptor are needed to activate NK cell

Front 129

Host detection of viral infection via Pattern recognition Receptors

Back 129

-Pattern Recognition Receptors are on leukocytes and other cell types
-TLRs (Toll-like Receptors)
-RIG-I-like receptors
-RIG-I-like helicases

Front 130

RNA virus detection via RIG-I-like receptors

Back 130

-Major sensors of viral infection, depending on cell type
-MDA-5 recognizes Picornaviruses
-RIG-I recognizes paramyxoviruses, NDV, SeV, Rhabdoviruses, Flaviviruses, Orthomyxoviruses

Front 131

RIG-I-like Receptors Viral Recognition

Back 131

-Paramyxoviruses:
--Newcastle Disease Virus
-Sendai Virus
-Rhabdoviruses
--rabies
--vesicular stomatitis virus
-Flaviviruses
--hepatitis
-Orthomyxoviruses
--influenza

Front 132

Virus PRR detection avoidance

Back 132

-Produce gene products that interfere with TLR signaling
-Vaccinia virus protein A46R bloks signaling of TLRs and contributes to virulence
-HCV produces serine protease that degrades TRIF
-Interfere with TLR and RIG-I signals

Front 133

Virus-induced interferon

Back 133

-Interferons are host-specific, but not virus specific
-IFN-a and IFN-b are most common
-IFNs are produced at a high cost to the host
-Production is brief and transient
--hours to days post infection
-Made by infected cell
-Virus can still replicate in cell and kill cell

Front 134

Type 2 interferons

Back 134

-IFN-g produced by T-cells and NK cells

Front 135

Type 1 interferons

Back 135

-Interferon is produced by infected cells and plasmacytoid dendritic cells
-Produced by infected immune and non-immune cells
-Produced in large amounts by plasmacytoid dendritic cells
-Are produced by any affected cell

Front 136

New Proteins in response to IFNa and IFNb

Back 136

-IFN is release by first virus infected cell when it attaches to IFN receptor on 2nd uninfected cell
-Triggers cascade of events in 2nd cell
--2nd cell is IFN activated
--IFN response pathway
-More than 100 genes are affected
-Anti-viral state

Front 137

Protection by Virus-induced interferon

Back 137

-Induced cell: cell in anti-viral state is infected and host enzymes are activated
-Enzymes degrade host and viral nucleic acids
--Stops protein synthesis
-No new viral particles are made, no spread of virus to other cells
-Cell dies via apoptosis

Front 138

Viral infection in Induced cell vs. uninduced cell

Back 138

-both cells die
-In induced cell, no virus is produced and no virus is spread
--IFN is bound to cell
--no further infection
-In uninduced cell, virus replicates and spreads to other cells
--Infection is propagated
--no IFN bound to cell

Front 139

Antiviral State Effector Proteins

Back 139

-Produced by the cell
-Most interfere with viral entry, replication, and budding
-Some affect NK cell activation
--NK activated, target cell is lysed
-High cost for cell

Front 140

Viral Anti-interferon strategies

Back 140

-Viruses induce proteins that interfere with IFN action
-Block IFN receptors
-Interfere with IFN receptor signaling
-Produce proteins that allow virus to replicate, despite antiviral state
--inactivate antiviral state affectors
--ex: Influenza virus NS1 protein, allows for protein translation during antiviral state
-Virulence factors are important

Front 141

Effects of IFN

Back 141

-Up-regulation of antigen presentation by MHC-I
-Up-regulation of antigen presentation by MHC-II
--professional APCs
-"Shuts down" regional lymph node
--increased influx of lymphocytes and decreased exit
--Leads to increased antigen presentation
-Activation of NK cells

Front 142

MHC-I of infected cells

Back 142

-Virus-derived antigen is presented on MHC-I of infected cell
-Virus infects cell and viral proteins are synthesized in cytosol
-Peptide fragments of viral proteins are bound by MHC-I in ER
-Bound peptides are transported by MHC-I to the cell surface
-Viral fragments are displayed on the cell surface
-recognized by NK cells and CD8 T-cells

Front 143

T-effector cell generation

Back 143

-Cellular response of adaptive immune response
-APCs pick up antigen and migrate to draining lymph node
-Antigen is presented to naive CD8 T-cells (MHC-I) and CD4 T-cells (MHC-II)
-Causes T-cell proliferation and differentiaion
-During viral infection, cytokine environment typically induces IFN-g producing cells
--Th1 and CTLs

Front 144

Effector T-cells during infection

Back 144

-Go to site of infection
-CD8 positive CTLs recognize and kill infected targets
-CD4 positive Th1 cells produce IFN-g at site of infection
--activate macrophages and other phagocytes

T-cells are released and recruited for immune response

Front 145

Cytotoxic T-cell Mediated Killing of Infected cells

Back 145

-Cytotoxic T-cell recognizes viral peptide and MHC-I complex on infected cell
-Kills infected cell

Front 146

Viral strategies to reduce antigen presentation

Back 146

-Interfere with MHC-I loading
--inhibit antigen-processing and loading of MHC molecules
--Prevent transport of MHC to surface of the cell, degrade instead
-Block proteosome
-Block loading of MHC-I
-Block transport
-Degrade loaded MHC-I complex
-Divert MHC-I from surface to lysosome fro degradation
-DECREASE MHC-I ON CELL SURFACE

Front 147

Effector B-cell generation
Humoral Immune Response

Back 147

-Early B-cell response is mostly IgM
--leads to generation of germinal center reactions
-Germinal center reactions lead to high affinity IgG
-Mucosal responses lead to IgA production

Front 148

Steps in B-cell activation

Back 148

1. B-cell binds virus via viral coat protein
2. Virus particle is internalized and degraded
3. Peptides from internal proteins of the virus are presented to T-cell
--CD4 T-cell activates B-cell
4. Activated B-cell produces antibody against viral coat protein
--B-cell differentiates

Front 149

Virus neutralization by Antibody

Back 149

-Virus is coated and neutralized by antibodies
-Coated virus cannot enter other cells
-Antibody blocks binding of viral receptor and can also block a fusion event

Front 150

Antibody-Dependent Cytotoxicity

Back 150

1. Antibody binds to antigens on surface of target cells
2. Fc receptors on NK cells recognize antibody
3. Cross-linking of Fc receptors signals to NK cell to kill target cell
4. Target cell is killed, dies via apoptosis

Front 151

Primary Antibody Response

Back 151

-IgM is first antibody produced
--lasts 5-8 days
--has low affinity for antigen
--binds complement with high avidity due to multimeric character
-Class switching gives rise to IgG
--IgG lasts for longer but arises later (2-3 weeks)
--Has higher affinity for antigen
-Serum IgA goes up
-Secretory IgA is produced when virus infects via mucosa

Front 152

Secondary Antibody Response

Back 152

-IgM does the same thing it did during primary response
-IgG levels should appear sooner, increase more, and stay higher for longer than during primary response
--Higher affinity, more effective

Front 153

Booster response

Back 153

-Anamnestic response
-Memory repsonse

Front 154

Immuopathology vs. Successful viral clearance

Back 154

-Important balance of immune system!!
-Do not want to kill the body in the process of killing viruses

Front 155

Mechanisms to limit immunopathology

Back 155

-Produce anti-inflammatory cytokines
--IL-10
-regulatory cells
--Tregs, alternatively activated macrophages
-Viruses can induce immunosuppressive factors to reduce immune responses
--viral IL-10

Front 156

Clever viral mechanisms

Back 156

-Soluble Fc receptors that bind antibody
--decrease circulating antibody titers
-Produce chemokine binding receptors and molecules
--prevent recruitment of immune cells
-Produce chemokines that will recruit target cells for virus
--brings cells to infect to the virus
-Infects critical immune cells
--Ex: CD4 infection in HIV

Front 157

Immunological memory

Back 157

-MOST POTENT weapon against reinfection!
-Circulating antibody
-Antibody on body surfaces
-Circulating CD4 and CD8 T-cells, ready to respond to re-infection
-Shortcut response! respond within hours

Front 158

Goals of Veterinary Vaccines

Back 158

-Improve health and welfare for companion animals
-Be safe and promote health
-Increase production of livestock in a cost-effective manner
--cost-benefit resulting from vaccine is bottom-line
Prevent animal-human transmission from wildlife

Front 159

When is a vaccine needed?

Back 159

-When prevention is better than slaughter to control disease
--slaughter is not an option with humans, have to vaccinate
-When there are no drugs to treat or cure a disease
--most viral diseases!
-When virulence is due to toxin
--no time for antibiotic activity

Front 160

Eradication and Vaccination

Back 160

-Eradication is the goal, especially when there is an economic impact
-FMD, Rabies, Rinderpest
-Vaccination can lead to near extinction of viruses
--canine rabies in US
--Canine hepatitis virus in US
--Rinderpest
-Human vaccine successes:
--Polio, Measles, smallpox

Front 161

Impact of Veterinary vaccines on Public Health

Back 161

-Reduction in use of veterinary pharmaceuticals and hormones and residues in human food chain
-Use of antibiotics in animal production has been severely restricted
-Important impacts on human health through vaccination of animals

Front 162

Salmon Disease Crisis in Chile

Back 162

-Infectious Salmon Anemia (orthomyxovirus) is wreaking havoc on Atlantic Salmon
-Vaccine is available but ineffective
-Moving farms to pristine areas to reduce cycle of virus
--will also cause tons of environmental damage to pristine area

Front 163

Veterinary vaccines vs. Human vaccines

Back 163

-Less return on animal vaccines vs. human vaccines
--lower prices and smaller market size
--results in MUCH lower investment in R+D in animal vaccines
-Economic returns drive vaccine industry
-Veterinary vaccine development has less stringent regulatory and preclinical trial requirements
--also shorter time to market launch
--faster return on investment in R+D, but not as high of a return

Front 164

Why to we vaccinate?

Back 164

-To induce immunological memory without causing disease
-Adaptive immune response takes time to develop
--need primary infection
-Secondary infection takes MUCH less time for response
-Want to induce cellular (cytotoxic T-cells, IFN-g) and humoral (antibodies) immunity

Front 165

Live vaccines

Back 165

-Usually attenuated, not highly pathogenic
-Highly antigenic, cause big response
-Few inoculations needed
-Prolonged humoral and cellular immunity
-NO adjuvant is needed
-May have residual virulence reversion
-Can spread to unvaccinated animals
-Difficult to store

Front 166

Killed/Protein vaccines

Back 166

-Less immunogenic
-Need to be boosted
-Poor stimulator of cellular immunity
-Needs adjuvant to activate innate immune response
-Safer, will not spread to other animals
-Easy to store and manipulate

Front 167

Veterinary live vaccines

Back 167

-Live attenulated virus for vaccines
-Can use closely related virus from another host that will not cause disease
-Can package the virus in cell lines of chicken embryos
-Induce random mutations to make modified virus
-Select for a reduced virulence

Front 168

Action of Veterinary live vaccines

Back 168

-Induce mild infections and good cellular and humoral immunity
-Effective in small amounts, lead to biological amplification
-Long duration, can last a lifetime
-Do not require adjuvants
-Easy administration in drinking water, intranasal, or intraocular route
-Risky, can have residual virulence and reversion to pathogenic version
-Usually only need 1 shot, but use 2 to catch everything
-Wide range of herd immunity, big advantage

Front 169

Live vaccines as a source of environmental contamination

Back 169

-Porcine Respiratory and Reproductive Syndrome vaccine in Denmark
-European and American viruses are 55-80% identical
--cause distinguishable serological responses
--NOT the same virus
-Vaccinated pigs in Denmark with American strain
--caused reversion of virus and pigs had both types of viruses
-Virus reverted and became virulent

Front 170

Smallpox Vaccine Success

Back 170

-Live attenuated vaccine
-One host, only humans with NO wildlife reservoir
-No Asymptomatic shedding
--know if someone is sick and can contain
-Long incubation period
-Very obvious disease
-Very effective vaccine that is stable in the field
-Fear of illness enhanced cooperation
--worldwide compliance
-"Ring vaccination" plan, started at a focus and moved outwards
-Monitoring and reporting were critical

Front 171

Rinderpest Vaccine

Back 171

-Plowright vaccine
-Attenuated vaccine produced from Kabete O strain
--passaged 90 times in culture
-Lots of mutation with minimal reversion
-Safe, live viral vaccines are likely to require a number of attenuating mutations distributed throughout the genome

Front 172

Rinderpest virus

Back 172

-Morbillivirus
--related to measles and canine distemper virus
-Cattle plague
-Origin of veterinary medicine!
-Emerged from central/east asia and spread to Africa and Europe
-Domestic cattle are highly susceptible
--all domestic and wild ruminants are susceptible
--high morbidity and very high mortality
-Virulent and mild strains exist

Front 173

Rinderpest Vaccine Success

Back 173

-Short incubation and highly contagious virus
-Disease is easy to recognize
--Diarrhea, discharge, dehydration, death (and skin lesions)
-Fear enhanced worldwide cooperation
-High mortality led to famine
-huge effects on economies of many countries
-Ring vaccination used
-Effective vaccine produced in cell culture, stable in the field
-Rapid diagnostic tests for monitoring
-Well-developed plan for eradication

Front 174

Veterinary Whole Inactivated or Killed Vaccines

Back 174

-Viral inactivation achieved through heat or chemicals
--formaldehyde, thiomersal, ethylene oxide, beta-propriolactone
--proteins kill virus
-higher production costs and need for adjuvants
--makes vaccine more expensive to manufacture
--more inputs needed

Front 175

Benefits to Veterinary Whole Inactivated or Killed Vaccines

Back 175

-More stable than live vaccines
-Do not revert to virulence, no risk
-Can be used in pregnant animals
-Will give herd immunity of vaccine coverate is very high

Front 176

Drawbacks to Veterinary Whole Inactivated or Killed Vaccines

Back 176

-Unable to infect cells and activate cytotoxic T-cells
--less protective
--rely on antibody production
-Need strong adjuvants, large doses, and several injections to induce immunity
-Duration of immunity is not as long
--not a natural response, manipulated response
-Greater risk of autoimmune disease, allergic disorders, and vaccine injection site sarcomas
--STRONG inflammatory reactions!

