©Jason MacConnell 2025 ALL RIGHTS RESERVED.
BOC Microbiology Practice Questions With
Correct Answers A+
An organism identified as Cryptococcus species can be accurately identified as Cryptococcus
neoformans using which of the following characteristics?
- Positive urease test
- Presence of a capsule
- Positive phenol oxidase test
- Appearance of yellow colonies - Answer✔Positive phenol oxidase test
Consider the following results on an isolate from a CSF specimen, growing on cornmeal agar:
Blastospores = +, Pseudohyphae = -, Chlamydospores = -, Arthrospores = -
Which of the following tests should be performed next?
- Birdseed agar and urease
- India ink and glucose
- India ink and germ tube
- Germ tube and glucose - Answer✔Birdseed agar and urease
Consider the following test results on a 21-year-old female student with sore throat, extreme
fatigue, and lymphadenopathy. Lab results indicated that the rapid test for infectious
mononucleosis antibodies was negative. Bacterial cultures were also negative, as were
serological tests for antistreptolysin O (ASO), CMV, Hepatitis B, HIV-1, Influenza A, and
Influenza B.
- West Nile Virus
- Epstein-Barr Virus
- Herpes simplex virus
- Rubella - Answer✔Epstein-Barr Virus
A technologist performed susceptibility testing via the disk diffusion method on 7H11 plates, on
a specimen from a patient with classic TB. Which of the following are first-line antibiotics that
would be prescribed for treatment of this?
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
- Isonicotinic acid hydrazine (INH), rifampin, ethambutol
- Ampicillin, penicillin, carbenicillin
- Ampicillin, penicillin, methicillin
- Vancomycin, methicillin, carbenicillin - Answer✔Isonicotinic acid hydrazine (INH), rifampin,
ethambutol
A CSF culture from an immunocompromised patient grew gram-negative coccobacilli on
chocolate agar. Further testing revealed the following:
Motility = -, Indophenol Oxidase = +, MacConkey = no growth
Antibiotic testing showed that it was highly susceptible to penicillin. Which of the following
organisms is most likely present?
- Pseudomonas stutzeri
- Moraxella lacunata
- Acinetobacter spp
- Pseudomonas aeruginosa - Answer✔Moraxella lacunata
A medical technologist receives a stool specimen on a patient with diarrhea who has just
returned from visiting South America. The patient is suspected of having an infection caused by
Vibrio cholerae. Which of the following media would be best for the identification and recovery
of this organism?
- Blood agar
- TCBS agar
- XLD agar
- MacConkey agar - Answer✔TCBS agar
A gram negative, non-lactose fermenter was recovered from a culture from patient suffering
from 2nd degree burns. Which of the following tests would best differentiate Acinetobacter spp
and Pseudomonas aeruginosa?
- String test and coagulase test
- Growth on MacConkey, catalase, growth at 37C
- Motility, oxidase, growth at 42C
- Growth on blood agar, oxidase, growth at 35C - Answer✔Motility, oxidase, growth at 42C
Cultures from a hospital hot water system gave the following results:
Growth at 42C = +
Growth on Lowenstein-Jensen medium = no pigmentation after exposure to light
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
Niacin accumulation = -
Nitrate reduction test = -
Which of the following organisms is most likely present?
- Mycobacterium marinum
- Mycobacterium haemophilum
- Mycobacterium ulcerans
- Mycobacterium xenopi - Answer✔Mycobacterium xenopi
In a nitrate reduction test, a positive result is indicated by a red color change. Which of the
following reagent(s) is (are) used in the reaction?
- Sulfanilic acid and alpha-naphthylamine
- Potassium hydroxide and alpha-naphthol
- o-Nitrophenyl-B-D-galactopyranoside
- Erlich's and Kovac's reagent - Answer✔Sulfanilic acid and alpha-naphthylamine
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 - Answer✔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 - Answer✔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:
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
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 - Answer✔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 - Answer✔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 - Answer✔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 - Answer✔Micrococcus spp
BOC Microbiology Practice Questions With
Correct Answers A+
An organism identified as Cryptococcus species can be accurately identified as Cryptococcus
neoformans using which of the following characteristics?
