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76 Cards in this Set

  • Front
  • Back
What is Gardasil?

9.1 General Properties of Viruses

•__________ made of ___________

surrounded by a _____________

•Only ______

•No nucleus, organelles, cytoplasm

•AKA virions
-obligate intracellular parasite, nucleic acid, protein coat

-replicate inside host
9.2 Nature of the Virion
Viral Components-

•Nucleic acid-________

–Can be___________

•Capsid-__________ surrounding nucleic acid

•Envelope-______________ surrounding the capsid of
-either DNA or RNA

-single-stranded or double stranded; linear or circular

-protein coat

-lipid bilayer
Capsid proteins are arranged to give virion symmetry
–Rod-shaped, protein subunits twist up
-Helical symmetry
–Roughly _____

–___ equilateral equilateral triangles or faces

•Complex viruses-

–Head- ________

–tail & _____
-Icosahedral symmetry



-genome surrounded by capsid

-tail fibers
•Enzymes- some viruses have 1 or more to help _____________

•Bacterial viruses
–Bacteriophage/phage- viruses that infect _____
-infect host cell or for replication of viral genome

PART II Growth and Quantification
9.3 The Virus Host; 9.4 Quantification of Viruses

•Must be grown with living host cells.
3 types of hosts:

1. Prokaryotes
–Ex- _______

2. Plants
–Ex- _________

3. Animals
–Ex- ________
-Bacteriophage lambda with E.Coli

-Tobacco mosaic virus with Tobacco

-HIV with lymphocytes
Quantification methods:
1. Animal infectivity
–Inject sensitive animals with ___________________

2. Plaque assay
–Used to count _________
-10-fold serial dilutions of viral sample, determine % survival

-bacterial & some animal viruses
(each plaque results from infection by a single virus particle)
PART III Viral Replication 9.5 – 9.7
1. Attachment to __________

2. Penetration of either _________
-specific receptor on host cell, usually a membrane protein

-whole virus (eukaryotic) or just its genome (prokaryotic)
3. Synthesis of nucleic acid and protein- host machinery replicates _________________

4. Assembly and packaging of structural _______________

5. Release-___________; new virions can infect new host cell
-viral genome & makes viral proteins

-subunits & genome into capsid

-Lysis of host cell or by budding
Viral Restriction and Modification by the Host

•Bacteria synthesize ____ as protection against viral invaders

–Restriction endonucleases _________

•Viruses can__________________ by the host’s restriction endonucleases
–Encode proteins to inhibit host restriction systems

•Host cells have similar means of protecting their DNA from __________

-cleave DNA at specific sequences

-modify their DNA to avoid digestion

-degredation by viral endonucleases
2 types of phage:
•simple life cycle


•Eg. T4 which infects E. coli

-infect host, make copies of themselves, lyse the host cell
T4 life-cycle:
Attachment & penetration

•____ of T4 attach to cell wall

•T4 genome is 1 linear molecule of ________

•DNA is ______. Rest of phage _____

-double stranded DNA

-inserted into host.
-remains outside host cell
Replication & synthesis of new proteins

•DNA is _______

•Resulting _____ is translated to make proteins for __________

•100’s of copies of ________

Assembly & release of viral particles

•DNA is inserted into _______

•Host cell is _____________

-mRNA, new viral heads & tails

-viral DNA are also made

-empty capsids & tails are added

-lysed to release viruses
Lysogenic phage/Temperate viruses- Fig 9.16

•Enter a state called _____-viral genome integrates into host chromosome & is replicated with host chromosome

•Don’t immediately make new phage particles

• The virus is called a _______, when its genome exists as part of host genome

• Bacterial host cells that harbor __________

•Eventually, new phage are made (lytic cycle occurs) and cells ______

•Induction of ____ --> _____ --> _______

•Ex. Lambda which infects E. coli


-prophages are called lysogens


-prophage, lytic cycle, host cell lysis
The lambda life cycle- Lysogeny

•Lambda genome is _________

•Attaches to host cell wall & _______

•DNA is inserted into E. coli chromosome between the _________

•Lysogenic cell- __________

•When chromosome replicates, lambda DNA __________

•Regulation of lytic versus lysogenic events in lambda is controlled by several promoters and regulatory proteins.
-double-stranded linear DNA

-injects its DNA into cell

-gal & bio genes

-cell with lambda DNA in its chromosome

-replicates with it
•Change in__________________ causes lambda to come out of chromosome and form new viruses

