Abstract
Cultures of Vibrio fluvialis and Vibrio furnissii isolated from the environment (40 strains) and diarrheal humans (8 strains) were examined for enterotoxicity and other biological activities. The CHO-K1 cell-elongation factor (CEF) was found in 18 and the cell-killing factor (CKF) in 39 of the 48 strains. CEF produced by two strains of V. fluvialis was appreciably neutralized by anti-cholera toxin serum (ACT) but CKF was not. Live cultures of all the human strains tested (3/3) and some environmental strains (8/16) caused fluid accumulation in rabbit ileal loops; the activity shown with concentrated (×10) filtrate was not neutralized by ACT. Cholera toxin (CT)-like substance was detected by ELISA in 28 of 38 cell-free extracts of V. fluvialis and V. furnissii. The correlation between CEF and CKF was discussed. These results and ELISA suggest that CEF has an immunological relation to CT and is distinct from CKF. None of culture filtrates of the 48 strains causcd fluid accumulation in suckling mice. Most strains had mouse-lethal and hemolytic activities.
