Finals Flashcards
1
Q
The potentially lethal intoxication type of food poisoning often associated with improperly canned food is caused by
A. Bacteroides Fragilis
B. Clostridium botulinum
C. Clostridium perfringens
D. Clostridium septicum
A
B. Clostridium botulinum
2
Q
Which of the following is not considered a zoonotic disease?
A. Anthrax
B. Botulism
C. Brucellosis
D. Leptospirosis
A
B. Botulism
3
Q
An anaerobically incubated blood agar plate shows colonies
surrounded by an inner zone of complete red cell lysis and an outer zone of incomplete cell lysis (double zone of hemolysis). The most likely presumptive identification of this isolate would be
A. Clostridium perfringens
B. Clostridium tetani
C. Fusobacterium nucleatum
D. Prevotella melaninogenica
A
A. Clostridium perfringens
4
Q
A cervical mucosal abscess specimen was sent to the laboratory
for bacteriologic examination. The culture of this sample grew an anaerobic gram-negative bacillus that was inhibited by bile, produced a black pigment, and was negative for indole
production and positive for glucose, sucrose, and lactose fermentation. This isolate would most likely be:
A. Bacteroides fragilis group
B. Bacteroides ureolyticus
C. Porphyromonas gingivalis
D. Prevotella melaninogenica
A
D. Prevotella melaninogenica
5
Q
Which one of the following is not true of Clostridium tetani ?
A. It produces rapid tissue necrosis.
B. It is a gram-positive, spore-forming bacillus.
C. Microorganisms in soil contaminate puncture wounds.
D. Disease is caused by an exotoxin acting on the central
nervous system
A
A. It produces rapid tissue necrosis.
6
Q
The characteristic colony morphology of Actinomyces israelii on
solid agar resembles
A. “Medusa head”
B. A molar tooth
C. A fried egg
D. Ground glass
A
B. A molar tooth
7
Q
What is the predominant indigenous flora of the colon?
A. Anaerobic, gram-negative, non-sporeforming bacteria
B. Anaerobic, gram-positive, non-sporeforming bacteria
C. Aerobic, gram-negative, non-sporeforming bacteria
D. Aerobic, gram-positive, spore-forming bacteria
A
A. Anaerobic, gram-negative, non-sporeforming bacteria
8
Q
Obligately anaerobic, gram-negative bacilli, recovered from an abdominal wound, were found to be resistant to penicillin. Growth of this organism was not inhibited by bile. What is the most likely identification of this isolate?
A. Bacteroides fragilis group
B. Clostridium septicum
C. Eubacterium lentum
D. Fusobacterium nucleatum
A
A. Bacteroides fragilis group
9
Q
Which of the following is described as obligately anaerobic gram-positive cocci?
A. Capnocytophaga
B. Peptostreptococcus
C. Propionibacterium
D. Veillonella
A
B. Peptostreptococcus
10
Q
Color Plate 29 * shows the filamentous gram-positive rod recovered from an aspirate of a closed chest abscess. It grew only under anaerobic conditions and was not acid-fast. What is the most likely presumptive identification of the isolate seen?
A. Actinomyces israelii
B. Bacteroides fragilis
C. Clostridium septicum
D. Propionibacterium acnes
A
A. Actinomyces israelii
11
Q
Growth on kanamycin-vancomycin laked blood agar incubated anaerobically is primarily used for
A. Bacteroides fragilis
B. Bifidobacterium dentium
C. Clostridium perfringens
D. Peptostreptococcus anaerobius
A
A. Bacteroides fragilis
12
Q
The diagnosis of pseudomembranous colitis (Clostridium difficile associated disease) is often made by
A. Serology
B. Culturing blood specimens
C. Assays to detect toxin in stool
D. Acid-fast stain of fecal material
A
C. Assays to detect toxin in stool
13
Q
The anaerobic, gram-negative, curved, motile bacilli associated with bacterial vaginosis belong to the genus
A. Actinomyces
B. Bifidobacterium
C. Lactobacillus
D. Mobiluncus
A
D. Mobiluncus
14
Q
An infant was seen in the emergency department with symptoms of neuromuscular weakness and constipation. The diagnosis of infant botulism was confirmed by the demonstration of toxin in the child’s stool. The child most likely contracted this disease by
A. A scratch wound caused by a cat
B. Ingestion of spores that germinated in the intestine
C. A puncture wound with a contaminated household item
D. Ingestion of preformed toxin found in a contaminated jar of
pureed vegetables
A
B. Ingestion of spores that germinated in the intestine
15
Q
The majority of the gram-positive, nonspore-forming, anaerobic
bacilli isolated from clinical material will be
A. Bifidobacterium dentium
B. Capnocytophagia ochracea
C. Eubacterium limosum
D. Propionibacterium acnes
A
D. Propionibacterium acnes
16
Q
Which of the following clostridia has a terminal spore that causes the cell to swell?
