[Nonculturable forms of Yersinia pseudotuberculosis in the soils of a natural focus of pseudotuberculosis].

Soil samples taken from the natural focus of pseudotuberculosis, characterized by the persistent presence of Y. pseudotuberculosis, were studied. Bacteria were detected by means of polymerase chain reaction with the use of 2 test systems; one of them was specific to the chromosomal invasiveness gene (inv) and the other, to gene yopA, localized on plasmid pCad. In 10 out of 24 sample of genetic material of the total soil microflora, Y. pseudotuberculosis gene inv was detected, two of these samples being also containing gene yopA. The calculated concentration of Y. pseudotuberculosis varied 10(2)-10(4) microbial cells per 1 g of soil. Bacteriological studies yielded negative results, which is indicative of the existence of Y. pseudotuberculosis in the soil of the natural focus in the nonculturable form.