Medical Micro Final Exam

Front 1

What are the 3 classification systems of bacteria?

Back 1

phenotypic, analytic, genotypic

Front 2

Describe the phenotypic classifications of bacteria

Back 2

-microscopic morphology (gram stain; shape of organism [rod, curved, spiral])

-macroscopic morphology (shape & size of colonies-rod, curved, spiral; odor on colonies, prop on blood agar)

-biotyping (biochem markers)

-serotyping (antigen makeup)

-antibiogram patterns (abx)

-phage typing (virus susceptibility)

Front 3

Describe the analytic classifications of bacteria

Back 3

physical makeup (FA, lipid, protein, etc)

Front 4

Describe the genotypic classification of bacteria

Back 4

most precise method to classify bacteria

molecular bio stuff

Front 5

What organisms are considered prokaryotic organisms (i.e. have a PRIMITIVE nucleus)?

Back 5

-bacteria

-blue-green algae (cyanobacteria)

-archaebacteria

Front 6

What organisms are considered eukaryotic organisms (i.e. have a TRUE nucleus)?

Back 6

-algae

-protozoa (unicellular)

-fungi

-slime molds

-metazoa

Front 7

T or F: Viruses are particles, not living organisms

Back 7

T

Front 8

What are the main features of a prokaryote that distinguishes it from eukaryotes?

Back 8

-has a nucleiod (no membrane)

-single, circular CH

-no mitosis

-don't have histones

-no mitochondria

-have CELL WALLS, which HAVE PEPTIDOGLYCAN

-cell memb LACKS sterols

-ribosome = 70S

-smaller cell size

-diff in stxr of flagella

Front 9

What are the main features of a eukaryote that distinguishes it from prokaryotes?

Back 9

-true nucleus (with memb)

-undergoes mitosis

-have histones

-multiple CHs

-have mito and other organelles

-cell memb HAS STEROLS

-ribosome = 80S

-LACK PEPTIDOGLYCAN in CELL WALL

-larger cell size

Front 10

What is a capsule?

Back 10

the layer that lies outside of the cell wall of some bacteria that protects it from phagocytosis; usually composed of polysaccharides

FYI: determines virulence factor

Front 11

What are the two types of bacterial cell wall stains?

(Hint: think of stains)

Back 11

Gram +

Gram -

Front 12

What is a gram + cell wall?

Back 12

-STAINS PURPLE

-LACK LIPOPOLYSACCHARIDE (LPS)/endotoxin

-Lack lipoprotein & phospholipid

-THICK peptidoglycan layer (mesh-like layer)

-Have teichoic acids

Front 13

What is a gram - cell wall?

Back 13

-DON'T STAIN

-CONTAIN LPS!!!!!

-Contain lipoprotein & phospholipid

-THIN peptidoglycan layer

-LACK teichoic acids

-have an additional outer memb which contains lipids

Front 14

What is the Gram staining protocol/mechanism?

Back 14

Remember:Come In And Stain.

The C is for crystal violet, I is for iodine, A is for alcohol or acetone, and S is for safranin.

Steps: both gram types are stained with crystal violet; then the iodine fixes the crystal violet to both cells. Adding the decolorizer (alcohol/acetone) washes away stain in gram - to become colorless; Safranin is a secondary stain, so gram - will stain red-pink b/c cell wall is vacant; however in gram +, safranin can't stain b/c original crystal violet is still attached

Front 15

What is coccus?

bacillus?

coccobacillus?

Back 15

round

rod

b/w round and rod

Front 16

T or F: The cell wall is a virulence factor, not the cell memb

Back 16

T

Front 17

T or F: In gram + cells in a harsh envt, the bacteria divides and creates a super resistance

Back 17

T

Front 18

What are the minimum needs of bacterial metabolism?

Back 18

-Source of Carbon

-Nitrogen

-Energy source (ATP)

-Water & ions

-Iron (impt in some bacteria)

Front 19

What is an obligate anaerobe?

Back 19

can't grow in oxygen

Front 20

What is an obligate aerobe?

Back 20

requires oxygen for growth

Front 21

What is a facultative anaerobe?

Back 21

can grow with or without oxygen

Front 22

T or F: Pyruvate Fermentation (fermentation product) can be used to identify bacteria [b/c bacteria make pyruvate]

Back 22

T

Front 23

What are the 4 bacterial growth phases?

Back 23

-Lag phase

-Log (exponential) phase

-Stationary phase

Decline phase

Front 24

What is the Lag phase in bacterial growth?

Back 24

the time it takes the bacteria to adjust to new media

Front 25

What is the Log (exponential) phase in bacterial growth?

Back 25

when bacteria grow and divide -- they double every cycle

Front 26

What is the Stationary phase in bacterial growth?

Back 26

occurs when media runs out of nutrients; bacteria stop growing

Front 27

What are the 3 types of genetic transfer b/w bacterial cells?

