8.4 Miscellaneous and Fastidious Gram - Rods Flashcards
A visitor to South America who returned with diarrhea is supected of being infected with V. cholerae. Select the best medium for recovery and identification of this organism.
A. MacConkey agar
B. Blood agar
C. TCBS agar
D. XLD agar
C. TCBS agar
A curved gram-negative rod producing oxidase-positive colonies on blood agar was recovered form a stool culture. Given the following results, what is the most likely identification?
-Lysine decarboxylase=+
-Indole=+
-VP=Neg
-Urease=+/-
-TCBS=Green colonies
-Arginine decarboxylase=Neg
-KIA=Alk/Acid
-Lactose=Neg
-String test=Neg
A. Vibrio cholerae
B. Vibrio parahaemolyticus
C. Shigella spp.
D. Salmonella spp.
B. Vibrio parahaemolyticus
A gram-negative S-shaped rod recovered form selective media for Campylobacter species gave the following results:
-Catalase=+
-Motility=+
-Growth at 42C=+
Grape odor=Neg
-Oxidase=+
-Hippurate hydrolysis=+
-Nalidixic acid=Susceptible
-Pigment=Neg
-Cephalothin=Resistant
The most likely identification is
A. Pseudomonas aeruginosa
B. Campylobacter jejuni
C. Campylobacter fetus
D. Pseudomonas putida
B. Campylobacter jejuni
Which atmospheric condition is needed to recover Campylobacter sp.. from specimens inoculated onto a Campy-selective agar at 35C-37C and 42C?
A. 5% O2, 10% CO2, and 85% N2
B. 20% O2, 10% CO2, and 70% N2
C. 20% O2, 20% CO2, and 60% N2
D. 20% O2, 5% CO2, and 75% N2
A. 5% O2, 10% CO2, and 85% N2
Which group of tests best differentiates Helicobacter pylori and C. jejuni?
A. Catalase, oxidase, and Gram stain
B. Catalase, oxidase, and nalidixic acid sensitivity
C. Catalase, oxidase, and cephalothin sensitivity
D. Urease, nitrate, and hippurate hydrolysis
D. Urease, nitrate, and hippurate hydrolysis
Which of the following test should be done first in order to differentiate Aeromonas spp. from the Enterobacteriaceae?
A. Urease
B. OF glucose
C. Oxidase
D. Catalase
C. Oxidase
Which is the best rapid test to differentiate Plesiomonas shigelloides form a Shigella species on selective enteric agar?
A. Oxidase
B. Indole
C. TSI
D. Urease
A. Oxidase
Which are the best two tests to differentiate A. hydrophilia from P. shigelloides?
A. Oxidase and motility
B. DNase and VP
C. Indole and lysine decarboxylase
D. Growth on MacConkey and blood agar
B. DNase and VP
Which genus (in which most species are oxidase and catalase positive) of small gram-negative coccobacilli is associated mainly with animals but may cause endocarditis, bacteremia, as well as wound and dental infections in humans?
A. Actinobacillus
B. Pseudomonas
C. Campylobacter
D. Vibrio
A. Actinobacillus
Which of the following tests may be used to differentiate Cardiobacterium hominis from Actinobacillus spp.?
A. Gram Stain
B. Indole
C. Anaerobic incubation
D. Oxidase
B. Indole
A mixture of slender gram-negative rods and coccobacilli with rounded ends was recovered from blood cultures following a patient’s root canal surgery. Given the following results after 48 hours, what is the most likely organism?
-Catalase=Neg
-Urease=Neg
-Oxidase=+
-Indole=Neg
-Ornithine decarboxylase=+
-Lysin decarboxylase=+
-X and V requirement=Neg
-Carbohydrates=Neg (no acid produced)
-Growth on blood and chocolate agar=+ (with pitting of agar)
-Growth on MacConkey agar=Neg
A. Eikenella corrodens
B. Actinobacillus spp.
C. Cardiobacterium hominis
D. Proteus spp.
A. Eikenella corrodens
Kingella kingae can best be differentiated from Eikenella corrodens using which medium?
A. Sheep blood agar
B. Chocolate agar
C. MacConkey agar
D. XLD agar
A. Sheep blood agar
Kingella kingae is usually associated with which type of infection?
A. Middle ear
B. Endocarditis
C. Meningitis
D. Urogenital
B. Endocarditis
Cultures obtained form a dog bite wound produced yellow, tan, and slightly pink colonies on blood and chocolate agar with a margin of fingerlike projection appearing as a film around the colonies. Given the following results at 24 hours, which is the most likely organism?
-Oxidase=+
-Growth on MacConkey agar=Neg
-Catalase=+
-Motility=Neg
A. Actinobacillus spp.
B. Eikenella spp.
C. Capnocytophaga spp.
D. Pseudomonas spp.
C. Capnocytophaga spp.
Smooth gray colonies showing no hemolysis are recovered from an infected cat scratch on blood and chocolate agar but fail to grow on MacConkey agar. The organisms are gram-negative pleomorphic rods that are both catalase and oxidase positive and strongly indole positive. The most likely organism is:
A. Capnocytophaga spp.
B. Pasteurella spp.
C. Proteus spp.
D. Pseudomonas spp.
B. Pasteurella spp.
Which media should be used to recover Bordetella pertusis from a nasopharyngeal specimen?
A. Chocolate agar
B. Blood agar
C. MacConkey agar
D. Bordet-Gengou agar
D. Bordet-Gengou agar