From Farm to Table: Follow-Up of Shiga Toxin-Producing Escherichia coli Throughout the Pork Production Chain in Argentina.

ROCÍO COLELLO; MARÍA E. CÁCERES; MARÍA J. RUIZ; MARCELO SANZ; ANALÍA I. ETCHEVERRÍA; NORA L. PADOLA

Frontiers in Microbiology

Frontiers Media S.A.

Lugar: Lausanne; Año: 2016 vol. 7 p. 1 - 7

Pigs are important reservoirs of Shiga toxin-producing Escherichia coli (STEC). Theentrance of these strains into the food chain implies a risk to consumers becauseof the severity of hemolytic uremic syndrome. This study reports the prevalence andcharacterization of STEC throughout the pork production chain. From 764 samples,31 (4.05%) were stx positive by PCR screening. At farms, 2.86% of samples were stxpositive; at slaughter, 4.08% of carcasses were stx positive and at boning rooms, 6%of samples were stx positive. These percentages decreased in pork meat ready for saleat sales markets (4.59%). From positive samples, 50 isolates could be characterized. Atfarms 37.5% of the isolates carried stx1/stx2 genes, 37.5% possessed stx2e and 25%,carried only stx2. At slaughter we detected 50% of isolates positive for stx2, 33% forstx2e, and 16% for stx1/stx2. At boning rooms 59% of the isolates carried stx1/stx2,14% stx2e, and 5% stx1/stx2/stx2e. At retail markets 66% of isolates were positivefor stx2, 17% stx2e, and 17% stx1/stx2. For the other virulence factors, ehxA and saawere not detected and eae gene was detected in 12% of the isolates. Concerningputative adhesins, agn43 was detected in 72%, ehaA in 26%, aida in 8%, and iha in6% of isolates. The strains were typed into 14 E. coli O groups (O1, O2, O8, O15,O20, O35, O69, O78, O91, O121, O138, O142, O157, O180) and 10 H groups (H9,H10, H16, H21, H26, H29, H30, H32, H45, H46). This study reports the prevalenceand characterization of STEC strains through the chain pork suggesting the verticaltransmission. STEC contamination originates in the farms and is transferred from pigsto carcasses in the slaughter process and increase in meat pork at boning rooms andsales markets. These results highlight the need to implement an integrated STEC controlsystem based on good management practices on the farm and critical control pointsystems in the food chain.