Back 27

-Conjugation

-Transformation

-Transduction

Front 28

What is conjugation?

Back 28

mating or quasisexual (pseudosexual) exchange of genetic info b/w bacteria

Quasisexual n. - One who lacks clear definition of sexual orientation or interest. (haha, those crazy bacteria)

Front 29

What is transformation?

Back 29

when bacteria take up DNA fragments and incorporate them into their own genomes

MOA: Donor cell lysis and releases DNA fragments, which then enter recipient cell and integrates into host DNA

Front 30

What is transduction?

Back 30

when genetic info is transferred b/w bacteria by bacteriophages

Front 31

Name some virulence factors:

Back 31

capsules; pilli (fimbriae); flagella (debated)

Front 32

What are the 3 groups of bacteria according to infection?

Back 32

Normal flora

Virulent Bacteria

Opportunistic Bacteria

Front 33

What is normal flora?

Back 33

bacteria that aid in digestion; vit K production

but, can cause disease if they enter sterile sites

Front 34

what are virulent bacteria?

Back 34

cause disease by damaging host tissue; promote their own growth by damaging host tissue or organ fxn and cause disease

Front 35

what are opportunistic bacteria?

Back 35

they take advantage of the situation

e.g. AIDS pt

Front 36

What are the main bacterial virulence mechanisms?

Back 36

Adherence; Invasion; Colonization; Immune response inhibitors; Toxins

Capsules, Endotoxin, Superantigen, Resistence to Abx,

Front 37

Which bacterial group (according to infection) uses the colonization virulence mechanism?

Back 37

normal flora & opportunists

Front 38

What is a biofilm matrix?

Back 38

a sticky web of polysaccharides that protect the bacteria

Front 39

What is a pathogenicity island?

Back 39

They are incorporated in the genome of pathogenic microorganisms but are usually absent from those non-pathogenic organisms of the same or closely related species.

can be transfer b/w bacteria

Front 40

What are toxins?

Back 40

bacterial products that directly harm tissue or trigger destructive biologic activities; initiates cytokine release

Types:
degradative enzymes that lyse cell

specific receptor binding proteins initiate toxic rxns

cell wall components cause toxic rxns

Front 41

T or F: Only gram - bacteria make endotoxin

Back 41

T

LPS is an endotoxin
(LPS found only on gram -)

Front 42

T or F: LPS is a powerful activator of inflammatory rxns

Back 42

T

Front 43

T or F: Untreated LPS is BAD, so need to take care of gram - bacteria right away

Back 43

T

Front 44

What is an endotoxin?

Back 44

are potentially toxic, natural compounds found inside bacteria; not secreted in soluble form by live bacteria, but is a structural component in the bacteria which is released mainly when bacteria are lysed.

Front 45

What is an exotoxin?

Back 45

a soluble protein excreted by a bacteria

ex: tetanus toxin

Front 46

T or F: Both gram + and gram - bacteria produce exotoxins

Back 46

T

Front 47

T or F: Dimeric toxins have 2 subunits: A and B

Back 47

T

Front 48

T or F: "B" subunit of dimeric toxins binds to the cell surface receptor

Back 48

T

Front 49

T or F: "A" subunit of dimeric toxins is transferred in to the cell

Back 49

T

Front 50

C. diphtheriae toxin MOA:

Back 50

inhibition of protein synthesis (elongation factor 2)

Front 51

V. cholerae toxin MOA:

Back 51

hyperactivation (increases AC, the cAMP)

leads to severe diarrhea

Front 52

C. tetani & C. botulinum toxins MOA:

Back 52

effects on nerve-muscle (tetanus - continuous stimulation; botulinum (botox) - blocks stimulation by blocking ACH, thus paralyzing)

Front 53

What are superantigens?

Back 53

a special group of toxins that connects via binding the MHCII on the antigen presenting cell with the TLR on the CD4+ T cell; thus it simultaneously activates a T-cell and binds a MHCII molec WITHOUT the presence of an antigen, ultimately tissue damage

FYI: can trigger life-threatening auto-immune-like responses

ex: Toxic shock syndrome

Front 54

What are some microbial defenses against immunologic clearance?

Back 54

encapsulation; antigenic mimicry; antigenic masking; antigenic shift; destruction of phagocyte; inhibition of chemotaxis, phagocytosis, phagolysosome fusion; intracellular replication; resistance to lysosomal enzymes

Front 55

Which microbial defense against immuno clearance is the "biggie"?

Back 55

encapsulation

Front 56

List some examples of encapsulated microorganisms?

Back 56

Staphylococcus aureus; Streptococcus pneumoniae; Bacillus anthracis; E.coli; Salmonella sp.; Pseudomonas aeruginosa

Front 57

List some examples of intracellular pathogens:

Back 57

Myobacterium sp.; Chlamydia sp.; Salmonella typhi; Shigella dysenteriae

Front 58

What is sepsis (septicemia; "blood poisoning")?

