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: 1 00 samples of cooked ham, 150 samples of salami, 100 samples of porcin e cheese (artisan cold foods), and 100 samples of mortadella. Enrichme nts 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-Shigell a agar and MacConkey agar. Isolates were identified through biochemica l, serological, and phagotyping methods. The following biovars (B), se rovars (O), and phagovars (Lis) were isolated from cooked ham B2 0:9 L is X 3 (1%), from salami B1 0:5 Lis X(z) and B2 0.9 Lis X3 (1.33%), fr om porcine cheese B2 0:9 Lis X, (2%), and from mortadella (0%). Virule nce tests (calcium dependent growth at 37-degrees-C and autoagglutinat ion activity at 37-degrees-C) were always negative. Serovar B2 0:9 Lis X3 associated with human disease was isolated. It is concluded from t he results of this study that Y. enterocolitica isolates from cold foo ds lack of pathogenic importance.