EN
Pathogenicity of Yersinia enterocolitica in vitro was determined simultaneously by means of three tests: production of piramidaze at 30°C, autoagglutination at 37°C and inhibition of growth on MOX agar medium plate at 37°C. The strains were collected from diseased people, a dead chinchilla and from healthy pigs and foxes after their slaughter. The findings showed that the test for piramidase production proved to have better usefulness to distinguish pathogenic strains from apathogenic ones. Pigs in contrast to foxes were found to be the reservoir of Yersinia enterocolitica strains pathogenic for man.