BOC Microbiology Practice Questions with Revised
Answers| Verified 100% Correct
Which of the following would not be appropriate when collecting a urine for culture?
- The collected sample must be plated within 2 hours unless refrigerated
- The container must be sterile
- The sample may be held at 2C - 8C for up to 48 hours prior to plating
- The midstream void technique must be used - ✔✔The sample may be held at 2C -
8C for up to 48 hours prior to plating
A culture was ordered on pulmonary secretions from an 8-year-old cystic fibrosis patient
who had come down with pneumonia. Consider the following results from a pure
culture of gram-negative bacilli:
Oxidase = +, Motility = +, Glucose OF (open) = +, Gelatin hydrolysis = +, Growth at 42C =
+, Arginine dihydrolase = +, Pigment = red, non-fluorescent, Flagella = + with polar
monotrichous
Which of the following organisms is most likely responsible for the pneumonia?
- Burkholderia (P.) pseudomallei
- Burkholderia (P.) cepacia
- Pseudomonas aeruginosa
- Pseudomonas stutzeri - ✔✔Pseudomonas aeruginosa
A vaginal swab was cultured using Thayer-Martin media. The colonies that grew stained
as gram-negative diplococci. Additional testing yielded the following results:
Catalase = +, Oxidase = +, Superoxol = -, Glucose = +, Lactose = +, Maltose = +, Sucrose =
-, Fructose = -
Which of the following is most likely present?
,- No answer text provided
- Neisseria lactamica
- Neisseria gonorrhoeae
- Neisseria sicca - ✔✔Neisseria lactamica
Blood cultures on a 5-day-old gave the following results:
Gram stain = gpc in chains, Beta hemolysis, CAMP test = +, Hippurate hydrolysis = -, Salt
tolerance = +, Bile solubility = -, Bile esculin = -, Bacitracin = resistant, PYR = -,
Trimethoprim/sulfamthoxazole = resistant
Which of the following is most likely present?
- Group B streptococci
- Group D streptococci
- Group A streptococci
- Nongroup A, nongroup B, nongroup D streptococci - ✔✔Group B streptococci
Which of the following is true regarding Streptococcus spp?
- Facultative anaerobe, oxidase-negative, catalase-negative
- Aerobic, oxidase-positive, and catalase-positive
- Facultative anaerobe, beta hemolytic, catalase-positive
- May be alpha, beta, or gamma hemolytic, catalase-positive - ✔✔Facultative
anaerobe, oxidase-negative, catalase-negative
A swab from a diabetic ulcer is sent to the lab for culture and yields the following
results:
Colony morph = creamy, pale yellow, B-hemolytic colonies on BAP, Catalase = +, Glucose
OF = open tube +, sealed tube -, Mannitol salt = - Slide coagulase = -
Which of the following is likely present?
,- Micrococcus spp
- Staphylococcus epidermidis
- Staphylococcus aureus
- Streptococcus spp - ✔✔Micrococcus spp
An immunocompromised 55-year-old female patient undergoing chemotherapy
treatment received three units of packed RBCs. Three days later, the patient passed
away and the results from the autopsy listed septic shock as the cause of death.
Cultures of the blood bags gave the following results:
Growth on BAP and MAC = aerobic, gram-negative rods, Lactose = -, Sucrose = +, Citrate
= -, Indole = -, VP = -, H2S = -, Urease = +, Motility @ 22C = +, Motility @ 37C = -
Which of the following is most likely present?
- Citrobacter freundii
- Escherichia coli
- Yersinia entercolitica
- Enterobacter cloacae - ✔✔Yersinia entercolitica
Which of the following has the inability to grow on artificial media or in cell culture?
- Chlamydia trachomatis
- Treponema pallidum
- Herpes simplex virus
- Neisseria gonorrhoeae - ✔✔Treponema pallidum
An organism is recovered from a vaginal culture from a 24-year-old patient who is 32
weeks pregnant. The gram stain reveals gram positive cocci, colonies on blood agar are
beta-hemolytic and biochemical testing shows that the organism is catalase negative.
Which tests are necessary for further identification
- PYR, bile solubility, optochin
, - Glucose, CAMP, oxidase
- Methicillin, PYR, coagulase
- CAMP, PYR, bacitracin - ✔✔CAMP, PYR, bacitracin
Which of the following gram negative bacilli are characterized by the production of a
black pigment and red fluorescence when exposed to UV light?
- All of the answers are correct
- Bacteroides spp and Fusobacterium spp
- Fusobacterium spp and Actinomyces spp
- Porphyromonas spp and Prevotella spp - ✔✔Porphyromonas spp and Prevotella spp
Of the following, which genus is catalase-positive, oxidase-negative small, gram-
negative coccobacilli that are mostly associated with animals, but may be attributed to
wound and dental infections, bacteremia, and endocarditis in humans?
- Campylobacter
- Acintobacillus
- Pseudomonas
- Vibrio - ✔✔Acintobacillus
A specimen is sent to the lab from a male patient. The label indicates that is urethral
discharge. Which of the following media should be used for culture?
- Eosin-methylene blue and sheep blood agars
- Sheep blood and phenylethyl alcohol agars
- Chocolate and modified Thayer-Martin agars
- Thioglycollate broth and chocolate agar - ✔✔Chocolate and modified Thayer-Martin
agars
Answers| Verified 100% Correct
Which of the following would not be appropriate when collecting a urine for culture?
