Exam 3 Test Files Flashcards
(148 cards)
1
Q
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
A
C: produces an ADP-ribosylase that targets host elongation factor 2
2
Q
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
A: it is a unique component of the Bordetella pertussis cell wall
3
Q
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
A
E: obligate intracellular pathogen
4
Q
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
A
E: VacA protein increases urea flow into the stomach
5
Q
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
A
X C: becomes the main species present in disease sites
6
Q
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
A
X E: Porphyromonas gingivalis
7
Q
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
A
X A: syphilis
8
Q
Which Streptococcal virulence factor is correlated with the progression of infective endocarditis? Answer: __1__ 1/1
A
Answer 1: PAAP
9
Q
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”
A
X D: infection is polymicrobial (multiple species)
10
Q
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
A
X E: mucins aggregate and clear oral bacteria via lectin-like interactions
11
Q
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
A
X A: lysozyme cleaves the bond between N-acetylglucosamine and N-acetylmuramic acid
12
Q
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
A
> D: aggressive periodontitis
13
Q
What is one of the types of oral bacteria strongly associated with acute necrotizing ulceratize gingivitis? Answer: __1__
A
Answer 1: Fusobacterium nucleatum
14
Q
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
A
X C: presence of acid stress response proteins
15
Q
Name a bacterium that is a common late colonizer of dental plaque when oxygen is depleted, especially between teeth? Answer: __1__
A
prevotella
16
Q
What bacterial gene is used in current methods for classifying bacteria, including identifying new species?
13 Answer: __1__ 1/1
A
Answer 1: 16s rRNA
17
Q
What is true of dental plaque?
A
18
Q
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
A
> E: upregulation of ammonia production from arginine and urea
19
Q
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
A
X C: Chlamydia trachomatis
20
Q
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
A
X A: Chlamydia trachomatis
21
Q
17 Which form of Chlamydia replicates within a host cell? Answer: __1__ 1/1
A
Answer 1: reticulate body
22
Q
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
A
X A: Rickettsia
23
Q
What is a symptom of late stage, chronic disease associate with Borrelia burgdorferi? Answer: __1__
A
Answer 1: Arthritis
24
Q
What is uniquely associated with congenital syphilis? X A: gummas X B: rash X C: chancre X D: aortic aneurysm X E: mulberry molars
A
X E: mulberry molars
25
Name a bacterium that may be detectable by an acid-fast staining test of a sputum smear. Answer: __1__
Answer 1: Mycobacterium tuberculosis
26
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)
27
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
28
Name a bacterium that survives in alveolar macrophages. Answer: __1__
Answer 1: Mycobacterium tuberculosis
29
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
30
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
31
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
32
Which Clostridium species is part of the normal human bacterial flora? Answer: __1__
Answer 1: C. difficle
33
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
34
```
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
35
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
36
```
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
37
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
38
```
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
39
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
40
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
41
```
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
42
```
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
43
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
44
```
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
45
```
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
46
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
47
```
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
48
What is the main method of transmission of Neisseria meningitides? Answer: __1__
Answer 1: airborne (sputum)
49
```
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
50
46 Lipooligosaccharide (LOS) lacks what component of lipopolysaccharide (LPS)? Answer: __1__ 1/1
LIOAnswer 1: O-antigen
51
```
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
52
```
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
53
```
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
54
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
55
```
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
56
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
57
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
58
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
59
Which of the following is true about Neisseria gonorrhoeae?
> D: undergoes phase variation of Opa proteins
60
What factor is the most important in allowing intravascular survival of Neisseria meningitidis?
> A: bacterial capsule
61
Which of the following is true about infections by Neisseria meningitidis?
> E: preventable by vaccination against capsular polysaccharides for some meningiococcal strains
62
Which of the following is the mostly likely characteristic of Campylobacter jejune?
