title: Virulence factors associated with Escherichia coli present in a commercially produced competitive exclusion product.
abstract: In this study, we assessed the pathogenic potential of Escherichia coli associated with a commercial competitive exclusion (CE) product by examining the phenotypic characteristics associated with E. coli virulent for humans and domestic animals. Most E. coli isolates were capable of proliferating in iron-deplete chicken sera. Interestingly, none of the E. coli isolates from the commercial CE product contained the bacterial adhesin Tsh characteristic of avian pathogenic E. coli associated with airsacculitis and colisepticemia. In terms of virulence potential for humans, most E. coli isolates (78%) were sensitive to killing by 12.5% human sera. Because of their sensitivity to human sera, the E. coli in the CE product are not likely to cause a serious systemic infection in humans and, therefore, do not present a risk of causing septicemia in humans. Because these isolates also lack the gene tsh, they are also less likely to cause systemic disease or airsacculitis in poultry than pathogenic strains commonly isolated from diseased birds.
authors.affiliation: Department of Avian Medicine, College of Veterinary Medicine, The University of Georgia, Athens 30602, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Maurer
authors.forename: Charles L
authors.initials: CL
authors.lastname: Hofacre
authors.forename: Richard E
authors.initials: RE
authors.lastname: Wooley
authors.forename: Penelope
authors.initials: P
authors.lastname: Gibbs
authors.forename: Robrecht
authors.initials: R
authors.lastname: Froyman
mesh_terms: D018830:Adhesins, Escherichia coli / Q000096:biosynthesis; D000400:Air Sacs / Q000382:microbiology; D000818:Animals; D002645:Chickens; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D005506:Food Contamination; D006388:Hemagglutinins / Q000096:biosynthesis; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D010641:Phenotype; D011201:Poultry Diseases / Q000382:microbiology*; D011202:Poultry Products / Q000382:microbiology*; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000662:veterinary; D012307:Risk Factors; D017262:Siderophores / Q000032:analysis / Q000096:biosynthesis; D014774:Virulence
chemical_list: D018830:Adhesins, Escherichia coli; D006388:Hemagglutinins; D007106:Immune Sera; D017262:Siderophores; C112027:tsh protein, E coli