Exam 3 Test Files Flashcards
What is a property of Corynebacterium diphtheriae?
A: infections often involve major bacteremia
B: bacterium is a Gram-negative rod
C: produces an ADP-ribosylase that targets host elongation factor 2
D: effects of bacteria mainly caused by bacterial endotoxin
E: infections cause whooping cough
C: produces an ADP-ribosylase that targets host elongation factor 2
What is a property of the dissaccharide-tetrapeptide component of bacterial peptidoglycan that is the tracheal
cytotoxin of Bordetella pertussis?
A: it is a unique component of the Bordetella pertussis cell wall
B: it is shed from bacterial cells instead of being absorbed and recycled
C: it acts as an adenylate cyclase
D: it is an A-B toxin that ADP ribosylates a G protein
E: it is a fimbrial protein
A: it is a unique component of the Bordetella pertussis cell wall
Which of the following is not a property of Pseudomonas aeruginosa?
A: alginate production, promoting biofilm formation
B: Gram-negative rod
C: simple nutritional requirements
D: growth at temperatures up to 43oC
E: obligate intracellular pathogen
E: obligate intracellular pathogen
What is the role the Helicobacter pylori VacA protein?
A: VacA protein is a flagellar protein
B: VacA protein is a mucinase
C: VacA protein is a urease
D: VacA protein removes phosphates from membrane phospholipids
E: VacA protein increases urea flow into the stomach
E: VacA protein increases urea flow into the stomach
Which is NOT a property of the keystone pathogen for periodontitis?
X A: produces gingipains
X B: inhibits of IL-8 synthesis by epithelial cells
X C: becomes the main species present in disease sites
X D: causes uncontrolled growth of other bacterial species in disease sites
X E: activates inflammation in disease sites
X C: becomes the main species present in disease sites
Which bacterium is considered the keystone pathogen for periodontitis? X A: Prevotella intermedia X B: Fusobacterium nucleatum X C: Streptococcus mutans X D: Treponema denticola X E: Porphyromonas gingivalis
X E: Porphyromonas gingivalis
Which disease has oral manifestations that include gummas? X A: syphilis X B: botulism X C: anthrax X D: infective endocarditis X E: Legionnaires' disease
X A: syphilis
Which Streptococcal virulence factor is correlated with the progression of infective endocarditis? Answer: __1__ 1/1
Answer 1: PAAP
Which of the following is characteristic of Ludwig’s angina? 1/1
X A: Staphylococcus aureus is the predominant organism
X B: facultative anaerobes are the predominant organisms
X C: infection is usually by a single bacterial species
X D: infection is polymicrobial (multiple species)
X E: is always characterized by “sulphur granules”
X D: infection is polymicrobial (multiple species)
How do mucins act as antibacterial agents? 1/1
X A: mucins cleave the bond between N-acetylglucosamine and N-acetylmuramic acid
X B: mucins inhibit the transpeptidation reaction that crosslinks peptidoglycan polymers
X C: mucins bind iron, making it unavailable for bacteria to use
X D: mucins inhibit bacterial and host cysteine proteases
X E: mucins aggregate and clear oral bacteria via lectin-like interactions
X E: mucins aggregate and clear oral bacteria via lectin-like interactions
How does lysozyme act as an antibacterial agent? 1/1
X A: lysozyme cleaves the bond between N-acetylglucosamine and N-acetylmuramic acid
X B: lysozyme inhibits the transpeptidation reaction that crosslinks peptidoglycan polymers
X C: lysozyme binds iron, making it unavailable for bacteria to use
X D: lysozyme inhibits bacterial and host cysteine proteases
X E: lysozyme aggregates and clears oral bacteria via lectin-like interactions
X A: lysozyme cleaves the bond between N-acetylglucosamine and N-acetylmuramic acid
Aggregatibacter actinomycetemcomitans is very typically associated with which oral disease? 1/1
X A: Ludwig’s angina
X B: caries
X C: gingivitis
X D: aggressive periodontitis
X E: acute necrotizing ulceratize gingivitis
> D: aggressive periodontitis
What is one of the types of oral bacteria strongly associated with acute necrotizing ulceratize gingivitis? Answer: __1__
Answer 1: Fusobacterium nucleatum
What is a property characteristic of cariogenic bacteria (versus noncariogenic bacteria)?