> C: acquired as a zoonotic infection, often from undercooked chicken, and causes a mild, self-limiting gastroenteritis
63
To what surface feature of enteric bacteria does the term H-antigen refer? 1/1
> A: flagella
64
What is not a property associated with Salmonella enterica serovar typhi?
> C: produces a cholera-like toxin
65
Which bacterium produces the vast majority (70-90%) of urinary tract infections (bladder infections, for example)? 1/1
> B: Escherichia coli
66
Bacteroides fragilis is the most frequently isolated bacterium from abscesses caused by intestinal bacteria. This is partly because
> D: its ability to resist phagocytosis
67
17 Which of the following is not a virulence factor for Helicobacter pylori?
> D: Shiga-like toxin
68
18 Hemolytic uremic syndrome is a complication of infection by which organism? 1/1
> B: Escherichia coli O157:H7
69
Shiga toxin
> C: removes a specific adenine base from 28S rRNA, stopping translation
70
20 Which of the following is not a property of Pseudomonas aeruginosa? 1/1
> E: obligate intracellular pathogen
71
21 What is a property of the dissaccharide-tetrapeptide component of bacterial peptidoglycan that is the tracheal 1/1
> B: it is shed from bacterial cells instead of being absorbed and recycled
72
These gram positive pleiomorphic rods produce a pseudomembrane in the throat that can block the airway.
> C: Corynebacterium diphtheriae
73
23 Clostridium botulinum produces an A-B exotoxin that blocks the release of which neurotransmitter from axon 1/1
> A: acetylcholine
74
Which Clostridial species is part of the normal human bacterial flora?
> B: Clostridium difficile
75
Which organism produces alpha toxin (a lecithinase-phospholipase C) and theta toxin (a hemolytic toxin), that partially account for the organism's tissue-destructiveness that often requires amputation to save the patient's life?
> C: Clostridium perfringens
76
26 Which of the following best describes tetanospasmin, a virulence factor for Clostridium tetani? 1/1
> D: A-B exotoxin that blocks release of the neurotransmitter glycine
77
This Gram-negative coccobacillus is transmitted zoonotically mainly from contact with wild animals such as 1/1 birds, rabbits, or tick bites. The bacteria are able to grow in macrophages, resulting in systemic spread that can
lead to ulceroglandular, oculoglandular, and pulmonary infections. A vaccine is available for high-risk
individuals.
> B: Francisella tularensis
78
What virulence property does Haemophilus influenzae capsule b confer on these bacteria?
> A: allows the bacteria to cause systemic infections
79
What bacterium lives inside amoeba in the environment and is typically transmitted by an aerosol route to humans through ventilation systems in buildings?
> A: Legionella pneumophila
80
What bacterium grows at tempertures from 1oC to 45oC, is resistant to salt and acid conditions, and is a food- borne pathogen that causes systemic disease in immune-compromised individuals?
> B: Listeria monocytogenes
81
This Gram-negative coccobacillus is transmitted zoonotically via fleas and eventually infects lymph nodes, where 1/1 it can cause a purulent infection. In some individuals the bacteria can subsequently spread to the lungs and be
transmitted by aerosol from human to human.
> A: Yersinia pestis
82
Which of the following is true for Mycobacterium tuberculosis?
> C: the bacterium exhibits a very slow growth rate (doubling time of 1 day)
83
15 33 A positive result with an acid-fast staining test on a sputum smear is indicative of which type of bacteria?
> A: Mycobacterium tuberculosis
84
Which of the following is true for cord factor of Mycobacterium tuberculosis?
> B: is a glycolipid that adheres to cell surface mycolic acids
85
35 Which of the following is true for leprosy?
> A: individuals normally clear the bacterial agent via cell-mediated immunity
86
36 Bacteria of which genus are Gram positive filamentous rods that are opportunistic pathogens, causing bronchopulmonary infections and brain abscesses?
> C: Nocardia
87
A zoonotic disease is associated with which of the following bacteria?
> B: Borrelia burgdorferi
88
Which form of Chlamydia replicates within a host cell?
