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

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

Amsterdam

Congreso; VTEC 2012 -8th. International Symposium on Shiga Toxin (verocytotoxin) – Producing Escherichia coli Infections.; 2012

Congress Commitee

Prevalent STEC serotypes isolated from cattle, foods and environment in Argentina Padola N.L.1, Etcheverría A.I.1, Lucchesi P.M.A.2, Krüger A.2, Sanz M.E.3, Fernández D.2, Alonso M.Z.2, Polifroni R.2, Arroyo G.H.2, Parma A.E.3 1Facultad Ciencias Veterinarias-UNCPBA-CIC, Dept. of SAMP, Tandil, Argentina, 2Facultad Ciencias Veterinarias-UNCPBA-CONICET, Dept. of SAMP, Tandil, Argentina, 3Facultad Ciencias Veterinarias-UNCPBA, Dept. of SAMP, Tandil, Argentina 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 five 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 w ere characterized by multiplex PCR to detect vt1, vt2, eae, ehxA and saa and then were serotyped. Results: The prevalent serotypes w ere 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 w ere serotypes shared between cattle and foods, between cattle and the environment and among cattle, foods and environment. Ninety eight seroytpes (18%) w ere non-typable (Table 1). Serotype Percentage of strains (%) Virulence profiles (n=447) Cattle Foods Environment O178:H19 13 95 5 0 vt1 vt2 saa ehxA, vt1 vt2 saa ehxA O130:H11 9 93 7 0 vt1 vt2 saa ehxA, vt1 saa ehxA O113:H21 8 86 14 0 vt2 saa ehxA, vt1 vt2 saa ehxA, vt1 eae ehxA, vt2 O26:H11 5 91 0 9 vt1 eae ehxA, vt2 eae ehxA O91:H21 5 95 5 0 vt2 saa ehxA, O171:H2 5 86 14 0 vt2 O117:H7 3 50 50 0 vt2 O145:H- 3 93 0 7 vt1 eae ehxA, vt2 eae ehxA, vt1 eae, vt2 eae O157:H7 3 93 7 0 vt2 eae ehxA O8:H19 2 45 45 10 vt1 vt2 ehxA, vt1 ehxA, vt2 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.