Detection and survival of Yersinia enterocolitica in goat cheese produced in San Luis, Argentina

VALERIA LAZARTE OTERO; CECILIA LUCERO ESTRADA; GABRIELA ISABEL FAVIER; LIDIA VELÁZQUEZ; MARÍA ESTHER ESCUDERO; ANA MARÍA STEFANINI DE GUZMÁN

JOURNAL OF FOOD SAFETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 30 p. 982 - 995

0149-6085

Detection limits and the survival of Yersinia enterocolitica in goat cheese were determined by culture and by nested polymerase chain reaction (PCR). Thirty goat cheese samples inoculated with 104 to 101 cfu/g Y. enterocolitica O:9 or O:3 strains were enriched for 0, 3 and 18h in trypticase soy broth (TSB), modified Rappaport broth and a formulated in our laboratory broth (FLB). The lowest detection limits were 1 x 103 cfu/g by culture on Mac Conkey agar after 3 h TSB and FLB enrichments, and 1 x 102 cfu/g by nested PCR at 3 h from all enrichment broths. Y. enterocolitica survival was studied in 20 goat cheese samples contaminated at levels of 1 x 106 cfu/g and stored at 4° and 22°C for 120 days. Y. enterocolitica was detected during 7 and 30 days at 22 and 4°C, respectively. Total and fecal coliforms were recovered from microflora of goat cheese, but indigenous Y. enterocolitica was not detected.