Front 177

Subunit Vaccines

Back 177

-Isolated Protective viral antigens or recombination product
--target specific viral proteins
-Isolated antigens generally produce poor protective immunity
-Require repeated administration with strong adjuvants
-Ex:
--Porcilis PCV-2
--Classical Swine Fever virus vaccine

Front 178

DIVA problem with Vaccines

Back 178

-Differentiating Infected from Vaccinated Animals
-Existing vaccines cannot be used because they interfere with disease surveillance
-Serological testing will show antigens present, cannot tell if the infection is from the virus or the vaccine
-Can result in loss of "disease free" status in a country
-Differentiation is possible through genetic engineering of vaccines
--"Marker vaccines"

Front 179

Marker Vaccines

Back 179

-Allow Differentiation of Infected from Vaccinated Animals (DIVA)
-Can identify pathogen vs. vaccination
-Add "tags" to plasmid genome
-Used in Infectious Bovine Rhinotracheitis, Pseudorabies, Classical Swine Fever, FMD, WNV, etc.
-Need vaccine AND diagnostic test

Front 180

Genetically Engineered Vaccines

Back 180

-Reverse genetic approach used to construct chimera vaccine
-Take HA gene from one virus, combine with NA gene from another version
-Make virus with antigen and other markers
-Can use immunoassay to detect antibodies against N3 and N1 proteins

Front 181

Live Viral Vector Vaccines

Back 181

-Poxviruses used as vectors for exogenous genes
-Deliver vaccine antigens
-Have been used for human gene therapy
-Poxviruses can accomodate large amounts of foreign genes, can infect mammalian cells
--results in expression of large quantities of encoded proteins
-Ex: Rabies virus, FeLV,

Front 182

DNA vaccines

Back 182

-VERY SAFE vaccine
-Immunization of animals with naked DNA that encodes protective viral antigens
-particularly effective in fish
-Ex: Apex-IHN for Salmon
--protects Atlantic Salmon from infectious hematopoietic necrosis
--DNA vaccine encodes surface glycoprotein of IHN
--administered intramuscularly

Front 183

Human Successful Vaccines

Back 183

-Smallpox, Polio
-Measles, Mumps, Rubella
--autism debate
-Rotavirus, Hepatitis B
-Diphtheria, pertussis, tetanus
-Rabies

Front 184

Animal Successful Vaccines

Back 184

-Rinderpest
-Rabies
-Canine Hepatitis, Canine distemper
-Diseases controlled but not eradicated:
--FMD

Front 185

Upper Respiratory tract

Back 185

-Nose
-Nasal Cavity
-Pharynx
-Larynx
-Collection and delivery of air to the lungs
-Warming, filtering, and humidifying air
-Rhinitis, Pharyngitis, Laryngitis

Front 186

Lower Respiratory Tract

Back 186

-Trachea
-Bronchi
-Bronchioles
-Alveoli
-Distributes air throughout the lung
-Exchanges CO2 and O2 with the blood
--only occurs in alveoli
-Tracheitis, bronchitis, bronchiolitis, Pneumonia

Front 187

Respiratory tract and Pathogens

Back 187

-Most common portal of entry into the body
-Upper respiratory infections are mostly caused by viruses
--Normally not life-threatening
-Lower respiratory tract infections are mostly mixed infections
--often are life-threatening
--especially in susceptible individuals

Front 188

Respiratory Tract Defense Mechanisms

Back 188

1. Ciliated Epithelial Cells
2. Goblet cells
3. Innate immune components

Front 189

Ciliated Epithelial Cells in Respiratry tract

Back 189

-Beat in unison, wave-like fashion
-Propel mucus and entrapped foreign material towards oropharynx for removal or swallowing

Front 190

Innate immune components fo Respiratory Tract

Back 190

-Cells from innate immune system
-Pathogen recognition receptors
-Anti-microbial peptides
-Protect against infection and invasion
-Also trigger inflammation

Front 191

Influenza Virus as a Respiratory Virus

Back 191

-Different versions of the virus infect horses, dogs, cats, pigs, birds, ferrets, humans
-Has potential to jump through different animal species
-Lack of protective immunity in new hosts favors epidemics
-Swine act as a mixing area

Front 192

Influenza Virus Pathogenesis

Back 192

1. Virus is inhaled, binds to hair-like microvilli and cilia on surface of cells that line upper respiratory tract
-HA proteins attach virus to cell membrane
2. Virus grows in respiratory tract epithelium
3. Virus grows for 2-3 days without inducing inflammation
-incubation period
-After a few days inflammation is induced and symptoms become apparent
-MASSIVE infiltration of inflammatory cells

Front 193

Consequences of Anti-viral immune response

Back 193

-Onset of symptoms (know virus is invading the body
-Clearance of virus and infected cells
-Protection from future reinfection
-Will also have destruction of epithelial cells and loss of integrity of mucus layer
-Will be more susceptible to secondary infections
--immune system barrier is broken

Front 194

Secondary infections in the lower respiratory tract

Back 194

-Secondary infections are not a huge deal for upper respiratory tract, easily cleared
-BIG deal for lower respiratory tract
--have danger of complicated pneumonia due to secondary bacterial infections
-Non-pathogenic microflora has ability to invade and become pathogenic with viral infection
-Will have enhanced bacterial growth, inflammation, and lethality

Front 195

Transmission of Respiratory Viruses

Back 195

1. Inhalation of aerosolized virus
2. Direct contact with infected individuals
3. Contact with contaminated objects (fomites)

Close contact and over-crowding promote transmission
Increased humidity will decrease transmission
-droplets are too heavy, do not stay syuspended

Front 196

Prevention of Respiratory Virus Transmission

Back 196

-Isolation
-Vaccines

Front 197

Feline Respiratory DIseases

Back 197

-Still a problem even with widesread use of vaccines
-Most common in cats grouped together
-Open-mouthed breathing, weakness, severe coughing
-Feline calicivirus (RNA virus)
-Feline Herpesvirus-1 (dsDNA virus)
-Pasturella
-Chlamydophila felis
-Mycoplasma

Front 198

Feline Calicivirus

Back 198

-Non-enveloped, positive sense single-stranded RNA virus
-Major cause of upper respiratory tract disease in cats
-Predominant in colony cats
-Generally subclinical or mild infections
-Virulent strains lead to pneumonia in young kittens
-More virulent strains can spread systemically
--higher rate of mortality
-Some recovered cats remain persistently infected, may shed virus for months to years

Front 199

Feline Calicivirus Diagnosis and Control

Back 199

-Sings:
--nasal and eye discharge
--Ulcers on the oral mucosa
-Laboratory tests to distinguish from Feline herpesvirus 1
-Inactivated and modified live virus vaccines are available
--protects against clinical disease, does not prevent subclinical infection or carrier state

Front 200

Feline herpesvirus 1

Back 200

-Alpha herpesvirus
-Latent in the trigeminal ganglia
-50% of respiratory illness in household cats
-Low mortality with fair morbidity
-ranges from mild disease to serious
--most serious in kittens
-24-48 hour incubation period
-Secondary infections leading to pneumonia can occur
-once cat is infected, is infected for life

Front 201

Feline Herpesvirus 1 Diagnosis and Control

Back 201

-Signs:
--acute rhinitis
--fever
--conjunctivitis
-Inactivated or live attenuated vaccines are available
-Often combined with vaccines for feline parvo and calicivirus

Front 202

Pasteurella multocida in cats

Back 202

-Bacteria, gram- rods
-Commensal found on mucosa of nasopahrynx
-Host-adapted serotypes and biotypes
-Some serotypes are highly contagious primary pathogens
-Common secondary pathogen in cats
--stress related
-Causes rhinitis, otitis, bronchitis, pneumonia

Front 203

Chlamydophila felis

Back 203

-Intracellular bacteria
-gram- rods
-Causes feline pneumonitis
-Respiratory tract symptoms
-conjunctivitis, fever, conjunctivitis, nasal discharge, coughing, sneezing
-Contagious and widespread
-Not fatal, debilitated cats recover slowly
-Transmission via direct contact with infected secretions and droplet infection
-Control with attenuated live vaccine
--use restricted to cats at risk of exposure

Front 204

Infectious tracheobronchitis
ITB

Back 204

-Kennel Cough
-Viral and bacterial pathogens
-Group of pathogens
-Viral:
--canine adenovirus 2 (canine hepatitis virus)
--Canine herpesvirus 2
--Canine influenza
--Canine parainfluenza 2
-Bacteria:
--Bordetella bronchiseptica
--Streptococci, pasteurella, pseudomonas, mycoplasma

Front 205

Kennel Cough

Back 205

-Single-agent infections are generally mild and self-limiting
-Multiple agent infections are more serious and can result in pneumonia
--more common
-Clinical signs attributed to infection by 1 or many bacterial and/or viral agents
-HIGHLY contagious
-Dry, hacking cough, retching gagging
-Prevent via vaccination

Front 206

Cacnine herpesviruses

Back 206

-DNA viruses
-Latent in trigeminal ganglia
-Present in respiratory and gential tracts
-Closely related to FHV and PRV, but host-restricted
-Causes MAJOR viral infection in pups
--acute fatal generalized infection
--leading cause of death in puppies
-Can cause abortions or stillbirths
-Milder in adult dogs
-May be associated with Kennel Cough
-S: weakness, lethargy, crying, genital sores, death of newborn pups
-No vaccine available

Front 207

Canine Adenovirus 2

Back 207

-Double-stranded DNA virus
-Aerosol transmission
-Localized respiratory disease in canines
-Mild when alone
-Can be associated with Kennel Cough
-Can be more severe in combination with Bordatella, parainfluenza virus, canine herpes virus
-Looks like kennel cough
-Vaccination does not prevent infections, but will minimize symptoms

Front 208

Canine Parainfluenza Virus

Back 208

-Paramyxovirus
-Single-stranded RNA, negative sense genome
-Most common in dogs with infectious tracheobronchitis
-Infection typically in upper respiratory tract
--allows secondary infection by other agents
-Can shed for about 1 week
-Will have nasal discharge and dry unproductive cough
-Vaccine is available and routine in puppies

Front 209

Bordetella Bronchiseptica

Back 209

-Gram- bacteria
-Obligate aerobe
-Most common agent isolated from dogs
-Preferentially attaches to and replicates on cilia of respiratory epithelium
-Synthesizes potent toxins that impair phagocytic function, induce ciliostasis
-Facilitates infection from opportunistic agents
-Looks like kennel cough
-Prevent secondary infection with antibiotics

Front 210

Respiratory Diseases of Bovines

Back 210

-AKA shipping fever
-Mix of viruses and bacteria
-Viruses:
--bovine herpesvirus 1
--bovine parainfluenza
--Bovine viral diarrhea virus
--Bovine respiratory syncytial virus
--Bovine corona virus, adenovirus, and rhinovirus
-Bacteria:
--pasteurella hemolytica
--Pasturella multocida
--Haemophilus somnus
--Mycoplasma
--Chlamydia

Not all are present in any one outbreak

Front 211

Bovine Respiratory Disease

Back 211

-Most common disease of feedlot cattle
-Most costly disease of cattle
--$1 billion per year in losses
--$3 billion spent on preventatives and treatment
-Pneumonia accounts for a lot of mortality in dairy calves (24%)
-Combination of respiratory pathogens and compromised innate immune system predisposes animals to BRD

Front 212

Porcine Respiratory Diseases
Bacterial

Back 212

-Pasturella multocida: bronchopneumonia
-Pasturella multocida and Bordetella bronchiseptica: Atrophic rhinitis
-Actinobacillus pleuropneumoniae
--hemorrhagic necrotiing pneumonia
--Severe and contagious disease in pigs less than 6 months