10
X A: decreased synthesis of extracellular polysaccharides
X B: reduced number of phosphoenol pyruvate phophotransferase system (PEP-PTS) transporters
X C: presence of acid stress response proteins
X D: decreased activity of proton pumps
X E: ammonia production from atmospheric nitrogen
X C: presence of acid stress response proteins
Name a bacterium that is a common late colonizer of dental plaque when oxygen is depleted, especially between teeth? Answer: __1__
prevotella
What bacterial gene is used in current methods for classifying bacteria, including identifying new species?
13 Answer: __1__ 1/1
Answer 1: 16s rRNA
What is true of dental plaque?
Which property of bacteria in a dental biofilm is associated with decreasing the risk of dental caries?
14
X A: upregulation of genes for polysaccharide synthesis
X B: multiple sugar transporters
X C: slow growth
X D: increased activity of proton pumps
X E: upregulation of ammonia production from arginine and urea
> E: upregulation of ammonia production from arginine and urea
What bacterium lacks peptidoglycan and is the agent of the most sexually transmitted infections, characterized by mucopurulent discharges? X A: Neisseria gonorrheae X B: Mycoplasma genitalium X C: Chlamydia trachomatis X D: Treponema pallidum X E: Vibrio cholera
X C: Chlamydia trachomatis
Which organism is an obligate intracellular pathogen? 16 X A: Chlamydia trachomatis X B: Treponema pallidum X C: Clostridium perfringens X D: Legionella pneumophila X E: Neisseria meningitidis
X A: Chlamydia trachomatis
17 Which form of Chlamydia replicates within a host cell? Answer: __1__ 1/1
Answer 1: reticulate body
18 Bacteria of which genus are transmitted to humans by bites of infected ticks? 1/1 X A: Rickettsia X B: Helicobacter X C: Clostridium X D: Chlamydia X E: Vibrio
X A: Rickettsia
What is a symptom of late stage, chronic disease associate with Borrelia burgdorferi? Answer: __1__
Answer 1: Arthritis
What is uniquely associated with congenital syphilis? X A: gummas X B: rash X C: chancre X D: aortic aneurysm X E: mulberry molars
X E: mulberry molars
Name a bacterium that may be detectable by an acid-fast staining test of a sputum smear. Answer: __1__
Answer 1: Mycobacterium tuberculosis
Which of the following is true for Mycobacterium tuberculosis?
X A: the Mantoux reaction is not part of a diagnostic test for exposure to this bacterium
X B: a 2 week course of penicillin is a standard treatment for infection
X C: the bacterium exhibits a very slow growth rate (doubling time of 1 day)
X D: the bacterium is Gram-negative
X E: the bacterium produces cytotoxins that cause most of the host cell damage during infection
X C: the bacterium exhibits a very slow growth rate (doubling time of 1 day)
What is a property of the bacterial agent of Legionnaires’ disease?
X A: causes systemic infections but is usually localized to the brain
X B: epithelial cells in the lung are this bacterium’s main target for invasion
X C: main route of transmission is by mosquito bite
X D: lives in amoeba in water sources within ventilation systems
X E: gram-positive, spore-forming coccus
X D: lives in amoeba in water sources within ventilation systems
Name a bacterium that survives in alveolar macrophages. Answer: __1__
Answer 1: Mycobacterium tuberculosis
What type of virulence factor of Haemophilus influenzae serotype b is specifically correlated with the ability of these bacteria to cause systemic infections? Answer: __1_
Answer 1: capsule B
This Gram-negative coccobacillus is transmitted zoonotically via fleas and eventually infects lymph nodes, 1/1
producing characteristic swellings called “bubos.” Answer: __1__
Answer 1: Yersenia pestis
Which of the following is true about Bacillus anthracis?
