title: Detection of Yersinia spp. in meat products by enrichment culture, immunomagnetic separation and nested PCR.
abstract: The prevalence of Yersinia enterocolitica in meat products was assessed by four methods: cold enrichment in trypticase soy broth (A), enrichment in modified Rappaport broth at 25 °C (B), concentration by immunomagnetic separation (C) and yadA nested PCR (D). Furthermore, the pathogenic potentials of the isolates were established by phenotypic and genotypic tests, and their genomic relationships were determined by pulsed-field gel electrophoresis (PFGE). A total of 238 samples were collected at retail level in the city of San Luis, Argentina, during the period 2007-2008. The highest Yersinia prevalence in meat products was observed by method D (92 positive samples), followed by methods A (13 positive samples) and C (5 positive samples); however, no isolation was obtained by method B. Fourteen Y. enterocolitica and 4 Yersinia intermedia strains were recovered by culture. All Y. enterocolitica 2/O:9 strains gave results related to virulence by phenotypic tests and exhibited the genotype virF(+)myfA(+)ail(+)ystA(+). Two biotype 1A strains showed a genotype virF(-)myfA(-)ail(+)ystA(+)ystB(+). The 14 Y. enterocolitica strains isolated during this work plus one reference strain were separated into 11 genomic types by PFGE. This genomic heterogeneity of the isolates shows the diversity of Y. enterocolitica strains in our region. It is the first time that IMS was used to search Y. enterocolitica strains from naturally contaminated meat products.
authors.affiliation: Microbiología General, Área Microbiología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de los Andes 950, Bloque 1, 1° Piso, 5700 San Luis, Argentina.
authors.forename: Cecilia S M Lucero
authors.initials: CS
authors.lastname: Estrada
authors.forename: Lidia Del Carmen
authors.initials: Ldel C
authors.lastname: Velázquez
authors.forename: Gabriela Isabel
authors.initials: GI
authors.lastname: Favier
authors.forename: María Silvia Di
authors.initials: MS
authors.lastname: Genaro
authors.forename: María Esther
authors.initials: ME
authors.lastname: Escudero
mesh_terms: D000818:Animals; D001118:Argentina; D002417:Cattle; D002645:Chickens; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology / Q000379:methods; D005838:Genotype; D007074:Immunoglobulin G / Q000097:blood; D018189:Immunomagnetic Separation / Q000379:methods*; D008461:Meat Products / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods*; D011817:Rabbits; D013552:Swine; D015008:Yersinia enterocolitica / Q000254:growth & development / Q000302:isolation & purification* / Q000472:pathogenicity
chemical_list: D004269:DNA, Bacterial; D007074:Immunoglobulin G