- Positive urease test
- Presence of a capsule
- Positive phenol oxidase test
- Appearance of yellow colonies - Answer✔Positive phenol oxidase test
Consider the following results on an isolate from a CSF specimen, growing on cornmeal agar:
Blastospores = +, Pseudohyphae = -, Chlamydospores = -, Arthrospores = -
Which of the following tests should be performed next?
- Birdseed agar and urease
- India ink and glucose
- India ink and germ tube
- Germ tube and glucose - Answer✔Birdseed agar and urease
Consider the following test results on a 21-year-old female student with sore throat, extreme
fatigue, and lymphadenopathy. Lab results indicated that the rapid test for infectious
mononucleosis antibodies was negative. Bacterial cultures were also negative, as were
serological tests for antistreptolysin O (ASO), CMV, Hepatitis B, HIV-1, Influenza A, and
Influenza B.
- West Nile Virus
- Epstein-Barr Virus
- Herpes simplex virus
- Rubella - Answer✔Epstein-Barr Virus
A technologist performed susceptibility testing via the disk diffusion method on 7H11 plates, on
a specimen from a patient with classic TB. Which of the following are first-line antibiotics that
would be prescribed for treatment of this?
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
- Isonicotinic acid hydrazine (INH), rifampin, ethambutol
- Ampicillin, penicillin, carbenicillin
- Ampicillin, penicillin, methicillin
- Vancomycin, methicillin, carbenicillin - Answer✔Isonicotinic acid hydrazine (INH), rifampin,
ethambutol
A CSF culture from an immunocompromised patient grew gram-negative coccobacilli on
chocolate agar. Further testing revealed the following:
Motility = -, Indophenol Oxidase = +, MacConkey = no growth
Antibiotic testing showed that it was highly susceptible to penicillin. Which of the following
organisms is most likely present?
- Pseudomonas stutzeri
- Moraxella lacunata
- Acinetobacter spp
- Pseudomonas aeruginosa - Answer✔Moraxella lacunata
A medical technologist receives a stool specimen on a patient with diarrhea who has just
returned from visiting South America. The patient is suspected of having an infection caused by
Vibrio cholerae. Which of the following media would be best for the identification and recovery
of this organism?
- Blood agar
- TCBS agar
- XLD agar
- MacConkey agar - Answer✔TCBS agar
A gram negative, non-lactose fermenter was recovered from a culture from patient suffering
from 2nd degree burns. Which of the following tests would best differentiate Acinetobacter spp
and Pseudomonas aeruginosa?
- String test and coagulase test
- Growth on MacConkey, catalase, growth at 37C
- Motility, oxidase, growth at 42C
- Growth on blood agar, oxidase, growth at 35C - Answer✔Motility, oxidase, growth at 42C
Cultures from a hospital hot water system gave the following results:
Growth at 42C = +
Growth on Lowenstein-Jensen medium = no pigmentation after exposure to light
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
Niacin accumulation = -
Nitrate reduction test = -
Which of the following organisms is most likely present?
- Mycobacterium marinum
- Mycobacterium haemophilum
- Mycobacterium ulcerans
- Mycobacterium xenopi - Answer✔Mycobacterium xenopi
In a nitrate reduction test, a positive result is indicated by a red color change. Which of the
following reagent(s) is (are) used in the reaction?
- Sulfanilic acid and alpha-naphthylamine
- Potassium hydroxide and alpha-naphthol
- o-Nitrophenyl-B-D-galactopyranoside
- Erlich's and Kovac's reagent - Answer✔Sulfanilic acid and alpha-naphthylamine
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 - Answer✔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 - Answer✔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:
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
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 - Answer✔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 - Answer✔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 - Answer✔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 - Answer✔Micrococcus spp
