The Serological Properties of the Cell Surface Proteins of Vibrio cholerae

Abstract

The serological properties of cell surface proteins of Vibrio cholerae belonging to both the biotypes (classical and El Tor) and the serotypes (Ogawa and Inaba) were investigated. Proteins were isolated by extracting V. cholerae with EDTA in the presence of sodium chloride. The surface localization of these proteins was confirmed with (a) radioiodinated protein A as an immunoprobe and (b) antiserum absorption studies with whole bacteria. There were similarities among the polypeptides of cell surface proteins isolated from various V. cholerae types. Antisera to these proteins agglutinated several V. cholerae strains, irrespective of biotype, serotype and antibiotic sensitivity. The antisera did not agglutinate pathogenic enteric bacteria such as enterotoxigenic Escherichia coli, Salmonella typhi, Shigella spp., Aeromonas hydrophila and Yersinia enterocolitica. The cell surface proteins of V. cholerae were immunogenic in rabbits as high titres of anti-protein specific antibodies were detected by the ELISA technique in the immune sera. These results suggest that the cell surface proteins are common antigens of V. cholerae and can be developed as a potential vaccine candidate against cholera.

Antigens involved in resistance to mucosal association by Vibrio cholerae

“…As reported by others (e.g., Kabir, 1983;Sears et al, 1984), SDS-PAGE separation and immunoblotting indicated that there were physico-chemical and serological similarities among the major monomeric sub-units of OMPs prepared from strains of the common serotypes of V. cholerae. Furthermore, it is obvious that LPS association with a number of these proteins precludes direct assessment of their protective capacity.…”

Temperature-sensitive mutants of Actinobacillus pleuropneumoniae induce protection in mice

“…The sera were treated as previously described (17) to remove antibodies to the LPS. Briefly, 1 ml of serum was mixed with 5 mg of LPS isolated from A. pleuropneumoniae and 0.5% sodium azide.…”

Immunological responses of rabbits to various somatic and secreted antigens of Vibrio cholerae after intra-duodenal inoculation

“…Cell-surface proteins were extracted from V. cholerae cells with EDTA-NaCl as described by Kabir (1983a), Briefly, 2 g (wet weight) of V. cholerae cells was washed twice with cold EDTA-NaCl(5 ml; 0.12 M EDTA, 0.77 M NaCl, pH 7-2). The combined extracts obtained after centrifugation (20 000 9, 30 min) were concentrated by negative pressure dialysis against PBS and again centrifuged for 15 min.…”

“…Its cells possess somatic components that include lipopolysaccharides (LPS) and surface proteins that are immunogenic in man and in experimental animals (Majumdar et al, 1981 ;Kabir, 1982Kabir, , 1983a. V .…”