ASCP Microbiology 3

Question 1

Viridans streptococci cause which serious infection by colonizing damaged heart valves?

Accepted Answer

Bacterial endocarditis

Answer

Pneumonia

Answer

Meningitis

Answer

Pyelonephritis

Question 2

Which parasite is identified by finding trophozoites with ingested red blood cells in stool?

Accepted Answer

Entamoeba histolytica

Answer

Giardia lamblia

Answer

Cryptosporidium parvum

Answer

Trichomonas vaginalis

Question 3

The KOH preparation of skin scrapings showing hyphae and yeast ('spaghetti and meatballs') is diagnostic of:

Accepted Answer

Tinea versicolor (Malassezia furfur)

Answer

Candida albicans

Answer

Aspergillus fumigatus

Answer

Dermatophyte infection

Question 4

Stool culture for cholera (Vibrio cholerae) uses which selective medium?

Accepted Answer

TCBS (thiosulfate-citrate-bile salts-sucrose) agar

Answer

Blood agar

Answer

MacConkey agar

Answer

XLD agar

Question 5

Which test is used to detect penicillin susceptibility differences between S. pneumoniae isolates?

Accepted Answer

1-µg oxacillin disk diffusion or MIC testing

Answer

Kirby-Bauer disk diffusion with ampicillin

Answer

Oxacillin screen agar

Answer

Beta-lactamase chromogenic test

Question 6

Which organism forms germ tubes when incubated in serum at 37°C for 2–3 hours?

Accepted Answer

Candida albicans

Answer

Candida glabrata

Answer

Candida tropicalis

Answer

Cryptococcus neoformans