Part 2 Flashcards
(40 cards)
When cleansing the skin with alcohol and then iodine for the collection of a blood culture, the iodine (or iodophor) should remain in contact on the skin for at least:
A. 10 seconds
B. 30 seconds
C. 60 seconds
D. 5 minutes
C. 60 seconds
What is the purpose of adding 0.025% - 0.050% sodium polyanethol sulfonate (SPS) to nutrient broth media for the collection of blood cultures?
A. Inhibits phagocytosis and complement
B. Promotes formation of a blood clot
C. Enhances growth of anaerobes
D. Functions as a preservative
A. Inhibits phagocytosis and complement
Select the media of choice for recovery of Vibrio cholerae from a stool specimen:
A. MacConkey agar and thioglycolate media
B. TCBS and alkaline peptone water
C. Blood agar and selenite F broth
D. Cycloserine-cefoxitin-fructose agar
B. TCBS and alkaline peptone water
Blood agar plates are ideally prepared with 5% RBCs obtained from:
A. Sheep
B. Horses
C. Humans
D. Dogs
A. Sheep
Cycloserine-cefoxitin-fructose agar (CCFA) is used for the recovery of:
A. Yersinia enterocolitica
B. Yersinia intermedia
C. Clostridium perfringens
D. Clostridium difficile
D. Clostridium difficile
Prereduced and Vitamin K1 supplemented blood agar plates are recommended isolation media for:
A. Mycobacterium marinum and M. avium
B. Bacteroides, Peptostreptococcus and Clostridium spp.
C. Proteus spp.
D. Enterococcus spp.
B. Bacteroides, Peptostreptococcus and Clostridium spp.
Which procedure is appropriate for culture of genital specimens in order to recover Chlamydia spp.?
A. Inoculate cycloheximide treated McCoy’s cells
B. Plate onto blood and chocolate agr
C. Inoculate into thioglycolate broth
D. Plate onto modified Thayer-Martin agar within 24 hours
A. Inoculate cycloheximide treated McCoy’s cells
The Voges-Proskauer (VP) test detects which end product of glucose fermentation?
A. Acetoin
B. Nitrite
C. Acetic acid
D. H2S
A. Acetoin
At which pH does the methyl red (MR) test become positive? A. 7.0 B. 6.5 C. 6.0 D. 4.5
D. 4.5
A positive Simmons citrate test is seen as:
A. Blue color in the medium after 24-hour incubation at 35 oC
B. Red color in the medium after 18-hour incubation at 35 oC
C. Yellow color in the medium after 24-hour incubation at 35 oC
D. Green color in the medium after 18-hour incubation at 35 oC
A. Blue color in the medium after 24-hour incubation at 35 oC
Which of the following reagents is added to detect the production of indole?
A. p-dimethylaminobenzaldehyde
B. MR
C. Bromcresol purple
D. Cytochrome oxidase
A. p-dimethylaminobenzaldehyde
Which genera are positive for phenylalanine deaminase?
A. Enterobacter, Escherichia and Salmonella
B. Klebsiella and Enterobacter
C. Morganella, Providencia and Proteus
D. Proteus, Escherichia and Shigella
C. Morganella, Providencia and Proteus
An isolate of E.coli recovered from the stoll of a patient with severe bloody diarrhea should be tested for what sugar before sending to a reference laboratory for serotyping?
A. Sorbitol
B. Mannitol
C. Raffinose
D. Sucrose
A. Sorbitol
Which genera of Enterobacteriacea are usually nonmotile at 36oC?
A. Shigella, Klebsiella and Yersinia B. Escherichia, Edwardsiella and Enterobacter C. Proteus, Providencia and Salmonella D. Serratia, Morganella and Hafnia
A. Shigella, Klebsiella and Yersinia
Which single test best separates Klebsiella oxytoca from Klebsiella pneumoniae?
A. Urease
B. Sucrose
C. Citrate
D. Indole
D. Indole
A visitor to South America returns with diarrhea, and infection with Vibrio cholerae is suspected. Select the bast media for recovery and identification of this organism.
A. MacConkey Agar
B. Blood Agar
C. TCBS Agar
D. Xylose lysine desoxycholate agar
C. TCBS Agar
What atmosphric condition is needed to recover Campylobacter spp. from specimens inoculated onto a Campy-selective agar at 35-37 oC and 42 oC?
A. 5% O2, 10% CO2, and 85% N2
B. 10% O2, 10% CO2, and 80% 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
A mixture of slender gram-negative rods and coccobacilli with rounded ends was recovered from blood cultures from a patient following root canal surgery. Given the following results after 48 hours, what is the most likely organism? Catalase 0 Oxidase + Lysine decarboxylase 0 Indole 0 Urease 0 X and V requirement 0 Ornithine decarboxylase + Growth on BAP +, with pitting of agar Carbohydrates 0 Growth on MacConkey 0
A. Eikenella corrodens
B. Actinobacillus sp.
C. Cardiobacterium hominis
D. Proteus spp.
A. Eikenella corrodens
Which medium should be used to recover Bordetella pertussis from a nasopharyngeal specimen?
a. Chocolate agar
b. Blood agar
c. MacConkey Agar
d. Bordet-Gengou agar
d. Bordet-Gengou agar
Which media is recommended for the recovery of Brucella spp. from blood and bone marrow specimens?
A. Biphasic Castaneda bottles with Brucella broth
B. Blood culture bottles with Brucella broth
C. Bordet-Gengou agar plates and thioglycolate broth
D. Blood culture bottles with thioghlycolate broth
A. Biphasic Castaneda bottles with Brucella broth
In addition to CO2 requirement and biochemical characteristics, Brucella melitensis and Brucella abortus are differentiated by growth on media containing which two dyes?
A. Basic fuchsin and thionine
B. Methylene blue and crystal violet
C. Carbol fuchsin and iodine
D. Safranin and methylene blue
A. Basic fuchsin and thionine
Which medium is best for recovery of Legionella pneumophila from clinical specimens?
A. Chocolate agar
B. Bordet-Gengou agar
C. New yeast extract agar
D. Buffered charcoal yeast extract agar
D. Buffered charcoal yeast extract agar
The majority of Haemophilus influenzae infections are caused by which of the following capsular serotypes?
A. a
B. b
C. c
D. d
B. b
Which Haemophilus sp. is difficult to isolate and recover from genital ulcers and swollen lymph nodes?
A. H. aphrophilus
B. H. haemolyticus
C. H. ducreyi
D. H. parahaemolyticus
C. H. ducreyi
