| Congresso Brasileiro de Microbiologia 2023 | Resumo: 49-1 | ||||
Resumo:The adherence of Escherichia coli to epithelial cells and abiotic surfaces is a multifactorial phenotype that involves the coordinate action of both fimbrial and afimbrial adhesins. Enteropathogenic (EPEC) and enteroaggregative (EAEC) E. coli are the diarrheagenic E. coli pathotypes most frequently isolated in epidemiological studies carried out in Brazil and in several other countries. Typical (tEPEC) and atypical EPEC (aEPEC) produce a histopathological lesion in infected epithelial cells that is termed attaching and effacing (AE), whose intimate adherence of the bacteria to the epithelial cell is mediated by the interaction of the adhesin intimin to its translocated receptor Tir (Translocated intimin receptor). One of the first phenotypic features described in tEPEC was the localized adherence (LA), which is mediated by a type IV fimbriae known as bundle-forming pilus (BFP). On the other hand, EAEC isolates produce an adherence pattern characterized by organization of the bacteria cells in a stacked brick like arrangement (AA pattern), which is mediated by the production of one of the five aggregative adhesion fimbrae (AAF), described so far, or a type IV pilus termed aggregate-forming pilus (AFP). Very recently, our laboratory identified a novel autotransporter adhesin (ATA) in aEPEC isolates of serotype O2:H16. The main objective of this study was to evaluate the co-production of the novel ATA with well-characterized adhesins of the EPEC (Intimin and BFP) and EAEC (AAF/I – AAF/V and AFP) on bacterial autoaggregation and biofilm formation on abiotic surfaces phenotypes. Several EPEC and EAEC isolates were electroporated with the pBAD-Myc/His-A plasmid vector carrying the gene encoding the novel ATA, as well as with the empty vector. Then, the bacteria isolates harboring the cited plasmids were subjected to autoaggregation and biofilm formation assays. A synergistic association was found for biofilm production between the novel ATA and E. coli isolates producing BFP, Intimin, AAF/II and AAF/III adhesins. Nevertheless, an inhibitory association – in both biofilm production and autoaggregation phenotypes – was observed in EAEC isolates producing the AAF/V adhesin. On account of the observed scenarios, this study concluded that the effect of association between the novel autotransporter adhesin and other E. coli adhesins can vary resulting in synergistic, inhibitory or neutral associations for the aggregation and biofilm production phenotypes. Palavras-chave: Autotransporter adhesins, Escherichia coli, Virulence Agência de fomento:Fundação de Amparo à Pesquisa do Estado de São Paulo | |||||