Back 58

the collective term for bacteremia and fungemia (bacteria and fungi in the blood)

characterized by a whole-body inflammatory state

Front 59

What volume of blood should be collected for an accurate/good blood culture of a pt with sepsis?

Back 59

20 mL

Front 60

What is the most impt factor that influences the recovery of microorganisms in blood collected from a patient with sepsis?

Back 60

the volume of blood collected

Front 61

What is continuous septicemia?

Back 61

INTRAVASCULAR infections

overwhelming sepsis (septic shock)

Front 62

What is intermittent septicemia?

Back 62

infections LOCALIZED distally (e.g. lungs, urinary tract)

Front 63

T or F: Timing of blood collection is impt

Back 63

T

ex: in malaria pts it's impt b/c they get fevers every few hrs, so blood sample timing is impt

Front 64

Blood routine culture

Back 64

-bottle w/ routine culture

-adults (at least 20 mL/culture); children (varies)

Front 65

CSF collection

Back 65

immediately deliver to lab (no heat/cool)

Front 66

Respiratory collection

Back 66

direct lung aspiration, expectorated sputum, bronchoscopy

Front 67

Ear collection

Back 67

aspirate with syringe

Front 68

Eye collection

Back 68

conjunctival and/or corneal scraping; direct aspiration; immediate innoculation

Front 69

What are the definitions and properties of a virus?

Back 69

-filterable agents
-obligate intracellular parasites
-can't make energy or proteins independently
-RNA or DNA
-have either a naked capsid or an envelope morphology
-are assembled and are not replicated by division

Front 70

T or F: Viruses are not living

Back 70

T

Front 71

T or F: Viruses must be infectious to endure in nature and its components must self-assemble

Back 71

T

Front 72

What are the viral classifications/names based upon?

Back 72

stxr, biochem characteristics, disease, means of transmission, host cell, tissue/organ it infects

Front 73

What is a virion?

Back 73

a virus in its extracellular state; a virus particle; consists of a nucleic acid genome surrounded by a capsid (protective protein coat) or membrane (envelope)

FYI: clinically impt viruses make 18nm to 300nm virions

Front 74

What parameter/unit is used to measure size of virion?

Back 74

nanometer

Front 75

List some human DNA viruses:

Back 75

parvovirus; papovavirus; adenovirus; herpesvirus; poxvirus

Front 76

T or F: DNA viruses are either single or doubled stranded

Back 76

T

Front 77

T or F: Viruses are either DNA or RNA, but never both

Back 77

T

Front 78

What are some examples of virion stxral proteins?

Back 78

capsomers - the head of the capsid

viral attachment protein (VAP) - to bind to target cell

hemagglutinins (HA) - VAPs that bind to erythrocytes

Front 79

What are some examples of virion enzymatic proteins?

Back 79

polymerases - for replication

Front 80

What is a nucleocapsid?

Back 80

the genome of a virus (DNA or RNA) + the protein coat (capsid); may be helical or icosahedral (20 faces)

FYI: in simple viruses, the nucleocapsid is the entire virus; but in most complex viruses the nucleocapsid is contained within an envelope

Front 81

T or F: The outer layer of a virus is either a capsid or an envelope

Back 81

T

Front 82

T or F: Removal or disruption of outer package inactivates the virus

Back 82

T

Front 83

T or F: Viruses are either naked capsid viruses or envelope viruses

Back 83

T

Front 84

T or F: Naked capsid viruses are released from cell by lysis

Back 84

T

Front 85

What are the consequences of naked capsids?

Back 85

-can be spread easily (on fomites [like a cloth, bedding, clothes,etc], hand-to-hand, etc)

-can dry out & retain infectivity

-can survive the adverse conditions of the gut

-can be resistant to detergents & poor sewage tx

-Ab may be sufficient for immunoprotection

Front 86

what are the components of the virus envelope?

Back 86

memb, lipids, proteins, glycoproteins

FYI: naked capsid is only protein

Front 87

T or F: Naked capsid viruses are acute b/c produce a lot and quick

Back 87

T

Front 88

T or F: Envelope viruses are disrupted/labile to the following:
acid, detergents, drying, heat

Back 88

T

Front 89

What does labile mean?

Back 89

susceptible to alteration or destruction

Front 90

T or F: Envelope viruses produce chronic infections b/c slow production

Back 90

T

Front 91

What are the consequences of envelope viruses?

