PROTOZOA

Protozoa

Eukaryotic, unicellular microorganisms known for independent motility, typically heterotrophic, some photosynthetic (e.g. Euglena), found in moist environments, with parasitic and free-living forms.

Trophozoite

The free-living, vegetative form of a protozoan, often active and motile.

Cyst

Resting, protective form of protozoa resistant to harsh conditions, analogous to bacterial spores.

Phylum Mastigophora

Protozoa with one or more flagella, reproduce mainly by fission, jerky movement is characteristic.

Euglena gracilis

Flagellated protozoan with chlorophyll, capable of photosynthesis, considered both alga and protozoan.

Giardia lamblia

Causes giardiasis—intestinal distress, flatulence, abdominal distention.

Trichomonas vaginalis

Causes trichomoniasis, a sexually transmitted disease.

Trypanosomes

Hemoflagellates transmitted via vectors, cause diseases like sleeping sickness and Chagas disease.

Trypanosoma brucei

Causes sleeping sickness, transmitted by tse tse fly

Trypanosoma cruzi

Causes Chagas disease

Leishmania donovani

Causes kala-azar or black disease, transmitted by sand fly.

Phylum Sarcodina (Rhizopoda)

Amoeboid protozoa that move by pseudopodia, reproduce asexually by fission.

Entamoeba histolytica

Causes amoebic dysentery, forms tissue-destroying lesions, spreads via contaminated water.

Entamoeba gingivalis

Found in the mouth, can cause gingivitis.

Entamoeba coli

Non-pathogenic protozoan inhabiting the human colon.

Acanthamoeba

Free-living amoeba,causes eye-threatening corneal ulcers, transmitted via contaminated lens solution.

Naegleria fowleri

Causes primary amoebic meningoencephalitis, found in fresh water, usually fatal.

Phylum Ciliophora

Ciliated protozoa, have macronucleus and micronucleus, reproduce via conjugation and binary fission.

Paramecium

Ciliated protozoan, known for conjugation and genetic exchange.

Balantidium coli

Largest human protozoan parasite, causes bloody diarrhea and ulceration similar to amoebic dysentery.

Phylum Apicomplexa (Sporozoa)

All parasitic protozoa, no locomotion in adult form

Cryptosporidium parvum

Apicomplexan pathogen causing gastrointestinal illness.

Toxoplasma gondii

Causes toxoplasmosis, particularly severe in immunocompromised patients.

Plasmodium species

Cause malaria

Plasmodium falciparum

Causes most severe form of malaria, transmitted by Anopheles mosquitoes.

Plasmodium malariae

A species of malaria-causing protozoa in humans.

Plasmodium vivax

Another human malaria parasite, known for relapsing infections.

Plasmodium ovale,

Human malaria parasite with relapsing fever episodes.

Phylum Microsporodia

Spore-forming unicellular parasites, now classified as fungi or closely related, infect animals including humans.

Pneumocytis carinii

Cause of sometimes-lethal pneumonia in AIDS patient, over half the deaths known to be associated with AIDS.