Front 213

Porcine Respiratory Diseases
Viral

Back 213

-Porcine Herpesvirus 2: alpha herpesvirus
--rhinitis in young pigs up to 10 weeks old
-Swine Influenza: orthomyxovirus
--single stranded segmented RNA virus
-Porcine reproductive and respiratory syndrome virus
--most important swine disease in the US
--high economic impact

Front 214

Porcine Reproductive and Respiratory Syndrome Virus
PRRS

Back 214

-Arterivirus
-Enveloped +sense single stranded non-segmented RNA virus
-Pandemic disease that causes abortion and pre-weaning mortality
-Highly transmissible
-Pose-weaning respiratory syndrome
-Shed in urine, saliva, semen, feces
-85-95% of pigs in herds are seropositive within 2-3 months
-Long duration of infection and shedding in clinically sound carriers
-Vaccines for some strains are available

Front 215

Viral Respiratory Diseases of Birds

Back 215

-Avian Influenza Virus
-Fowl Pox
-Avain Coronavirus
-herpes virus: layingotracheitis
-Newcastle disease virus

Front 216

Bacterial respiratory diseases of Birds

Back 216

-Klensiella
-Proteus
-Chlamydophila
-Pasturella
-Avian tuberculosis
-Mycoplasma gallisepticum

Front 217

Fungal Respiratory Diseases of birds

Back 217

-Fungal pneumonias
-Aspergillosis

Front 218

Integumentary system

Back 218

-Largest organ in the body, 12-24% of animal body weight
-70% water
-Skin, hair, nails, sweat and oil glands
-Main function is protection from bacteria, chemicals, temperature, dessication
-secretions can kill bacteria

Front 219

Skin Structure

Back 219

-2/3 layers
-Epidermis, dermis, subcutis/hypodermis/superficial fascia

Front 220

Epidermis

Back 220

-Multiple layers of cells
-Keratinocytes, melanocytes, langerhan's cells, Merkel cells
-Cells are produced from columnar basal cells are are attached to the basement membrane
-Rate of mitosis and keratinization is controlled by nutrition, hormones, tissue factors, immune cells in the skin, genetics

Front 221

Stratum Corneum

Back 221

-Compact layer of dead cells
-Impermeable barrier to loss of fluids, electrolytes, minerals, nutrients, and water
-Prevents penetration of infectious/noxious agents into skin
-Lipid content and keratin arrangement is critical for barrier function
-Continuously desquaminated/shed

Front 222

Melanocytes

Back 222

-Lovated in the basal cell layer
-Responsible for pigment production
-Under hormonal and genetic control

Front 223

Langerhan's cells

Back 223

-Mononuclear dendritic cells
-involved in regulating the immune system of the skin
-Damaged by excessive UV light exposure and glucocorticoids
-Process antigenic and allergenic material

Front 224

Merkel Cells

Back 224

-Specialized sensory cells
-Associated with skin sensory organs
--whiskers, pads

Front 225

Skin defenses

Back 225

-Not a favorable environment for microbial growth
-Dry
-Desquamination occurs, constant shedding allows body to get rid of transient bacteria
-Secretions and excretions
-Microbial interactions
-Immune system
-Keep bugs away that should not be there

Front 226

Microbial Flora

Back 226

-Important role in defense
-Normal skin flora
-Gram+ organisms mostly, yeast is also common
--staph, strep, corynebacterium, proprionibacterium, micrococci
-Transient flora: b-strep, E. coli, P. mirabilis, enterococci
-Normal flora is commonly the source of skin infections
-VERY complex system, provides protection and infection

Front 227

Dermatitis

Back 227

-Inflammation of the skin
-Can be produced by external irritants, burns, allergens, trauma, infection
-can be associated with concurrent internal or systemic disease
-Hereditary factors can also be involved
Pruritus, scaling, erythema, thickening or lichenification of the skin, hyperpigmentation, oily seborrhea, odor, hair loss
-Breaks in the skin allow for normal flora to become pathogenic

Front 228

Canine Pyoderma

Back 228

-Pus on the skin
-Any condition that results in the accumulation of neutrophilic exudate
-More common in dogs, less common in cats
-Microorganisms cause inflammation, which leads to pus
-Caused by infectious, inflammatory, neoplastic etiologies
-Classified by depth of infection, etiology, and primary or secondary
-Usually superficial, especially bacterial pyoderma
-

Front 229

Interdigital Furunculosis

Back 229

-Deep pyoderma
-Painful nodular lesions in the interdigital webs of dogs
-Histologically lesions represent areas of nodular pyogranulomatous inflammation
--may or may not see microorganisms
-Often get secondary bacterial infections due to licking
-Staphylococcus pseudointermedius is most common agent

Front 230

Bites and Wounds

Back 230

-Deep into skin, into dermis
-Blood supply can remove organisms
-Pasteurella multocida is most common
--present in the mouths of cats
--short gram- rods/coccobacilli
--stinky odor

Front 231

Post-operative wound infection

Back 231

-Primary MRSA infection
-Probably physician induced or from hospital
-Cause deep skin and soft tissue infections

Front 232

Bacterial Agent of Skin infections

Back 232

-Staphylococcus (all species)
-Actinomyces (dogs, cows)
-Pasteurella multocida (cats)
-Mycobacterium (cats)
-Dermatophilus congolensis (horses, sheep)
-Erysipelothrix rhusiopathiae (pigs)
-Arcanobacterium pyrogenes (cows)
-Dichelobacter nodosus (sheep)

Front 233

Fungal Agents of Skin Infections

Back 233

-Microsporum canis
-Malassezia

Front 234

Dermatophytosis

Back 234

-Infection of the keratinized tissue
--skin, hair, claws
-Can be due to:
--Epidermophyton
--Microsporum
--Trichophytom

Front 235

Cutaneous lobomycosis

Back 235

-Caused by yeast-like organism
-Affects skin and subcutaneous tissues
-Human pathogen
--transmitted from humans to dolphins or from dolphins to humans?
-Due to immunosuppression?

Front 236

Chytridiomycosis

Back 236

-infectious disease affecting amphibians
-Caused by chytrid fungus
--Batrachochytrium dendrobatidis
-Can cause sporadic deaths in some amphibian populations
-Major cause of amphibian die-offs?
-Origin and impact on populations is still unclear

Front 237

Avian Pox

Back 237

-Slow-spreading viral disease in birds
-Wart-like nodules on the skin
-Diphtheritic necrotic membranes lining the mouth and upper respiratory system
-Present in birds since forever
-Transmitted via direct or indirect contact
-No treatment

Front 238

Pox diseases

Back 238

-Acute viral diseases
-Affect many animals
--humans, birds
--not dogs
-Lesions of skin and mucosa
-Widespread, progress from macules to papules, vesicles, and pustules
-Infection via inhalation or through skin

Front 239

Musculoskeletal System

Back 239

-Bones, cartilage, muscles, ligaments, tendons
-Structural framework for body
-protects vital organs
-Provides capacity for locomotion

Front 240

Infections of the Musculoskeletal system

Back 240

-Initiated by introduction of microbes
-Direct inoculation from traumatic or iatrogenic events
--bites, trauma, catastrophic events
-Extension of infectious processes from contagious foci
--infection can be from somewhere else
-Hematogenous seeding from distally infected sites or septicemia
--blood brings infection to area

Front 241

Osteomyelitis

Back 241

-Infection of the bone
-Can be acute or chronic
-Lameness, pain, abscesses at the wound site, fever, anorexia, depression
-Radiographs will show bone changes
-Deep fine-needle aspirates, cytology, and blood cultures revela evidence of infection
-Bone changes at site indicate infection

Front 242

Septic Arthritis

Back 242

-Inflammation in a joint
-Can result in changes to joint cartilage, joint fluid, bones, or joint capsule
-Can be immune-mediated, infective, idiopathic
-Infective arthritis comes from bacterial infection in a joint
--hematogenous infection
--traumatic injury
--iatrogenic infection from joint injection or surgery

Front 243

Immune-mediated Arthritis

Back 243

-Inflammatory polyarthritis
-Secondary to deposition of immune complexes
-Can be erosive or non-erosive

Front 244

Lyme disease

Back 244

Can manifest in MANY ways
-Limb and joint disease
-Neurologic, cardiac, renal abnormalities
-Lymphadenopathy

Front 245

Common bacterial agents in Musculoskeletal Infections

Back 245

-Actinomyces
-Actinobacillus
-Arcanobacterium
-Fusobacterium necrophorum
-Beta-streptococcus
-Borrelia burgdorferi
-Brucella canis
-Chlamydophila
-Clostridium
-E. coli
-Erysipelothrix
-Leptospira
-Mycoplasma
-Pasteurella
-Salmonella
-Staphylococcus

Front 246

Fungal agents causing musculoskeletal infections

Back 246

-Aspergillus
-Blastomyces
-Coccidioides
-Subcutaneous mycoses

Front 247

Myositis

Back 247

-Infection of muscle
-Localized abscess, granuloma, or diffuse inflammatory process in muscle
-Can be due to trauma, injections, bite wounds, contagious infectious process, subcutaneous abscess, osteomyelitis
-Granulomatous myositis caused by Mycobacterium, Actinomyces, or Actinobacillu

Front 248

Necrotizing Myositis
Blackleg

Back 248

-Caused by Clostridium chauvoei
-Acute, febrile disease of cattle and sheep
-Causes swelling in the muscles
-Can prevent with vaccination

Front 249

Mycobacterium bovis

Back 249

-Granulomatous disease of muscle
-Usually chronic, but can also have an acute rapidly progressive form
-Affects all vertebrates

Front 250

Septicemia

Back 250

-Presence of pathogenic organisms in the blood stream leading to sepsis
-Bacterial sepsis and septic shock
-Characterized by vascular collapse and multi-organ failure
-Most commonly gram- bacteria
--Enterobacteriaceae
-Pseudomonas aeruginosa and Staphylococcus can also cause sepsis and speticc shock
-Loss of control of cases lets organism get into the bloodstream

Front 251

Septic Shock

Back 251

-Caused by LPS virulence factor in gram- organisms
--binds to receptor signaling complexes on monocytes and macrophages
-Causes dysregulation of the immune response
-Production of excessive levels of proinflammatory cytokines
-Cytokines are responsible for the systemic effects
--cytokine storm

Front 252

Function of the Digestive System

Back 252

-Process food
-Provide nutrition of the body
-Complex physical, secretory, and absorptive processes
-Represents an open tube to the environment
-Opportunity for exposure to pathogens

Front 253

Anatomy of the Digestive System

Back 253

-Varies between animals
-Carnivores: oral cavity, esophagus, stomach, small and large intestines
-Herbivores: more fermentation
--ruminant digestion
--cecal digestion
-Poultry: specialization with crop, glandular stomach, and muscular stomach

Front 254

Properties of the Digestive System

Back 254

-Anatomic, physiologic, and immunologic mechanisms protect from pathogens
-Acid production in the stomach provides a major barrier to infection
--inactivates viruses and kills most enteric bacteria

Front 255

Peristalsis

Back 255

-Moves digesta caudally
-Major role in host defense in small intestine
-Regulates microbial population in the small intestine
-Maintains distribution and number of normal gut flora

Front 256

Mucus and mucosal integrity in the GI system

Back 256

-Important barrier to infection of the digestive system
-Prevents systemic infection
-Mucus binds to microbes, blocks interaction with epithelial cells
-Normal flora is a powerful defense
--produces, maintains, and regulates the mucus layer
-C. difficile will destroy the mucus layer and allow other microbes to invade

Front 257

Microbial Flora

Back 257

-Complex ecosystem inhabits digestive tract
-normal flora protects against pathogens
-Plays an important role in physiological health of the host
-Promotes functional villi formation
-Synthesizes nutrients
-Contributes to the establishment of a functional mucus consistency

Front 258

Establishment of GI microbial flora

Back 258

-Normal microbial flora is established soon after birth
-Organisms are acquired from mother and environment
-Flora establish a niche using bacterial and host properties
--bacteriocins and microcins
--production of fatty acids by obligate anaerobes
-Proportions may change over time but microorganisms do not

Front 259

Disruption of GI microbial flora

Back 259

-Antibiotics
-Disrupt susceptible oral flora, leads to population with resistant Enterobacteriaceae and environmental organisms
--enterbacteriaceae moves in
-Results in dramatic shift in population
-Obligate anaerobic communities in mouth and large bowel are affected
--leads to overgrowth of resistant enterobacteriaceae due to decreased fatty acid levels
--removal of long-chain fatty acids that keep microbes in check

Front 260

Oral Flora composition

Back 260

-Obligate anaerobes make up most of the normal oral flora
--every individual is different
-Streptococci
-Enterobacteriaceae
-Pateurella
-Actinomyces
-Neisseria
-Simonsiella
-Gingival crevice is entirely obligate anaerobes
--bacteriodes
--fusobacterium
--peptostreptococcus
--Porphyromonas
--Prevotella