- The collected sample must be plated within 2 hours unless refrigerated
- The container must be sterile
- The sample may be held at 2C - 8C for up to 48 hours prior to plating
- The midstream void technique must be used - ✔✔The sample may be held at 2C -
8C for up to 48 hours prior to plating
A culture was ordered on pulmonary secretions from an 8-year-old cystic fibrosis patient
who had come down with pneumonia. Consider the following results from a pure
culture of gram-negative bacilli:
Oxidase = +, Motility = +, Glucose OF (open) = +, Gelatin hydrolysis = +, Growth at 42C =
+, Arginine dihydrolase = +, Pigment = red, non-fluorescent, Flagella = + with polar
monotrichous
Which of the following organisms is most likely responsible for the pneumonia?
- Burkholderia (P.) pseudomallei
- Burkholderia (P.) cepacia
- Pseudomonas aeruginosa
- Pseudomonas stutzeri - ✔✔Pseudomonas aeruginosa
A vaginal swab was cultured using Thayer-Martin media. The colonies that grew stained
as gram-negative diplococci. Additional testing yielded the following results:
Catalase = +, Oxidase = +, Superoxol = -, Glucose = +, Lactose = +, Maltose = +, Sucrose =
-, Fructose = -
Which of the following is most likely present?
,- No answer text provided
- Neisseria lactamica
- Neisseria gonorrhoeae
- Neisseria sicca - ✔✔Neisseria lactamica
Blood cultures on a 5-day-old gave the following results:
Gram stain = gpc in chains, Beta hemolysis, CAMP test = +, Hippurate hydrolysis = -, Salt
tolerance = +, Bile solubility = -, Bile esculin = -, Bacitracin = resistant, PYR = -,
Trimethoprim/sulfamthoxazole = resistant
Which of the following is most likely present?
- Group B streptococci
- Group D streptococci
- Group A streptococci
- Nongroup A, nongroup B, nongroup D streptococci - ✔✔Group B streptococci
Which of the following is true regarding Streptococcus spp?
- Facultative anaerobe, oxidase-negative, catalase-negative
- Aerobic, oxidase-positive, and catalase-positive
- Facultative anaerobe, beta hemolytic, catalase-positive
- May be alpha, beta, or gamma hemolytic, catalase-positive - ✔✔Facultative
anaerobe, oxidase-negative, catalase-negative
A swab from a diabetic ulcer is sent to the lab for culture and yields the following
results:
Colony morph = creamy, pale yellow, B-hemolytic colonies on BAP, Catalase = +, Glucose
OF = open tube +, sealed tube -, Mannitol salt = - Slide coagulase = -
Which of the following is likely present?
,- Micrococcus spp
- Staphylococcus epidermidis
- Staphylococcus aureus
- Streptococcus spp - ✔✔Micrococcus spp
An immunocompromised 55-year-old female patient undergoing chemotherapy
treatment received three units of packed RBCs. Three days later, the patient passed
away and the results from the autopsy listed septic shock as the cause of death.
Cultures of the blood bags gave the following results:
Growth on BAP and MAC = aerobic, gram-negative rods, Lactose = -, Sucrose = +, Citrate
= -, Indole = -, VP = -, H2S = -, Urease = +, Motility @ 22C = +, Motility @ 37C = -
Which of the following is most likely present?
- Citrobacter freundii
- Escherichia coli
- Yersinia entercolitica
- Enterobacter cloacae - ✔✔Yersinia entercolitica
Which of the following has the inability to grow on artificial media or in cell culture?
- Chlamydia trachomatis
- Treponema pallidum
- Herpes simplex virus
- Neisseria gonorrhoeae - ✔✔Treponema pallidum
An organism is recovered from a vaginal culture from a 24-year-old patient who is 32
weeks pregnant. The gram stain reveals gram positive cocci, colonies on blood agar are
beta-hemolytic and biochemical testing shows that the organism is catalase negative.
Which tests are necessary for further identification
- PYR, bile solubility, optochin
, - Glucose, CAMP, oxidase
- Methicillin, PYR, coagulase
- CAMP, PYR, bacitracin - ✔✔CAMP, PYR, bacitracin
Which of the following gram negative bacilli are characterized by the production of a
black pigment and red fluorescence when exposed to UV light?
- All of the answers are correct
- Bacteroides spp and Fusobacterium spp
- Fusobacterium spp and Actinomyces spp
- Porphyromonas spp and Prevotella spp - ✔✔Porphyromonas spp and Prevotella spp
Of the following, which genus is catalase-positive, oxidase-negative small, gram-
negative coccobacilli that are mostly associated with animals, but may be attributed to
wound and dental infections, bacteremia, and endocarditis in humans?
- Campylobacter
- Acintobacillus
- Pseudomonas
- Vibrio - ✔✔Acintobacillus
A specimen is sent to the lab from a male patient. The label indicates that is urethral
discharge. Which of the following media should be used for culture?
- Eosin-methylene blue and sheep blood agars
- Sheep blood and phenylethyl alcohol agars
- Chocolate and modified Thayer-Martin agars
- Thioglycollate broth and chocolate agar - ✔✔Chocolate and modified Thayer-Martin
agars
