Construction of aerobactin and sit operon mutant of avian pathogenic Escherichia coli E058 and evaluation of its pathogenicity

Abstract:

Abstract:［Objective］To elucidate the pathogenesis role of the vir region of APEC O2 strain E058.［Methods］The gene aerobactin/sitABC operon knockout mutants E058Δvir of APEC E058 strain was generated using Red recombination system． A series of pathogenicity tests including chick embryo inoculation，the competition experiment and the colonization and persistence in vivo were used to evaluate the pathogenicity of APEC E058Δvir and the wild-type strain E058.［Results］E058Δvir was similar to its parental strain E058 in the growth curves，invasion assays of HD-11 cell and in vitro competition assay． In the colonization and persistence test，the recovery colonies of E058Δvir were significantly decreased in all of the organs tested (P＜0.001).［Conclusions］These results indicate that the virulence factors encoded by aerobactin/sit operon genes were important for the pathogenesis of APEC E058.