[Determination of Vibrio cholerae enterotoxin by the passive immune hemolysis technic]

To determine the antigenic determinants of cholera toxin, the passive immune hemolysis test was used. This test, proved to be highly sensitive (100-200 pg/ml) and specific, yielded results quicker than all other immunological methods for the determination of cholera toxin. The study of 36 cholera and NAG-vibrio strains revealed that V. cholerae synthesized the greatest amount of the toxin, whereas V. eltor formed a heterogenous group, comprising strains capable of synthesizing the toxin in considerable amounts, as well as strains synthetizing no toxin. Some strains of NAG-vibrio were found to produce insignificant amounts of the toxin.