Immunochemical characterisation of Vibrio cholerae O139O antigens and production of a diagnostic antiserum without absorption

Rabbits and mice immunised with chemically extracted O-antigens (O-Ags) of Vibrio cholerae O139 (O-AgB and O-AgD) developed antibodies (Abs) which app eared to be highly specific in ELISA for the relevant antigens and K choler ae O139 strains without absorption, in contrast to the Abs against the heat ed O-Ag (O-AgH), An ELISA test based on the use of these Abs was shown to d etect V. cholerae O139 strains down to concentrations of (9.4 x 10(4))-(7.5 x 10(5)) vibrios/ml and demonstrated no cross-reaction with other vibrios including representatives of serogroup O22, Native and proteinase K-treated O-AgB, O-AgD, O-AgH, as well as whole-cell lysates of K cholerae O139 stra ins of different origin were used in immunoblotting with these Abs, Clear d ifferences in the patterns of zones of specific reaction between chemically extracted and heated O-Ags and between lipopolysaccharide profiles of the C:cholerae O139 strains of different origin were observed. Serogroup-specif ic protein bands in the native O-AgB and O-AgD preparations were defined. T he approach described for obtaining serogroup-specific Abs against vibrios and other bacteria seems to be promising for the development of specific di agnostic tests and further investigation of bacterial antigenic structure.