> D: reticulate body
89
What is true about Mycoplasma pneumoniae? 1/1
> D: immune protection fades after recovery from infection
90
Bacteria of which genus cause Rocky Mountain Spotted Fever?
> A: Rickettsia
91
Which of the following is best associated with the viridans Streptococci?
> C: dental caries
92
What role does catalase have for those pathogenic bacteria that express it?
> C: Removes hydrogen peroxide produced by phagocytes
93
Scarlet fever is a caused by what organism?
> A: Streptococcus pyogenes
94
What symptoms are uniquely associated with tertiary syphilis?
> A: gummas
95
What is true about antigenic variation involving the pilin protein of Neisseria gonorrhoeae?
> C: involves recombination between silent and expressed copies of the pilin gene
96
Which enteric bacterium is acquired as a zoonotic infection, often from undercooked chicken, and causes a mild, self-limiting gastroenteritis?
> E: Campylobacter jejune
97
Hemolytic uremic syndrome is a complication of infection by which organism?
> B: Escherichia coli O157:H7
98
Which enteric bacterium can invade M cells in the gut, survive in macrophages, and eventually infect many different organs in the body?
> A: Salmonella enterica serovar typhi
99
Which bacterium produces the vast majority (70-90%) of urinary tract infections (bladder infections, for example)?
> B: Escherichia coli
100
Which of the following is true about cholera?
> B: supportive rehydration therapy is the main method used for treatment
101
What pathogen resides in the stomach and induces the host to secrete urea through the mucosal epithelium?
> A: Helicobacter pylori
102
Which of the following virulence factors is the dissaccharide-tetrapeptide component of bacterial peptidoglycan?
> B: tracheal cytotoxin of Bordetella pertussis
103
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.
> C: Corynebacterium diphtheriae
104
Which of the following describes Pseudomonas aeruginosa?
> D: can grow at temperatures up to 43oC
105
Blockage of acetylcholine release from host cells is caused by a virulence factor of which bacterium?
> D: Clostridium botulinum
106
Which Clostridial species is part of the normal human bacterial flora?
> B: Clostridium difficile
107
What spore forming bacterium produces an A-B exotoxin that blocks GABA (gamma-aminobutyric acid) release from axon endings of interneurons that control motor neurons within muscles?
> B: Clostridium tetani
108
A positive result with an acid-fast staining test of bacteria in a sputum smear is indicative of
> A: Mycobacterium tuberculosis
109
Which bacterium is considered the keystone pathogen for periodontitis?
> E: Porphyromonas gingivalis
110
What Haemophilus influenzae virulence factor allows strains of these bacteria to cause systemic infections?
> C: capsule b
111
What bacterium lives inside amoeba in the environment and is typically transmitted by an aerosol route to humans through ventilation systems in buildings?
> A: Legionella pneumophila
112
What bacterium grows at tempertures from 1oC to 45oC, is resistant to salt and acid conditions, and is a food-borne pathogen that causes systemic disease in immune-compromised individuals?
> B: Listeria monocytogenes
113
This Gram-negative coccobacillus is transmitted zoonotically via fleas and eventually infects lymph nodes, producing a characteristic swellings called bubos.
> A: Yersinia pestis
114
Which of the following is true for cord factor of Mycobacterium tuberculosis?
> B: is a glycolipid that adheres to cell surface mycolic acids
115
Which of the following is true for leprosy?
> A: individuals normally clear the bacterial agent via cell-mediated immunity
116
A zoonotic disease is associated with which of the following bacteria?
> B: Borrelia burgdorferi
117
What is a symptom of late stage, chronic disease associate with Borrelia burgdorferi?
> D: arthritis
118
Which organism is an obligate intracellular pathogen?
> A: Chlamydia trachomatis
119
What bacterium lacks peptidoglycan and is the agent of the most sexually transmitted infections, characterized by mucopurulent discharges?
> C: Chlamydia trachomatis
120
What is true about Mycoplasma pneumoniae?
