Exam 46: Intestinal Protozoa

An intestinal protozoan appeared 8 µm in diameter with a small,compact,centrally located karyosome.Four nuclei were observed in the mature cyst.The organism can be identified as:

The polar tubule,which is responsible for the entrance of infective sporoplasm into the host cell,is found in which of the following genera?

This flagellate is pear-shaped with "falling leaf" motility.It contains variant-specific surface proteins (VSPs)on its surface,which provide a mechanism for the organism to survive in the small intestine as a result of its ability to resist intestinal proteases.The organism is:

The cyst form of Balantidium coli is the infective stage.It has one large kidney-shaped macronucleus and one small,round micronucleus.The troph is quite large,measuring 50 to 150 µm in length and 40 to 70 µm in width.What single feature is associated with this organism?

Outbreaks of infection with the organism Cyclospora are linked to contaminated raspberries,lettuce,and snow peas.The stain of choice to identify the oocysts in stool samples is:

When cooking meat,an internal temperature of ____°C must be reached to kill organisms such as Toxoplasma and Sarcocystis.

Which of the following intestinal protozoa has no cyst stage,ranges from 9 to 12 µm in diameter,and has two nuclei in 60% of clinical specimens?

The drug of choice for the parasite Blastocystis hominis,which is believed to produce proteases and is considered a virulence factor responsible for its pathogenesis,is:

Which of the following flagellates has a single nucleus in the cyst and the typical curved,cytostomal fibril,which is called a shepherd's crook?

A patient is diagnosed with a severe intestinal disease caused by E.histolytica.Which of the following treatments should be administered?

A tissue sample is sent to the laboratory and microscopically examined for the presence of amebae.To differentiate between the host cells and the organism,_______ stain is used to allow the organisms to appear bright pink with a green-blue background.

The organism Sarcocystis has an obligatory two-host life cycle-an intermediate host and definitive host.The sporocysts found in a stool specimen,which measure 9 to 16 µm,are broadly oval with slightly ___________ ends.

Asexual amplification,called merogony,is associated with the life cycle of which organism?

A patient has amebic colitis.A microscopic examination reveals the following: ·18 µm in diameter ·Fine granules ·Centrally located karyosome ·Cytoplasm with a "ground-glass" appearance ·RBC inclusions This protozoan can be identified as:

The peripheral chromatin,which contains fine granules that are uniform in size and are evenly distributed,can be found in which one of the following protozoa?

Which of the following nonpathogenic protozoa has a very large glycogen vacuole in its cyst form and measures approximately 5 to 20 µm in diameter?

Highly active antiretroviral therapy (HAART)is the most effective prophylaxis and treatment in patients with acquired immunodeficiency syndrome (AIDS)with which type of infection?

E.coli,a protozoan that ranges from 15 to 25 µm in diameter,can contain up to eight nuclei in mature cysts.How would the karyosome expect to appear on a stained slide?

The Cystoisospora belli organism,which contains two sporocysts with four sporozoites each,is recovered from fecal specimens and has also been implicated in traveler's diarrhea.The drug of choice to treat infection caused by C.belli is: