Presence of Shiga Toxin-Producing (STEC) in Fresh Beef Marketed in 13 Regions of ITALY (2017).

The aim of this study was to determine the prevalence of Shiga toxin-producing in fresh beef marketed in 2017 in 13 regions of Italy, to evaluate the potential risk to human health. According to the ISO/TS 13136:2012 standard, 239 samples were analysed and nine were STEC positive, from which 20 strains were isolated. The STEC-positive samples were obtained from Calabria ( = 1), Campania ( = 1), Lazio ( = 2), Liguria ( = 1), Lombardia ( = 1) and Veneto ( = 3). All STEC strains were analysed for serogroups O26, O45, O55, O91, O103, O104, O111, O113, O121, O128, O145, O146 and O157, using Real-Time PCR. Three serogroups were identified amongst the 20 strains: O91 ( = 5), O113 ( = 2), and O157 ( = 1); the O-group for each of the 12 remaining STEC strains was not identified. Six subtypes were detected: , , , , and . Subtype was the most common, followed by and . Subtype was identified in only one -negative strain and occurred in combination with , and . The presence in meat of STEC strains being potentially harmful to human health shows the importance, during harvest, of implementing additional measures to reduce contamination risk.