[Determination of toxigenicity of Escherichia coli and Vibrio cholerae strains by radioimmunologic method].

A solid phase variant of radioimmunoassay has been elaborated for screening toxin-producing strains of E. coli and V. cholerae grown on agar plates. The method is based on the ability of cholera-like toxins to be absorbed on nitrocellulose filters and their further identification with the use of homologous sera and [125I]-A protein from staphylococci. Sensitivity of the method reaches 20 pg. The proposed technique permits identification of intracellular enterotoxin and is aimed at a massive screening of E. coli strains, NAG-vibrios and V. cholerae strains for toxin production.