Resumo

Extra-intestinal pathogenic Escherichia coli (ExPEC) possess virulence traits that allow it to adhere, invade and colonize body sites outside of the gastrointestinal tract. Human diseases caused by ExPEC include principally urinary tract infections, neonatal meningitis and sepsis. Differentially of others groups of E. coli like intestinal pathogenic E. coli, Extra-intestinal E. coli (ExPEC) is composed by pathotypes few studied. In this way, we had analyzed genotypic characteristics of 100 ExPEC strains: 50 UPEC (Uropathogenic E. coli), 1 NMEC (Neonatal Meningitis E. coli) and 49 SEPEC (Human Sepsis-associated E. coli) strains for ECOR phylogrouping (chuA, yjaA, tspE4.C2), and adhesin genes: fimH, papC, sfa/sfoc. Phylogenetic analysis of ExPEC showed 61.1% of UPEC and 38.8% of SEPEC strains belonged to group B2; while 22.2% (UPEC), 53.1% (SEPEC) and NMEC strains belonged to phylogroup D. It was observed low frequencies of intestinal ECOR groups A and B1: UPEC (16.7%) and SEPEC (8.1%). The frequency of genes harbored by ExPEC pathotypes were: fimH⁺ [90.00% (UPEC); 98.0% (SEPEC)]; papC⁺ [65.0% (UPEC); 71.4% (SEPEC)]; and sfa/sfoc⁺ [25.6% (UPEC); 12.2% (SEPEC)]. Adherence assay in VERO, HUVEC and NCI culture cells shown that ExPEC fimH⁺ adhered to this cellular lineages in a D-manose resistant-like way [90.0% (UPEC), 100% (SEPEC)], or FimH-independent. For analysis of the Outer Membrane Proteins (OMP’s) by one-dimensional SDS-PAGE electrophoresis, we selected three ExPEC strains (H⁺/ papC⁺/ sfa/sfoc^-) being one UPEC, one NMEC and one SEPEC strain. Electrophoretic profile showed OMP’s differential expression between 30 to 70KDa proteins produced by ExPEC strains that can be involved in the bacterial adherence, niches colonization, invasion and dissemination in the human body.