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76 Cards in this Set
- Front
- Back
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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 |
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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 |
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Capsid proteins are arranged to give virion symmetry
1._________ –Rod-shaped, protein subunits twist up |
-Helical symmetry
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2._______
–Roughly _____ –___ equilateral equilateral triangles or faces •Complex viruses- –Head- ________ –tail & _____ |
-Icosahedral symmetry
-spherical -20 -genome surrounded by capsid -tail fibers |
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•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
-bacteria |
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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 |
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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) |
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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) |
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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 |
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Viral Restriction and Modification by the Host
•Bacteria synthesize ____ as protection against viral invaders –Restriction endonucleases _________ •Viruses can__________________ by the host’s restriction endonucleases –Glucosylation –Methylation –Encode proteins to inhibit host restriction systems •Host cells have similar means of protecting their DNA from __________ |
-enzymes
-cleave DNA at specific sequences -modify their DNA to avoid digestion -degredation by viral endonucleases |
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2 types of phage:
–_____ –______ Lytic •simple life cycle •_______________ •Eg. T4 which infects E. coli |
-lytic
-lysogenic -infect host, make copies of themselves, lyse the host cell |
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T4 life-cycle:
Attachment & penetration •____ of T4 attach to cell wall •T4 genome is 1 linear molecule of ________ •DNA is ______. Rest of phage _____ |
-Tail-fibers
-double stranded DNA -inserted into host. -remains outside host cell |
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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 _____________ |
-transcribed
-mRNA, new viral heads & tails -viral DNA are also made -empty capsids & tails are added -lysed to release viruses |
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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 |
-lysogeny
-prophage -prophages are called lysogens -lyse -prophage, lytic cycle, host cell lysis |
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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 |
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Induction
•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 |
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Bacteriophage with different types of nucleic acids:
Single-stranded •DNA phage –Ex. _____ •RNA phage –Ex. _____ –Single-stranded –Used as ______ –Complementary copies are also made and used as _____________ –New phage RNA is packaged, cells _____ |
-M13
-MS2 -mRNA to make proteins -templates for making more phage RNA |
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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 |
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3.Latent
–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 -growth -malignant tumors |
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Animal viruses
•Can be single or double stranded _______ |
-DNA or RNA
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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 |
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Double-stranded RNA viruses-
•Reoviruses- __________ •Rotavirus- member of reovirus family, most common cause of ________ |
-only animal viruses with double stranded RNA
-infant diarrhea |
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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 |
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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 |
-"backward"
-RNA genome -reverse transcriptase copies RNA into DNA -host genome like a temperate/lysogenic -mRNA & RNA for new viruses |
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9.14 Viroids and Prions
Viroids •Small, _____ •Mostly _____ Prions •_____ •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 |
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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 |
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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
-chlorine |
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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 |
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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 |
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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 |
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28.3 Drinking Water Purification- fig 28.8
•Drinking water plants- industrial size physical and chemical systems to ____________ •Clarification- ______ •Filtration •Disinfection- –Usually by _____ |
-remove contaminants from water sources to make the water potable
-suspended solids are coagulated & removed -chlorination |
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•UV radiation as an
____________ – physical not chemical –short ________ –no _____ |
-alternative to chlorine for disinfection
-contact time -by-products |
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•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 |
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Pathogenic _____________
•Vibrio cholerae – Cholera •Salmonella typhi –typhoid fever Legionella pneumophila –Legionellosis (Legionnaires’ Disease) |
-bacteria killed by chlorine treatment
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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 |
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•Epidemics in areas with ______
•_________ in some countries •Sporadic outbreaks along ___________ Pathogenesis •Requires large __________ |
-little or no sewage treatment
-Endemic -US Gulf Coast due to raw shell fish -inoculum (10^8-10^10 cells) due to stomache acid |
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•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% -1% |
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Salmonella typhi- typhoid fever
•Gram negative __________ •Causes __________; mainly transmitted by ______ •Less than _____ cases per year in US |