Front 261

Rumen Flora Composition

Back 261

-Complex microbial community
-Bacteria, fungi, and protozoa
-In delicate balance with host to maintain proper fermentation in rumen
-Most are obligate anaerobes
--bacteria specifically designed for digestion of cellulose-rich forage

Front 262

Infections of the digestive system

Back 262

-Important in all domestic animals
-Some pathogens are host-specific, others can affect many different animal species
-Need to maintain non-specific resistance and specific immunity

Front 263

Infections of the Oral Cavity

Back 263

-Susceptible to infection by various endogenous and exogenous microbes
--endogenous= bacterial and fungal
--exogenous= viral
-Mostly due to anaerobes

Front 264

Infections of the Esophagus

Back 264

-Uncommon due to rapid transit time
-Stratified squamous epithelium lines esophagus, relatively impenetrable

Front 265

Infections of the stomach, ruminant forestomach, and abomasum

Back 265

-Stomach is not a hospitable environment for pathogens
--high acidity and mechanical breakdown of material
--Contractile nature causes relatively rapid transit of ingested material
-Damage to mucosal surface of rumen/reticulum or disruption in rumen flora can lead to serous and potentially fatal cosequences
-Sudden dietary changes lead to a pH reduction
--kills acid-sensitive rumen flora
--damages rumen mucosa
-Disruptions do not need to be infectious, but allow for infection

Front 266

Infections of the small and large intestine

Back 266

-Affect all domestic animals
-Clinically and economically important in horses, production animals, and poultry
-Result in vomiting and diarrhea
-Severity, duration, and characteristics of diarrhea differ based on infectious agent and host species

Front 267

Salmonella pathogenesis in the digestive tract

Back 267

-Major food-borne pathogen
-Persists in intestinal epithelium and lymph nodes for 3-6 weeks
--intermittent shedding
-Shedding can reactivate during periods of stress
-All 25 salmonella serovars can be pathogenic
-Need to ingest a large number of organisms to produce GI colonization
-If organisms survive passage through the stomach they can colonize middle portions of the ileum
-Attach preferentially to the tips of villi, invade, multiply

Front 268

Salmonella Virulence Factors

Back 268

-Exotoxins
-Adhesion pilli
-Capsule
-Adhesins
-Virulent enzyme
-Flagella
-LPS
-Fe binding protein

Front 269

Salmonella Gastroenteritis

Back 269

-Variable clinical signs
--vomiting, diarrhea, sometimes both
-Acute episodes occur 3-5 days after exposure, minimum of 12 hours after exposure
--usually acute condition, not chronic
-Fever, malaise, anorexia, vomiting, abdominal pain, diarrhea
-Cats frequently hypersalivate due to vomiting
-Diarrhea will be watery, mucoid, and bloody if severe
--watery due to dilution with fluids from the body
--mucoid due to erosions of the gastric layer
-Pale mucus membranes, weakness, dehydration
-Cardiovascular collapse, shock, icterus before death
-Pneumonia can also be associated with acute disease

Front 270

CNS signs of Salmonella gastroenteritis

Back 270

-Hyperexcitability
-Incoordination
-Posterior paresis
-Blindness
-Convulsions

Front 271

Salmonella lab diagnosis

Back 271

-Culture is the gold standard
-PCR first, and if positive confirm with culture
-Presence of organism may not indicate clinical disease
-Negative culture should not eliminate possibility of infection

Front 272

Salmonella prevalence in dogs and cats

Back 272

-Low prevalence
--reported in 1-4% of dogs, 0.3-8% in cats
-1.3-30.9 million pets potentially infected in US

Front 273

Salmonella Treatment

Back 273

-Varies with extent of disease
-Fluid replacement
-Antibiotic therapy is NOT indicated
-Drug Tx induces resistant strains, prolongs convalescent shedding
-Amoxicilin, chloramphenicol, 3rd generation cephalosporins
-Severe systemic cases may require plasma transfusion

Front 274

Antibiotic therapy is NOT indicated for treatment of uncomplicated Gastroenteritis

Back 274

Salmonella

Front 275

Campylobacter

Back 275

-Gram- motile bacterium with polar flagellum
-Mostly infection of companion animals
-Caused by campylobacter jejuni or C. coli
-Diarrhea
-Zoonotic, animals can serve as source for human infection
-Common contamination of poultry meat

Front 276

Campylobacter pathogenesis

Back 276

-Severity depends on number of organisms ingested
-2-10 day incubation period
-Invades epithelium of small intestine and causes inflammation
--inflammation leads to disease progression
-Virulence factors have been identified in C. jejuni
-Stress may increase the severity of disease

Front 277

Campylobacter virulence factors

Back 277

-Is a PATHOGEN!
-Enterotoxins
-Cytotoxins antigenically similar to cholera toxin
-Adherence factors
-Invasion of intestinal epithelial cells causes congestion, edema, mucosal ulcers and occasional sepsis

Front 278

Campylobacter clinical signs

Back 278

-Same presentation as salmonella (diarrhea, vomiting)
-May have asymptomatic carriers
-Mostly affects young dogs, less than 6 months
-Diarrhea will be mildly loose, water, mucoid, bloody feces
-Acute diseases will present with water, mucus, or bile-streaked diarrhea
--May or may not have blood and leukocytes
-5-15 day duration of disease
-Diarrhea can be chronic, intermittent, or last for several months
-Has a lower infectious and zoonotic dose than salmonella
-Can do a fecal smear to ID

Front 279

Campylobacter in Cats

Back 279

-Clinical signs are poorly documented
-Infection can be asymptomatic
-Can be observed with other organisms
--giardia, toxocara
-Animals less than 6 months old show signs
--depression, anorexia, diarrhea

Front 280

Campylobacter prevalence in dogs

Back 280

-1-34% infection in healthy adult dogs
-up to 53% infection in adult dogs with diarrhea
-5-39% prevalence in normal puppies
-75% prevalence in puppies with diarrhea
-Conflicting reports on prevalence

Front 281

Campylobacter lab diagnosis

Back 281

-Microscopy
--Spirals indicate campylobacter
-Viable at room temp for 3 days in feces
-Culture in O2 reduced atmosphere
-Oxidase+ and catalase+
-Susceptible to nalidixic acid
-Resistant to cephalothin

Front 282

Campylobacter treatment

Back 282

-Efficacy of antibiotic therapy is not known
--not thought to effectively alter the course of disease in dogs and cats
-Therapy may be needed in severe cases
-Erythromycin is the drug of choice (Baytril)
-Fluoroquinolones are over-used, campylobacter is resistant

Front 283

Icosahedral RNA viruses

Back 283

-Enveloped viruses
-Non-enveloped viruses

Front 284

Helical RNA viruses

Back 284

-All are enveloped viruses
-Rhabdoviridae
-Paramyxoviridae
-Orthomyxoviridae
-Coronaviridae
-Retroviridae

Front 285

Positive sense RNA genome viruses

Back 285

-RNA is the same sense as the mRNA
-RNA is considered to be infectious
-Initial event is translation by host ribosomes
-Synthesizes a -sense Intermediate RNA as part of replicaiton scheme

Front 286

Negative sense RNA genome viruses

Back 286

-RNA is not in the same sense as the mRNA
-Initial event is transcription
-RNA is NOT infectious
-Synthesizes a +sense intermediate RNA
-Need a viral polymerase, virus bring polymerase with it
-Has an extra step in viral production and replication

Front 287

Picornavirus properties

Back 287

-Small RNA viruses
-Large family of human and animal pathogens
-Icosahedral capsids
-Non-enveloped
-Apthovirus genus
--Foot and Mouth

Front 288

Picornavirus genome

Back 288

-Linear
-+sense
-Single-stranded RNA
-Single piece of +sense RNA with a poly A tail
-VPg at the 3' end acts as a capping protein
-Translated into a polyprotein
--one large reading frame
--Cleaved at the same time that it is transcribed
--Proteins are grouped according to function

Front 289

Aphthoviruses

Back 289

-causative agent for foot and Mouth disease
-7 serotypes
--A, O, C, SAT1, SAT2, SAT3, Asia
-Still significant veterinary pathogen
-Not in US, but could cause MAJOR epidemic
--could be a major bioterrorism agent

Front 290

Foot and Mouth Disease

Back 290

-Tiny circular/smooth particles
-Endemic in a number of countries
--S. America, Europe, Africa, Asia
-North America is Virus-free
--Last outbreak in 1929 in Chicago area
-High restrictions on imports and exports
-Vaccination is not "virus free"

Front 291

Pathogenesis of Foot and Mouth

Back 291

-Highly contagious
-Most feared disease of cattle worldwide
-Transmission via aerosol inhalation and contaminated food
-Easily spread
-Non-envloped virus, very stable in the environment
-Replicates in the pharynx, causes primary viremia within 24 hours
--secondary virema allows virus to spread to other target organs
-High fever within 48 hours
-Will have vesicles on the skin of the animal
-Signs: excessive salivation, slobbering
--vesicles prominent on the oral mucosa/tongue
--vesicles on the coronary bands around the feet
-Animals have difficulty moving, walking, eating, drinking
-Loss of condition in animals
-Secondary bacterial infections are common
-Hard to differentiate from other viruses

Front 292

FMD look-alike viruses

Back 292

-Swine vesicular disease (Enterovirus)
-Vesicular stomatitis (Rhabdovirus)
-Vesicular Exanthema of Swine (Clicivirus)

Animal with ulcers on skin or oral mucosa cannot be assumed to have FMDV before additional testin
-Can start diagnosis based on which animals get which diseases

Front 293

Diagnosis of FMDV infection

Back 293

-Rapid diagnosis is most important
--need to start quarantine and eradication procedures
-Collect specimens from vesicular fluid
--on epithelial tissue near edge or ruptured vesicles
-Samples should be frozen immediately if possible
-Maintain samples in neutral pH with buffer
--Acidic conditions will inactivate the virus
-Diagnostic tests exist, ELISA assay is most used

Front 294

Swine vesicular disease vs FMDV

Back 294

-Cannot tell the difference between viruses based on vesicles!

Front 295

Why is FMDV so feared?

Back 295

-Where virus has been eliminated, virgin soil epidemic could develop rapidly
--there is no immunity to the virus
-Virus is efficient at shutting down the host cell
--can produce up to 1 million virions per infected cell within hours of infection
--Uses host cell proteins and functions to make viral proteins
-Large amounts of highly contagious virus can be excreted from infected animals before onset of clinical signs
--can excrete virus up to 24 hours before clinical signs
-Long distance spread of FMDV can occur
--carried on wind currents!
-Virus can survive frozen, cured, and partially cooked meat

Front 296

2001 outbreak of FMDV in UK

Back 296

-Origin of outbreak traced to virus-containing swill that was fed to pigs
-4,047,000 animals were slaughtered
-more than 10,000 farms affected
-First clinical signs observed in feb 2001, took a year to get rid of
-Type O panAsia strain
-No vaccination used to control, just slaughter
--Devastating!

Front 297

Problems with vaccinating for FMDV

Back 297

-Current commercial vaccines would interfere with serological monitoring
--DIVA issue
-Current killed vaccines may be contaminated with live virus
-Immunity is strain-specific, would not be able to protect against all strains of the virus
-Immunity is not life-long
-Carrier states exist

Front 298

Future of vaccinations for FMDV

Back 298

-Development of marker vaccines
--protective, lack 1 or 2 specific viral proteins
--can distinguish vaccination vs. infection in animals
-Development of diagnositc kits

Front 299

Humans and FMDV infection

Back 299

-Humans can be infected
-Infections are usually mild or sub-clinical
-Humans can act as carriers of the virus
--humans, clothing, boots, tires, anything!
--Contribute to the spread

Front 300

Coxsackie A virus

Back 300

-Hand, foot, mouth disease virus
-Similar to foot and mouth virus
-only in humans

Front 301

Calicivirus structure

Back 301

-Cup-like shapes on surface
-Icosahedral protein shell
-Non-enveloped virus

Front 302

Caliciviruses of Veterinary Importance

Back 302

1. Vesicular exanthema of swine
2. San Miguel sea lion virus
3. Canine calicivirus
4. Feline calicivirus

Front 303

Vesicular Exanthema of Swine

Back 303

-Calicivirus
-Foot and Mouth disease look-alike, causes very similar lesions
-Mostly in pigs
-Originated from San Miguel sea lion virus
--Feeding contaminated sea lion and seal meat to pigs?
--RNA virus, is able to mutate genome frequently
-Causes cutaneous vesicular disease

Front 304

RNA viruses and mutations

Back 304

-No proof-reading capability in genome
-RNA polymerase will make mistakes in replication and mistakes will not be repaired
--passed on
-High mutation frequency

Front 305

Canine calicivirus

Back 305

-Dog host
-Usually a mild diarrhea disease
-On own not too big of a deal

Front 306

Feline Calicivirus

Back 306

-MAJOR upper respiratory tract infection in cats
-Affects wild and domestic cats
-40-50% of upper respiratory tract disease
--rhinitis, vesiculation, ulceration of the oral epithelium
-Number of different strains, range from mild to very virulent
-Virulent strains appear through mutations
--causes significant disease in cats
--vasculitis, systemic disease
-A percentage of cats remain persistently infected, can shed virus for months to years
-Persistent infection!

