首页 | 本学科首页   官方微博 | 高级检索  
     


Prevalence of Shiga toxin-producing Escherichia coli in food products of animal origin as determined by molecular methods
Authors:Rantsiou Kalliopi  Alessandria Valentina  Cocolin Luca
Affiliation:Dipartimento di Valorizzazione e Protezione delle Risorse Agroforestali, Facoltà di Agraria, Università di Torino, Italy. kalliopi.rantsiou@unito.it
Abstract:In this study we report on the prevalence and distribution of Shiga toxin-producing Escherichia coli (STEC) in food products of animal origin, collected in the Piedmont region of Italy, as determined by a combination of quantitative PCR (qPCR) protocols, applied directly to the samples, and of culture-dependent isolation and subsequent molecular identification and characterization of isolates. The qPCR protocols were developed and optimized in this study and targeted the rpoB gene (as a marker for total E. coli) and the stx?, stx? and eaeA genes (as markers for potentially virulent E.coli). They were then used to test for STEC in 101 food samples, before and after enrichment. A STEC prevalence of 42% (21/50) for dairy products and 70% (36/51) for meat products was obtained. A total of 54 STEC isolates were recovered from dairy and meat samples, resulting in a prevalence of 36% and 27% in dairy and meat products, respectively, by the culture method. A large number of strains carried the stx? gene (39 out of the 54 STEC strains) compared to strains that carried stx? (30 out of 54); only 11 out of 54 strains contained the eaeA gene, while 14 strains contained both stx? and stx?. Eight of the 54 isolates belonged to the O157 serogroup, and none belonged to serogroups O26, O145, O111 or O103. Strains isolated from meat products were diverse, as determined by Enterobacterial repetitive intergenic consensus-PCR (ERIC), while those isolated from dairy products were more similar and grouped together by cluster analysis. The results of the qPCR approach showed a high prevalence of STEC in dairy and meat based products, mainly fermented, indicating a possible safety risk for these types of food commodities.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号