Immunization with live aroA recombinant Salmonella typhimurium producing invasin inhibits intestinal translocation of Yersinia pseudotuberculosis.

The Yersinia pseudotuberculosis inv gene encodes invasin, a 103-kDa outer membrane protein that allows bacteria to enter mammalian cells. The gene was subcloned into the attenuated aroA mutant of Salmonella typhimurium SL3261. Invasin was produced by the recombinant Salmonella strain and increased the ability of microorganisms to translocate from the intestinal lumen to the mesenteric lymph nodes. Specific antibodies for invasin were detected in sera and intestinal secretions of mice following oral immunization with the live Inv+ Salmonella strain. The immunization strongly inhibited intestinal translocation of Y. pseudotuberculosis when this pathogen was inoculated to mice but failed to prevent Yersinia dissemination from the gut lymphoid tissue.