Notes on Philippine Medically Important Protozoans Part 2 (Coccidian and Sporozoan) Meccar Moniem Elino, BSBio IV , Davao Doctors College Instructor: Mrs. Chalee Sienes-Reyes, RMT, MSMT, Ph.D

Reference: Philippine textbook of Medical Parasitology 2nd ed.(2004) UP. Edited by Vicente Y. Belizario, Jr. and Winifreda U. de Leon

Trophozoite Cyst Infective

Stage Transmission

Naegleria fowleri

Trophozoite with broad

pseudopods Actively motile

Forms the flagellate stage

Single-walled cyst Does not encyst in tissues

Cyst

penetration in broken skin or

entry thru olfactory

Acanthamoeba

Trophozoite with filamentous

pseudopods Sluggishly motile

Does not form flagellate stage Double-walled cyst

May encyst in tissues

Double-walled cyst May encyst in tissues

Cyst

penetration through

ulcerated or broken skin

Balantidium coli an actively motile ciliate; highly

specialized for reproduction and food intake (cytostome)

a latent survival stage is significant in transmission; infective stage with one

large nucleus cysts

ingestion of contaminated food or drink

with contaminated

water; fecal/oral

Giardia lamblia

flagellate protozoan( 10 x 10 um) having two large nuclei, a large

sucking disc, and many flagella; face - like appearance

slightly smaller the trophozoite with four nuclei and parabasal body

cyst

ingestion of contaminated food or drink

with contaminated

water; fecal/oral

Trichomonas vaginalis only a flagellate trophozoite with

four flagella and undulating membrane

x Trophozoite sexual contact

Cryptosporidium parvum Sporozoan(coccidian) parasite exhibits both asexual(schizogony) and sexual(gametogony) in the brush border of the intestinal epithelium

Oocyts are released from the cells and transmitted

sporulated oocysts

fecal/oral

Cyclospora cayetanensis a sporozoan(coccidian) parasite of the small intestine

asexual and sexual cycle similar to Cryptosporidium but oocysts are larger sporulated

oocysts

ingestion of contaminated food or drink

with contaminated

water; fecal/oral

Toxoplasma gondii

intracellular coccidian(sporozoan) parasite infecting various tissues(systemic) but confined to intestines in felines

infected tissues release pseudocysts containing bradyozoites feline intestines release oocyts containing tachyzoites

Pathogenesis : cellular death due to intracellular muliplication of trophozoites

especially severe in fetal and cerebral tissues

Eat of infected

undercooked/raw meat

Babesia microti The organisms resemble P.falciparum

they vary more in shape and in size; and they do not produce pigment evidence of Maltese cross formation

Bite/Skin

Penetration