Investigation of east1 gene homologous (SHEAST), type IV pili and biofilm formation among atypical Enteropathogenic Escherichia coli (aEPEC)

Abstract

Atpical enteropathogenic Escherichia coli (aEPEC) strains are genetically related to the enterohemorrhagic E. coli (EHEC) strains and are both considered emerging pathogens. Colonization of the intestinal mucosa is central to the establishment of the enteric E. coli infections in humans that is mediated by specific adherence factors. EPEC and EHEC contain intimin, an adhesin that mediates intimate bacterial adherence of intestinal epithelial cells. Recently, we found many EHEC adhesin encoding genes including E. coli common pilus (ECP) in aEPEC strains. A recent study demonstrated that EHEC O157:H7 produces adhesive type IV pili, termed hemorrhagic coli pilus (HCP), that together with intimin-Tir and ECP contributes to the colonization of the gastrointestinal tract of humans and bovines. Another recent study published the first description of biofilme formation by an aEPEC O55:H7, which displays a high degree of genetic relatedness to EHEC. EHEC strains belonging to serotypes O26, O111, O145 e O157 possess the EAST1 gene homologous (SHEAST), which has not been investigated yet in aEPEC strains. The aim of this study is to investigate the presence of SHEAST and type IV pili, and analyze biofilm formation in our collection of aEPEC. (AU)