Serological Activity of ‘Bacteroides fragilis’ Endotoxins—Strains Isolated in Poland

Abstract

Antigens were extracted by the phenol‐water method from each of the 11 strains of ‘Bacteroides fragilis’ species, isolated from clinical material. Nine of these strains had been identified by the direct immunofluorescence test (IFT) as ‘B. fragilis spp. fragilis’, and two as ‘B. fragilis ssp. thetaiotaomicrori’. These antigens were then used in the immunodiffusion test (ID), performed with antisera of six serotypes. Results of the ID test agreed in nine cases with those of IFT. An antigenic heterogeneity among strains of ‘B. fragilis ssp. fragilis’ strains was noted. Antigens prepared in the same way from two strains did not react in the ID test with any of the antisera used although cells were positively stained in the IFT by specific anti‐‘B. fragilis’ serotype conjugates.

Crossed Immunoelectrophoresis and Enzyme-linked Immunosorbent Assay of the Cell-surface Antigens of Bacteroides fragilis

“…The antigenic properties of purified lipopolysaccharide (LPS) have also been studied (Hofstad, 1975(Hofstad, , 1977Meizel-Mikolajczyk et al, 1981). All investigations have shown complex patterns of cross-reactions and thus considerable antigenic diversity associated with heat stable antigens.…”