•Hundreds of _______

•Viruses are ________
-environmental conditions

-lambda chromosomes are formed

-assembled then cell lyses to release viruses
Bacteriophage with different types of nucleic acids:
•DNA phage
–Ex. _____
•RNA phage
–Ex. _____

–Used as ______

–Complementary copies are also made and used as _____________

–New phage RNA is packaged, cells _____


-mRNA to make proteins

-templates for making more phage RNA
9.12 Overview of Animal Viruses
4 Types of infection by animal viruses:

1. Lytic
–Destruction of _____

2. Persistent

–New virions leave _____

–Cell does not ___, but remains ___ and will produce ______
-host cells

-host by budding

-die, infected, virions indefinately

–Virus is not _______

–Symptoms appear only when ________

4. Transformation

–Virus can change ________

–Genetic changes that regulate _____

–Benign or _____
-actively replicating, dormant

-virus emerges from latency

-normal cell into cancer cell


-malignant tumors
Animal viruses
•Can be single or double stranded _______
RNA viruses

Positive-strand RNA viruses (SS)-___________

•Ex. poliovirus, coronaviruses & rhinoviruses (_______)

Negative-strand RNA viruses (SS)- _____________

•Ex. rhabdoviruses (rabies), Ebola virus, measles, influenza, RSV
-genomic RNA is used directly as mRNA for making proteins

-(cold viruses)

-genomic RNA does not serve directly as mRNA but is transcribed into a complement that functions as mRNA
Double-stranded RNA viruses-

•Reoviruses- __________

•Rotavirus- member of reovirus family, most common cause of ________
-only animal viruses with double stranded RNA

-infant diarrhea
DNA viruses
•parvoviruses- only group with _____

•herpesvirus group (DS) - causes ___,____,____

•Are able to remain _________ in the body for years, becoming _________

•poxvirus group (DS) causes smallpox (vaccinia), cowpox, & some tumors
-single-stranded DNA

-cold sores, venereal disease, chicken pox

-latent, active during stressful conditions
9.13 Retroviruses

•Retro means_____-

•Cause HIV & some forms of cancer

•Single stranded ______

•Enzyme __________

•DNA integrates into ________

•Viral DNA is transcribed into __________

•New viruses are assembled and released

-RNA genome

-reverse transcriptase copies RNA into DNA

-host genome like a temperate/lysogenic

-mRNA & RNA for new viruses
9.14 Viroids and Prions


•Small, _____

•Mostly _____


•BSE (mad cow), scrapie (sheep), Creutzfeld-Jakob, kuru (humans), chronic wasting disease (deer, elk)
•Fig 9.29 Normal protein takes on
-naked ss RNA

-crop diseases

-Protein-only infectious agent
Control of Viruses and Eukaryotic Pathogens 20.10 Antiviral Drugs

Effective antiviral agents must target ______

Anti-HIV drugs:


• Azidothymidine (AZT)


–bind HIV protease, preventing the protease from processing viral polypeptides


–synthetic peptide that binds to an HIV membrane protein preventing the viral membrane from binding to the host cell membrane
-virus-specific enzymes and processes

-Reverse transcriptase inhibitor

-protease inhibitors

-fusion inhibitors
28.1 Public Health and Water Quality

•Prior to coliform counting procedures such as MPN technique, water was ________

•Fig 28.1 With the discovery that ___________ was an effective disinfectant, large water supplies could be treated.
-filtered to reduce turbidity

28.2 Wastewater and Sewage Treatment
•Sewage- liquid effluent contaminated with ___________

•Wastewater- from domestic sewage or industrial sources that must be treated to ___________

–so it can no longer support __________

–to eliminate _______
-human or animal fecal materials

-reduce organic & inorganic materials

-microbial growth

-potentially toxic materials
Primary wastewater treatment-Fig 28.3

•Uses ____________

•Water passes through ______, then is allowed to settle several hours

anoxic secondary wastewater treatment- fig 28.5

•Digestive & ______ of many bacteria

•Occurs in ___________
-physical seperation methods

-gates & screens

-fermentative reactions

-sludge digesters or bioreactions
aerobic secondary wastewater treatment- fig 28.6

•Digestive _____

•Can use _____________

Optional tertiary

•(chlorine, UV, O3) treatment before ?
-reactions of microbes

-tricling filter or activated sludge process
28.3 Drinking Water Purification- fig 28.8

•Drinking water plants- industrial size physical and chemical systems to ____________

•Clarification- ______



–Usually by _____
-remove contaminants from water sources to make the water potable

