Pathogenicity of Escherichia coli from dogs with UTI in relation to urovirulence factors

Six strains of Escherichia coil, isolated from urine of dogs with urinary t ract infection (UTI), were examined to assess of urovirulence factors (UVFs ) in the pathogenesis of UTI in an experimental pyelonephritis mouse model. From the results of ID50 and LD50, isolates having different UVFs in the s ame O serotypes varied in pathogenicity, and isolates having the same UVFs in different O serotypes had nearly the same pathogenicity. Histopathogenic examination revealed that the presence of pap, hly and cnf1 contributed gr eatly to the development of upper UTI. It has also been suggested that hly and cnf1 significantly related to the LD50 Of the strain in the mouse model , confirming that UVFs are closely related to the pathogenicity of canine U TI.