THE ROLE OF PIGS AS PHARYNGEAL CARRIERS OF HUMAN PATHOGENIC YERSINIA ENTEROCOLITICA STRAINS

From March 2007 to January 2008, a total of 170 pigs at slaughter were tested for Y. enterocolitica contamination in tonsils tissue. The animals came from 125 different farms located in four regions of Northern Italy. Y. enterocolitica was isolated from 19 out of 170 (11.2%) tonsils samples. The prevalent bio-serotype (68.4%) was 4/O:3, followed by bioserotypes 1A/O:8 (15.8%), 1A/O:5 (10.5%) and 4/O:8 (5.2%). Among bio-serotype 4/O:3, several strains possessed yadA, ail and ystA virulence genes.