A. C. botulinum
B. C. difficile
C. C. perfringens
D. C. tetani
A
D. C. tetani
17
Q
The gram-negative, non-spore-forming, anaerobic bacillus frequently implicated in serious clinical infections such as brain and lung abscesses is
A. Bacteroides urealyticus
B. Eubacterium lentum
C. Fusobacterium nucleatum
D. Peptostreptococcus anaerobius
A
C. Fusobacterium nucleatum
18
Q
Which one of the following is a non-spore-forming,
gram-positive, anaerobic bacillus?
A. Clostridium
B. Fusobacterium
C. Propionibacterium
D. Veillonella
A
C. Propionibacterium
19
Q
Which of the following statements is not characteristic of Clostridium botulinum?
A. Infant botulism is the most common clinical form.
B. Pathogenicity is related to a potent neuro toxin.
C. Oval spores are located terminally.
D. Of the seven toxogenic types, types A, B, E, and F are associated with human botulism.
A
C. Oval spores are located terminally.
20
Q
A tube of semisolid medium that contains resazurin appears pink. What does this indicate?
A. Acid environment
B. Alkaline environment
C. Motility
D. Presence of oxygen
A
D. Presence of oxygen
21
Q
Identify the Fusobacterium sp. considered to be the most frequent isolate recovered from clinical infections.
A. F. varium
B. F. nucleatum
C. F. mortiferum
D. F. necrophorum
A
B. F. nucleatum
22
Q
Septicemia caused by which of the following is generally associated with an underlying malignancy?
A. Bifidobacterium dentium
B. Clostridium septicum
C. Eubacterium lentum
D. Lactobacillus catenaforme
A
B. Clostridium septicum
23
Q
Which of the following is the most potent bacterial exotoxin known?
A. Botulinum toxin
B. Erythrogenic toxin
C. C. difficile toxin B
D. C. perfringens alpha-toxin
A
A. Botulinum toxin
24
Q
Which Clostridium sp. is most commonly recovered from cases of gas gangrene?
A. C. bifermentans
B. C. perfringens
C. C. sordellii
D. C. difficile
A
B. C. perfringens
25
Which of the following organisms is not gram-positive?
A. Eubacterium lentum
B. Bifidobacterium dentium
C. Propionibacterium acnes
D. Suttonella wadsworthensis
D. Suttonella wadsworthensis
26
Which of the following statements is not true of clostridia?
A. Pseudomembranous colitis is due to a toxin produced by C. difficile.
B. Clinically significant clostridia are found in the normal flora of the colon and in the soil.
C. Botulism is caused by ingesting preformed toxin and can be prevented by boiling food prior to eating.
D. C. tetani spores will form in the presence of oxygen; therefore, anaerobiosis in a wound is not required to cause tetanus
D. C. tetani spores will form in the presence of oxygen; therefore, anaerobiosis in a wound is not required to cause tetanus
27
Gram-positive bacilli with central spores are seen in the direct Gram stain of a tissue biopsy. After 24 hours of incubation, no growth is seen on the sheep blood agar plate incubated aerobically and the chocolate agar plate incubated in increased CO2. Which of the following is the likely cause of the infection?
A. Bacillus
B. Clostrdium
C. Lactobacillus
D. Prevotella
B. Clostrdium
28
Small alpha-hemolytic colonies are seen on a sheep blood agar plate after 48 hours of incubation on a vaginal culture. This describes which of the following?
A. Bacteroides
B. Clostridium
C. Lactobacillus
D. Porphyromonas
C. Lactobacillus
29
Which of the following statements is true regarding Clostridium perfringens?
A. There are five serologic types
B. Sppres are terminally located
C. Alpha-toxin is produced by all strains
D. Spores are readily seen in laboratory media
C. Alpha-toxin is produced by all strains
30
Which is a correct statement regarding Clostridium tetani?