-bacillus; can colonize intestine
-gastroenteritis, contaminated water -400 |
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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
-aerosols -cooling towers of air conditioning systems; also in hot tubs -Pontiac fever -Legionellosis |
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•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 –Cryptosporidiosis •Entamoeba histolytica –Amoebic dysentery |
-pathogenic protozoans from entering the water supply
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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 |
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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 |
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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 |
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•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 |
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•Disease- a microbe causes ________
•Infection precedes disease. •Infection often begins at________________ found throughout the body. |
-damage or injury to host that impairs host function
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Normal Human Flora
•There are _________________ Sites where bacteria are normally found: •Skin •Oral cavity •Gastrointestinal tract •Respiratory tract •Urogenital tract |
-billions of microbial cells living in and on the human body
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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 |
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Bacterial species commonly associated with the skin:
•Most are_______ •Staphylococcus •Gram _____ •Propionibacterium •Gram _____ •Propionibacterium acnes can cause _____ |
-Gram +
-Gram +, aerobic cocci - +, anaerobic rods -can cause acne |
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•Acinetobacter
•Gram _____ •Few G ________ |
- (-) rods
- (-) bacteris found on skin |
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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) |
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•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 -dextran -tooth enamel make teeth more resistant to tooth decay |
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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) |
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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 |
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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 |
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•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 |
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Common anaerobic intestinal flora:
•Bacteroides •Clostridium •Enterococcus •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 |
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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 |
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Opportunistic pathogens which can be found in the nasopharynx:
•Staphylococcus aureus •Causes ________ •Streptococcus pneumonia •Causes ________ |
-sinus & ear infections
-sinus infections & bronchitis |
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•Streptococcus pyogenes
•Causes _________ •Corynebacterium diphtheriae •Cause ________ |
-sinus infections & "strep" throat
-diphtheria |
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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 |
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Normal flora of urogenital tract
•Bladder is _______ •Several types of ___ are associated with urethra •Escherichia •Klebsiella •Proteus •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 |
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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) |
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Invasion & Colonization
Invasion: •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 |
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Colonization:
•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 ____ & _____ •Siderophores: -Compounds that ___ & make it available to the bacterial cell •Leukosidin: -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 |
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Localized infection - Organisms ______
Systemic infection - Organisms _______ |
-grow locally at site of invasion
-spread through body using blood or lymphatic systems |
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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 |
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Examples of virulence factors which break down tissues:
•Hyaluronidase- •Destroys ____ that holds ___ together •Produced by _____&_____ •Collagenase- •Breaks down ______ •Produced by _____ |
-polysaccharide that holds animal cells together
-staphyloccus & streptococcus -down collagen -Clostridium |
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•Streptokinase-
•Breaks down _____ •Clots are made by____j to wall off ___ & prevent their spread to _____ •Made by ________ •Hemolysins- ______ of animal cells- lyse _____ •Disrupt |
-fibrin clots
-host, bacterial infections, healthy tissues -Streptococcus pyogenes -cytoplasmic membrane, lyse red blood cells |
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Toxins:
•Compounds produced by pathogens that ______ 3 major groups of toxins: •Exotoxins •Enterotoxins •Endotoxins |
-damage tissues far from infection site
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Exotoxins
•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 -diphtheria -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 |
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Enterotoxins
•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 |
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Endotoxins
•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 |
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Nonspecific Host Defenses:
Anatomical defenses: 1. Skin -______ -______ 2. Mucus -_______ 3. Enzymes -______ |
-Physical barrier
-Dry, low pH -Traps bacteria -Lysozyme in tears |
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Inflammation
•Redness, ________ •Histamine _____ •Capillaries ____:Fluids containing ___ leak into wound •Clot forms to ______ •Septic shock- ____&___ spread through body |
-swelling, pain, heat
-released -to dilate, WBC's -localize pathogen -infection and inflammation |
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Fever:
•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 |
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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 |
