Virulence factors associated with Escherichia coli present in a commercially produced competitive exclusion product.
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.
Maurer
John J
JJ
Department of Avian Medicine, College of Veterinary Medicine, The University of Georgia, Athens 30602, USA.
Hofacre
Charles L
CL
Wooley
Richard E
RE
Gibbs
Penelope
P
Froyman
Robrecht
R
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
D018830:Adhesins, Escherichia coli; D006388:Hemagglutinins; D007106:Immune Sera; D017262:Siderophores; C112027:tsh protein, E coli