Biovars, Serovars, and Phagovars of Yersinia enterocolitica Isolated From 450 Samples of Cold Food in San Luis, Argentina.

A search of Yersinia enterocolitica in foods of animal origin has been carried out. Isolates were obtained from 450 samples of cold foods: 100 samples of cooked ham, 150 samples of salami, 100 samples of porcine cheese (artisan cold foods), and 100 samples of mortadella. Enrichments were performed in 0.067 M phosphate buffered saline solutions, pH 7. 6, containing 1% sorbitol and 0.15% biliary salts. The samples were postenriched in 0.5% KOH. Subcultures were done in Salmonella-Shigella agar and MacConkey agar. Isolates were identified through biochemical, serological, and phagotyping methods. The following biovars (B), serovars (O), and phagovars (Lis) were isolated from cooked ham B 0:9 Lis X (1%), from salami B 0:5 Lis X and B 0:9 Lis X (1.33%), from porcine cheese B 0:9 Lis X (2%), and from mortadella (0%). Virulence tests (calcium dependent growth at 37°C and autoagglutination activity at 37°C) were always negative. Serovar B 0:9 Lis X associated with human disease was isolated. It is concluded from the results of this study that Y. enterocolitica isolates from cold foods lack of pathogenic importance.