Morphology and reproductive mode of Blastocystis hominis in diarrhea and in vitro.

The in vitro culture of Blastocystis hominis in Roswell Park Memorial Institute (RPMI) 1,640 medium containing 20% calf serum is described. The morphological and reproductive mode studies of B. hominis in symptomatic patients' faeces and in further RPMI 1,640 medium-cultured samples were undertaken by light microscopy using iodine staining and hematoxylin staining. Three distinct morphological forms, vacuolar, granular and amoeboid, were distinguished in faeces and in vitro cultures. The cystic form was detected in long-term cultures. Five modes of reproduction, namely, binary fission, endodyogeny, plasmotomy, budding and schizogeny were observed.