Immunochemical studies on the lipopolysaccharides of Bordetella pertussis

Abstract

Lipopolysaccharide (LPS) was extracted from three Phase I strains (18334, 1494, and 134) and one Phase IV strain (11615) of B. pertussis. LPS was also obtained from ATCC 190 and NCTC 8632 which are listed as B. pertussis Phase IV but proved to be Lophomonas sp. and Brucella melitensis type 1. Chromatographic studies and chemical analysis revealed that all four B. pertussis LPS contained hexosamine, heptose, and hexose.The antigenic structure of the extracted LPS was studied by the techniques of passive immune lysis, lysis inhibition, and Ouchterlony immunodiffusion using homologous and heterologous rabbit antisera. The four B. pertussis LPS possessed at least six antigenic determinants. Four of these, designated A, C, E, and F, were found only in LPS of strains 18334 and 1494 (Phase I). Determinant D was found only in strain 134 (Phase I) and strain 11615 (Phase IV). All four strains of B. pertussis shared a sixth determinant, B. Antigen C was shared with the LPS of Lophomonas sp. (ATCC 190) and antigen F with the LPS of Brucella melitensis (NCTC 8632).There was no close correlation between the pattern of antigenic determinants on the LPS and other properties of B. pertussis, such as growth characteristics and possession of the protective antigen and the histamine-sensitizing factor.