ANALYSIS OF THE SUPERANTIGEN-PRODUCING ABILITY OF YERSINIA-PSEUDOTUBERCULOSIS STRAINS OF VARIOUS SEROTYPES ISOLATED FROM PATIENTS WITH SYSTEMIC OR GASTROENTERIC INFECTIONS, WILDLIFE ANIMALS AND NATURAL ENVIRONMENTS

Yersinia pseudotuberculosis is a pathogen causing gastroenteritis as w ell as acute and systemic infections. This organism produces a superan tigenic exotoxin, designated Y. pseudotuberculosis-derived mitogen (YP M). We consider this exotoxin to be the primary pathogen of the system ic type infection. In this study, we examined 101 Y. pseudotuberculosi s strains isolated from various sources, patients with the systemic or the gastroenteric type of infections, wildlife animals and natural en vironments for the presence of the YPM gene and the production of YPM or other related superantigens. We found that all of the strains isola ted from patients with systemic type infection carried the YPM gene an d produced YPM. A certain proportion of the organisms isolated from pa tients with the gastroenteric type infection, wildlife animals or natu ral environments did not carry the YPM gene nor produced superantigens . These results suggest that YPM is involved in the pathogenesis of th e systemic type of Y. pseudotuberculosis infection.