title: Role of the ehxA gene from Escherichia coli serotype O82 in hemolysis, biofilm formation, and in vivo virulence.
abstract: Enterohemorrhagic Escherichia coli (EHEC) strains cause serious gastrointestinal disease, which can lead to potentially life-threatening systemic complications such as hemolytic uremic syndrome. Although the ehx gene is established as a major virulence factor of EHEC, the role of this gene in colonization and biofilm formation remains to be elucidated. We constructed recombinant isogenic mutants of the ehxA locus of E. coli HLJ1122 (serotype O82) using the λ Red homologous recombination system. Significantly higher levels of adherence to human epithelial cells (HEp-2) cells were observed for strain HLJ1122 compared with the mutant strain HLJ1122-ΔehxA (P < 0.05). Strain HLJ1122 also exhibited significantly higher levels of biofilm formation than strain HLJ1122-ΔehxA (P < 0.05). Mice infected with strain HLJ1122 showed severe destruction of the intestinal and gastric mucosa; in contrast, mice infected with HLJ1122-ΔehxA showed limited intestinal pathology, displaying minimal inflammatory infiltrates compared with mock-infected mice. These results showed the multifunctional role of Ehx in E. coli virulence.
authors: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, People's Republic of China.
authors: Chenggang
authors: C
authors: Jiang
authors: Tongqing
authors: T
authors: An
authors: Shujie
authors: S
authors: Wang
authors: Gang
authors: G
authors: Wang
authors: Wei
authors: W
authors: Si
authors: Yabin
authors: Y
authors: Tu
authors: Yonggang
authors: Y
authors: Liu
authors: Jianan
authors: J
authors: Wu
authors: Siguo
authors: S
authors: Liu
authors: Xuehui
authors: X
authors: Cai
mesh_terms: D000818:Animals; D001483:Base Sequence; D018441:Biofilms; D002478:Cells, Cultured; D004926:Escherichia coli / Q000145:classification / Q000472:pathogenicity / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005260:Female; D006460:Hemolysin Proteins / Q000235:genetics*; D006461:Hemolysis; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D065288:Serogroup; D014774:Virulence / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli
keywords: Escherichia coli; adhesion; adhérence; biofilm; ehxA gene; gène ehxA; virulence