Prevalent STEC serotypes isolated from cattle, foods and environment in Argentina

PADOLA, NORA L.; ETCHEVERRÍA, ANALÍA I.; LUCCHESI, PAULA M. A.; KRÜGER, ALEJANDRA; SANZ, MARCELO E.; FERNÁNDEZ, DANIEL; ALONSO, M.P.; POLIFRONI, ROSANA; ARROYO, GUILLERMO H.; PARMA, ALBERTO E.

Amsterdam

Congreso; 8th INTERNATIONAL SYMPOSIUM ON SHIGA TOXIN (VEROCYTOTOXIN)-PRODUCING Escherichia coli; 2012

Comité Internacional

Introduction & Objectives: VTEC is the main aetiological agent of HUS and cattle are the main reservoir of VTEC that is transmitted to humans through contaminated foods, water, direct contact with animals and the environment. Although the serotype more frequently implicated in HUS is O157:H7, there are several other serotypes associated with human infections. Argentina has the highest incidence of HUS (17/100 000 children under 5 years old), and several serotypes have been isolated from human cases in this country: O157:H7, O145:H-, O178:H19, O91:H21 and serogroups as O26, O174, and O111. The aim of this work was to determine the serotypes shared among cattle, foods and environment and assess which are the most prevalent in a collection of VTEC isolated in Argentina. Material & Methods:The isolates came from 4824 samples from cattle, foods (hamburger and minced meat) and environment of farms. From those, 545 were characterized by multiplex PCR to detect vt1, vt2, eae, ehxA and saa and then were serotyped. Results:The prevalent serotypes were O8:H19; O26:H11; O91:H21; O113:H21; O117:H7; O130:H11; O145:H-; O157:H7; O171:H2 and O178:H19, corresponding to 61 % of typable strains. There were serotypes shared between cattle and foods, between cattle and the environment and among cattle, foods and environment. Ninety eight seroytpes (18%) were non-typable Conclusions: The most prevalent serotypes shared among cattle,foods and environment in Argentina have been also isolated from human cases in several countries including our country, and carry virulence profiles that reflect the pathogenic potential of the strains. These results reinforce the idea of using non-selective methods for the diagnosis of VTEC.