-suspended solids are coagulated & removed

•UV radiation as an
– physical not chemical

–short ________

–no _____
-alternative to chlorine for disinfection

-contact time

•Table 28.1 & 28.2 - Sources of waterborne pathogens: ______

•Worldwide, lack of water treatment facilities and access to clean water _________
-Drinking water or Recreational water

-contribute to the spread of infectious diseases
Pathogenic _____________

•Vibrio cholerae
– Cholera
•Salmonella typhi
–typhoid fever Legionella pneumophila
–Legionellosis (Legionnaires’ Disease)
-bacteria killed by chlorine treatment
Vibrio cholerae- cholera

•Gram ______

•Major waterborne disease; mainly occurs in __________

•7 major pandemics since 1817
–2001- 184,000 cases; 2728 deaths; 94% were in Africa
–1961- 5 million cases; 250,000 deaths
- (-) curved rods

- developing parts of world
•Epidemics in areas with ______

•_________ in some countries

•Sporadic outbreaks along ___________

•Requires large __________
-little or no sewage treatment


-US Gulf Coast due to raw shell fish

-inoculum (10^8-10^10 cells) due to stomache acid
•Vibrio attaches to ___ in ____ then _____

•Causes severe diarrhea (“rice water” up to 20 liters per day) which can result in _____

•If untreated, mortality rate of _____

•Treatment- electrolyte replacement therapy

–Reduces mortality rate to _____
-epithelical cells, in small intestine, then releases enterotoxin

-death from dehydration

-25 to 50%

Salmonella typhi- typhoid fever

•Gram negative __________

•Causes __________; mainly transmitted by ______

•Less than _____ cases per year in US
-bacillus; can colonize intestine

-gastroenteritis, contaminated water

Legionella pneumophila- Legionellosis

•Gram _______

•Transmitted in _______

•First recognized after outbreak at American Legion meeting in 1976

•Commonly found in __________

•Symptoms can be: none, sore throat, cough, headache, fever or pneumonia.

–Mild symptoms are called _______

–More serious pneumonia type symptoms called ________
-negative bacillus


-cooling towers of air conditioning systems; also in hot tubs

-Pontiac fever

•The following organisms are very resistant to chlorine and UV radiation so sedimentation and filtration
methods must be used to prevent these _________

•Giardia intestinalis
– Giardiasis
•Cryptosporidium parvum
•Entamoeba histolytica
–Amoebic dysentery
-pathogenic protozoans from entering the water supply
Giardia intestinalis- Giardiasis

•Flagellated ________

•Causes ?

•Some people can be _________

•Can come from ______

•Is found in __________
-protozoan; produces tough cysts

-carriers (no symptoms)

-drinking water, ingesting swimming pool water, lake water, stream water

-97% of surface waters in US
Cryptosporidium parvum- Cryptosporidiosis

•Produces _________

•Caused ____________ in US (Wisconsin, 1993).

•Over 400,000 people were infected from ___________

•Causes _____________

•Common in ___________
-thick walled oocysts

-largest single outbreak of waterborne disease

-municipal water supply

-mild gastrointestinal illness

-cattle & other warm blooded animals
Entamoeba histolytica-Amoebic dysentery

•Anaerobic; produces ____

•Symptoms can be ?

•If intestinal wall is _____

–Intestinal ______

–Untreated- can ____________

•100,000 ________________
-produces cysts

-invaded, this condition is dysentery

-inflammation, fever, blood & mucus in stool

-invade liver, lung, brain

-deaths per year worldwide, several hundred per year in US
•Pathogens- microbes that_____

•Pathogenicity- ability of a _______

•Opportunistic pathogen- microbe that causes ___________

•Infection- a microbe is _______
-cause disease

-pathogen to cause disease

-disease when host defense is absent or compromised
•Disease- a microbe causes ________

•Infection precedes disease.

