An antibiotic used to suppress or kill contaminating fungi in media is:
B) amphotericin B
A first morning sputum is received for culture of acid fast bacilli. It is digested and concentrated by the Nacetyl L cysteine alkali method. Two Sabouraud dextrose slants are incubated in the dark at 35°C with 5%10%CO . The smears reveal acid fast bacilli, but the slants show no growth after 8 weeks. The explanation is:
C) improper media used
Which of the following reagents is added to detect the production of indole?
B) p Dimethylaminobenzaldehyde
Organisms that should be considered in a waterborne outbreak of diarrheal disease include:
A) Giardia lamblia and Cryptosporidium parvum
What are the most appropriate screening tests to presumptively differentiate and identify the nonfermentative gram negative bacilli from the Enterobacteraciae?
C) Oxidase, TSI, nitrate reduction , growth Correct! on MacConkey agar
A lactose negative, motile, Gram negative rod was isolated from stool. The following tests were inoculated resulting in the following:
A H S (trace)
citrate, urea, VP = ve
Phenylalanine deaminase and arginine dehydrogenase = ve
indole, ornithine and lysine decarboxylase = +ve
Which organism is it likely to be?
a) Edwardsiella tarda
b) Salmonella typhi
c) Proteus mirabilis
d) Yersinia enterocolitica
a) Edwardsiella tarda
Routine laboratory testing for Treponema pallidum involves:
D) Serological analysis
A Gram positive coccus that is B-hemolytic on sheep blood agar and is frequently associated with meningitis in a newborn is most likely:
D) Streptococcus agalactiae
DFA is used for the detection of:
HIV may be diagnosed by
A) All of the above
Biochemically, the Enterobacteriaceae are gramnegativerods that:
A) Ferment glucose, reduce nitrate to nitrite and are oxidase negative.
Kanamycin inhibits bacterial growth by:
D) Interfering with protein synthesis
A 23 year old female is seen by her physician for symptoms of uncomplicated cystitis. A culture of her urine grew a Gram positive coccus, which would most likely be
A) Staphylococcus saprophyticus
Subacute endocarditis is most frequently associated with
A) viridans streptococci
Fecal cultures are inoculated on thiosulfate citrate bile salts sucrose agar specifically for the isolation of
D) Vibrio species
Identify the swarming gramnegativebacillus that can be described as
A) Proteus mirabilis.
The presence of HbsAg, anti HBc and often Hbe Ag is characteristic of:
B) early acute HBV hepatitis
Which of the following are NOT characteristics of group D enterococci:
A) CAMP positive
TSI tubes were inoculated with isolates recovered from a stool specimen. They were incubated at 35°C o/n aerobically. Indicate the appropriate interpretation of the tubes shown. Tube "C" is an uninoculated control; NC = no change.
C) tube 1 K/NC, tube 2 K/A, tube 3 K/A H S, tube 4 A/A Gas
The method most often used to check for a protective immune response (sufficiently high IgG levels) against most childhood viral diseases is
D) Candida albicans
Which Gram negative bacilli produce black pigment and brick red fluorescence when exposed to an UV light source?
D) Prevotella & Porphrymonas
Which of the following could be used for the routine isolation and speciation of yeast?
D) CHROM agar
Colonies of Neisseria sp. turn color when a redox dye is applied. The color change is indicative of the activity of the bacterial enzyme
A) Cytochrome oxidase
The etiologic agent of whooping cough is:
D) Bordetella pertussis
An infant was hospitalized with a severe, tender erythema that started on the face and then spread to the trunk and extremities. The child's epidermis was loose, and large areas of skin could be peeled off, leaving the sensitive underlying dermis exposed. The condition described is most consistent with a clinical syndrome associated with which organism?
B) Staphylococcus aureus
"Chinese letters" best describe which of the following seen on Gram stain?
C) Corynebacterium diphtheriae
In Complement fixation, what are the expected results from the positive and negative control?
B) Positive - no lysis / Negative – lysis
IFA differs from DFA in that:
B) Antibodies to the virus of interest are detected
A single codon is made up of how many nucleotides?
The most common etiologic agent of infections associated with the surgical insertion of prosthetic devices such as artificial heart valves and cerebrospinal fluid shunts is
B) Staphylococcus epidermidis
Rickettsiae infecting man multiply preferentially within which of the following cells?:
Primary amoebicmeningoencephalitis(PAM) may be caused by:
A) Naegleria fowleri
A leg wound culture from a hospitalized 70 year old diabetic man grew motile, lactose negative colonies on MacConkey agar. Given the following biochemical reactions at 24 hours, what is the most probable organism?
H S (TSI) = ve
MR = ve
Phenylalanine deaminase = ve
Ornithine and lysine decarboxylase = +ve
Arginine decarboxylase = ve
Gelatin = +ve
Indole = ve
VP = +ve
DNase = +ve
Urea = ve
D) Serratia marcescens
Flocculation tests for syphilis use antigen composed of:
Which combination of tests can presumptively identify Enterohemorrhagic Escherchia coli (EHEC)?
D) fermentation on MAC and no fermentation on SMAC
Which of the following characteristics would NOT be used to identify Streptococcus species?
IMMUNO vaccination immunoglobulin response
A) All of the above
In which technique is the signal amplified instead of the actual target DNA?
C) branched DNA amplification
Precipitates of diphtheria toxin and antitoxin formed in agar gels are an in vitro means for detecting toxigenic strains of Corynebacterium diphtheriae. The name of this test procedure is the
C) Elek test
The etiologic agent of epidemic relapsing fever is Borrelia recurrentis, which is transmitted by:
A) human body lice
A) Coccidiodes immitis
Most people have antibodies to the following because of previous exposure that caused little or no illness.
A) All of the above
Chocolate agar base containing vancomycin, colistin, nystatin, and trimethoprim is also known as___________ and is used for ______________________
B) modified ThayerMartinagar, cultivation and isolation of Neisseria
The term syncytia is used to describe
D) multinucleated cells formed from the fusion between cells penetrated by virions and other host cells nearby.
Which group of tests differentiates Acinetobacter spp. from Pseudomonas aeruginosa?
C) Oxidase, motility, growth at 42°C
Chlamydia trachomatis produces all the following conditions in adult women EXCEPT:
D) Bacterial vaginosis
The specimen of choice for detecting rotavirus is a
B) stool specimen.
Specimens for Mycobacterium studies that require concentration, decontamination, or liquefaction include
The image shows a smear from a vaginal swab indicating the presence of small rods and clue cells. This indicates bacterial vaginosis due to: