Shiga toxin-producing Escherichia coli in meat and vegetable products in Emilia Romagna Region, years 2012-2013

In 2012-2013 Emilia-Romagna Region introduced a monitoring plan for Shiga toxin-producing Escherichia coil (STEC) in foodstuff. Six hundred eighty-nine meat samples and 273 fruit and vegetable products were analyzed according to ISOTS13136. Pre-enriched samples were tested by multiplex real time PCR targeting the virulence genes eae, Ay! and stx2. Stx2 positive samples were investigated for the presence of serogroup 0104 associated gene. 0103. 0111. 0145, 0157, 026 associated genes were tested on samples positive for stx in association with cue gene. Isolation of E. coli strains was attempted from samples positive for serogroup-associated genes. Thirtyfour meat products (4.9%) resulted positive for stxl and/or stx2 genes and 46 (6.7%) for stxl and/or stx2 genes in association with cue gene. Forty-five (6.5%) samples resulted positive at least at one serogroup. Serogroup 0103, 0104, 0111. 0145, 0157 and 026 genes were detected respectively in 1.3, 0.3, 0.1, 3.9, 2.9 and 2.5% samples; 0.6% samples resulted positive for STEC isolation (2 E coil 0103 and 2 E. coli 0157). It is worth noting that STEC virulence genes were detected at high frequency (19%) in fresh pork meat sausages. Four (1.5%) vegetable samples were positive for stx 1 and/or stx2 genes and 1 (0A%) for stxl and/or stx2 genes in association with cue gene; none resulted positive for the tested serogroups. Only a low number of samples positive by molecular methods were confirmed by cultural isolation. It is therefore of the uttermost importance for appropriate risk management, to be fully aware of the meaning of the analytical result.