Serotyping and the antigens of Vibrio cholerae.

A flagellar antigen common to all strains of Vibrio cholerae was demonstrated and techniques for its detection were established. Anti-flagellar sera agglutinated but did not immobilize cultures of V cholerae. V cholerae, V metschnikovii, V fluvialis and V anguillarum were shown to have minor H antigenic determinants in common, but the major H antigenic determinants were specific to individual species. At least 83 different 0 antigens were found within the species V cholerae. The majority were immunologically distinct and a micro-method for performing 0 typing was developed and used to 0-type cultures of V cholerae, 1,197 cultures of V cholerae isolated from patients and the environment from several different areas of the world were examined. A wide range of different 0 types was found and the epidemiological significance of the findings was studied with particular regard to human gastro-enteritis. 0 typing of V cholerae was found to be highly discriminating compared with the limited discrimination of biotyping and phage-typing. Tests for biological activity showed no exclusive relationship with 0 type. Investigations of the heat-stabiIity of suspensions of V cholerae demonstrated a phenomenon of thermal inactivation of 0 agglutination. This was thought to be due to the blocking of 0 antigenic sites during the early stages of heating by a glyco-proteinaceous complex which was removed by further heating. Three patterns of thermal inhibition of agglutination were found and the patterns were shown to be strain and not serotype related. The separation of the species mimicus from V cholerae was not supported as they appeared to be antigenically indistinguishable. Several batches of V choleras 01 agglutinating anti sera used in diagnostic laboratories were found to be unsatisfactory. A specification for the production and designation of diagnostic agglutinating antiserum was given