Back 91

-must stay WET

-can't survive the GI tract

-spreads in large droplets, secretions, organ transplants, and blood transfusions

-does not need to kill cell to spread

-may need Ab and cell-mediated immune response for protection and control

-elicits hypersensitivity and inflammation to cause immunopathogenesis

Front 92

T or F: Envelope viruses are released via cell lysis or budding

Back 92

T

Front 93

T or F: Naked viruses have a tight icosahedral nucleocapsid since have no envelope

Back 93

T

Front 94

T or F: Naked capsid viruses assemble large # of progeny inside cell and are released at one time by cell lysis

Back 94

T

Front 95

T or F: Many enveloped viruses release small quantities of virus over a long period of time

Back 95

T

Front 96

T or F: None of the negative RNA viruses are naked!!!!!

Back 96

T

Front 97

T or F: Negative RNA viruses are all envelope viruses

Back 97

T

Front 98

T or F: In envelope viruses, the virus buds out of the cell by modifying the host's memb

Back 98

T

Front 99

T or F: Budding does not kill cell outright, but host cell death occurs over time due to "viral take-over" or apoptosis

Back 99

T

Front 100

T or F: HIV is a cytotoxic virus

Back 100

T

Front 101

What is tropism?

Back 101

refers to the way in which different viruses/pathogens have evolved to preferentially target specific host species, or specific cell types within those species.

Front 102

T or F: Tropism is determined by specific surface proteins or glycoproteins on each virus; also depends on the the specific cellular receprtors

Back 102

T

Front 103

Naked viruses bind to host cell receptors thru specific proteins on the ______.

Enveloped viruses bind to host cell thru viral glycoproteins embedded in the _____.

Back 103

Capsid

Envelope

Front 104

T or F: The cell provides substrates, energy, and machinery necessary for synthesis of viral proteins and viral genome replication; processes not provided by the cell must be encoded in the viral genome

Back 104

T

Front 105

What are the 8 steps in viral replication?

Back 105

Recognition of the target cell

Attachment

Penetration

Uncoating

Macromolecular synthesis

Assembly of virus

Budding of enveloped virus

Release of virus

Front 106

What happens in the macromolecular synthesis step of viral replication, and specifically which proteins are produced?

Back 106

early mRNA & enzymatic and nucleic acid-binding proteins

then the genome replicates, and late mRNA and stxral protein synthesis

Post-TLNal modifcation

Front 107

One round of viral replication has several phases. What are they?

Back 107

early phase (recognition, attachment, penetration, uncoating and deliverance of genome)

late phase (genome replication, macromolecular synthesis, viral assembly and synthesis)

eclipse phase (new virions appear, still sitting around)

latent period (includes eclipse phase and ends with release of new viruses; extracellular infectious viruses are not detected in this period)

Front 108

T or F: Mechanism of virus internalization depends on the virion type; but most non-enveloped viruses enter cell by receptor-mediated endocytosis or viropexis

Back 108

T

Front 109

What is endocytosis?

Back 109

a normal cellular process; the uptake of receptor-bound hormones, etc

Front 110

T or F: Picornaviruses and papoviruses enter host cell by viropexis

Back 110

T

Front 111

What is viropexis?

Back 111

when the hydrophobic stxrs on the capsid of the virus are exposed after viral binding to the cell. these stxrs help the virus or viral genome trick the cell, thus it slips thru the cell memb (direct penetration)

Front 112

T or F: Envelope virus fuse their memb with the host cell memb

Back 112

T

Front 113

What is a syncytium?

Back 113

a large cell-like stxr filled with cytoplasm containing many nuclei; promotes cell-cell fusion to form multinucleated giant cells

Front 114

T or F: Paramyxoviruses, herpesviruses, and retroviruses (e.g. HIV) induce syncytia formation

Back 114

T

Front 115

T or F: Many DNA viruses establish persistent infections

Back 115

T

Front 116

T or F: DNA viruses must interact with host TXNal machinery

Back 116

T

Front 117

Most RNA viruses replicate in the _____

Back 117

cytoplasm

Front 118

T o F: Cells cannot repllicate RNA, thus RNA viruses must encode or carry an RNA-dependent RNA pol

Back 118

T

Front 119

T or F: RNA viruses are prone to mutation b/c they are host-cell dependent

Back 119

T

Front 120

T or F: RNA viruses, except + RNA genome, must carry or encode polymerases

Back 120

T

Front 121

What is common tropism?

Back 121

when one tissue can be affected by many viruses

ex: hepatitis

Front 122

What is the purpose of virulence factors?

Back 122

promotes efficiency of viral replication and transmission

promote access and binding of virus to target tissue

promote escape of virus from host defenses or immune system

Front 123

What does attenuation mean?

Back 123

reduction of the virulence of a virus, while keeping it alive

Front 124

T or F: Loss of any virulence factors causes attenuated viruses (e.g. live virus vaccines)

Back 124

T

Front 125

What are the determinants of viral disease?

Back 125

nature and severity of disease

Front 126

What are the basic steps in viral disease?

Back 126

incubation period

symptomatic period

convalescence period

Front 127

What is convalescence?

Back 127

the gradual recovery of health and strength after illness by the pt

Front 128

What is the incubation period?

