Production and Characterization of Cholera toxin-like Enterotoxin by a Non-Ol Vibrio cholerae Isolated from Food

HIN-CHUNG WONG AND JUI-HSI WENG

Department of Microbiology, Soochow University, Taipei, Taiwan , R.O.C.

ABSTRACT

   Non-O1 V.cholerae caused small localized outbreaks of diarrhoeal diseases and produced cholera toxin-like enterotoxins, heat-stable enterotoxins and thermostable direct hemolysin-like hemolysins. In this paper, we reported on the production of a cholera toxin-like enterotoxin of a non-01 strain isolated from food in Taiwan and the bioactivity and thermostability of this toxin. Production of toxin was optimum by stationary culture in casamino acid yeast extract lincomycin medium incubated at 30℃. This toxin was heat-labile and its cytotonic activity as assayed by Chinese hamster ovary cell was neutralized by anti-cholera toxin antiserum. However, this toxin failed to produce lines of identity with the anti-cholera toxin antiserum in a double gel diffusion assay.

Key words : Cholera toxin, enterotoxin, Vibrio cholerae, food