EN
The study has been taken up to collect more data on Yersinia enterocolitica isolated from pigs as the main reservoir and source of infection with strains pathogenic for humans. Bacteriological examinations, bio- and serotyping were conducted on 616 rectal swabs, taken from 308 fattening pigs. Two samples were taken from each animal to determine the ability of Y. enterocolitica to grow under different temperature conditions (warm and cold culture). It has been proven that low temperature constitutes a suitable culture condition. 138 Yersinia enterocolitica strains were isolated (22.40%), most of which (65.22%) were obtained in cold culture and 99.28% included in biotype 3 (one strain belonged to biotype 2). Serotyping yielded a positive result in 107 strains with the diagnostic serum for antigen O:3, in 18 - with the serum for antigen O:9, and 13 strains were determined to be non-typable. The results indicated that asymptomatic infections with Y. enterocolitica strains of the biotypes and serotypes pathogenic for humans are common in pig population.