Back 128

asymptomatic, but the virus is amplified may be spreading to secondary sites (FYI:primary sites = oral mucosa and upper resp tract)

prodrome (non-specific early symptom); better recovery if can detect & treat at this point

Front 129

What is the symptomatic period?

Back 129

tissue damage, systemic effects

viremia (transport of virus in blood)

Front 130

What is the convalescence period?

Back 130

when the body repairs the damage

Front 131

What is the most common route of inquisition (entry) of a virus into the body?

Back 131

Inhalation

Front 132

What is secondary viremia?

Back 132

replication of viruses in macrophages, blood vessels, or liver; which precedes the delivery of the virus to its target tissue

Front 133

T or F: In viremia, viruses may remain free in plasma or be cell-associated in lymphocytes and macrophages

Back 133

T

Front 134

T or F: Viruses spread during the incubation period

Back 134

T

Front 135

What are the 3 outcomes of viral infection at the cellular level?

Back 135

Failed infection (abortive infection)

Cell death (lytic infection)

Infection without cell death (persistent infection)

Front 136

What is abortive viral infection?

Back 136

failed infection

Front 137

What is lytic viral infection?

Back 137

cell death

Front 138

What is persistent viral infection?

Back 138

infection without cell death

Front 139

What are the 4 types of persistent infection?

Back 139

Chronic (non-lytic productive; usually envelope)

Latent (dormancy; limited macromolecular but no viral synthesis)

Recurrent

Transforming (immortalizing)

Front 140

What are some impt determinants of viral pathogenesis in its interaction with the target tissue?

Back 140

access, stability in the body, temperature, pH of GI, ability to cross skin or mucosa epithelial cells, ability to establish viremia, ability to spread thru reticuloepithelial system, target tissue, VAPs, tissue receptors

Front 141

What are inclusion bodies?

Back 141

accumulation of viral proteins and stxrs

Front 142

What are some cytopathologic activities of viruses?

Back 142

production of cytotoxic viral proteins, inhibition of cell's macromolecular synthesis, inclusion bodies, altered cell metabolism (cell immortalization)

Front 143

What are the main mechanisms of viral cytopathogenesis?

Back 143

inhibition of cell protein synthesis, inhibition and degradation of cell DNA, alteration of cell memb stxr, inclusion bodies, virion toxicity

Front 144

What are the host cells protective responses to viral pathogenesis?

Back 144

Antigen-non-specific antiviral responses

Interferon

NK cells & macrophages

Antigen-specific immune responses

T-cell responses

Ab responses

Front 145

What is the Sx associated with interferon immunoresponse?

Back 145

flu-like systemic symptoms

Front 146

What is the Sx associated with T-cell immunoresponse?

Back 146

delayed-type hypersensitivity and inflammation

Front 147

What is the Sx associated with Ab/complement immunoresponse?

Back 147

Ab-dependent cellular cytotoxicity, immune complex disease

Front 148

What is the incubation period for influenza?

Back 148

1-2 days

Front 149

What is the incubation period for common cold?

Back 149

1-3 days

Front 150

What is the incubation period for HIV?

Back 150

1-10 years

Front 151

What are the mechanisms of viral transmission?

Back 151

aerosol (via air); food & water; fomites; direct contact with secretions (saliva, semen); sexual contact; birth; blood transfusion or organ transplant; zoonoses

Front 152

What is zoonoses?

Back 152

from/via animals, insects (arbovirus)

Front 153

What is epidemiology?

Back 153

branch of medicine dealing with the transmission and control of disease throughout populations

Front 154

What are some disease and viral factors that promote transmission?

Back 154

stability of virions in response to envt (drying, detergents, temperature, etc)

replication and secretion of virus into transmissible aerosols and secretions

asymptomatic transmission

ineffectiveness of immune response to control reinfection or recurrence

Front 155

What is an outbreak?

Back 155

viral infection due to introduction of the virus in to a new location

has a common source (e.g. food), can be stopped if source is identified

Front 156

What is an epidemic?

Back 156

occurs OVER A LARGE AREA

introduction of virus in an immunologically naive population

Front 157

What is a pandemic?

Back 157

a WORLDWIDE epidemic, from a new virus (e.g. HIV)

Front 158

What 5 things do lab methods achieve in the laboratory Dx of viral disease?

Back 158

-Description of virus-induced cytopathologic effects (CPEs) on cells

-electron microscopic detection of viral particles (but this is only done at research institutes)

-isolation & growth of virus particles (but is unlikely to be done)

-detection of viral components (i.e. proteins, genome, enzymes)(commonly done)

-evaluation of the pt's immune response (serology)

Front 159

What is CPE?

Back 159

cytopathologic (cytopathic) effects

refers to degenerative changes in cells (especially in tissue culture) associated with the multiplication of certain viruses

Front 160

What is serology?

