Production of vibrio El Tor toxin in a liquid medium.

Watanabe, Yoshikazu (U. S. Army Medical Center, Japan), and Oscar Felsenfeld. Production of vibrio El Tor toxin in a liquid medium. J. Bacteriol. 82:43-47. 1961.-High toxin titers (as measured by mouth lethality and hemolytic activity) were obtained from culture supernatants of strains of El Tor vibrio isolated from patients in Indonesia. Cultivation of the organism in vitro revealed that the concentration of ferrous ion in the medium was critical for the production of maximal yields of toxin. Toxins produced under appropriate conditions were antigenic in rabbits and produced antibodies capable of neutralizing both the hemolytic and lethal actions in multiple proportion. Suggestive evidence has been obtained that the hemolytic and lethal toxins may be separate molecules.