Construction of uropathogenic Escherichia coli strain with ppk1 gene deletion and study on its biolog-ical properties / 中华微生物学和免疫学杂志

ABSTRACT

Objective To construct a Polyphosphate kinase 1 ( ppk1) gene deletion mutant of uro-pathogenic Escherichia coli (E.coli) CFT073, and to explore the biological properties of the mutant strain . Methods The ppk1 gene deletion strain (△pk1) was constructed based on CFT073 E.coli strain by usingλRed homologous recombination technology .A comparison analysis was conducted on adhesive and invasive abilities between CFT073 wild type strain and △pk1 strain in in vitro model of human bladder cancer epithe-lial cell 5637 .Crystal violet staining method was used to evaluate the influences of ppk1 gene deletion on biofilm formation.Results The CFT073 ppk1 deletion mutant strain was successfully constructed .Com-pared with the wild type strain ,△pk1 strain showed impaired adhesive and invasive abilities to 5637 cells. Moreover , the absorbance values of crystal violet at 570 nm at each time point of the mutant strain group were also lower than those of the wild-type strain group .Conclusion The ppk1 gene deletion mutant of uro-pathogenic E.coli CFT073 could be successfully constructed by Red homologous recombination technology and its biological properties indicates that ppk1 gene plays an important role in the pathogenesis of uropatho-genic E.coli infection through regulating the abilities of adhesion , invasion and biofilm formation .