Front 307

Diagnosis and control of feline Calicivirus

Back 307

-Upper respiratory tract signs (suggestive)
-Ulcers on oral mucosa (suggestive)
-Laboratory tests must bee used to distinguish from Feline Herpesvirus 1
-Make Dx based on rising antibody titer in paired serum sample
-Vaccines exist
--killed and modified live vaccines
--protect against clinical disease but do not prevent against subclinical infection or carrier state

Front 308

Astroviridae
Astrovirus

Back 308

-Non-enveloped virions with star-like appearance
-Linear, +sense single-stranded RNA genome
-Infect a wide-range of domestic animals
-Cause mild gastroenteritis
-Serious disease occurs rarely, in ducks
-Transmitted via fecal-oral route
--possibly via contaminated feed and water
-No vaccine exists due to mild nature

Front 309

Flaviviruses

Back 309

-"Yellow"
-Flavivirus: Yellow fever, Dengue, west nile
--arthropod-borne viruses
-Pestivirus: BVDV
--non-arthropod-borne viruses
-Spherical, Enveloped virions
-Icosahedral symmetry
-Linear, +sense single-stranded RNA
-Cytoplasmic replication
-Express proteins as a poly-protein

Front 310

Bovine Viral Diarrhea Virus
BVDV

Back 310

-Pestivirus
-Transmitted via contact, congenital
-Occurs in cattle and calves
-Mostly an inapparent disease
-Can be congenital disease
-persistent infection
-Mucosal infection is severe, causes infection
-Occurs world-wide

Front 311

BVDV mucosal disease

Back 311

-Severe form of disease
-Can only occur in persistently infected animals

Front 312

Polyprotein

Back 312

-Long protein chain transcribed from viral RNA
--one long open reading frame
-Structural proteins are usually at 5' end
-Non-structural proteins are usually at 3' end
-Cleavage occurs from viral proteins

Front 313

Bovine Viral Diarrhea Virus
BVDV

Back 313

-Common in cattle populations worldwide
-2 groups: Type 1 and Type 2
--Type 2 is associated with hemorrhagic syndrome and thrombocytopenia
--both are cytopathic
-Can cause acute infections or more chronic mucosal disease from persistent infection
-Persistently infected animals continuously shed viruses for life
--never clear the virus
-Prone to secondary bacterial infections
-Vertical and horizontal transmission

Front 314

Cytopathic BVDV

Back 314

-Cause destruction of cells, lysis of cells in cell culture
-Cause cell death

Front 315

Vertical transmission of BVDV

Back 315

-From mother to offspring
-Allows for persistent infection

Front 316

BVDV mucosal disease

Back 316

-Devastating erosion of the intestinal lining
-Characterized by fever, depression, profuse watery diarrhea
-Erosive lesions in mouth, on foot pads, in intestine
-Typically low WBC counts
-Animals become progressively weak or dehydrated, succumb to infection within 5-7 days
-Non-cytopathic version of virus can mutate and become cytopathic
--leads to mucosal disease

Front 317

Pathogenesis of BVDV in cattle

Back 317

Pregnant animal is infected with non-cytopathic biotype
-Fetus is infected day 40-125 of gestation
-Fetus recognizes viral antigen as "self" and will not react to virus
-MAJOR problem! Source of virus shed!

Can be born with persistent infection

Front 318

Development of BVDV mucosal disease

Back 318

1. Mutation of a non-cytopathic version of virus to a cytopathic version
-Specific mutation event gives rise to new viral protein
2. infected from cytopathic virus from external environment

Front 319

Prevention of BVDV herd infection

Back 319

1. Monitoring: test all new animals introduced into the herd
-Blood tests to identify persistently infected animals
2. Biosecurity: quarantine new animals until test results are known
3. Vaccination: tough, many strains of the virus and many mutations
-no vaccines are very good

Front 320

Treatment and control of BVDV

Back 320

-Prevent infections!
-Prevent birth of presistenly infected animals
-Cannot treat animals with mucosal disease
-Vaccine have been developed, but are not that effective
-remove persistently infected animals from the herd!!

Front 321

Hog Cholera Virus

Back 321

-Pestivirus
-Economically important
-Extremely contagious disease
-Eradicated in the US
-Virus enters oronasal route
--tonsils are primary site of viral replication
-Acute infection that results in systemic spread of virus
-Has been eradicated by many countries

Front 322

Hog Cholera prevention and control

Back 322

-Reportable disease
-Restrictions are important for trade and export
-Many countries have a slaughter and eradication procedure
-Live-attenuated vaccines have been developed
-Marker vaccines to get around DIVA have been developed
--helped in eradication

Front 323

Arboviruses

Back 323

-Arthropod-borne viruses
-West Nile Virus
-Togavirus
-EEE, WEE, VEE

Front 324

West Nile Virus

Back 324

-First detected in birds in 1999
-Maintained in bird-mosquito cycle, transmitted via bite of an infected mosquito
-Endemic in the US
-Has spread across US over 10-15 years
-Can cause encephalitis in equines and humans
-Clinical signs range from fever to death
-Severe cases of encephalitis are RARE
--linked to immunocompromised individuals
-No human vaccine
-Inactivated vaccines for horses
-Control mosquito population!

Front 325

West Nile Virus Vaccines for Horses

Back 325

1. Innovator: inavtivated whole-virus vaccine
2. PrevNile: yello fever chimeric vaccine
3. Recomniteck: recombinant canarypox-vectored WNV vaccine
-Used DNA virus as a vector to express WNV proteins
4. Vetera: killed WNV vaccine

Front 326

Togaviruses

Back 326

-Arborvirus
-Spherical, enveloped virion with icosahedral capsid
-Alphaviruses: in animals
-linear, +sense single-stranded RNA virus
-Polyprotein encodes structural and non-structural proteins
-Cytoplasmic replication, virus buds from the plasma membrane

Front 327

Eastern Equine Encephalitis

Back 327

-East of Mississippi
-Transmitted by mosquito
-Equine host
-Encephalitic disease is rare

Front 328

Western Equine Encephalitis

Back 328

-In Western US
-Transmitted by mosquito
-Equine Host
-Encephalitic disease is rare

Front 329

Venezuelan Equine Encephalitis

Back 329

-In South America and SE USA
-transmitted by mosquito
-Equine Host
-Encephalitic disease is rare

Front 330

Clinical features of EEE, WEE, VEE

Back 330

-Infections often lead to sub-clinical febrile disease or neurological disease
-EEE is most severe in horses and humans
-High titer of virus during secondary viremia can be transmitted back to mosquito (rare)
-Severe depression, wide stance, hanging head, wandering, impaired vision, photophobia, constant head pressing
-Animals can recover but will have neurological sequelae
--dementia, paralysis
-Inactivated vaccines exist but need boosters
-Immunity from natural infection appears to be life-long

Front 331

Transmission cycle of EEE

Back 331

-Aggressive mosquito transmission
-Wild birds and mosquitoes are the "endemic" cycle
-Horses and humans are dead-end hosts
--not required for progression/continuation of the virus in nature

Front 332

EEE in the USA

Back 332

-Neuroinvasive disease in humans is prevalent in the southeast
-Swampy, marshy areas of the state
-Usually outbreaks in horses precedes outbreaks in humans

Front 333

WEE transmission cycle

Back 333

-Virus is maintained in a bird/mosquito cycle
-Specific birds and mosquito species can vary
-Humans and horses are dead-end hosts

Front 334

Pathogenesis for Alphavirus and Flavivirus infections

Back 334

1. Arthropod bite, introduced by mosquito
-mosquito injects the virus into the bloodstream where it cab begin to replicate
2. Primary viremia, virus is in the blood and replicates
-virus is often cleared in immunocompetent individuals
3. Secondary viremia in immunocompromised hosts
4. Virus spreads to target organs via bloodstream
-CNS is target organ for EEE, WEE, an d VEE
-Other viruses target other organs

Subclinical infection: Virus is removed by the reticuloendothelial system
-Virus may be cleared or may spread
-Amount of virus in the blood and duration of viremia varies

Front 335

Coronaviruses

Back 335

-Large, pleomorphic, enveloped virion
-Large club-shaped peploers
-Linear, positive-sense single-stranded RNA genome
--one of largest RNA genomes
-Infectious RNA replicates in the cytoplasm
-Buds into the golgi apparatus of the cell to acquire envelope
--released from cell via exocytosis
-Has a "crown"

Front 336

Coroniavirus Replication

Back 336

-Endocytosed into the cell
-1st step is translation (+sense RNA)
--Only translate 5' most-protein to begin with
-Transcribe a -sense copy of the genome
--forms a -sense "nested set" of the mRNA
--all other viral proteins are translated from nested set
-Replicate in the cytoplasm
-Do not bud from the plasma membrane, are exocytosed from the cell

Front 337

Unique features of Coronavirus

Back 337

1. Exocytosed from the cell, does not bud from plasma membrane
2. Forms a 3' nested set of mRNA transcripts that viral proteins are made from

Front 338

Coronaviruses of Veterinary importance

Back 338

-Feline Coronavirus
-Transmissible gastro-enteritis virus
-Infectious bronchitis virus
-Turkey coronavirus
-Bovine coronavirus
-Canine coronavirus

Front 339

Feline Coronavirus

Back 339

-Has a mutated version that gives rise to Feline Infectious Peritonitis virus

Front 340

Transmissible Gastroenteritis virus

Back 340

-Highly contagious in piglets
-Causes vomiting, profuse yellowish diarrhea, weight loss, dehydration
-high morality in piglets
--more susceptible due to inefficient gastric secretions to inactivate the virus and milk diet will buffer secretions
-Enters body by ingestion
-Clinical signs begin 18-72 hours
-Attenuated vaccine is not effective
-need to control with management

Front 341

Porcine Epidemic Diarrhea Virus

Back 341

-New virus!
-Coronavirus similar to Transmissible Gastroenteritis virus
-Fecal-oral transmission, also fomites
-Widespread in europe
-Enveloped virus, but stable under certain conditions
-Virus damages villi in small intestine
-Fluid loss, dehydration, diarrhea
-HIGHLY contagious
-40% mortality
-Can be identified by ELISA
-Not zoonotic

Front 342

Feline Infectious Peritonitis

Back 342

-Mutation of Feline enteric Coronavirus
-Severe systemic disease in cats
-Progressive, debilitating, lethal disease in wild and domestic cats
-Usually associated with immunosuppressed animals
-Anorexia, chronic fever, malaise, neurological symptoms sometimes
-Virus infects and replicates in monocytes and macrophages
--extensive tissue damage to immune-complex formation
-Immune Enhancement allows virus get into cells
-Live-attenuated vaccine applied to nasal mucosa
--allows low-level viral replication
--favors induction of cell-mediated immunity, some protection is achieved

Front 343

Immune Enhancement

Back 343

-Non-neutralizing Antibodies bind to the surface glycoprotein of the virus
-Virus-antibody complexes are readily taken up by macrophages via Fc receptors
-Worsens disease, helps virus get into cells
-Little old lady taxi example

Front 344

FIP pathology

Back 344

1. FIP viral replication in the macrophages
2. B-cells are activated, produce non-protective antibodies
3. Immune complexes form in circulation
4. Causes immune-mediated vasculitis, worsens disease

Wet FIP: effusive form with vascular permeability abd swelling in abdominal cavity
-fast death

Dry FIP: non-effusive, progressively fatal, slower death

Front 345

Avian Infectious Bronchitis

Back 345

-Highly transmissible respiratory disease of Poultry
-"Gasping disease"
-Affects respiratory cells in trachea and bronchi
-Virus replicates in ciliated epithelial cells, spreads to many organs
-Outbreaks can be explosive, highly contagious
-Thickened mucosal membranes, serous exudate in nasal passages, trachea, and bronchi
-Vaccine exists, given in drinking water

Front 346

Severe Acute Respiratory Syndrome
SARS

Back 346

-Coronavirus
-Viral respiratory illness
-Spread person to person, respiratory route
-Flu-like symptoms, often leads to pneumonia
-No specific treatments or vaccines currently
-Origin of virus is unclear
--species jumper? close contact between humans and animals

Front 347

Arteriviridae general properties

Back 347

-Coronavirus related virus family
-Enveloped virions with icosahedral capsid
-single linear +sense single-stranded RNA
-Replicates in cytoplasm and forms nested set of translation
-Virions bud from the ER into intracellular vesicles, released from cell via exocytosis
-Ex: Porcine respiratory and reproductive syndrome virus, Equine Arteritis virus