A. It is proteolytic
B. It is lecithinase positive
C. It is characteristically nonmotile
D. It produces terminal spores
D. It produces terminal spores
31
Which anaerobic, gram-negative rod can be presumptively identified by its Gram stain morphology, and inhibition by bile and a 1-jag kanamycin disk?
A. Bacteroides fragilis group
B. Eubacterium lentum
C. Fusobacterium nucleatum
D. Porphyromonas gingivalis
C. Fusobacterium nucleatum
32
Which of the following tests is most appropriate for the presumptive identification of Prevotella melaninogenica?
A. SPS sensitivity test
B. Naglertest
C. Cytotoxin assay
D. Fluorescence test
D. Fluorescence test
33
Which of the following tests is most appropriate for the identification of Clostridium difficile?
A. SPS sensitivity test
B. Naglertest
C. Cytotoxin assay
D. Fluorescence test
C. Cytotoxin assay
34
Which of the following tests is most appropriate for the presumptive identification of Clostridium perfringens?
A. SPS sensitivity test
B. Reverse CAMP test
C. Cytotoxin assay
D. Esculin hydrolysis
B. Reverse CAMP test
35
Which of the following tests is most appropriate for the presumptive identification of Peptostreptococcus anaerobius?
A. SPSdisk
B. Colistindisk
C. Kanamycin disk
D. Vancomycin disk
A. SPSdisk
36
A curved appearance on Gram stain is characteristic of which of the following?
A. Actinomyces israelii
B. Clostridium septicum
C. Fusobacterium nucleatum
D. Propionibacterium acnes
C. Fusobacterium nucleatum
37
Pumlent material from a cerebral abscess was submitted to the laboratory for smear and culture. On direct Gram stain, gram positive cocci in chains and gram-negative bacilli with pointed ends were seen. Plates incubated aerobically exhibited no growth at 24 hours. On the basis of the organisms seen on the smear, what is the most likely presumptive identification of the etiologic anaerobic agents?
A. Veillonella sp. and Clostridium sp.
B. Eubacterium sp. and Veillonella sp.
C. Peptostreptococcus sp. and Nocardia sp.
D. Fusobacterium sp. and Peptostreptococcus sp.
D. Fusobacterium sp. and Peptostreptococcus sp.
38
Which of the following is an important virulence factor of Bacteroides fragilis?
A. Endotoxin
B. Exotoxins
C. Polysaccharide capsule
D. Protease
C. Polysaccharide capsule
39
Which of the following is not true of Bacteroides fragilis ?
A. Lipase and lecithinase negative
B. Anaerobic gram-negative bacillus
C. Commonly associated with intraabdominal infections
D. Among the most antimicrobialsensitive anaerobic bacteria
D. Among the most antimicrobialsensitive anaerobic bacteria
40
Aspiration of vomitus can lead to pneumonia. Which of the following would not be a likely causative agent in aspiration pneumonia?
A. Bacteroides gracilis
B. Mobiluncus sp.
C. Porphyromonas sp.
D. Prevotella melaninogenica
B. Mobiluncus sp.
41
To ensure that anaerobic conditions have been achieved in anaerobic jars or chambers, an oxygen-sensitive indicator is employed, such as
A. Bromcreosol purple
B. Methylene blue
C. Methyl red
D. Phenol red
B. Methylene blue
42
Egg yolk agar showing a precipitate in the medium surrounding the colony is positive for
A. Lecithinase production
B. Lipase production
C. Protease activity
D. Starch hydrolysis
A. Lecithinase production
43
After 72 hours of anaerobic incubation, small olive-green to black colonies are seen. A Gram stain reveals gram-postive cocci. What is the most likely identification of this organism?
A. Fingoldia magna
B. Peptococcus niger
C. Peptostreptococcus anaerobius
D. Veillonella parvula
B. Peptococcus niger
44
Which of the following is an important cause of food poisoning?
A. Bacteroides fragilis
B. Bacteroides ureolyticus
C. Clostridium perfringens
D. Clostridium histolyticum
C. Clostridium perfringens
45
Which bacterium is part of the normal vaginal flora that helps resist the onset of bacterial vaginosis?
A. Peptostreptococcus sp.
B. Peptococcus sp.
C. Lactobacillus sp.
D. Mobiluncus sp.
C. Lactobacillus sp.
46
Chlamydia trachomatis causes which of the following?
