Proper media for culture of a urethral discharge from a man include:
D.
A sheep blood agar plate inoculated with 0.001 mL of urine grows 70 colonies of Staphylococcus aureus. How many colony forming units per mL of urine should be reported?
A.
The lowest concentration of antibiotic that inhibits growth of a test organism is the:
D.
Which of the following clean catch urine culture colony counts indicates the patient likely has a urinary tract infection?
D.
The steam autoclave method of sterilization:
C.
The expected colony count in a suprapubic urine from a healthy individual is:
A.
An aspirate of a deep wound was plated on blood agar plates and incubated aerobically and anaerobically. At 24 hours there was growth on both plates. This indicates that the organism is a(n):
A.
The proper blood-to-broth ratio for blood cultures to reduce the antibacterial effect of serum in adults is:
A.
A penicillin-resistant Neisseria gonorrhoeae produces:
D.
Which selective medium is used for the isolation of gram-positive microorganisms?
B.
The most sensitive substrate for the detection of beta-lactamases is:
C.
A Staphylococcus aureus isolate has an MIC of 4 ug/mL to oxacillin. There is uncertainty as to whether this represents an oxacillin (heteroresistant) resistant strain or a hyperproducer of beta-lactamase.
Strain Oxacillin Amoxocillin-clavulanic acid
Strain A Susceptible Susceptible
Strain B Susceptible Resistant
Strain C Resistant Susceptible
Strain D Resistant Resistant
Based on the above results for oxacillin and amoxicillin-clavulanic acid, which strain is heteroresistant:
C.
An Enterococcus isolated from multiple blood cultures in a patient endocarditis should be:
D.
In the Kirby-Bauer disc diffusion susceptibility test, which variable is critical when testing Pseudomonas species for antibiotic susceptibility to aminoglycosides?
B.
The procedure that assures the most accurate detection of mecA-mediated oxacillin resistance in routine broth microdilution susceptibility testing against S aureus is:
B.
When performing a stool culture, a colony type typical of an enteric pathogen is subcultured on a blood agar plate. The resulting pure culture is screened with several tests to obtain the following results:
TSI: Acid butt, alkaline slant, no gas, no H2S
Phenylalanine: Negative
Motility: Positive
Serological typing: Shigella flexneri (Shigella subgroup B)
The serological typing is verified with new kit and controls. The best course of action would be to:
A.
Susceptibility testing performed on quality control organisms using a new media lot number yielded zone sizes that were too large for all antibiotics tested. The testing was repeated using media from a previously used lot number, and all zone sizes were acceptable. Which of the following best explains the unacceptable zone sizes?
D.
Three sets of blood cultures were obtained from an adult patient with fever and suspected endocarditis. The aerobic bottle of one set had growth of Staphylococcus epidermidis at 5 days of incubation. This indicates that:
D.
In order to isolate Campylobacter coli/jejuni, the fecal specimen should be:
A.
An expectorant sputum is sent to the laboratory for culture from a patient with respiratory distress. The gram stain of the specimen shows many squamous epithelial cells (>25/lpf) and rare neutrophils. The microscopic appearance of the organisms present include:
Moderate gram-positive cocci in chains and diplococci
Moderate gram-negative diplococci
Moderate palisading gram-positive bacilli all in moderate amounts
This gram stain is most indicative of:
A.
Which type of microscope would be most useful in examining viruses and the structure of microbial cells?
C.
After satisfactory performance of daily disk diffusion susceptibility quality control is documented, the frequency of quality control can be reduced to:
A.
In disk diffusion susceptibility testing, as an antimicrobial agent diffuses away from the disk, the concentration of antibiotic is:
B.
The most common cause for failure of GasPakTM anaerobic jar to establish an adequate environment for anaerobic incubation is:
C.
Which of the following is the most appropriate method for collecting a urine specimen from a patient with an indwelling catheter?
A.
Which one of the following specimen requests is acceptable?
D.
Which of the following groups of specimens would be acceptable for anaerobic culture?
A.
A liquid fecal specimen from a three-month-old infant is submitted for microbiological examination. In addition to culture on routine media for Salmonella and Shigella, this specimen should be routinely:
D.
Cerebrospinal fluid from a febrile 25-year-old man with possible meningitis is rushed to the laboratory for a stat gram stain and culture. While performing the gram stain, the technologist accidentally spills most of the specimen. The smear shows many neutrophils and no microorganisms. Since there is only enough CSF to inoculate one plate, the technologist should use a:
B.
A diabetic foot swab from a 82-year-old woman with recurrent infections is submitted for culture. The gram stain reveals:
Many neutrophils, no squamous epithelial cells
Many gram-negative bacilli
Many gram-positive cocci in chains
The physician requests that all pathogens be worked up. In addition to the sheep blood and MacConkey agar plates routinely used for wound cultures, the technologist might also process a(n):
C.
Which of the following is the most appropriate specimen source and primary media battery?
A.
Which of the following is the most appropriate organism and media combination?
C.
A gram stain from a swab of a hand wound reveals:
Moderate neutrophils
No squamous epithelial cells
Moderate gram-positive cocci in chains
Moderate large gram-negative bacilli
Select the appropriate media that will selectively isolate each organism.