Front 348

Porcine Respiratory and reproductive Syndrome Virus
PRRS

Back 348

-Arterivirus, coronavirus
-First emerged in US in 1987
-Leads to reproduction issues, stillbirths, abortions
-Economically important disease of wild and domesticated pigs
-Anorexia, fever, blue discoloration of snout and ears, abortions, stillbirths
-Pneumonia in piglets
-Virus can spread quickly via aerosol, contact, semen
-Relatively stable enveloped virus
-Highly infectious

Front 349

PRRS Pathogenesis

Back 349

-targets pulmonary macrophages
-Early antibody response is not able to clear virus
-Immune enhancement promotes viral efficacy
--production of non-neutralizing antibodies
--worsens disease, allows virus to get into macrophages
-Spreads throughout the body in macrophages, replicates in macrophages
-Spreads across the placenta and affects the fetus
-Live and killed vaccines exist

Front 350

Reoviruses

Back 350

-Respiratory Enteric Orphan virus
-First identified in rodents
-Non-enveloped, spherical virions with 3 concentric capsid layers
-Have segments of double-stranded RNA
-Bluetongue, rotavirus
-5' cap on the +sense RNA strand only and no poly A tail
-Infectious subviral particles are formed when outer capsid is removed
-Replicates in the cytoplasm
-Only partially uncoats for replication

Front 351

Reovirus replication

Back 351

-Divided into 2 phases
-Replicates in the cytoplasm
-Only partially uncoats for replication
-Early transcription and late stage of transcription
-Genetic/RNA re-assortment can occur
--swapping of genes between different reoviruses
--important for pathogenesis

Front 352

Reovirus Capsid Layers

Back 352

-3 capsid layers on top of each other
-Outer capsid: infectious particle
-Middle capsid: ISVP
--still infectious
-Inner capsid: core, non-infectious
--Double-stranded segments of RNA sit in the core and never really leave
--mRNA come out of pores into cytoplasm but genomic RNA stays in core

Front 353

Bluetongue Disease

Back 353

-Reovirus, orbivirus
-Affects sheep and cattle, significant virus
-Transmitted by biting midges, biting flies
--Arthropod borne virus
-Hematopoietic and endothelial blood cells are main targets
--replicates and destroys endothelial cells
--destruction leads to "blueing"
-Outbreaks in US and UK
-Fever, loss of body condition, ulcers in mouth, hemorrhage, lameness, blue/purple tongue, abortions and congenital malformations

Front 354

Rotavirus Infection

Back 354

-Reovirus
-widespread, can affect every mammal
-Cause severe diarrhea, esp in young animals
--"milk scours"
-Viral factories, can see dense accumulations of viral replication
-Infection leads to destruction of epithelial cells on villi in small intestine
-Replicate to EXTREMELY high titers, TONS of viral particles excreted per gram of feces
-Can lead to secondary bacterial infections
--E. coli and Salmonella

Front 355

Human Rotavirus vaccines

Back 355

-Contravertial vaccine
-Oral, tetravalent recombinant vaccine
--Mix and match rotaviral segments
-Reassortment technique for vaccines

Front 356

Retroviridae Properties

Back 356

-Enveloped virus, fairly large particle
-Icosahedral and helical capsid
-2 copies of +sense RNA genome (diploid genome)
-Only +sense RNA virus where 1st step is NOT translation
--1st step is conversion of +sense RNA into double-stranded DNA
-Goes from RNA back into DNA, hence "retroviridae"

Front 357

Unique feature of the Retroviridae Family

Back 357

-Start with viral RNA, converted into double-stranded DNA, then forms viral mRNA and RNA genome
-Completed via reverse transcriptase
-DNA integrates into host genome, acts as integrated DNA protein
--host cell machinery is used to express viral RNA

Front 358

Types of Retroviruses

Back 358

-A-type: non-enveloped, immature particles present in the cell
-B-type: enveloped, extracellular particles with a condensed, acentric core and prominent spike proteins
-C-type: enveloped, estracellular particles with a central core, barely visible spike proteins
-D-type: largest particles, spike-less

Front 359

Key Retrovirion properties

Back 359

1. Enveloped virions
2. Contains reverse transcriptase, carried in with virus
3. Genome is diploid, 2 copies of +sense ssRNA
-Only example of diploid viral genome
4. Only viral RNA synthesized and processed by host cell mRNA processing machinery
5. Only genome to be associated withspecific tRNA
6. Only +sense RNA virus that does not form mRNA right after infection
7. Contains reverse transcriptase!

Front 360

Reverse Transcriptase

Back 360

-Carried along with retroviruses
-RNA-dependent DNA polymerase function
--converts RNA into DNA
-DNA-dependent DNA polymerase function
--converts DNA into DNA to make double-stranded DNA
-integrasae function
--allows insertion into host chromosome
-RNAse function
--Degrades RNA template

Front 361

Retroviral Proteins

Back 361

1. GAG gene: Group-specific antigen
--Internal proteins/structural proteins of the virus
--Matrix protein, capsid protein, and nucleocapsid protein, protease itself
2. POL gene: polymerase
--reverse transcriptase and integrase
3. Envelope gene: encodes for surface protein ad transmembrane protein

Front 362

Retrovirus Replication

Back 362

1. Attachment to specific cellular receptor
2. Penetration
--some fuse at plasma membrane, others are endocytosed
3. Reverse transcriptase to form double-stranded DNA
4. Entry of DNA to nucleus via nuclear pores
5. Incorporation of DNA into chromosome of the cell
--provirus
6. Host cell transcription, translation, and replication
7. Packaging of newly-made viral proteins and budding
8. Processing of newly-made proteins does not occur until virus has budded away from the cell
--cleavage and maturation within the viral particle

Front 363

Provirus

Back 363

-integrated DNA genome of retrovirus in host cell genome

Front 364

Characteristics of Cells transformed by Viruses

Back 364

1. Viral DNA sequences are present either integrated into cellular DNA as provirus or as episomes
2. Transformed cells have a greater growth potential
-Lose contact inhibition, can divide infinitely in culture
-can grow in suspension or semi-solid agar
3. Altered cell morphology
4. Altered cell metabolism and membrane changes
5. Chromosomal abnormalities
6. Virus-specific tumor associated antigens
7. Capacity to produce malignant neoplasms when innoculated into immunosuppressed animals

Front 365

Oncogene

Back 365

-Has potential to cause transformation/tumors
-Can be protoncogene
-V-onc is a viral oncogene
--All are derived from cellular genes, cellular genes are incorporated into cellular genome
--transported along with virus whenever it buds and goes to other cells
--Levels can be over-expressed in viruses
-C-onc is a cellular chromosome oncogene

Front 366

Retroviral induction of oncogenes

Back 366

-Virus carries cellular oncogene with it to other cells
-Induces gene to replicate more than it would normally
-Can become cancerous

Front 367

C-onc genes

Back 367

-Transcriptional activators or repressors
--bind to promoters
-Receptors, especially for growth factors
-Growth factors
-Protein kinases
-Intracellular signal transducers

Front 368

Control of cell growth

Back 368

-Growth factors: bind to growth-factor receptors
--set off series of signaling events that end up with expression of genes
-Can lead to transformation of cell
-Abnormal gene expression leads to cell transformation

Front 369

Oncornavirus Genome Structure

Back 369

-RNA virus carrying a potential oncogene in addition to normal viral protein genes
-Results in over-expression of protein, now under control of viral promoters
--viral promoters in Long-terminal repeat sequences
-LTR regions are strong promoter and enhancer elements
--Drive expression of normal viral proteins AND incorporated oncogene
--over-express oncogene and rapidly leads to transformation

Front 370

Retrovirus Oncogenes
V-onc

Back 370

-Not essential for virus replication
-Extra gene for the virus
-Acquired over time by viruses
-Allows virus to get cell to grow and divide uncntrollably
--allows spread of virus

Front 371

Replication defective oncoviruses

Back 371

-Virus picks up C-onc, but in the process looses a portion of the normal viral genome
-Lost essential genes in recombination event
-Virus is now "replication defective"
--cannot produce all of the proteins it needs to replicate
-Requires a helper virus with complete polymerase gene
-"Hitchikers"

Front 372

Mechanisms of Retrovirus oncogenicity

Back 372

1. Transducing retroviruses
2. cis-activating retroviruses
3. trans-activating retroviruses
4. Inactivation of tumor-suppressor genes

Front 373

Transducing retroviruses

Back 373

-Retroviruses that contain an oncogege, carry in cell-derived oncogene as part of genome
-Often replication defective
-Can transform cells rapidly, bring in potential oncogene with it

Front 374

Cis-activating retroviruses

Back 374

-High efficiency of tumor formation
-C-Onc is not carried by viral genome
-Integration of v-onc occurs right next to a c-onc in the host chromosome
-LTR of retrovirus causes over-expression of host protein
--leads to up-regulation and transformation of C-onc

Front 375

Trans-activating retroviruses

Back 375

-Rare
-Carry additional viral proteins that act as transcriptional activators
-Carry in accessory proteins
-Proteins can bind to cellular promoters to enhance promotion
-Viral-encoded regulatory proteins
-Turna on viral protein expression and host-cell expression

Front 376

Inactivation of tumor-suppressor genes by retroviruses

Back 376

-Viral genome inserts in the middle of tumor-suppressor genes
-No signal to tell cell to stop dividing
-Cell divides indefinitely

Front 377

Viral genome without Onc gene

Back 377

-No transformation of cells in culture
-Low efficiency for tumor production
-Prolonged latent period until tumors develop
-Leukemia viruses

Front 378

Viral genome with Onc gene

Back 378

-Can be replication competent (replicates on own)
--avian sarcoma virus
-Replication defective, needs helper virus
-Rapidly transform cells, rapidly induces tumors
-Animals infected by virus are likely to develop tumors

Front 379

Endogenous retroviruses

Back 379

-Retroviruses that are inserted into the chromosome of the host genome
-Usually vertical transmission
-Considered to be dormant
-Typically not activated, rarely form tumors
-Defective pieces often, remnants of retroviral insertion

Front 380

Exogenous retroviruses

Back 380

-Come from nature
-Can infect the host
-Can be slow-transforming or rapidly-transforming

Front 381

Avian Leukosis virus

Back 381

-Endemic in all flocks of chickens
-Most chickens will become infected within a few months of hatching
-Have bred resistant flocks, lack receptor for virus
-Horizontal and vertical transmission
--vertical transmission was the major problem
-Proviral DNA is integrated, activates c-onc
-Defective viruses arise and are often rapidly fatal

Front 382

Horizontal and vertical transmission of Avian Leukosis Virus

Back 382

-Bird to bird horizontally
-Vertical transmission via congenital infection or genetic transmission
-Chick develops tolerance to the virus, will not mount an immune response
--chances of developing leukemia are high
-Can be passed in germ line to eggs and chicks

Front 383

Feline Leukemia Virus

Back 383

-Oncornavirus
-Replication competent, has Gag, Pol, Envelope
-Does not carry and oncogene
-Induces leukemia or lymphosarcomas
--slow, rare event
--not rapidly transforming
-Cannot infect other species
-Endemic worldwide
-1-7% of cats in US are infected
-Causes immune suppression, weakens immune system
--many cancer deaths in cats

Front 384

Feline Sarcoma Virus

Back 384

-Replication defective form of FeLV
-Has lost Pol, picked up FMS oncogene
-Rapidly causes transformation and fibrosarcomas
-ALWAYS transmitted with FeLV, cannot infect on own
--needs envelope glycoprotein or polymerase from FeLV to be transmitted and infectious

Front 385

Feline Immunodeficiency Virus

Back 385

-Lentivirus
-replication competent, but does not cause tumors
-Causes immunodeficiency disease

Front 386

FeLV pathogenesis

Back 386

-Healthy cat is infected, can mount immune response and recover
--self-limiting infection
-Can get into bloodstream and replicate to high levels
--Primary viremia
-Persistent infection causes persistent viremia for months
--usually ends with leukemia virus related disease
-Cats shed virus in secretions and saliva
-Spread by grooming or biting

Front 387

FeLV diagnostic testing and control

Back 387

-ELISA/Snap test exists
--tests against GAG antigen of virus
-Vaccines exist, inactivated vaccines
--only 70% effective

Front 388

FeLV vs FIV

Back 388

-85% of infections are due to FeLV/FSV, rest are FIV
-FIV does not cause neoplasia, but does cause immunodeficiency
--lentivirus
-Both are labile, enveloped virus, easily inactivated
-FeLV can be transmitted vertically in-utero or in milk
-FIV is not transmitted by milk or in-utero
-FIV is more cell-associated, harder to transmit
--found in saliva, biting is major route of spread
-FeLV is spread by grooming, fleas, biting