A. Rat-bite fever
B. Inclusion conjunctivitis
C. A skin disease found predominantly in tropical areas
D. Zoonosis in birds and parrot fever in humans
B. Inclusion conjunctivitis
47
Which one of the following microorganisms cannot be cultivated on artificial cellfree media?
A. Chlamydia trachomatis
B. Mycoplasma hominis
C. Mycoplasma pneumoniae
D. Ureaplasma urealyticum
A. Chlamydia trachomatis
48
The etiologic agent of primary atypical pneumonia is
A. Chlamydia trachomatis
B. Chlamydiophila psittaci
C. Mycoplasma pneumoniae
D. Ureaplasma urealyticum
C. Mycoplasma pneumoniae
49
The recommended medium for the recovery of Mycoplasma pneumoniae from clinical specimens is
A. Charcoal yeast extract medium
B. Fletcher semisolid medium
C. Middlebrook
D. SP4agar
D. SP4agar
50
Chlamydophila (Chlamydia) psittaci infections in humans most commonly result after exposure to infected
A. Amphibians
B. Arthropods
C. Avians
D. Mammalians
C. Avians
51
Which of the following is not true of Coxiella burnetii?
A. It is an obligate intracellular parasite.
B. It is transmitted from animals to humans by inhalation.
C. A rash appears first on the extremities and then on the trunk.
D. Is the etiologic agent of Q fever, which may be acute or
chronic.
C. A rash appears first on the extremities and then on the trunk.
52
Which of the following is true about mycoplasmas?
A. Resistant to penicillin
B. Not able to survive extracellularly
C. Easily stained using the Gram stain
D. Grow on routine nonselective culture media
A. Resistant to penicillin
53
Corneal scrapings are collected and examined microscopically using a direct fluorescent test to detect inclusion bodies for the diagnosis of infection caused by
A. Chlamydia trachomatis
B. Ehrlichia chaffeensis
C. Mycoplasma hominis
D. Rickettsia prowazekii
A. Chlamydia trachomatis
54
Which of the following Mycoplasmataceae has not been connected with human genital infections?
A. Mycoplasma genitalium
B. Mycoplasma hominis
C. Mycoplasma pneumoniae
D. Ureaplasma urealyticum
C. Mycoplasma pneumoniae
55
Which of the following is not true about Chlamydophila (Chlamydia) pneumoniae?
A. Common agent of lower respiratory tract infection
B. Humans become infected from animal reservoirs.
C. Tetracycline and erythromycin are effective treatments.
D. Research has found an association with artherosclerosis
B. Humans become infected from animal reservoirs.
56
What is the reference method for detection of Chlamydia trachomatis in cases of sexually transmitted disease?
A. Tissue culture
B. Nonculture El A methods
C. DNA-amplification techniques
D. Culture on modified Thayer-Martin agar
C. DNA-amplification techniques
57
Colonies said to have the appearance of a "fried egg" are characteristic of
A. Ehrlichia chaffeensis
B. Mycoplasma genitalium
C. Mycoplasma hominis
D. Ureaplasma urealyticum
C. Mycoplasma hominis
58
Human infection with the causative agent of Q fever is acquired by
A. Inhalation of infectious material
B. The bite of a mite (chigger)
C. The bite of a body louse
D. The bite of the arthropod Phlebotomus
A. Inhalation of infectious material
59
For nonspecific staining ofRickettsia the recommended stain is
A. Gimenez stain
B. Gomori silver stain
C. Gram stain
D. Kinyoun stain
A. Gimenez stain
60
Rocky Mountain spotted fever is transmitted by the bite of a tick infected with
A. Rickettsia akari
B. Rickettsia conorii
C. Rickettsia prowazekii
D. Rickettsia rickettsii
D. Rickettsia rickettsii
61
Transmission of the sylvatic form of typhus infection caused by Rickettsia prowazekii is associated with
A. Bats
B. Rabbits
C. Raccoons
D. Squirrels
D. Squirrels
62
The mild type of typhus fever that is caused by recrudescence of an initial attack of epidemic typhus is known as
A. Brill-Zinsser disease
B. Qfever
C. Sao Paulo typhus
D. Tsutsugamushi disease
A. Brill-Zinsser disease
63
The causative agent of endemic or murine typhus is
A. Rickettsia akari
B. Rickettsia conorii
C. Rickettsia prowazekii
D. Rickettsia typhi
D. Rickettsia typhi
64
A screening test for the identification of Mycoplasma
pneumoniae isolates is the
A. Acid-fast stain
B. Gram stain
C. Lysis of red blood cells
D. Catalasetest
C. Lysis of red blood cells
65
A genital specimen is inoculated into 10 B broth. After overnight incubation, an alkaline reaction is noted without turbidity. What is the most likely explanation?
