Detection of virulence-associated genes characteristic of intestinal Escherichia coli pathotypes, including the Enterohemorrhagic / Enteroaggregative O104:H4 in bovines from Germany and Spain
Investigation published in Microbiology and Immunology
August 1st, 2015
Cattle are reservoirs of Enterohemorrhagic Escherichia coli but their role in the epidemiology of other pathogenic E. coli remains undefined. We describe a new set of quantitative real-time PCR assays for the direct detection and quantification of nine virulence associated genes (VAGs) characteristic of the most important human E. coli pathotypes and four serotype-related genes (wzxO104 , fliCH4 , rbfO157 , fliCH7 ) that can be used as a surveillance tool for detection of pathogenic strains. A total of 970 cattle fecal samples were collected in slaughterhouses from Germany and Spain and 134 pooled samples and analyzed with this tool. Results showed that stx1, eae, and invA were more prevalent in Spanish samples while bfpA, stx2, ehxA, elt, est, and the rbfO157 /fliCH7 combination were observed in similar proportions in both countries. Genes characteristic of the hybrid O104:H4 strain of the 2011 German outbreak (stx2/aggR/wzxO104 /fliCH4 ) were simultaneously detected in six fecal pools from one German abattoir, near the outbreak epicenter. Although no isolate harboring the full stx2/aggR/wzxO104 /fliCH4 combination was cultured, sequencing of the aggR positive PCR products revealed 100% homology to the aggR from the outbreak strain. Concomitant detection of VAGs from a novel human pathogenic E. coli strain in cattle samples by this direct approach implies that the E. coli gene pool in these animals can be implicated in de novo formation of such highly-virulent strains. The application of this set of qPCRs in surveillance studies can be an efficient early-warning tool for the emergence of zoonotic E. coli in livestock
Cabal A., Geue L., Gomez S., Barth S., Barcena C., Hamm K., Porrero MC., Valverde A., Canton R., Menge C., Gortazar C., Dominguez L. and Alvarez J..
Servicio de Zoonosis de Transmisión Alimentaria y Resistencia a Antimicrobianos (ZTA). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). | |
Sanidad y Biotecnología (SaBio). Instituto de Investigación en Recursos Cinegéticos (IREC). Consejo Superior de Investigaciones Científicas (CSIC). Universidad de Castilla La Mancha (UCLM). Gobierno de Castilla-La Mancha (JCCM). | |
Institute of Molecular Pathogenesis. Friedrich Loeffler Institut-Bundesforschungsinstitut fuer Tiergesundheit (FLI). | |
Hospital Universitario Ramón y Cajal. Consejería de Sanidad. Comunidad de Madrid. | |
Unidad asociada de Resistencia a Antibióticos y Virulencia Bacteriana. Consejo Superior de Investigaciones Científicas (CSIC). | |
Department of Veterinary Population Medicine. College of Veterinary Medicine. University of Minnesota (UMM). | |
Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS). Universidad Complutense (UCM). Universidad Autónoma de Madrid (UAM). Universidad de Alcalá (UAH). Salud Madrid. Comunidad de Madrid. | |