Front 389

Lentiviruses

Back 389

-Slow, persistent retroviruses
-EIA: causes life-long infection, no vaccine
-Caprine arthritis-encephalitis

Front 390

Equine Infectious Anemia Virus

Back 390

-Initially infects macrophages, then lymphocytes
-In acute disease: fever, anemia, weakness, blood-stained feces
-80% of cases can be fatal
-recovery is possible, but will have life-long persistent infection
--may have recurrent episodes
-Life-long cell-associated viremia
-Coggins test
-Transmitted from horse to horse via stable flies or horse flies
--higher transmission in summer
-Virus does not survive very long within vector, has 30 min/1 hour to transmit virus

Front 391

Coggins Test for EIA

Back 391

-Agar Gel Immunodiffusion (AGID)
-Center well is loaded with viral antigen
-Blood sample and antigen migrate through the gel
-Positive recaction (antibody recognizes antigen), get precipitant line
--indicates infection

Front 392

Caprine Arthritis-Encephalomyelitis
CAE

Back 392

-Lentivirus that affects goats
-Economically important disease
-2 possible syndromes
--Encephalomyelitis in kids, 2-4 months
--arthritis in older goats
-Acquired via colostrum or milk
-Rate of infection can be reduced by removing kids from does as soon as they pass through birth canal
-Can do coggins test to test for disease

Front 393

Retroviruses in reptiles

Back 393

-Inclusion body disease
-Disease is terminal in animals that exhibit clinical signs
-Can have asymptomatic carriers
-Neurological symptoms with paralysis, CNS disorders
-"Star gazing," reflexes are gone
-Thought to be associated with type C endogenous retrovirus, still unknown

Front 394

Fish over the last century

Back 394

-Biomass over the last 100 years has decreased dramatically!
-Fishing has stayed the same
-We are running out of fish
-80% of world's fish catch species have been exploited beyond or close to harvest capacity

Front 395

Cod in Newfoundland Grand Banks

Back 395

-Early 1990 collapse due to over-fishing
-Have not yet recovered a decade later

Front 396

Dramatic decline of fish worldwide

Back 396

-Large predatory fish in oceans has dropped by 90%
-Dramatic decline in trophy fish size in key west
-Large predatory fish weight has declined 88%
-Average length of sharks has declined 50%
-Seafood faces total collapse by 2048

Front 397

Fish Farming

Back 397

-Has allowed humans to maintain fish intake
-1 out of every 2 fish consumed are farmed
-2 million tons of extra fish will be required annually for the next 30 years
-More than 1/3 of fish in farms do not reach marketable size
--results in $9 billion in losses for industry
--More than 80% are lost to diseases

Front 398

Sustainable fish farming

Back 398

-Solution to fish issue?
-Massive scale farming leads to contamination of area and watersheds

Front 399

Ornamental fish

Back 399

-US is single largest importer of ornamental fish in the world
-Corals and marine aquarium business is booming
-Lots of illegal trade for ornamental fish
-Aquarium industry is over $1 billion in US

Front 400

Disease state of fish

Back 400

-Occurs through interactions of the host, pathogen, and environment

Front 401

Conditions influencing fish health and infectious disease

Back 401

-Physiological status of the fish
--natural resistance to bugs
-Vaccinatino
-Host species
-Host age
-Husbandry, how clean the facilities are
-Environment
-Attrition
--huge area of research
-Correct nutrition can increase fish immune system
-Pathogen itself

Front 402

Farming fish stresses fish

Back 402

-Cows have had time to get used to farming
-Fish farming is relatively new, only last 20-100 years
-Fish get stressed! They are still really wild animals!
-Immune function is depressed when fish are stressed
--allows infection with important bacteria

Front 403

Fish stress and Disease

Back 403

-Immune system is depressed when fish are stressed
-HPA axis is activated
--leads to release of catecholamines and cortisol
-High amounts of cortisol leads to immune system depression
-Opportunistic organisms can come in and kill animals

Front 404

Fish Bacterial diseases

Back 404

-Most prominent group of fish diseases
-Frunculosis

Front 405

Frunculosis
Aeromonas salmonicida

Back 405

-Oldest and most well-studied disease
-Still very prevalent
-Have vaccines that will prevent disease
-Caused by Aeromonas salmonicida
-Presents as ulcers in skin of the fish
--Extensive hemorrhage in the muscle of the fish when the bacteria goes through the skin
--Ascites

Front 406

Aeromonas salmonicida

Back 406

-Gram- bacteria
-Causes frunculosis in fish
-Has 2 types of virulent factors
--A-layer (proteins that cover bacteria)
--Extracellular products (toxins and proteases)

Front 407

Aeromonas salmonicida vs. Aeromonas hydrophilla

Back 407

-A. salmonicida is much more pathogenic
-Can compare on culture
--A. salmonicida produces pigment

Front 408

Aeromonas salmonicida extracellular products

Back 408

-Virulence factor
-Toxins and proteases
-Damage the skin and muscle of the fish
-Host neutralizes extracellular products with alpha-2-macroglobulin and complement

Front 409

Fish species infected by Aeromonas salmonicida

Back 409

-LOTS of fish species
-Eel
-Minnow
-Carp
-Catfish
-Cod

Front 410

Aeromonas salmonicida diagnosis

Back 410

-Lots of ways to identify bacteria
-best way is to do a serological test (ELISA)
-Can do a PCR

Front 411

Furunculosis Treatment

Back 411

-Antibiotics
-Resistance exists
--plasma-mediated and mutational drug resistance

Front 412

Furunculosis Vaccine

Back 412

-2 vaccines exist
-Adjuvant needs to be made out of oil to be effective
-Vaccines do not provide protection against all strains of A. salmonicida
--atypical A. salmonicida

Front 413

Enteric red-mouth disease

Back 413

-Disease of fish
-Causes hemorrhage in the operculum
-Also causes splenomegaly and hemorrhage within the viscera
-Caused by Yersinia Ruckeri
-Mostly affects salmonid species
-

Front 414

Yersinia ruckeri

Back 414

-Gram- bacteria
-Causes Enteric red-mouth disease in fish
-Affects a wide-range of salmonid species and other fish species
-Virulence is associated with a plasmid
-Treat with antibiotics
-Control with vaccines, can induce cell-mediated immunity
--induces IgT mucosal fish antibody

Front 415

Columnaris disease

Back 415

-Becoming more widespread
-Does not kill animals, leaves animals with lesions
--animal can have massive lesions and still survive
--cannot sell fish with lesions
-Caused by Flexibacter columnaris
-Mostly an epithelial disease, lesions are on skin of animal
-Affects salmonids and other species of fish
-Treat with antibiotics
-Vaccine is experimental, not available on market yet

Front 416

Flexibacter columnaris

Back 416

-Gram- bacteria
-Elongated bacterial filaments
-Unknown virulence factors
--secretes a lot of Extracellular products, but not sure what they do
-Susceptible to classical complement pathway, but not the alternate complement pathway

Front 417

Enteric Septicemia of Fish

Back 417

-Important for catfish
--most widely farmed fish in the US
-Caused by Edwarsiella ictaluri bacteria
-High seasonal occurrence
--highest May-June and September-October
--Correlates with favorable water temps
-Most important disease affecting catfish
-Acute form of the disease induces necrosis of the spleen and liver
-Chronic form is characterized by nasal ulcer
-Vaccine is available but not 100% effective
--injectable disease
-bacteria is susceptible to Classic Complement Pathway

Front 418

Bacterial Kidney Disease

Back 418

-Caused by Renibacterium salmonimarum
-Granuloma formation in the kidney
-No bacteria are available

Front 419

Bacterial Cold water disease

Back 419

-Caused by some bizarre, no-slide bacteria
-Forms yellow
-Bacteria shows up when the water is cold (15C)
-In small fish: "Rainbow Trout Fry Syndrome"
-Different pathogenicity in adult and small fish
-Mostly an epithelial disease
-Vaccines are not available
-IgT is main immunoglobulin in skin that is induced

Front 420

Edwarsiella ictaluri

Back 420

-Gram- bacteria
-Causes Enteric Septicemia of catfish
-High seasonal occurrence in May-June and September-October

Front 421

Renibacterium salmonimarum

Back 421

-Causes bacterial kidney disease
-Intracellular gram- bacteria
-Induces granulomas
-Can see lesions in the kidney
-VERY harmful
--induces hemolytic, proteolytic, exotoxin, catalase, and DNAse activities
--Penetrates skin and goes systemic
-P57 major virulence factor
--promotes intracellular invasion of leukocytes
--Induces immunosuppression

Front 422

Intracellular pathogens and Vaccines

Back 422

-Common that vaccines do not exist

Front 423

Vibriosis

Back 423

-Induced by Vibrio anguilarum and Vibrio salmonicida
-Produce skin lesions on abdominal area
--location on abdomen is indicative of Vibrio infection
-Affects many different fish species
-Occurs with sudden changes in the water temperature
-Vaccine exists, but is not always cost-effective

Front 424

Vibrio anguilarum

Back 424

-Gram- bacteria
-Affects both fresh and salt water fish
--affects many different fish species
-Can attack immunosuppressed fish during sudden changes in water temperature
-Secretes very virulent/lethal Extracellular products
--ECPs agglutinate fish RBCs
-Vaccine exists but is not always cost-effective

Front 425

Viral Fish Diseases

Back 425

-Prevalent, but not as prevalent as bacterial fish diseases
-Infectious Hematopoietic Necrosis Virus (IHNV)

Front 426

Infectious Hematopoietic Necrosis Virus
IHNV

Back 426

-Fish virus
-"Ebola of the fish"
-Can kill fish in 3 days
-Mainly affects small fish (Fry)
--Salmonid species
-Causes hemorrhage in the skin of the fish
-Can cause scoliosis
-Will see thick trailing fecal cast in affected animals
-VERY deadly
-No commercial vaccines available
-Immunization of fish with IHNV induces neutralizing antibodies

Front 427

Life cycle of IHNV

Back 427

-Can be transmitted horizontally between small fish
-Can be transmitted vertically from adult to egg

Front 428

Viral hemorrhagic Septicemia Virus
VHSV

Back 428

-Very similar to IHNV
-Mostly affects salmonids
-Can see bilateral exopthalmos, eyes protrude from the head
-Lots of hemorrhage everywhere in the body
-Causes marked kidney necrosis
-Lots of loss of hematopoietic cells
-No commercial vaccines available

Front 429

DNA vaccine for IHNV

Back 429

-First commercially available DNA vaccine! very exciting
-Used in fish

Front 430

Koi Herpesvirus
KHV

Back 430

-DNA virus in herpesvirus family
-Not a zoonotic disease
-Affects carp and ornamental variants like Koi
-Has led to HUGE mortality in fish
-Highly contagious
--90% prevalence in carp populations
-Identify virus with cell tissue culture and PCR

Front 431

Koi Herpesvirus signs of disease

Back 431

-lethargy
-erratic swimming behavior
-Increased mucus production
-Hemorrhage in liver
-Gill necrosis

Front 432

Fungal diseases in Fish

Back 432

-Oomycetes "water molds"

Front 433

Saprolegnia

Back 433

-Water mold/fungal disease of fish
-Not primary pathogens, opportunistic and attack diseased fish
--immunosuppressed fish
-Can consume a fish within a few days
-Fish can be swimming around with half of body covered
--kills fish slowly, suffer a lot
-induce lymphocytopenia and impair hematopoietic organs
-No vaccines available
--treatment with malachite green or 0.5% NaCl

Front 434

Persistent UTI

Back 434

-Bacteruria with the same organism that continues during therapy with appropriate microbial agent

Front 435

Relapsing UTI

Back 435

-Infection with the same microorganism that recurs within several weeks of end of microbial therapy
-Bacteria "hides" and comes back when antimicrobials are gone

Front 436

UTI Reinfection

Back 436

-Infection with initial microorganism responds to therapy
-Infection by a different agent occurs weeks to months after the course of antibiotic therapy
-Common with older dogs or animals that are susceptible to something else
-Continual new infections due to weak immune system in urinary tract

Front 437

UTI Superinfection

Back 437

-Infection with new organisms develop during the therapy for the initial organism
-Usually associated with an in-dwelling catheter
-Can be due to severe anatomic abnormalities or surgical diversion techniques

Front 438

Simple-uncomplicated UTI

Back 438

-No underlying structural or functional abnormality suspected
-Resolved with therapy and fine afterwards

Front 439

Complicated UTI

Back 439

-Infection is associated with structural or functional abnormalities within the urinary tract
-Animal may have impaired immunocompetence
-Will have continued infection of the animal

Front 440

Prevalence of Bacteriuria
men vs. women

Back 440

-Early on in life women are slightly higher
-At puberty, women are MUCH more likely to get UTI
-At around 50, men start having more UTIs
-Same prevalence around age 70

Length of the urethra is the main issue, shorter length in women
Very similar to dogs

