HISTOPATHOLOGICAL EVALUATION OF IN VITRO ICHTHYOPHTHIRIUS MULTIFILIIS CULTURE IN RED KOI (AKA MATSUBA) TISSUE

摘要

In order to develop any effective means of prevention or therapy against Ichthyophthirius multifilis infection, in this project, the in vitro culture of Ichthyophthirius multifilis trophont containing tissue cysts has been developed. This enables researchers to produce antigens and vaccine and to supply pure organisms without any contamination. Healthy Red koi (Aka Matsuba) tail fin and skin were inoculated into tissue culture media, Leibovitz L-15. The trophonts were exposed to tissue culture within 1 hr after removal from the heavily infected Red koi mucus. Twenty-four hours after introduction of trophonts into tissue (skin) culture, most trophonts observed were adjacent to the basement membrane of the epithelial layer of skin. Additionally, higher numbers of mucous cells in the tail fin epithelium were noted 12 h after trophont introduction into culture. The histological sections of the skin of Red koi (Aka Matsuba) revealed large trophonts of the I. multifiliis after 10 days that were prominently lodged in the epidermal layers. In this research, the ability to culture I. multifiliis opens new opportunities to develop vaccines, test drugs, and clone parasites for genome sequencing.