X A: produces an ADP ribosylase called edema factor
X B: produces a metallo-protease called lethal factor
X C: this is the only Bacillus species that does not form spores
X D: bacteria are Gram negative rods
X E: produces tracheal cytotoxin
X B: produces a metallo-protease called lethal factor
Which Clostridium species is part of the normal human bacterial flora? Answer: __1__
Answer 1: C. difficle
Botulism results in 1/1
X A: flaccid muscle paralysis due to blocking release of the neurotransmitter glycine
X B: spastic muscle paralysis due to blocking release of the neurotransmitter dopamine
X C: flaccid muscle paralysis due to blocking release of the neurotransmitter GABA
X D: spastic muscle paralysis due to blocking release of the neurotransmitter glycine
X E: flaccid muscle paralysis due to blocking release of the neurotransmitter acetylcholine
X E: flaccid muscle paralysis due to blocking release of the neurotransmitter acetylcholine
These gram positive rods establish themselves in the throat and kill cells by expressing a toxin that ADP- ribosylates elongation factor 2, causing inhibition of cellular translation. X A: Bacillus anthracis X B: Bordetella pertussis X C: Corynebacterium diphtheriae X D: Helicobacter pylori X E: Pseudomonas aeruginosa
X C: Corynebacterium diphtheriae
What is a property of the dissaccharide-tetrapeptide component of bacterial peptidoglycan that is the tracheal cytotoxin of Bordetella pertussis?
X A: it is only found in Bordetella pertussis cell walls
X B: it is shed from bacterial cells instead of being absorbed and recycled
X C: it acts as an adenylate cyclase
X D: it is an A-B toxin that ADP ribosylates a G protein
X E: it includes the lipid A portion of LPS
X B: it is shed from bacterial cells instead of being absorbed and recycled
The ability of Pseudomonas aeruginosa to produce a biofilm is dependent on 1/1 X A: spore formation X B: alginate production X C: capsule production X D: bacterial motility X E: shedding of lipopolysaccharide
X B: alginate production
What pathogen resides in the stomach and induces the host to secrete urea through the mucosal epithelium? 1/1 Answer: __1__
Answer 1: Helicobacter pylori
Which enteric bacterium is acquired as a zoonotic infection, often from undercooked chicken, and causes a mild, self-limiting gastroenteritis? X A: Salmonella enterica serovar typhi X B: Shigella dysenteriae X C: Vibrio cholera X D: Enteropathogenic E. coli X E: Campylobacter jejune
X E: Campylobacter jejune
What is a property of cholera toxin and the system for spreading the genes encoding it?
X A: a transposon carries the toxin genes
X B: the toxin results in bloody diarrhea
X C: the receptor involved in spreading the toxin genes is not normally expressed during infection
X D: the toxin genes are encoded in a phage genome
X E: the toxin is a lipase that damages cell membranes Item Description: 6 - Enterics - Vibrio cholerae 2017
X D: the toxin genes are encoded in a phage genome
Which of the following is true about cholera?
X A: the causative bacterium is an obligate human pathogen
X B: supportive rehydration therapy is the main method used for treatment
X C: severe dehydration is not usually associated with this disease
X D: Vibrio cholera is normally transmitted by inhalation
X E: Vibrio cholera is a component of the normal human flora
X B: supportive rehydration therapy is the main method used for treatment
Which enteric bacterium can invade M cells in the gut, survive in macrophages, and eventually infect many different organs in the body? X A: Salmonella enterica serovar typhi X B: Shigella dysenteriae X C: Vibrio cholera X D: Enterohemorragic E. coli X E: Streptococcus mutans
X A: Salmonella enterica serovar typhi
Most cases of cytitis (bladder infections) are caused by which bacterial genus? 1/1 X A: Escherichia X B: Klebsiella X C: Proteus X D: Staphylococcus X E: Salmonella
X A: Escherichia
What is the effect of shiga toxin on the host? 1/1
X A: increase in cAMP production
X B: ADP ribosylation of translation factor EF-2
X C: removal of a specific adenine base from 28S rRNA
X D: cleavage of IgA
X E: cleavage of sialic acid
X C: removal of a specific adenine base from 28S rRNA
Hemolytic uremic syndrome is a complication of infection by which organism? X A: Salmonella typhi X B: Escherichia coli O157:H7 X C: Clostridium difficile X D: Shigella dysenteriae X E: Vibrio cholera
X B: Escherichia coli O157:H7
Bacteroides fragilis is a strict anaerobe but is oxygen resistant because among its other properties it possesses X A: superoxide dismutase X B: neuraminidase X C: capsule X D: lipases X E: LPS
X A: superoxide dismutase
Which of the following is a feature of infections caused by a breach in the gut wall?
