Microbiology and Parasitology Quiz

Which bacterium is most commonly associated with strep throat?

• Staphylococcus aureus

• Streptococcus pyogenes

• Streptococcus pneumoniae

• Enterococcus faecalis

The best direct diagnosis of Echinococcus granulosus infection in humans is made by identification of

• Eggs in feces

• Adult worms in the intestine

• Adult worms in tissues

• Hydatid cysts in tissues

A Gram-positive, spore-forming rod associated with botulism is:

• Clostridium botulinum

• Bacillus cereus

• Listeria monocytogenes

• Corynebacterium diphtheria

Cysts are the infective stage of which intestinal flagellate?

• Balantidium coli

• Dientamoeba fragilis

• Entamoeba coli

• Giardia lamblia

Which bacterium is acid-fast positive due to mycolic acids in its cell wall?

• Nocardia asteroides

• Actinomyces israelii

• Mycobacterium tuberculosis

• Bacillus anthracis

Many parasites have different stages of growth within different hosts. The host where the sexual reproductive stage exists is called the

• Intermediate host

• Commensal

• Vector

• Definitive host

Escherichia coli O157:H7 is associated with which condition?

• Typhoid fever

• Hemolytic uremic syndrome

• Cholera-like diarrhea

• Scarlet fever

Which of the following is typical in cysts of Iodamoeba bütschlii?

• A glycogen mass

• Four nuclei with large karyosomes

• Blunt chromatoidal bars

• Many ingested bacteria

A positive coagulase test is diagnostic for:

• Staphylococcus aureus

• Staphylococcus epidermidis

• Streptococcus pyogenes

• Streptococcus agalactiae

Which is the most important feature in differentiating cysts of Entamoeba histolytica from E. dispar?

• Number of nuclei

• Size of cyst

• Shape of karyosome

• Distinguishing surface antigens by immunologic assays