A. pH change due to molecules in the clinical specimen
B. Presence of Mycoplasma genitalium
C. Presence of Mycoplasma hominis
D. Presence of Ureaplasma urealyticum
D. Presence of Ureaplasma urealyticum
66
Detection of antibody against cardiolipin is useful for the diagnosis of which of the following diseases?
A. Leptospirosis
B. Lyme disease
C. Relapsing fever
D. Syphilis
D. Syphilis
67
During the first week of leptospirosis, the most reliable way to detect the presence of the causative agent is by the direct
A. Culturing of blood
B. Culturing of urine
C. Examination of blood
D. Examination of cerebrospinal fluid
A. Culturing of blood
68
Serious congenital infections are associated with
A. Borrelia burgdorferi
B. Borrelia recurrentis
C. Treponema pallidum subsp. pallidum
D. Treponema pallidum subsp. pertenue
C. Treponema pallidum subsp. pallidum
69
A helicoidal, flexible organism was demonstrated in a blood smear. This motile organism was approximately 12 um long, approximately 0.1 um wide, and had semicircular hooked ends. The description of this organism corresponds most closely to the morphology of
A. Borrelia
B. Leptonema
C. Leptospira
D. Treponema
C. Leptospira
70
The etiologic agent of epidemic relapsing fever is Borrelia recurrentis, which is commonly transmitted by
A. Fleas
B. Lice
C. Mosquitoes
D. Ticks
B. Lice
71
Which of the following is not true of the VDRL test?
A. False-positive tests are more frequent than with the FTA-ABS test.
B. The antibody titer will decline if the patient is adequately treated.
C. Inactivated Treponema pallidum serves as the antigen.
D. The test is usually positive in secondary syphilis.
C. Inactivated Treponema pallidum serves as the antigen.
72
Borrelia burgdorferi, a spirochete transmitted by Ixodes dammini in the northeastern U.S., is the etiologic agent of
A. Lyme disease
B. Rat-bite fever
C. Relapsing fever
D. Q fever
A. Lyme disease
73
The axial fibrils of spirochetes most closely resemble which bacterial structure?
A. Cytoplasmic membrance
B. Flagellum
C. Pilus
D. Sporangium
B. Flagellum
74
Which of the following is not correct regarding spirochetes?
A. Motility is via axial filaments.
B. Spirochetes are gram positive.
C. They are visualized best using dark field or phase optics.
D. Those associated with human disease are 0.1-0.5 um in diameter and 5-30 um in length
B. Spirochetes are gram positive.
75
A positive VDRL test for syphilis was reported on a young woman known to have hepatitis. When questioned by her physician, she denied sexual contact with any partner symptomatic for a sexually transmitted disease. Which of the following would be the appropriate next step for her physician?
A. Treat her with penicillin
B. Identify her sexual contacts for serologic testing
C. Test her serum using a fluorescent treponemal antibody-absorbed assay
D. Reassure her that it was a biologic false-positive caused by her liver disease
C. Test her serum using a fluorescent treponemal
76
In August, a patient presented at a community hospital in New England with symptoms of a skin rash, headache, stiff neck, muscle aches, and swollen lymph nodes. A silver-stained biopsy of a skin lesion showed spirochetes. On the basis of the clinical syndrome and laboratory detection of a causative agent, the patient was diagnosed as having
A. Lyme disease
B. Plague
C. Rabbit fever
D. Relapsing fever
A. Lyme disease
77
Several international participants in an Eco-Challenge adventure race in Borneo became ill with symptoms of chills, diarrhea, headaches, and eye infections. The racers hiked in the mountains and jungles, swam in rivers, and slogged through flooded streams for 2 weeks. Contact with contaminated water and soil during the race was highly associated with illness. What is the most likely etiologic agent in this case?