X A: only strictly anaerobic bacteria will be involved throughout the course of the infection
X B: Salmonella are the main bacteria found in abscesses that are the result of these infections
X C: abscess formation proceeds from an anaerobic to an aerobic state due to bacterial metabolism
X D: Bacteroides is one of the first organisms to extensively grow in the infected area
X E: host production of a thick fibrin capsule at the infection site decreases blood flow into the area
X E: host production of a thick fibrin capsule at the infection site decreases blood flow into the area
Neisseria meningitidis X A: is gram positive X B: is an agent of arthritis X C: is mainly transmitted sexually X D: is encapsulated X E: infection is not preventable by vaccination
X D: is encapsulated
What is the main method of transmission of Neisseria meningitides? Answer: __1__
Answer 1: airborne (sputum)
Which programmed alteration of bacterial cell-surface protein expression is due to recombination of silent gene loci into the expressed gene locus for the protein? X A: antigenic variation X B: phase variation X C: relapsing expression X D: gene repression X E: slipped strand mispairing
X A: antigenic variation
46 Lipooligosaccharide (LOS) lacks what component of lipopolysaccharide (LPS)? Answer: __1__ 1/1
LIOAnswer 1: O-antigen
What organism causes scalded skin syndrome? X A: Streptococcus pyogenes X B: Staphylococcus aureus X C: Staphylococcus epidermidis X D: Streptococcus agalactiae X E: Staphylococcus saprophyticus
X B: Staphylococcus aureus
What bacterial virulence factor has an activity that results in creation of a fibrin coat around bacteria? X A: catalase X B: coagulase X C: protein A X D: beta-lactamase X E: exfoliative toxin
X B: coagulase
What is false about Staphylococcus aureus ? X A: is Gram negative 8 X B: is a facultative anaerobe X C: is beta hemolytic X D: is coagulase positive X E: is catalase positive
X A: is Gram negative 8
What is a role that staphylokinase plays for Staphylococcus aureus?
X A: inhibits phagocytic cysteine proteases
X B: degrades collagen, allowing bacteria to penetrate tissue
X C: competes with neutrophils for binding of Fc part of IgGs
X D: creates a fibrin coat around bacteria
X E: cleaves C3b and IgG
X E: cleaves C3b and IgG
What gram-positive coccus is one of the main causes of hospital acquired infections of the elderly? 1/1 X A: Enterococcus faecalis X B: Haemophilus influenzae X C: Mycoplasma pneumoniae X D: Chlamydia pneumoniae X E: Legionella pneumophila
X A: Enterococcus faecalis
What is true about rheumatic fever?
X A: associated with infections by Staphylococcus aureus
X B: becuase it is bacterial in origin, the fever is responsive to antibiotic therapy
X C: due to a type III hypersensitivity that is a late complication of bacterial infection
X D: involves abundant pus formation
X E: causes myocarditis in susceptible individuals
X E: causes myocarditis in susceptible individuals
What is true about Streptococcus pneumoniae? 1/1
X A: is an alpha-hemolytic, encapsulated bacterium
X B: is only found in individuals with symptomatic lung infections (coughing, fever, etc.)
X C: causes a mild, “walking pneumonia”
X D: is an enterobacterium
X E: is not a vaccine target
X A: is an alpha-hemolytic, encapsulated bacterium
Which of the following is NOT true regarding Streptococcus pyogenes M protein?
> A: anti-M protein antibodies are not produced during an infection by Streptococcus pyogenes
Which of the following is true about Neisseria gonorrhoeae?
> D: undergoes phase variation of Opa proteins