title: In vitro culture technique for Cryptocaryon irritans, a parasitic ciliate of marine teleosts.
abstract: A medium for the in vitro culture of Cryptocaryon irritans, which is an obligatorily parasitic ciliate of marine teleosts and causes 'white spot disease', was developed. The medium consisted of a layer of cultured fish cells (FHM), with an agarose gel layer covering the cell layer. The agarose gel contained 0.22% agarose, 10% fetal calf serum, 100 I.U. ml(-1) Penicillin G potassium and 100 microg ml(-1) streptomycin sulphate. Theronts of C. irritans transformed to trophonts and grew to 180 microm in mean length in the medium, although they gradually decreased in number. When trophonts fully developed in medium were transferred into seawater 4 d after inoculation, approximately 70% of them transformed to encysted tomonts and released theronts. When fish were challenged with theronts obtained from in vitro-raised parasites, approximately 40% of the theronts were recovered from fish, indicating comparative infectivity of in vitro-raised theronts to those of in vivo-raised theronts. This is the first report that C. irritans fully developed in vitro and its entire life cycle was completed without a host fish.
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan. atyoshi@mail.ecc.u-tokyo.ac.jp
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Yoshinaga
authors.forename: Kousuke
authors.initials: K
authors.lastname: Akiyama
authors.forename: Sayoko
authors.initials: S
authors.lastname: Nishida
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Nakane
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ogawa
authors.forename: Hitomi
authors.initials: H
authors.lastname: Hirose
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods / Q000662:veterinary*; D002460:Cell Line; D016798:Ciliophora / Q000166:cytology / Q000254:growth & development* / Q000472:pathogenicity; D016770:Ciliophora Infections / Q000469:parasitology / Q000662:veterinary*; D003470:Culture Media; D003530:Cyprinidae; D004847:Epithelial Cells / Q000166:cytology; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes; D008018:Life Cycle Stages; D011036:Poecilia / Q000469:parasitology; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D003470:Culture Media