Protozoa Flashcards
Cystoisospora spp.
Oocyst undergoes sporulation in environment and is infective with 2 sporocysts and 4 sporozoites. Host ingests and each sporozoite invade epithelial cell in intestine. forms a schizont via schizogony which is asexual repro. Merozoite from final schizont undergoes gametogony which produces either male or female. Wall forms around zygote, destroys host cell, leaves in feces. Sporozoites can become tachyzoites or bradyzoites. PPP less than 2 weeks. Causes coccidiosis which is disease of young. Most will get better with no treatment, but can use sulfadimexothine.
Sarcocystis
Gametogony in small intestine of DH, shed infective sporocysts in feces, Schizogony in IH, no treatment in DH.
Toxoplasma gondii
Cats is only DH, any warm blooded animal can be PH. Two life cycles. Enteroepithelial: PPP 3-10 days, only in cats, Schizogony in intestine then gametogony, oocysts in feces only for up to 2 weeks, sporulate in environment 1-5 days and can stay in soil for 8 months. The Extrointestinal cycle: PH ingests infective oocyst, which invade epithelium and enter the circulation, become tachzoites and destroy host cell and cause clinical toxoplasmosis. Can also be infective via badyzoites in tissue in PH.
Are kittens affected by T. gondii and can humans be?
Yes by transp/m, is great imitator for other diseases. Do IgM or IgG titer. No treatment for systemic disease. Humans infected by ingestion of infected tissues of bradyzoites or sporulated oocysts from cat feces, unpasteurized goat’s milk. Congenital is most serious but if woman has titer than fetus will be protected.
Giardia spp
C/D dogs, F cats, has trophozoite and cyst. Ingestion of cyst and trophozoites emerge and attach to small intestinal villa and form a protein coat and encyst. Cysts passed out are infective, PPP is 6-8 days. Cause flatulence, diarrhea. Use ZnSO4 for cyst recovery and Lugol’s iodine. May need to check more than one fecal. Treat with fenbendazole and bathe! Possibly zoonotic
Tritrichomonas foetus
Cats, 3 flagella anteriorly, intestinal lumen, no cyst stage. Transmitted by direct fecal-oral transmission of trophozoites. Chronic diarrhea, flatulence, dribbling. Hard to differentiate from Giardia. Ronidazole only effective.
