SEROLOGY OF CAMPYLOBACTER-FETUS SS JEJUNI (RELATED CAMPYLOBACTERS)

Abstract

Rabbit antisera against 2 strains of Campylobacter fetus (serotype A), 2 strains of C. fetus intestinalis (serotypes A and B, respectively), and 8 stains of C. fetus ssp. jejuni were used in serological studies of these strains with the use of coagglutination (COA), line-rocket immunoelectrophoresis (L-RIE) and rocket-line immunoelectrophoresis (R-LIE). Whole bacterial cells, either heated at 56.degree. C, boiled or autoclaved, were used in COA tests. Unheated sonicates were used in L-RIE, and sonicates, unheated, boiled or autoclaved, in R-LIE. The antigenic properties of C. fetus ssp. fetus and C. fetus ssp. intestinalis were distinctly different from those the thermophilic C. fetus ssp. jejuni strains as shown both by COA and L-RIE. Serotypes A and B of the 2 former spp. were also differentiated. In COA tests the C. fetus ssp. jejuni organisms gave the strongest reactions with homologous antibodies, but several interstrain cross-reactions were seen. By absorption strain, specific COA reagents were obtained. Several reactions of identity indicating cross-reactive antigens were also seen with L-RIE within the ssp. jejuni group. These results generally agreed with those obtained by COA. With the use of unheated, boiled or autoclaved organisms or sonicates, heat labile antigens were differentiated from heat stable ones with the use of COA and R-LIE. The apparent antigenic heterogeneity of campylobacteria indicates the importance of their serological grouping, e.g., for clinical and epidemiological investigations. COA and immunoelectrophoresis techniques can be effectively applied for such studies.