A. Borellia recurrentis
B. Brucella canis
C. Franciscella tularensis
D. Leptospira interrogans
D. Leptospira interrogans
78
"Lumpy jaw" is caused by:
A. Nocardia brasiliensis
B. Trichophyton rubrum
C. Actinomyces israelii
D. Microsporum canis
C. Actinomyces israelii
79
An aspirate of a deep wound was plated on blood agar plates and incubated aerobically and anaerobically. At 24 hours there was growth on both plates. This indicates that the organism is
a(n):
A. nonfermenter
B. obligate anaerobe
C. aerobe
D. facultative anaerobe
D. facultative anaerobe
80
The characteristic that is most commonly associated with the presence of strict anaerobic bacteria and can be taken as presumptive evidence of their presence in a clinical specimen is the:
A. presence of a single bacterial species
B. production of gas in a thioglycollate broth culture
C. growth on a blood agar plate incubated in an anaerobic jar
D. presence of a foul, putrid odor from tissue specimens and cultures
D. presence of a foul, putrid odor from tissue specimens and
cultures
81
Gram stain of a thigh wound showed many Gram-positive spore-forming bacilli. The specimen was placed on a brain heart infusion blood agar and incubated aerobically at 35C for 3 days. At the end of that time, the plates showed no growth. The most likely explanation is that some of the specimen should have been incubated:
A. on a chocolate agar
B. for 5 days
C. under 5% CO2
D. anaerobically
D. anaerobically
82
An aspirate of a deep wound was plated on blood agar plates aerobically and anaerobically. At 48 hours there was growth on the anaerobic plate only. The next step in the evaluation of this culture is to:
A. reincubate both plates for another 24 hours
B. Gram stain and begin organism identification
C. call physician and request blood culture
D. set up a Bauer-Kirby susceptibility test
B. Gram stain and begin organism identification
83
In general, anaerobic infections differ from aerobic infections in which one of the following?
A. they usually respond favorably to aminoglycoside therapy
B. they usually arise from exogenous sources
C. they usually polymicrobic
D. Gram stains of specimens are less helpful in diagnosis
C. they usually polymicrobic
84
The following growth results were observed on media inoculated with a foot abscess aspirate and incubated in 3-5% CO2.
SBA: 2+ large gray colonies
PEA: no growth
chocolate: 3+ large gray colonies
MacConkey: 3+ lactose fermenters
thioglycollate broth: Gram-negative bacilli and Gram-positive bacilli
Biochemicals were set up on the colonies from the MacConkey agar plate. What should the microbiologist do next?
A. set up biochemicals on the colonies from SBA
B. Gram stain colonies on SBA
C. subculture thioglycollate broth to SBA aerobic and SBA anaerobic
D. test colonies on chocolate agar with hemin and NAD
C. subculture thioglycollate broth to SBA aerobic and SBA anaerobic
85
Which of the following pairs of organisms usually grow on kanamycin, vancomycin, laked blood agar?
A. Bacteriodes and Prevotella
B. Mobiluncus and Gardnerella
C. Porphyromonas and Enterococcus
D. Veillonella and Capnocytophaga
A. Bacteriodes and Prevotella
86
Acceptable specimen sources for culture of anaerobic bacteria
includes:
A. abscess
B. stool
C. clean catch urine
D. vaginal
A. abscess
87
Propionibacterium acnes is most often associated with:
A. food poisoning
B. post-antibiotic diarrhea
C. tooth decay
D. blood culture contamination
D. blood culture contamination
88
The etiologic agent of botulism is:
A. highly motile
B. non spore-forming
C. a glucose fermenter
D. an exotoxin producer
D. an exotoxin producer
89
A strict anaerobe that produces terminal spores is:
A. Clostridium tetani
B. Corynebacterium diphtheriae
C. Bacillus anthracis
D. Propionibacterium acnes
A. Clostridium tetani
90
An anaerobic, box-car shaped, beta hemolytic Gram-positive bacillus isolated from a foot wound is most likely;
A. Actinomyces israelii
B. Clostridium perfringens
C. Bacillus subtilis
D. Eubacterium lentum
B. Clostridium perfringens
91
The laboratory is considering adoption of a rapid and sensitive " stand alone" method that detects Clostridium difficile toxins A and B. Which one of the following testing methodologies will provide this?