•Infection often begins at________________ found throughout the body.
-damage or injury to host that impairs host function
Normal Human Flora

•There are _________________

Sites where bacteria are normally found:
•Oral cavity
•Gastrointestinal tract
•Respiratory tract
•Urogenital tract
-billions of microbial cells living in and on the human body
Normal flora of the skin

•Microbes grow mostly in _________

•Associated with ___________

•Factors that affect types of normal flora- _________
-moist areas- underarms, genitals, etc

-sebaceous (oil) glands & apocrine (sweat) glands (pH 4-6)

-weather, age, personal hygiene
Bacterial species commonly associated with the skin:

•Most are_______


•Gram _____


•Gram _____

•Propionibacterium acnes can cause _____
-Gram +

-Gram +, aerobic cocci

- +, anaerobic rods

-can cause acne

•Gram _____

•Few G ________
- (-) rods

- (-) bacteris found on skin
Normal flora of the oral cavity

•Bacteria in the mouth prior to tooth formation are mainly ______________

•Acidic glycoproteins in saliva form a layer on teeth providing a firm __________, usually ___ species

•Extensive growth of these microbes results in ________

•microflora of dental plaques make ____ taht decalcify tooth enamel; results in ______-
-aerotolerant anaerobeds such as streptococcus & Lactobacillus

-attachment site for microbes, Streptococcus

-thick bacterial layers called dental plaque

-acids, dental caries (tooth decay, cavities)
•Tooth surfaces in and near the gingival crevice where food particles remain are common sites of tooth decay. Floss!!!

•Diets high in ______

•Lactic acid bacteria _______

•Streptococcus mutans produces_____________ (polysaccharide used for attachment to tooth surface) only when sucrose is present

•Diets containing fluoride during formation of ______________

•Incorporation of fluoride into the calcium phosphate crystal matrix increases resistance to decalcification.
-sucrose are cariogenic- cavity causing

-ferment the sucrose to lactic acid


-tooth enamel make teeth more resistant to tooth decay
Normal flora of the gastrointestinal tract

The stomach:

•pH ____

•Only ____ tolerant bacteria can colonize stomache wall- ex. ________

•Very few bacteria are found in stomach fluids
- 2

-acid, Helicobacter pylori (pepti ulcers)
The small intestine:

•# of bacteria _________

•Duodenum: few bacteria due to _________; mainly ______

•Jejunum: Enterococcus, Lactobacillus

•Ileum: microbiota reflects that of large intestine; large number of ______ & _____ like _____
-increases down through small intestine (due to rising pH)

-stomach acids; Gram + cocci and bacilli

-Bacteroides & facultative aerobes, E. coli
The large intestine:

•Fermentation vessel; ________, mostly _____

•Commonly _________

•Small number of facultative aerobes (E. coli); consume oxygen which allows obligate anaerobes to grow
-many bacterial (>300 species), mostly anaerobes

- 10" bacterial cells/gram of intestinal contents
•Diet affects intestinal flora- ex.

•Some vitamins are produced in intestine by bacteria-

•Antibiotics can reduce number of normal intestinal flora, can lead to digestive problems
-more meat in diet, more Bacteroids

- Vit B12, K, riboflavin, thiamine
Common anaerobic intestinal flora:

•Many adults also have methanogens which convert ____________________

•Bacteria in the intestinal tract are constantly being displaced downward by the flow of material & ____________

•The growth rate of bacteria in the lumen of the intestinal tract is ____________
-hydrogen & carbon dioxide to methane gas

-replaced by new microbes

- 1-2 doublings per day
Normal flora of the respiratory tract

Upper respiratory tract-

•Most bacteria that are breathed in are

•Are many
- nasopharynx, oral cavity, & throat

-trapped in mucus

-opportunistic pathogens in nasopharynx
Opportunistic pathogens which can be found in the nasopharynx:

•Staphylococcus aureus

•Causes ________

•Streptococcus pneumonia

•Causes ________
-sinus & ear infections

-sinus infections & bronchitis
•Streptococcus pyogenes

•Causes _________

•Corynebacterium diphtheriae

•Cause ________
-sinus infections & "strep" throat

Lower respiratory tract-

•Bacteria are _______

•Lower respiratory tract is lined with _____ to _________ where they are caught in ___ &____
-not normally found in lower respiratory tract

-cilia, push bacteria & dust particles up, caught in mucus & saliva
Normal flora of urogenital tract

•Bladder is _______

•Several types of ___ are associated with urethra

•Neisseria (____)

•Many of these are ______

•Lactobacillus acidophilus is often found in ______
-normally free of bacteria

-faculatative anaerobes (mostly Gram (-) rods)

-Gram (-) cocci

-opportunistic pathogens

-often found in vagina of adult women
Virulence Factors
•Structures & characteristics of _____ that allow them to ____

Adhesion- ability to ______

Virulence factors affecting adhesion:

•Capsule-outer _______, helps bacteria in ______

•Fimbriae- necessary for some organisms to attach. (_____)
-pathogens, cause disease

-adhere to mucus membranes

-polysaccharide layer, attachment

-(Neisseria & E.coli)
Invasion & Colonization
•Pathogens must be able to ________

