Mutations in the Histone-like Nucleoid Structuring Regulatory Gene (hns) Decrease the Adherence of Shiga Toxin-producing Escherichia coli 091:H21 Strain B2F1 to Human Colonic Epithelial Cells and Increase the Production of Hemolysin.

摘要

Non-O157 serotype Shiga toxin-producing E. coli (STEC) cause a significant amountof food-borne hemorrhagic colitis (HC) and life-threatening hemolytic uremic syndrome(HUS) worldwide and yet these strains do not encode intimin, a major adherence factorencoded by the most common serotype 0157:H7 isolated from documented cases ofHC andHUS. In this investigation, we attempted to isolate specific adhesins critical for attachmentofintimin-negative STEC 091 :H21 to human colonic epithelial cells. Transposon mutagenesisof B2F1 was accomplished with the mini-Tn5phoACmf mobile element and a mutant bankof B2F1 colonies that carried putative in-frame PhoA-positive transposon insenions wasisolated.