Comparison of lipopolysaccharide and protein immunogens from pathogenic Yersinia enterocolitica bio-serotype 1B/O:8 and 2/O:9 using SDS-PAGE.

Objective: Yersinia enterocolitica is an extracellular pathogen and its related antigens interact with the host immune system. We investigated the difference in immunological characteristics between a highly pathogenic and poorly pathogenic strain of Y. enterocolitica.

Methods: We used SDS-PAGE and western blotting to characterize lipopolysaccharide (LPS), Yersinia outer membrane proteins (Yops), membrane proteins, and whole-cell proteins from poorly pathogenic Y. enterocolitica bio-serotype 2/O:9, isolated from China, and highly pathogenic bio-serotype 1B/O:8, isolated from Japan.

Results: These two strains of Y. enterocolitica had different LPS immune response patterns. Comparison of their Yops also showed differences that could have accounted for their differences in pathogenicity. The membrane and whole-cell proteins of both strains were similar; immunoblottting showed that the 35 kD and perhaps the 10 kD proteins were immunogens in both strains.

Conclusion: The major antigens of the two strains eliciting the host immune response were the LPS and membrane proteins, as shown by comparing protein samples with reference and purified preparations.