title: Dynamics of shiga-toxin producing Escherichia coli (STEC) and their virulence factors in cattle.
abstract: Starting at birth, twenty Holstein calves were housed individually, in groups of five and finally in one large freestall while fecal samples were collected weekly for 25 weeks. From each sample, twenty isolates of Escherichia coli were screened for 6 virulence markers including shiga-toxin 1, 2, intimin, enterohemolysin, the fimbrial antigen efa1 and the adhesin saa. Dynamic models of transmission of E. coli were used to model the transmission of different virulotypes between calves and the loss of the same virulotypes from the calves. It was found that, once E. coli encoding shiga-toxins in combination with enterohemolysin were transmitted and established in a calf, they tended to be eliminated less efficiently compared to E. coli without this combination of virulence markers. It was concluded that the presence of certain combinations of virulence markers coincided with persistence of E. coli in the bovine gastrointestinal tract. In addition, the combinations of stx with either eae or ehxA in E. coli have a greater impact on the loss rates than on the transmission rates.
authors.affiliation: Central Veterinary Institute, Wageningen UR, P.O. Box 65, 8200 AB Lelystad, The Netherlands. dopferd@vetmed.wisc.edu
authors.forename: D
authors.initials: D
authors.lastname: Döpfer
authors.forename: L
authors.initials: L
authors.lastname: Geue
authors.forename: S
authors.initials: S
authors.lastname: Schares
authors.forename: B
authors.initials: B
authors.lastname: Mintel
authors.forename: B
authors.initials: B
authors.lastname: Hoffmann
authors.forename: E A J
authors.initials: EA
authors.lastname: Fischer
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D015169:Colony Count, Microbial / Q000662:veterinary; D004197:Disease Reservoirs / Q000662:veterinary; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008137:Longitudinal Studies; D008954:Models, Biological; D060885:Multiplex Polymerase Chain Reaction; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D037521:Virulence Factors