Detection of virulence‐associated genes characteristic of intestinal Escherichia coli pathotypes,including the enterohemorrhagic/enteroaggregative O104:H4, in bovines from Germany and Spain |
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| Authors: | Adriana Cabal Lutz Geue Susana Gómez‐Barrero Stefanie Barth Carmen Bárcena Katharina Hamm M.Concepción Porrero Aránzazu Valverde Rafael Cantón Christian Menge Christian Gortázar Lucas Domínguez Julio Álvarez |
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| Affiliation: | 1. VISAVET Health Surveillance Centre, Complutense University, Madrid;2. SaBio‐IREC, National Wildlife Research Institute, CSIC‐Castilla‐La Mancha University, Ciudad Real;3. Friedrich‐Loeffler‐Institut, Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany;4. Microbiology Unit, University Hospital Ramón y Cajal and Institute Ramón y Cajal for Health Research, Madrid;5. Antimicrobial Resistance and Bacterial Virulence Unit associated with the Spanish National Research Council, Madrid, Spain;6. Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA |
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| Abstract: | ![]()
Cattle are reservoirs of enterohemorrhagic Escherichia coli; however, their role in the epidemiology of other pathogenic E. coli remains undefined. 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 was developed. A total of 970 cattle fecal samples were collected in slaughterhouses in Germany and Spain, pooled into 134 samples and analyzed with this tool. stx1, eae and invA were more prevalent in Spanish samples whereas 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 located 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 by this direct approach of VAGs from a novel human pathogenic E. coli strain in cattle samples 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 could be an efficient early‐warning tool for the emergence of zoonotic E. coli in livestock. |
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| Keywords: | Escherichia coli virulence‐associated genes pathotypes O104:H4 |
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