Virulence profile of Escherichia coli O157 strains isolated from surface water in cattle breeding areas

• Autores: Tanaro, J D; Pianciola, Luis; D'Astek, Beatriz A; Piaggio, Mercedes C; Mazzeo, Melina; Zolezzi, Gisela; Rivas, Marta
• Año de publicación: 2018
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Letters in Applied Microbiology 2018; 66(6):484-490.
• Materia: Argentina; Escherichia coli; Linaje de la Célula; Virulencia; Toxina Shiga
• Institución: Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"

Fil: Tanaro, J D. Cátedra de Microbiología, Facultad De Bromatología, Universidad Nacional de Entre Ríos, Gualeguaychú; Argentina.
Fil: Pianciola, Luis. Laboratorio Central, Subsecretaría de Salud de Neuquén, Neuquén; Argentina.
Fil: D'Astek, Beatriz A. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Fil: Piaggio, Mercedes C. Cátedra de Microbiología, Facultad De Bromatología, Universidad Nacional de Entre Ríos, Gualeguaychú; Argentina.
Fil: Mazzeo, Melina. Laboratorio Central, Subsecretaría de Salud de Neuquén, Neuquén; Argentina.
Fil: Zolezzi, Gisela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Fil: Rivas, Marta. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Shiga toxin-producing Escherichia coli (STEC) O157:H7 is a worldwide concern. Cattle are their main reservoir and may contaminate watercourses through manure. We characterized a collection of 38 STEC O157:H7 strains isolated from surface water in feedlots areas (puddles inside pens formed after the rainfall or by spill around drinking troughs, and small water courses and lagoons, formed by runoff). Nineteen (50·0%) strains harboured stx2a /stx2c genes, 18 (47·4%) stx2c and one stx1a /stx2c . All strains harboured eae, ehxA, rfbO157 and fliCH7 genes, and the putative virulence determinants ECSP_0242, ECSP_2687 and ECSP_3620. All isolates tested as Lineage I/II by lineage-specific polymorphism assay-6. Nineteen (50%) belonged to the high virulent clade 8. The q21 allele was found in all strains and q933 /q21 alleles in 17 (44·7%). By XbaI-pulsed-field gel electrophoresis, 29 strains were grouped into seven clusters. Four clusters grouped isolates from distant places separated by 150-250 km. This may be related to vectors, like birds, involved in their spread. Otherwise, three clusters contained isolates recovered at same places with intervals of 1-9 months. This could be explained by the high environmental persistence of STEC O157:H7. These strains recovered from surface water showed similar genotypes to those found in the bovine reservoir and in human diseases, and could be linked to the high incidence of haemolytic uremic syndrome in Argentina.