Adherence-associated characteristics and pathogenicity of escherichia coli from avian colibacillosis

Escherichia coli isolates from avian colibacillosis were examined for adherence-associated characteristics and post-colonisation pathogenicity. The adherence-associated characteristics studied included expression of pili, ability to partition with a hydrophobic phase, and ability to bind to Biosilon plastic polar-surfaced microcarriers. None of the adherence-associated characteristics correlated absolutely with post-colonisation pathogenicity, and thus in vitro tests for these adherence-associated characteristics cannot be used to predict whether any given E. coli avian colibacillosis isolate will exhibit post-colonisation pathogenicity. The isolation of strain BT7 from avian colibacillosis, a piliated E. coli strain which binds to Biosilon polar-surfaced plastic microcarriers, but is not pathogenic, is reported.