BOC Microbiology Test Study Questions with 100%
Correct Answers | Verified
which organism is associated with immunodeficiency syndromes and melioidosis (a
glanders-like disease in southeast Asia and northern Australia)? - ✔✔Burkholderia
pseudomallei (known as" vietnamese time bomb")
Which biochemical test are needed to differentiate Burkholderia cepacia from S.
maltophilia? - ✔✔Pigment on blood agar, oxidase, and DNAse. (B. cepacia is green-
yellow on BAP, and S. maltophilia is Lavender-green, oxidase negative, and DNase
positive.)
The following results were obtained from a pure culture of gram negative rods
recovered from the pulmonary secretions of a 10-year old cystic fibrosis patients with
pneumonia:
=========================================
Oxidase pos, Motlity pos, Glucose OF (open) pos, Gelatin hydrolysis pos, Pigment -Red
(nonfluorescent), Growth at 42C, Flagella-polar, monotrichous, Arginine dihydrolase
pos. - ✔✔Pseudomonas aeruginosa (Pyrorubin, red pigment, is a characteristic of P.
aeruginosa, and oxidase positive as well as cystic fibrosis relation)
Alcaligenes faecalis (formerly A. odorans) is distinguished from Bordetella
bronchiseptica with which test? - ✔✔Urease (rapid). Both organisms are oxidase
positive, grow on Mac agar, and are motile by peritrichous flagella. Alcaligenes faecalis
is Urease negative.
Chryseobacterium spp. are easily distinguished from Acinetobacter spp. by which of the
following two tests? - ✔✔Oxidase, growth on Mac agar. (Acinetobacter is oxidase
negative, grow on MAC agar, and are occobadcillary on gram stain. Chryseobacterium
spp. are oxidase positive, no growth on Mac agar and are typically rod shaped)
, A gram-negative coccobacillus was recovered on chocolate agar from the CSF of an
immunosuppressed patient. The organism was nonmotile and positive for indophenol
oxidase but failed to grow on MAC agar. The organism was highly susceptible to
penicillin. The most probable identification is: - ✔✔Moraxella lacunata (Moraxella
spp. are oxidase positive and non-motile, as well as highly sensitive to penicillin and
usually seen in immunosuppressed patients).
Cetrimide agar is used as a selective isolation agar for which organism? -
✔✔Pseudomonas aeruginosa (Cetrimide aka acetyl trimethyl ammonium bromide, is
used for the identification/isolation of P. aeruginosa with the exception of P.
fluorescens, other psudomonads are inhibited along with other non-fermentative
bacteria.)
A specimen from a 15 year old burn patient was cultured after debridement, and the
following results were obtained:
=========================================
Oxidase pos, Catalase pos, Ornithine neg, Arg pos, Penicillin res, Lysine neg, Motility pos,
Glucose pos (open tube), Maltose neg (open tube), aminoglycosides susceptible,
colistin(polymixin b) susceptible. - ✔✔Pseudomonas aeruginosa ( Acinetobacter spp.
is oxidase negative and Moraxella spp. are highly susceptible to penicillin)
A yellow pigment-producing organism that is oxidase positive, nonmotile, and does not
grow on MacConkey agar is? - ✔✔Chryseobacterium meningosepticum (Oxidase
positive, yellow pigment, and do not grow on Mac agar.)
Which reagent(s) is (are) used to develop the red color indicative of a positive reaction
in the nitrate reduction test? - ✔✔Sulfanilic acid and Alpha-naphthylamine
A culture from an intra-abdominal abscess produced orange-tan colonies on blood agar
that gave the following results:
========================================
Correct Answers | Verified
which organism is associated with immunodeficiency syndromes and melioidosis (a
glanders-like disease in southeast Asia and northern Australia)? - ✔✔Burkholderia
pseudomallei (known as" vietnamese time bomb")
Which biochemical test are needed to differentiate Burkholderia cepacia from S.
maltophilia? - ✔✔Pigment on blood agar, oxidase, and DNAse. (B. cepacia is green-
yellow on BAP, and S. maltophilia is Lavender-green, oxidase negative, and DNase
positive.)
The following results were obtained from a pure culture of gram negative rods
recovered from the pulmonary secretions of a 10-year old cystic fibrosis patients with
pneumonia:
=========================================
Oxidase pos, Motlity pos, Glucose OF (open) pos, Gelatin hydrolysis pos, Pigment -Red
(nonfluorescent), Growth at 42C, Flagella-polar, monotrichous, Arginine dihydrolase
pos. - ✔✔Pseudomonas aeruginosa (Pyrorubin, red pigment, is a characteristic of P.
aeruginosa, and oxidase positive as well as cystic fibrosis relation)
Alcaligenes faecalis (formerly A. odorans) is distinguished from Bordetella
bronchiseptica with which test? - ✔✔Urease (rapid). Both organisms are oxidase
positive, grow on Mac agar, and are motile by peritrichous flagella. Alcaligenes faecalis
is Urease negative.
Chryseobacterium spp. are easily distinguished from Acinetobacter spp. by which of the
following two tests? - ✔✔Oxidase, growth on Mac agar. (Acinetobacter is oxidase
negative, grow on MAC agar, and are occobadcillary on gram stain. Chryseobacterium
spp. are oxidase positive, no growth on Mac agar and are typically rod shaped)
, A gram-negative coccobacillus was recovered on chocolate agar from the CSF of an
immunosuppressed patient. The organism was nonmotile and positive for indophenol
oxidase but failed to grow on MAC agar. The organism was highly susceptible to
penicillin. The most probable identification is: - ✔✔Moraxella lacunata (Moraxella
spp. are oxidase positive and non-motile, as well as highly sensitive to penicillin and
usually seen in immunosuppressed patients).
Cetrimide agar is used as a selective isolation agar for which organism? -
✔✔Pseudomonas aeruginosa (Cetrimide aka acetyl trimethyl ammonium bromide, is
used for the identification/isolation of P. aeruginosa with the exception of P.
fluorescens, other psudomonads are inhibited along with other non-fermentative
bacteria.)
A specimen from a 15 year old burn patient was cultured after debridement, and the
following results were obtained:
=========================================
Oxidase pos, Catalase pos, Ornithine neg, Arg pos, Penicillin res, Lysine neg, Motility pos,
Glucose pos (open tube), Maltose neg (open tube), aminoglycosides susceptible,
colistin(polymixin b) susceptible. - ✔✔Pseudomonas aeruginosa ( Acinetobacter spp.
is oxidase negative and Moraxella spp. are highly susceptible to penicillin)
A yellow pigment-producing organism that is oxidase positive, nonmotile, and does not
grow on MacConkey agar is? - ✔✔Chryseobacterium meningosepticum (Oxidase
positive, yellow pigment, and do not grow on Mac agar.)
Which reagent(s) is (are) used to develop the red color indicative of a positive reaction
in the nitrate reduction test? - ✔✔Sulfanilic acid and Alpha-naphthylamine
A culture from an intra-abdominal abscess produced orange-tan colonies on blood agar
that gave the following results:
========================================