A. cell culture cytotoxin assay
B. latex agglutination
C. lecithinase production
D. NAAT
D. NAAT
92
The reverse CAMP test, lecithinase production, double zone hemolysis, and Gram stain morphology are all useful criteria in the identification of:
A. Clostridium perfringens
B. Streptococcus agalactiae
C. Propionibacterium acnes
D. Bacillus anthracis
A. Clostridium perfringens
93
Which one of the following anaerobes is inhibited by sodium polyanethol sulfonate (SPS)?
A. Bacteriodes fragilis
B. Propionibacterium acnes
C. Peptostreptococcus anaerobius
D. Veillonella parvula
C. Peptostreptococcus anaerobius
94
Clotridium difficile can be detected by:
A. fluorescent staining
B. glutamate dehydrogenase
C. growth on LKV media
D. high-pressure liquid chromatograph
B. glutamate dehydrogenase
95
Anaerobic Gram-positive bacilli with subterminal spores were isolated from a peritoneal abscess. The colony has a swarming appearance. The most likely identification of this organism is:
A. Bacillus cereus
B. Clostridium septicum
C. Eubacterium lentum
D. Bifidobacterium dentium
B. Clostridium septicum
96
If a stool sample is sent to the laboratory to rule out Clostridium difficile, what medium should the microbiologist use and what is the appearance of this organism on this medium?
A. BBE; colonies turn black
B. Brucella agar; red pigmented colonies
C. CCFA; yellow, ground glass colonies
D. CNA; double zone hemolytic colonies
C. CCFA; yellow, ground glass colonies
97
A Gram stain of a peritoneal fluid showed large Gram-positive bacilli. There was 3+ growth on anaerobic media only, with colonies producing a double zone of hemolysis. To assist with the classic identification of the organism, the microbiologist could:
A. determine if the organism ferments glucose
B. perform the oxidase test
C. set up egg yolk agar plate
D. test for bile tolerance
C. set up egg yolk agar plate
98
A patient has a suspected diagnosis of subacute bacterial endocarditis. His blood cultures grow non spore-forming pleomorphic Gram-positive bacilli only in the anaerobic bottle. What test(s) will give a presumptive identification of this microorganism?
A. beta-hemolysis and oxidase
B. catalase and spot indole
C. esculin hydrolysis
D. hydrolysis of gelatin
B. catalase and spot indole
99
The Gram stain of drainage from a pulmonary sinus tract shows many WBCs and 3+ branching Gram-positive bacilli. Colonies grow only on anaerobic media after 3 days incubation. They are yellow-tan and have a molar tooth appearance. The most likely genus is:
A. Actinomyces
B. Bacteriodes
C. Fusobacterium
D. Nocardia
A. Actinomyces
100
Which organism is the most common anaerobic bacteria isolated from infectious processes of soft tissue and anaerobic bacteremia?
A. Bacteriodes fragilis
B. Fusobacterium nucleatum
C. Porphyromonas asaccharolytica
D. Clostridium perfringens
A. Bacteriodes fragilis
101
An organism from a peritoneal abscess is isolated on kanamycin-vancomycin laked blood agar and grows black colonies on BBE agar. It is nonpigmented, catalase positive, and indole negative. The genus of this organism is:
A. Acidominococcus
B. Bacteroides
C. Porphyromonas
D. Prevotella
B. Bacteroides
102
Which of the following sets of organisms may exhibit a brick red fluorescence?
A. Porphyromonas asaccharolytica and Clostridi
B. Clostridium difficile and Fusobacterium sp.
C. Prevotella melaninogenica and Porphyromonas asaccharolytica
D. Fusobacterium sp and Bacteroides fragilis
C. Prevotella melaninogenica and Porphyromonas asaccharolytica
103
A 1-2mm translucent, nonpigmented colony, isolated from an anaerobic culture of a lung abscess after 72 hours, was found to fluoresce brick- red under ultraviolet light. A Gram stain of the organism revealed a coccobacillus that had the following characteristics:
growth in bile: inhibited
vancomycin: resistant
kanamycin: resistant
colistin: susceptible
catalase: negative
esculin hydrolysis: negative
indole: negative
The identification of this isolate is:
A. Bacteroides ovalus
B. Propionibacterium acnes
C. Prevotella melaninogenica
D. Porphyromonas asaccharolytica
C. Prevotella melaninogenica
104
A thin, Gram-negative bacillus with tapered ends isolated from an empyema specimen grew only on anaerobic sheep blood agar. It was found to be indole positive, lipase negative, and was inhibited by 20% bile. The most probable identification of this isolate would be:
A. Bacteroides distasonis
B. Prevotella melaninogenica
C. Fusobacterium nucleatum
D. Clostridium septicum
C. Fusobacterium nucleatum
105
The presence of 20% bile in agar will allow growth of:
A. Fusobacterium necrophorum
B. Bacteroides fragilis
C. Prevotella melaninogenica
D. Porphyromonas asaccharolytica
B. Bacteroides fragilis
106
A control strain of Clostridium should be used in an anaerobe jar to assure that:
A. the plate media is working
B. an anaerobic environment is achieved
C. the jar is filled with a sufficient number of plates
D. the indicator strip is checked
B. an anaerobic environment is achieved
107
Which one of the following organisms could be used as the positive quality control test for lecithinase on egg yolk agar?
