[Analysis of a Yersinia enterocolitica isolated from human diarrheic feces in Argentina]

Some serotypes of Yersinia enterocolitica might cause diarrheas and/or invasive infections. The aim of this work was to analyze virulence factors and associated markers in a strain of Y. enterocolitica isolated from human diarrheic feces. The strain analyzed was included in the biotype 1A. The virulence markers determination as well as the search of the genes vir F and ail, were negatives. However, it was demonstrated enterotoxin production at 20 degrees C, and at 37 degrees C in osmolarity conditions and pH similar to the human intestine. The enterotoxin presented reactivity for the infant mouse test, although it could not be proven the presence of yst gene by PCR. The results obtained by us, coincident with those of other investigators, indicated that certain clinical isolates of Y. enterocolitica of the biotype 1A ("avirulent"), could be the etiological agent of the illness through other mechanisms of virulence, that would differ from those previously characterized in species of enteropathogenic Yersinia.