Back 160

scientific study of blood serum, esp the diagnostic identification of Ab in the serum; hence this is an evaluation of a pt's immune response

Front 161

T or F: It is impt to deliver viral specimens ASAP to the lab b/c there are many labile viruses, and there is a chance of bact/fungal overgrowth

Back 161

T

Front 162

T or F: Viruses are best transported and stored on ice, and in special media that have antibiotics, proteins (serum albumin or gelatin)

Back 162

T

Front 163

T or F: Tissue culture is one of many systems for the propagation of viruses

Back 163

T

Front 164

What are the 3 types of tissue culture?

Back 164

Primary

Diploid cell line

Tumor or immortalized cell line

Front 165

What is a primary cell culture?

Back 165

gets cells from specific tissue/organism

Front 166

What is a diploid cell line?

Back 166

single cell type

divide FINITE number of times, then die

Front 167

What is a tumor/immortalized cell line?

Back 167

single cell types

divide INFINITE number of times

Front 168

What is Tissue Culture Dose (TCD50)?

Back 168

How many Titers of virus that causes CPE in 50% of the tissue culture cells

Front 169

What is Lethal Dose (LD50)?

Back 169

How many Titers of virus that causes DEATH in 50% of a set of test animals

Front 170

What is an Infectious Dose (ID50)?

Back 170

How many Titers of virus that initiates a Sx/Ab or other response in 50% of a set of test animals

Front 171

T or F: Humoral immune response provides a Hx of a pt's infections

Back 171

T

Front 172

T or F: Serology can be used to identify the infecting agent, evaluate the course of infection, and/or determine the nature of the infection (whether it is primary or reinfection, and whether it is acute or chronic)

Back 172

T

Front 173

What is a titer?

Back 173

a measure of [ ] that employs serial dilutions

viral titer: The lowest [ ] of virus that still infects cells

Front 174

T or F: The Ab type, titer, and identity of antigenic target provide serologic data about an infection

Back 174

T

Front 175

T or F: Serologic testing is used to identify viruses and other agents that are difficult to isolate and grow in the lab or that cause diseases with slower courses

Back 175

T

Front 176

What are some examples of serologic assays?

Back 176

complement fixation, hemagglutination inhibiton, neutralization,, immunofluorescence (direct & indirect), latex agglutination, in situ enzyme immunoassay, ELISA, radioimmunoassay

Front 177

What are 6 viruses mentioned in class that can be diagnosed by serology?

Back 177

Epstein-Barr virus

Rubella virus

Hepatitis A, B, C, D, and E virus

HIV

human T-cell leukemia virus

Arboviruses (encephalitis viruses)

Front 178

What is seroconversion?

Back 178

the development of detectable specific antibodies to microorganisms in the blood serum as a result of infection or immunization

seroconversion occurs when Ab is produced in response to a primary infection

Front 179

What is the quick basic background to primary infection and reinfection?

Back 179

In the initial (primary infection) phase of the infection, immunoglobulin M (IgM) antibodies are produced and as these levels drop (and become undetectable) immunoglobulin G (IgG) levels rise and remain detectable. Upon reinfection, IgM antibodies usually do not rise again but IgG levels will increase. Thus an elevated IgM titer indicates recent primary infection, while the presence of IgG suggests past infection or immunization.

Front 180

T or F: IgM and IgG testing can indicate if infection is primary or reinfection

Back 180

T

Front 181

T or F: Specific IgM Ab, found during the first 2 to 3 weeks of infection is a good indicator of a recent primary infection

Back 181

T

Front 182

What is an anamnestic (secondary or booster) response?

Back 182

the immune system's ability to recall a previous infection by memory, thus producing a renewed rapid production of antibody, the second time the same antigen is detected

Front 183

T or F: Serology can be used to determine stage of slow or chronic infections (e.g. EBV, Hep B)

Back 183

T

Front 184

T or F: Initial stage Ab are common ones against virions & surfaces of infected cells. Later stage Ab are towards intracellular proteins/enzymes

Back 184

T

Front 185

T or F: Although serology can tell you if a viral infection is recent, it cannot tell you if when it occurred

Back 185

T

Front 186

T or F: There are limitations to the serology technique (e.g. cross rxns b/w viruses; the pt's Ab may be bound to viral antigen in immune complexes and thus inhibits detection; false + tests)

Back 186

T

Front 187

T or F: Fungi's main purpose is to degrade organic matter

Back 187

T

Front 188

Fungi lead a heterotrophic existence as what 4 things:

Back 188

-Saprobes

-Symbionts

-Commensals

-Parasites

Front 189

What is a saprobe fungus?

Back 189

an organism that lives on dead or decaying matter

Front 190

What are symbiont fungi?

Back 190

organisms that live together and in which the association is of MUTUAL advantage

Front 191

What are commensal fungi?

Back 191

organisms living in a close relationship in which one benefits from the relationship and the other neither benefits nor is harmed

Front 192

What are parasitic fungi?