> D: cells pass through filter that traps most other bacteria
121
Bacteria of which genus are transmitted to humans by bites of infected ticks?
> A: Rickettsia
122
What is uniquely associated with congenital syphilis?
> E: Hutchinson's incisors
123
A pregnant 22-year-old woman was seen at an urgent care clinic and presented with fever, malaise, headache and a macular rash (flat, red) over much of her body. Upon questioning, she reported that about 1 year earlier she had a painless ulcer on her vagina that healed spontaneously after a few weeks. A diagnostic test revealed the pathogen and the likely connection between her previous and current symptoms. What is the most likely diagnosis made following her urgent care visit?
> C: she has secondary syphilis
124
What is true of dental plaque?
> E: sugar consumption causes increased levels of Streptococcus mutans in plaque
125
Which bacteria are initial colonizers of the dental biofilm, binding to the salivary pellicle?
> C: Streptococcus gordonii
126
Dental caries correlates with
> C: gingival recession that occurs with age
127
Which oral bacteria are strongly associated with acute necrotizing ulceratize gingivitis?
> A: spirochetes plus Fusobacterium nucleatum
128
Which genus is specifically associated with aggressive periodontitis?
Aggregatibacter
129
Which genus of bacteria are typicaly associated with salivary gland infections?
> D: Staphylococcus
130
What enzymes create an extracellular network of branched sugar polymers within dental plaque?
> A: glucosyltransferases
131
How does lysozyme act as an antibacterial agent?
> A: lysozyme cleaves the bond between N-acetylglucosamine and N-acetylmuramic acid
132
Which of the following is characteristic of periodontal abscesses?
> D: infection contains multiple anaerobic species
133
Which Streptococcal virulence factor is correlated with the progression of infective endocarditis?
> D: platelet associated aggregation factor
134
What is an enveloped virus composed of?
> E: nucleocapsid plus membrane plus glycoproteins
135
Which class of virus always brings its own RNA polymerase into a cell during infection?
> C: negative-sense, single stranded RNA viruses
136
What virus is responsible for about 30% of cases of the common cold, has an RNA genome that can be directly translated into protein, but also requires a second phase of translation to produce several smaller mRNAs transcribed from a negative sense copy of the RNA genome?
> C: coronavirus
137
What is the receptor for SARS-CoV-2, the agent of COVID-19?
ACE2
138
Nonpolio enteroviruses such as EV-D68 are associated with increased cases of what disease as a possible emerging epidemic?
> B: acute flaccid myelitis
139
What virus has an RNA genome that can be directly translated into protein, and transcribes more mRNAs, all of which are the size of the full viral genome, from a negative sense copy of the viral RNA genome?
> A: rhinovirus
140
What virus is transmitted by Anopheles mosquitos from person-to-person and causes more severe disease in individuals that have partial immunity from a prior exposure to the virus?
> A: Dengue fever virus
141
What flavivirus is transmitted by mosquitos from person-to-person, can cause jaundice, and was the first virus proven to be spread by an insect vector?
> B: yellow fever virus
142
Which virus genome is directly translated into proteins upon entry into a cell?
> B: poliovirus
143
Antigenic shifts in influenza viruses are caused by
> D: random packaging of single stranded RNA genome segments during a coinfection with two types of influenza viruses
144
What are Koplik's spots?
> A: lesions of the oral cavity associated with measles
145
What paramyxovirus initially infects cells of the respiratory tract but characteristically replicates in the parotid gland after viremia?
> D: mumps virus
146
Members of what minus-stranded RNA virus family are characterized by a helical nucleocapsid and their ability to induce syncytia during infection?
> D: paramyxoviruses
147
What virus is characterized by cytoplasmic masses of nucleocapsids in brain tissue during the late stages of an infection?
> E: rabies virus
148
What paramyxovirus is limited to replication in the region of initial contact and does not demonstrate significant spread to other sites by viremia?
> A: respiratory syncytial virus