A. Bacteroides fragilis
B. Fusobacterium necrophorum
C. Clostridium perfringens
D. Clostridium sporogenes
C. Clostridium perfringens
108
Anaerobic gram-positive bacilli with subterminal spores were recovered from several blood cultures obtained from a patient diagnosed with a malignancy of the colon. The following results were recorded:
Indole = Neg
Urease = Neg
Lipase = Neg
Catalase = Neg
Lecithinase = Neg
Growth on blood agar = Swarming colonies
What is the correct identification?
A. Clostridium septicum
B. Clostridium perfringens
C. Clostridium sordellii
D. Propionibacterium acnes
A. Clostridium septicum
109
Anaerobic gram-negative bacilli were recovered from fluid obtained from drainage of a postsurgical abdominal wound. The following test results were recorded:
Kanamycin = Resistant
Vancomycin = Resistant
Colistin = Resistant
Growth on 20% bile plate = +
Pigment = Neg
Indole = V (Neg)
Nitrate = Neg
Urease = Neg
Lipase = Neg
What is the correct identification?
A. Prevotella spp.
B. Bacteroides fragilis group
C. Porphyromonas spp.
D. Clostridium spp.
B. Bacteroides fragilis group
110
Anaerobic, nonpigmented, gram-negative rods were recovered from an anaerobic blood agar plate after 48 hours of incubation. The Gram-stained smear showed thin bacilli with pointed ends. The colonies on blood agar had the appearance of dry, irregular, white breadcrumb-like morphology with greening of the agar. The following reactions were noted:
Kanamycin = Sensitive Vancomycin = Resistant
Colistin = Sensitive Nitrate = Neg
Indole = + Catalase = Neg
Lipase = Neg Urease = Neg
Growth on 20% bile agar = Neg
What is the correct identification?
A. Fusobacterium nucleatum
B. Bacteroides fragilis
C. Clostridium perfringens
D. Peptostreptococcus spp.
A. Fusobacterium nucleatum
111
Anaerobic gram-positive diphtheroids (nonspore formers) were cultured from two separate blood culture bottles (at 5 days) obtained from a 25-year-old patient admitted to the hospital with dehydration, diarrhea, and other flulike symptoms. Four other blood culture bottles did not grow any organisms at 7 days and were discarded. The following results were obtained from the recovered anaerobe:
Indole = + Nitrate = +
Catalase = + Kanamycin = Sensitive
Vancomycin = Sensitive Colistin = Resistant
Major acid from PYG broth by GLC = Propionic acid
What is the correct identification?
A. Eubacterium lentum
B. Propionibacterium acnes
C. Actinomyces spp.
D. Peptostreptococcus spp.
B. Propionibacterium acnes
112
Anaerobic gram-positive, spore-forming bacilli were recovered from the feces of a chemotherapy patient with severe diarrhea. The patient had undergone antibiotic therapy 1 week prior. The fecal culture produced growth only on the CCFA plate. No aerobic growth of normal flora was seen after 48 hours. The following results were noted:
Kanamycin = Sensitive Vancomycin = Sensitive
Colistin = Resistant Lecithinase = Neg
Lipase = Neg Nitrate = Neg
Indole = Neg Urease = Neg
Catalase = Neg Spores = +
CCFA agar = Growth of yellow, “ground-glass” colonies
that fluoresce chartreuse (yellow-green)
What is the correct identification?
A. Clostridium perfringens
B. Clostridium tetani
C. Clostridium sordellii
D. Clostridium difficile
D. Clostridium difficile