Back 192

organisms that live on or within a host, from which they derive benefits without making any useful contribution in return; in the case of pathogens the relationship is harmful to the host

Front 193

What is a heterotroph?

Back 193

an organism that requires organic substrates to get its carbon for growth and development

Front 194

Although fungi are eukaryotes, they are distinguished from other eukaryotes by what 2 impt features:

Back 194

-a rigid CELL WALL composed of chitin and glucan

-a cell memb in which ERGOSTEROL is substituted for cholesterol as the major sterol component

Front 195

What are the 2 simplest groupings of fungi based on morphology (i.e. unicellular or multicellular?

Back 195

-Yeasts (unicellular)

-Moulds (multicellular)

Front 196

What are yeasts?

Back 196

usually unicellular; produce daughter cells that may elongate to form sausagelike pseudohyphae; produce round, pasty, or mucoid colonies on agar; reproduce by budding or binary fission (where a progenitor/mother cell pinches off a portion of itself to produce a progeny/daughter cell)

Front 197

What are moulds?

Back 197

multicellular organisms consisting of threadlike tubular stxrs called hyphae; elongate at their tips ("apical extension");

Front 198

Hyphae are either _____ or ______.

Back 198

coenocytic (hollow & multiniucleate); septate (divided by partitions or cross-walls)

Front 199

What is a mycelium?

Back 199

a mat-like stxr produced when hyphae form together

Front 200

T or F: Moulds are described as filamentous, hairy, or woolly

Back 200

T

Front 201

What is aerial hyphae?

Back 201

when moulds produce vegetative hyphae that project above the surface of the culture medium; aerial hyphae may produce specialized stxrs known as conidia (asexual reproductive elements)

Front 202

What are conidia?

Back 202

asexual reproductive elements; are easily airborne and serve to scatter the fungus

Front 203

T or F: Many medically impt funghi are dimorphic since they exist in both a yeast and a mould form

Back 203

T

Front 204

T or F: Relative to bacteria, fungi are slow growing with cell-doubling times in terms of hours rather than minutes

Back 204

T

Front 205

T or F: ~200 funghi cause human disease

Back 205

T

Front 206

Funghi reproduce by the formation of ____.

Back 206

spores

Front 207

T or F: Spores may be telomorphs (sexual) or anamorphs (asexual)

Back 207

T

Front 208

T or F: Deuteromycetes (the largest grp of fungi causing infection to humans) does not produce known sexual spores

Back 208

T

Front 209

What are the 2 general types of asexual spores?

Back 209

Sporangiospores

Conidia

Front 210

What is mycosis?

Back 210

a condition in which funghi pass the resistance barriers of the human/animal body and establish infection

Front 211

What are 2 examples of endemic mycoses?

Back 211

blastomycosis

histoplasmosis

Front 212

Give an example of an opportunistic mycosis:

Back 212

candidiasis

Front 213

T or F: Candida spp. are the most common of the opportunistic fungal pathogens

Back 213

T

Front 214

Immune response to funghi

Back 214

The primary protective responses to fungal infection is TH1-mediated inflammatory reactions - Patients deficient in these responses (e.g., AIDS) are most susceptible to fungal (opportunistic) infections

IFN-γ and IL-2 activate macrophages and cytotoxic T and natural killer (NK) cells, respectively, for clearance of intracellular organisms

Cationic proteins from neutrophils may be important for some fungal infections (e.g., mucormycosis)

Nitric oxide is important against Cryptococcus and other fungi

Antibody, as an opsonin, may facilitate clearance of the fungi

Front 215

T or F: Viral genome may consist of either DNA or RNA that is either single or double stranded and is either linear or circular.

Back 215

T

Front 216

T or F: Malaria is the #1 cause of DALY's as well as death caused in parasitic infections

Back 216

T

Front 217

What is a DALY?

Back 217

"Disability Adjusted Life Years"; # of healthy years of life lost because of premature death or disability (is deadly if left untreated)

Front 218

Which 4 of the 7 major phyla/subgroups are impt in medical parasitology?

Back 218

Sarcomastigophora

Ciliaphora

Apicomplexa

Microspora

Front 219

The phylum Sarcomastigophora consists of ____ and _____.

Back 219

amebae; flagellates

Front 220

T or F: Locomotion of amebae is accomlished by the extrusion of pseudopodia ("false feet"); flagellates move by the lashing of their whip-like flagella

Back 220

T

Front 221

The phylum Ciliophora consists of the _____.

