Effect of typeⅢsecretion system deficient mutant of E.coli O157∶H7 on attachment of HeLa cells / 军事医学

ABSTRACT

Objective To construct the typeⅢ secretion system (T3SS) deficient mutant of O157∶H7 EDL933, and to detect its ability of attachment after infection with HeLa cells.Methods The recombinant DNA fragments obtained kana-mycin resistant gene were constructed by overlap extension PCR and transferred into EDL933/pKD46 to replace escR gene by homologous recombination.Results The T3SS-deficient mutant (ΔescR) was successfully construted.Compared with the wild-type EDL933, the growth rate and attachment on HeLa cells of ΔescR were significantly decreased.Conclusion The deletion of escR gene, which encodes T3SS structural protein EscR, affects the attachment of EDL933, suggesting a better basis for future studies of T3SS.