Balantidium coli

**Semantic type:** Eukaryote

**Definition:** A species of ciliated intestinal protozoan parasites in the family Balantiididae. Infection occurs by ingestion of a cyst, with the motile trophozoite residing in the large intestine. B. coli is the largest protozoan that infects humans.

**Synonyms:** - BALANTIDIUM COLI - Paramecium coli