Study of the virulence of Yersinia enterocolitica strains isolated from different food samples in San Luis city

LUCERO ESTRADA CECILIA; DI GENARO SILVIA; VELÁZQUEZ LIDIA; STEFANINI DE GUZMÁN ANA MARÍA

Mendoza

Jornada; XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo. I Reunión de la Don de Invetigación, Ciencia y Técnica dependiente del Ministerio de Salud. Gobierno de Mendoza; 2008

Sociedad de Biolgogía de Cuyo

Virulence of Yersinia enterocolitica results from a complex interplay between a series of chromosomal and plasmid-borne genes. The aim of the present study was to characterize some phenotypic and genotypic virulence markers of Y. enterocolitica strains isolated from food samples in our laboratory. A total of 35 strains of Y. enterocolitica, 33 local strains and 2 reference strains were studied. The following phenotypic tests were performed: autoagglutination (AA), calcium-dependent growth and Congo red absorption (CR-MOX), aesculin hydrolysis (Aes) and pyrazinamidase production (Pyr). Genetic virulence markers were assayed by mukltiplex PCR for detection of virF, ail, myfA and ystA genes. The reference Y. enterocolitica strains pYV (+), as well as 4 Y. enterocolitica 2/O9 strains isolated in our laboratory, showed virulence related phenotype and amplified every tested gene. One 3/O5 strain isolated from pork sausage was AA+ and exhibited the genotype virF+ myfA+ ail+ yst+.One 1A/O:6,30 strain isolated from minced meat was negative for the Aes and Pyr tests. This strain, along with a 1A/O:5 strain isolated from pork sausage, showed a genotype virF- myfA- ail+ yst+.The remaining 25 B1A strains lacked phenotypic and genotypic virulence markers. The presence of potentially virulent strains in pork meat, pork products and other meat foods corroborates the suspicion that they could be the sources of infection with this species bacterium.