•They can reach ______ through ___ or ____
-penetrate the outer layer of skin cells (epithelium)

-inner layers of skin cells, through lesions or mucus membranes
•Once it has invaded a host, it can establish itself and grow

Examples of virulence factors affecting invasion & growth

•The O & Vi _______

•O – ______. prevents ____

•Vi – _____. prevents ____ & _____

-Compounds that ___ & make it available to the bacterial cell

-Staphylococcus aureus produces this compound which ______, decreasing _____
-antigens of Salmonella

-cell surface polysaccharide, prevents phagocytosis

-capsule antigen, prevents complement binding & antibody mediated killing

-bind iron

-lyses white blooc cells, decreasing host resistance
Localized infection - Organisms ______

Systemic infection - Organisms _______
-grow locally at site of invasion

-spread through body using blood or lymphatic systems
Dissemination of the pathogen:
•Many pathogens make virulence factors which help them __________

•Many of these are _____ which break down ___
-spread from the initial infection site

-enzymes, tissues
Examples of virulence factors which break down tissues:

•Destroys ____ that holds ___ together

•Produced by _____&_____


•Breaks down ______

•Produced by _____
-polysaccharide that holds animal cells together

-staphyloccus & streptococcus

-down collagen


•Breaks down _____

•Clots are made by____j to wall off ___ & prevent their spread to _____

•Made by ________

•Hemolysins- ______ of animal cells- lyse _____

-fibrin clots

-host, bacterial infections, healthy tissues

-Streptococcus pyogenes

-cytoplasmic membrane, lyse red blood cells
•Compounds produced by pathogens that ______

3 major groups of toxins:
-damage tissues far from infection site
•Proteins secreted by bacteria that can _________

Examples of exotoxins:
Diphtheria toxin

•Inhibits ____

•Produced by Corynebacterium diphtheriae (causes ____)

•Toxin is produced by bacteria that are ____ which carries ____

Tetanus toxin

•Acts on _____;causes _____; can lead to ____

•Produced by Clostridium tetani which infects ____

Botulinum toxin

•Prevents _______-results in ____ or ____

•Produced by Clostridium botulinum

•Organism grows in _______, where it produces ____

•Botulism is caused by ____, not by ______
-damage tissues far from infection site

-protein synthesis


-lysogenized by phage B(beta), tox genes

-motor neurons, continual contraction of muscles, lockjaw

-deep wounds

-muscle contraction, respiratory or cardiac failure

-improperly stored foods, toxin

-ingesting toxin, not infection with C. botulinum

•Proteins that act on ____, cause ____

•Produced by _________ such as Clostridium, E. coli, Salmonella

•Cholera toxin

•Produced by _______

•Causes secretion of ___________
-small intestine, cause diarrhea

-food poisoning organisms

-Vibrio cholera

-massive amount of water into small intestine (diarrhea)-death by dehydration

•When ______ lyse, ____ portion of LPS is released

•LPS from many organisms, such as E. coli, Salmonella, Shigella, is toxic

•Cause ____,___,___- rarely fatal
-Gram (-) bacteria, lipid A

-diarrhea, fever, vomiting
Nonspecific Host Defenses:

Anatomical defenses:

1. Skin
2. Mucus
3. Enzymes
-Physical barrier
-Dry, low pH

-Traps bacteria

-Lysozyme in tears

•Redness, ________

•Histamine _____

•Capillaries ____:Fluids containing ___ leak into wound

•Clot forms to ______

•Septic shock- ____&___ spread through body
-swelling, pain, heat


-to dilate, WBC's

-localize pathogen

-infection and inflammation

•Some products of ______ are ____

•Endogenous ______ are produced by _____

•Higher temp:

–Increases ______

–Slows _________

–However, very high temp damages host tissue
-pathogens (endotoxin) are pyrogenic (fever-inducing)

-pyogens, leukocytes

-phagocytosis & antibody production

-bacterial growth
The host's ability to resist infection depends on:

•Age – _________ more susceptible

•Stress –____________ increases susceptibility

•Diet –_______________ increases susceptibility

•General health and lifestyle –____________ increase susceptibility

•Prior or concurrent disease- increases susceptibility

•Many hospital patients with ________(ex.cancer or heart disease) acquire nosocomial infections because they are _____

•Genetic conditions especially those affecting immune system
-young & old

-high stress

-low protein & calories

-smoing, excess alcohol consumption, drug use, & lack of sleep

-noninfectious diseases

-compromised hosts