D.
Upon review of a sputum gram stain, the technician notes that the nuclei of all of the neutrophils present in the smear are staining dark blue. The best explanation for this finding is:
B.
When performing a Kovac indole test, the substrate must contain:
C.
The ONPG test allows organisms to be classified as a lactose fermenter by testing for which of the following?
B.
Sodium bicarbonate and sodium citrate are components of which of the following?
A.
Chocolate agar base containing vancomycin, colistin, anisomycin, and trimethoprim is also known as:
D.
A medium that aids in the presumptive identification of organisms based on their appearance on the medium is called:
B.
SPS is used as an anticoagulant for blood cultures because it:
A.
When evaluating a new susceptibility testing system, if the new system characterizes a susceptible isolate as resistant, this is termed a:
C.
Which of the following methods is inadequate for the detection of vancomycin-intermediate S aureus?
B.
In a disk diffusion susceptibility test, which of the following can result if disks are placed on the inoculated media and left at room temperature for an hour before incubation?
C.
Which of the following factors would make an organism appear to be more resistant on a disk diffusion susceptibility test?
D.
First-generation cephalosporins can be adequately represented by:
D.
An antibiotic that inhibits cell wall synthesis is:
B.
Which one of the following organisms does not require susceptibility testing to the antimicrobial indicated when isolated from a clinically significant source?
A.
Which of the following antibiotics would routinely be tested and reported for isolates of Pseudomonas aeruginosa?
A.
Which of the following must be incubated in a microaerophilic environment for optimal recovery of the organism?
D.
Diagnosis of typhoid fever can be confirmed best by culture of:
D.
Vibrio parahaemolyticus can be isolated best from feces on:
D.
Which of the following media can be used to culture Campylobacter jejuni?
D.
Tests for beta-lactamase production in Haemophilus influenzae:
B.
Media used to support growth of Legionella pneumophila should contain which of the following additives?
A.
The best medium for culture of Bordetella pertussis is:
A.
The best medium for culture of Francisella tularensis is:
C.
The most rapid method for detection of Francisella tularensis is:
A.
When processing throat swabs for a group A Streptococcus culture, the medium of choice is:
C.
The ability to detect oxacillin-resistant Staphylococcus aureus may be enhanced by:
A.
The optimal wound specimen for culture of anaerobic organisms should be:
D.
A 21-year-old patient presents with pharyngitis. A throat swab is collected and submitted for anaerobic culture. This specimen should be:
A.
Anaerobic susceptibility testing is helpful in the management of patients with:
D.
An antibiotic used to suppress or kill contaminating fungi in media is:
D.
Production of beta-lactamase is inducible in which of the following:
D.
A sputum specimen is received for culture and gram stain. The gram stained smear from this specimen is seen in the image (total magnification 100x):
The technologist’s best course of action would be to:
D.
A technologist is reading a gram stain from a CSF and observes many neutrophils lancet-shaped gram-positive diplococci. Which set of chemistry and hematology CSF results would most likely be seen in someone with this type of infection?
CSF results
WBC
Glucose
Protein
A
Increased
Increased
Increased
B
Decreased
Decreased
Decreased
C
Increased
Decreased
Increased
D
Decreased
Increased
Decreased
B.
Refer to the following illustration:
Examine the broth microdilution susceptibility test shown above and determine the MIC for gentamicin.
D.
Which of the following tests is used to monitor bactericidal activity during antimicrobic therapy in cases of endocarditis?
D.
Quality control results for disk diffusion susceptibility tests yield the following results: aminoglycoside zones too small and penicillin zones too large. This is most likely due to the:
C.
When using a control strain of Staphylococcus aureus, the technologist notices that the zone around the oxacillin disk is too small. Which of the following is the most likely explanation?
A.
In the disk diffusion method of determining antibiotic susceptibility, the size of the inhibition zone used to indicate susceptibility has been determined by:
B.
Which of the following organisms may be mistaken for Neisseria gonorrhoeae in gram stained smears of uterine cervix exudates?
C.
A 73-year-old man diagnosed as having pneumococcal meningitis is not responding to his penicillin therapy. Which of the following tests should be performed on the isolate to best determine this organism’s susceptibility to penicillin?
A.
Salmonella enteritidis is isolated from multiple blood cultures in a patient with fever. Susceptibility results are as follows: ampicillin-susceptible, ceftriaxone-susceptible, ciprofloxacin-susceptible, trimethoprim/sulfamethoxazole-resistant. What is the next step?
D.
Which of the following antimicrobials would be inappropriate to report on an E coli isolated from a wound culture?
C.
The susceptibility results below are reported on an Enterococcus faecalis isolated from peritoneal fluid.
Ampicillin:
Susceptible
Vancomycin:
Resistant
Clindamycin:
Susceptible
Levofloxacin:
Resistant
Linezolid:
Susceptible
The physician calls questioning the results. Which of the following should have been done before the report was released?
d. Ciprofloxacin should have been added to the report since levofloxacin was resistant
