Blastocystis/Pythium/Entamoeba/Acanthamoeba

T/F: Blastocystis hominis is not a zoonotic disease.

False

Upon cyst ingestion, there is an infection of epithelial cells, after which the organism takes on two forms. What are they? (B. hominis)

Multivacular and amoeboid

How is B. hominis spread?

Unclear how it spreads, however, infection rate seems to be linked to.. consuming contaminated water close contact with infected animals.

What form of Blastocystis is passed in the feces?

Cysts

Why do certain anti-fungal treatments not seem to work against Pythium?

It’s not a true fungus… they lack ergosterol in their cell membranes, and their cell walls are composed of beta-glucan rather than chitin.

T/F: P. insidiosum is naturally a parasite of humans and animals.

False… it is naturally a parasite of plants. However, it appears to be capable of becoming a facultatively parasitic protist of vertebrates.

T/F: The motile form (biflagellated zoospores) is the form that moves between plants. *(P. insidiosum)

True

Zoospores of P. insidiosum have little to no effect on the host.

False, they extend highly invasive hyphae into the host tissue and are capable of causing fatal infection.

What are some clinical signs of infection for P. insidiosum?

Subcutaneous pythiosis.. Granular skin masses

Gi pythiosis.. Vomiting, diarrhea, weight loss, mesenteric lymphadenopathy, mucosal ulceration

Rapidly fatal if untreated

Treatment of P. insidiosum includes….

All treatments are correct

What organ system is impacted by the infection of E. histolytica?

Principally a parasite of the large intestine that causes amoebic dysentery in humans.

T/F: Can dogs serve as a host for E. histolytica.

True. Occasionally in some areas.

Parasitic form of Entamoeba histolytica?

trophozoites. When recovered from feces, they display amoeboid motion.

*Trophozoites are more likely to be found in liquid feces, whereas cysts are more commonly found in formed feces.

How do you treat E. histolytica?

Metronidazole

Does Acanthamoeba have a flagelated form?

NO, this lack of motility causes chronic amoebic encephalitis and acanthamoebic keratitis.

What organ is most commonly affected by infection of Acanthamoeba?

The eyes