Back 221

ciliates

Front 222

T or F: Ciliates include a variety of free-living and SYMBIOTIC species

Back 222

T

Front 223

T or F: Cilia are stxrally similar to flagella but are usually shorter and more numerous

Back 223

T

Front 224

T or F: The only ciliate parasite of humans is Balantidium coli, which contains two nuclei: a large macronucleus and a small micronucleus

Back 224

T

Front 225

The phylum Apicomplexa consist of ____ and _____

Back 225

Sporozoa; Coccidia

Front 226

T or F: Parasites from the phylum Microspora are characterized by the stxr of their spores, which have a complex, tubular extrusion mechanism (polar tubule) used to inject the infective material (sporoplasm) into host cells

Back 226

T

Front 227

T or F: Metazoa includes all animals that are not protozoa

Back 227

T

Front 228

Two groups of metazoa of particular medical importance are _____ and _____

Back 228

helminths (worms); arthropods (crabs, insects, ticks, etc)

Front 229

T or F: Helminths possess elaborate attachment stxrs such as hooks, suckers, teeth, or plates

Back 229

T

Front 230

T or F: Although some helminths have an alimentary system, none have circulatory systems

Back 230

T

Front 231

What 2 phyla are helminths broken into?

Back 231

Nematoda & Platyhelminthes

Front 232

T or F: The phylum nematoda consists of the roundworms, which have cylindrical bodies

Back 232

T

Front 233

T or F: Roundworms are the most common intestinal parasite

Back 233

T

Front 234

The phyla platyhelminthes consists of the _____.

Back 234

flatworms

Front 235

T or F: Flatworms have flattened bodies that are leaf-like or resemble ribbon segments

Back 235

T

Front 236

Platyhelminths (flatworms) can be further separated into _____ and ______.

Back 236

trematodes (flukes) & cestodes (tapeworms)

Front 237

T or F: Trematodes have leaf-shaped bodies; most are hemaphroditic

Back 237

T

Front 238

T or F: Cestodes (aka tapeworms) have bodies composed of ribbons of proglottids, or segments; all are hermaphroditic

Back 238

T

Front 239

There are 5 major classes of arthropods. What are they?

Back 239

Chilopoda

Pentastomids (tongue worms)

Crustacea

Arachnida

Insecta

Front 240

T or F: Chilopoda consist of terrestrial forms (e.g. centipedes)

Back 240

T

Front 241

T or F: Pentastomids (tongue worms) are blood-sucking endoparasites of reptiles, birds, mammals

Back 241

T

Front 242

T or F: Arachnida (4 pairs of legs) consist of mites, ticks, spiders, and scoprions; these are medically impt b/c serve as vectors for microbial diseases

Back 242

T

Front 243

T or F: Insecta (3 pairs of legs; presence of wings) consists of mosquitoes, flies, midges, fleas, lice, bugs, wasps, and ants;

Back 243

T

Front 244

T or F: To ensure survival under harsh envts, many parasitic protozoa develop into a CYST (less metabolically active)

Back 244

T

Front 245

What are 2 examples of amoebae?

Back 245

Entamoeba gingivalis (commensal)

Entamoeba histolytica (pathogen)

Front 246

Give one example of a flagellate

Back 246

Leishmania donovani

Front 247

Give one example of a ciliate?

Back 247

Balantidium coli

Front 248

T or F: Protozoan parasites can evade immuno responses by continuously changing their surface antigens

Back 248

T

Front 249

What is one major example of a coccidia and how is it medically impt?

Back 249

Plasmodium; and is impt b/c causes malaria (1-3 million deaths/yr)

Plasmodium vivax is most prevalent and widest geo distribution

P. falciparum is most lethal

Malaria only takes one mosquito bite to transmit

Front 250

T or F: Malaria has a 10-17 day incubation with flu-like Sx, headache, N & V. As infection progresses, RBCs rupture, typical chills, fever, sweating, shaking, very high temps (>103F)

Back 250

T

Front 251

Give 2 examples of Nematodes

Back 251

Toxocara cani & Toxicara cati

infects dogs and cats, respectively

Front 252

Give an example of a Trematode

Back 252

Schistosoma mansoni

Front 253

Give an example of a Cestode

Back 253

Taenia solium

Front 254

Name 3 examples of parasites transmitted via anthropod vectors

Back 254

Malaria

Trypanosomiasis

Filariasis

Front 255

Know these mechanisms:
1. Plasmodium Spp: Secrete toxic parasite products
2. E. Histolytica: Secretes toxic parasite products
3. Tapeworm: Causes mechanical tissue damage and immunopathology.

Back 255

just know it

Front 256

Know these rxn types:

1. Trypanosomes: Can cause Type I, or II or III or Type IV immune reaction.
2. Plasmodium spp (Malaria): Is a type III (Immune complex reaction)
3. Schistosomiasis: Type III or Type IV reaction.

Back 256

just do it

Front 257

EBV targets which cells?

Back 257

B cells

Front 258

What is a facultative parasite?

Back 258

those that can grow with or without oxygen

Front 259

What is an obligate parasite?

Back 259

cannot live independently of its host

Front 260

T or F: Enterococci are hard to distinguish from Streptococci

Back 260

T