A Rapid Visual Test to Characterize Cholera Vibrios

In an enzymatic reaction it was observed that lysates of Vibrio cholerae serovar 01 from human origin produced a reversal of the redox indicator while lysates of V. cholerae non-01 serovar, and 01 serovar isolated from the environment in cholera-free areas did not produce such change. This observation was utilized in a rapid visual test (RVT) which may be useful in the identification of cholera vibrios. There seems to be no correlation between RVT positives and toxin production. The composition of the media seems to be a major factor affecting the outcome of the test. The mechanism of the reaction is under study. Preliminary observations suggest participation of the oxidase system of V. cholerae , atmospheric oxygen and perhaps selective action of Triton X-100.