Front 441

UTI bacteria in dogs
Outpatients

Back 441

-E. coli: 80%
-Staphylococcus: 7%
-Proteus mirabilis: 6%
-Gram- bacteria: 4%
-Other gram+ bacteria: 3%

Front 442

UTI bacteria in dogs
Inpatients

Back 442

-E.coli: 44%
-Enterococci: 13%
-Staphylococcus intermedius: 12%
-Proteus mirabilis: 9%
-Klebsiella: 10%
-Pseudomonas: less than 5%

-Much more gram- bacteria due to antibiotic resistance

Front 443

Bacterial attributes contributing to UTI

Back 443

-Capsular antigens
-Hemolysins
-Urease
-Adhesion to uroepithelium
-Toxins
-Iron uptake systems
-Adhesion to uroepithelium
-Introital colonization

Front 444

Host factors contributing to UTI

Back 444

-Renal calculi
-Ureteric reflux
-Tumors in and adjacent to the urinary tract
-Pregnancy, bladder stones
-Neurological problems
--incomplete emptying, loss of sphincter control
-Prostatic hypertrophy
-Short urethra in women and dogs
-Catheterization

Front 445

Neutrophil migration during UTI

Back 445

-PMN in urine indicates infection
--should not normally be there
-Part of an active inflammatory response
-Neutrophils follow chemotactic gradient to epithelial surface and cross epithelium
--go from vasculature into tissue
-Neutrophils phagocytose bacteria in urinary tract
-Dead neutrophils go into the lumen and release mediators

Front 446

Uropathogenic E. coli

Back 446

-Intracellular bacterial community that is particularly pathogenic for the urinary tract
-Uropathogenic E. coli with type 1 pilli attach to epithelial surface and invade cells
-Bacteria replicates within the cells, form intracellular bacterial community
-Desquamination of epithelial cells allows bacteria to colonize deeper tissues
-Cells exfoliate and bacterial communites and neutrophils are put into lumen

Front 447

Bacterial Biofilms and UTI

Back 447

-Common cause of persistent infections
-Differentiated structured groups of cells with community properties
-Bacteria do not just float around, stick to surfaces
-Aggregate in hydrated polymeric matrix to form biofilm
-root of many persistent and chronic bacterial infections

Front 448

Intracellular bacterial communities and UTI

Back 448

-Formation is similar to biofilms

Front 449

Biofilm Production and Maturation

Back 449

1. Attachment and EPS production
2. Dearly development of the biofilm
3. Maturation of the biofilm
4. Dispersion of the bacteria within the biofilm

Front 450

Intracellular bacterial community production and maturation

Back 450

1. Colonization and invasion of cell
2. Early IBC, rapid intracellular growth
3. Mid IBC, change to biofilm-like properties
4. Late IBC, fluxing out and filamentation

Front 451

Entry points for bacteria in a catheter system

Back 451

-Urethra meatus and around the catheter
-Junction between the catheter and collection tube
-Connection to drainage
-Reflux from bag to tubing

Front 452

Guidelines for Catheter Care

Back 452

-Avoid catheterization whenever possible
-Minimize catheter duration
-Use intermittently if possible
-Use good aseptic technique when placing
-Use closed sterile drainage system
-Maintain gravity drain
-Use topical antiseptics around meatus in women
-Wash hands before and after inserting catheters and collecting specimens, and after emptying drainage bags

Front 453

Percent of patients with bacteriuria

Back 453

-Very minimal with bladder aspiration
-Highest with clean catch, more contaminated
-"Sweet spot" of 10x10^5 for bacteria

Front 454

Ampicillin and Amoxycillin for UTI

Back 454

-Oral antibacterials
-Beta-lactams
-More than 50% of gram- rods causing UTI are beta-lactamase producers
--beta-lactams are not effective
-Maybe not the best choice

Front 455

Augmentin for UTI

Back 455

-Oral antimicrobial
-Betalactam and beta-lactmase inhibitor
-Active against most gram- rods that are resistant to ampicillin due to beta-lactamase production

Front 456

Cephalexin and Cefaclor for UTI

Back 456

-Beta-lactam
-Relatively beta-lactamase stable
-Have wider spectrum than ampicillin
-Not active against enterococci

Front 457

Trimethoprim for UTI

Back 457

-Nucleic-acid synthesis inhibitor
-Increasing incidences of resistant strains

Front 458

Cotrimoxazole

Back 458

-Oral antibiotic for UTI
-Urinary antiseptic
-Used for complicated UTI only
-Not active in alkaline pH, therefore not useful for proteus infections

Front 459

Nalidixic acid

Back 459

-Oral antimicrobial for UTI
-Quinolone
-For uncomplicated UTI
-Gram- infections only
-Not active against gram+ bacteria

Front 460

Ciprofloxacin

Back 460

-Antimicrobial used for UTI
-Fluoroquinolone
-Very broad spectrum antibiotic
-Only oral agent active against pseudomonas aeruginosa
-Not active against enterococci

Front 461

Antibiotic treatment for UTI

Back 461

-Antibiotic must be secreted in the active form into urine, otherwise ineffective
-Kidney needs to be functioning

Front 462

How to treat UTI

Back 462

1. Acidic urine:
-Rods= E.coli, treat with Trimethoprim or Enrofloxacin
-Cocci= Enterococci, Streptococci, treat with Apicillin or Amoxicillin
2. Alkaline urine:
-Rods= Proteus mirabilis, treat with Ampicillin or Amoxicillin
-Cocci= Staphylococci, treat with Cephalexin or Amoxicillin-clavulanate

Front 463

Antimicrobial Tx for E. Coli UTI

Back 463

-Trimethoprim-sulfonamide
-Amoxicillin-clavulanate
-Fluoroquinolone
-Chloramphenicol

Front 464

Antimicrobial Tx for Staphylococcus UTI

Back 464

-Amoxicillin-clavulanate
-1st generation cephalosporins

Front 465

Antimicrobial Tx for Streptococcus or Enterococcus UTI

Back 465

-Ampicillin
-Amoxicillin

Front 466

Antimicrobial Tx for Proteus mirabilis UTI

Back 466

-Ampicillin
-Amoxicillin

Front 467

Antimicrobial Tx for Pseudomonas UTI

Back 467

-Tetracycline
-Fluoroquinolone

Front 468

Antimicrobial Tx for Klebsiella UTI

Back 468

-1st generation cephalosporins
-Trimethoprim-sulfonamide
-Amoxicillin-clavulanate
-Fluoroquinolone

Front 469

Antimicrobial Tx for Enterbacter UTI

Back 469

-Trimethoprim-sulfonamide
-Fluoroquinolone

Front 470

Causes of persistent UTI

Back 470

-Antimicrobial resistance
-Poor owner compliance
-Inadequate dosing
-Issue with the kidney
--inadequate urine concentration of antimicrobial
--poor absorption/secretion
-Inadequate drug penetration, wrong drug

Front 471

Ascending UTI in dogs and cats

Back 471

-E. coli
-Proteus
-Other coliforms
-Staphylococcus

Front 472

Hematogenous nephritis in Dogs and Cats

Back 472

-Leptospira with various serovars
-Vaccination status of the animal is important for Dx!

Front 473

Ascending UTI in horses

Back 473

-E. coli and coliforms
-Streptococcus
-Staphylococcus aureus

Front 474

Hematogenous nephritis in Horses

Back 474

-Actinobacillus equuli
-Leptospira of various serovars

Front 475

Ascending UTI in Ruminants

Back 475

-Corynebacterium renale with mixed flora
-Coliforms

Front 476

Hematogenous nephritis in Ruminants

Back 476

-Leptospira of various serovars
-Pyogenic bacteria
--gram+ cocci
--anaerobes
--Truperella pyrogenes
-E. coli

Front 477

Ascending UTI in Swine

Back 477

-Actinobaculum suis with mixed flora
--Eubacterium suis
-Coliforms

Front 478

Hematogenous nephritis in Swine

Back 478

-Erysipelothrix rhusiopathiae
-Leptospira of various serovars
-Pyogenic bacteria
--gram+ cocci
--anaerobes
--Truperella pyrogenes
-E. coli

Front 479

Ascending/venereal Genital Tract Infections in Dogs

Back 479

-Canine Herpes Virus
-Brucella canis
-E. coli and other coliforms
-Pseudomonas
-Streptococcus
-Staphylococcus
-Anaerobes

Front 480

Hematogenous Genital Tract infections in Dogs

Back 480

-Canine parvovirus
-E. coli and coliforms
-Streptococcus

Front 481

Ascending/Venereal Genital Tract infections in Cats

Back 481

-E. coli and coligorms
-Pseudomonas
-Streptococcus
-Staphylococcus
-Pseudomonas
-Anaerobes

Front 482

Hematogenous Genital Tract infections in Cats

Back 482

-Feline coronavirus/ FIP
-Feline retrovirus (FeLV)
-Feline parvovirus (Panleukopenia)
-E. coli and coliforms
-Streptococcus

Front 483

Ascending/Venereal Genital Tract infections in Horses

Back 483

-Equine Herpes virus 3
-Taylorella equigenitalis (CEM)
-Streptococcus (group C)
-Klebsiella pneumoniae
-Actinobacillus equuli
-Pseudomonas aeruginosa
-E. coli
-Anaerobes

Front 484

Hematogenous Genital Tract infections in Horses

Back 484

-Arterivirus (EVA)
-Equine Herpes virus 1 and 4
-Leptospira of various serotypes
-Salmonella abortusequi

Front 485

Ascending/Venereal Genital Tract infections in Cattle

Back 485

-Campylobacter fetus, venerealis
-Brucells abortus
--B. suis
--B. melitensis
-Anaerobes

Front 486

Hematogenous Genital Tract infections in Cattle

Back 486

-Orbivirus (Bluetongue)
-Pestivuris (BVD)
-Bovine herpes virus 1
-Brucella abortus
-Chalmydophila abortus
-Leptospira of various serotypes
-Listeria monocytogenes
-Salmonella dublin and other species
-Aspergillus fumigatus

Front 487

Ascending Genital Tract infections in Sheep and Goats

Back 487

-Brucella ovis
-Anaerobes

Front 488

Hematogenous Genital tract infections in Sheep and goats

Back 488

-Orbivirus (Bluetongue)
-Pestivirus (Border disease)
-Brucella melitensis and Brucell abortus
-Chalmydophila abortus
-Coxiella burnetii
-Leptospira of various serotypes
-Campylobacter fetus
-Campylobacter jejuni
-Salmonella abortusovis and other salmonella species

Front 489

Ascending genital tract infections in Swine

Back 489

-E. coli and coliforms
-Anaerobes

Front 490

hematogenous Genital Tract infections in Swine

Back 490

-Porcine Herpes virus 1, 2
-Pestivirus (classical swine fever)
-Porcine enteroviruses
-Porcine parvovirus
-Porcine arterivirus (PRRS)
-Brucella suis and Brucella abortus
-Leptospira of various serotypes

Front 491

Major bacterial agents of Bovine Mastitis

Back 491

-Staphylococcus
-Streptococcus agalactiae
-Streptococcus dysgalactiae
-Streptococcus uberis
-E. coli
-Klebsiella pneumoniae
-Enterpbacter aerogenes
-Truperella pyrogenes

Front 492

Staphylococcus aureus Mastitis

Back 492

-Lives in udder lesions and mucous membranes
-Causes subclinical, chronic, acute, and peracute mastitis
-Can cause gangrenous mastitis
-High percentage of subclinical carriers can occur within a herd

Front 493

Streptococcus agalactiae Mastitis

Back 493

-Hangs out in the milk ducts
--intramammary infection
-Causes acute or chronic mastitis
-Recurring clinical cases are common
-Infection can occur in maiden heifers

Front 494

Streptococcus Dysgalactiae Mastitis

Back 494

-Lives in the buccal cavity and genitalia of cattle
-Causes acute mastitis

Front 495

Streptococcus uberis Mastitis

Back 495

-Lives on skin, in tonsils, vagina, and feces of animals
-Causes acute mastitis
-Can cause mastitis during the dry period

Front 496

E. coli, Klebsiella pneumoniae, and Enterobacter aerogenes Mastitis

Back 496

-Live in feces, sawdust, and bedding
-Common in housed cows
-Coliform mastitis
-peracute toxemia
-usually occurs in fresh cows with low somatic cell counts
-Life threatening mastitis
-Little or no fibrosis of the udder will occur in recovered animals

Front 497

Truperella pyrogenes Mastitis

Back 497

-Lives on skin and mucous membranes
-Peracute, suppurative mastitis

Front 498

"Summer Mastitis"

Back 498

-Caused by Truperella pyrogenes, Peptostreptococcus indolicus, and occasional other anaerobes
--Part of normal flora
-Infection is thought to be fly-borne
-Most common in dry cows and heifers
-Foul-smelling udder secretions
-Loss of a quarter or death can occur