Distribution of the pilS gene in Escherichia coli pathovars, its transfer ability and influence in the typical enteropathogenic E. coli adherence phenotype

Genetic and Virulence Profiles of Enteroaggregative Escherichia coli (EAEC) Isolated From Deployed Military Personnel (DMP) With Travelers' Diarrhea

“…Finally, a regulator encoded by eilA was shown in some EAEC to influence the capacity to adhere to HEp-2 cells and form biofilms (Sheikh et al, 2006). Other factors that may contribute to adherence by EAEC include heat-resistant hemagglutinin (Bhargava et al, 2009), long polar fimbriae (Ross et al, 2015), E. coli common pilus (Avelino et al, 2010), and Pil (Dudley et al, 2006;Garcia et al, 2019).…”

Recombinant PilS: Cloning, Expression and Biochemical Characterization of a Pil-Fimbriae Subunit

“…Furthermore, the presence of the pilS was searched in a large collection of pathogenic groups of E. coli [14], detecting the presence of pil genes in all DEC pathovars and uropathogenic E. coli (UPEC) strains. However, whether these positive strains carry a complete pil operon and whether Pil has a role as a possible virulence factor in these strains is yet to be determined [14].…”

“…Pil fimbriae is a type IV pili originally described as involved in plasmid conjugation mechanisms in the Salmonella plasmid R64 [11,12]. However, it was further reported as a widespread virulence factor since the genes that comprise the pil operon were also identified in other plasmids in different diarrheagenic E. coli pathotypes, as Enteroaggregative E. coli (EAEC), Enteropathogenic E. coli (EPEC), Enterotoxigenic E. coli (ETEC), and Shiga Toxin producing E. coli (STEC) [10,[13][14][15][16]. In addition to pathotypes, different Pil operon genes, including pilS and pilV that encode the fimbrial structural protein and the fimbrial adhesin, respectively [17][18][19], were also detected in strains isolated from distinctive geographic regions in different decades, with genes present in more than 20 E. coli serotypes [14,16,20].…”

“…However, it was further reported as a widespread virulence factor since the genes that comprise the pil operon were also identified in other plasmids in different diarrheagenic E. coli pathotypes, as Enteroaggregative E. coli (EAEC), Enteropathogenic E. coli (EPEC), Enterotoxigenic E. coli (ETEC), and Shiga Toxin producing E. coli (STEC) [10,[13][14][15][16]. In addition to pathotypes, different Pil operon genes, including pilS and pilV that encode the fimbrial structural protein and the fimbrial adhesin, respectively [17][18][19], were also detected in strains isolated from distinctive geographic regions in different decades, with genes present in more than 20 E. coli serotypes [14,16,20]. As described in Salmonella, Pil possibly display a significant function in conjugation mechanisms in E. coli, since insertional inactivation of pilS reduced conjugal transfer of the carrying plasmid by four orders of magnitude, and its presence was detected in conjugative transfer in the majority of EPEC strains [14,20].…”

“…In addition to pathotypes, different Pil operon genes, including pilS and pilV that encode the fimbrial structural protein and the fimbrial adhesin, respectively [17][18][19], were also detected in strains isolated from distinctive geographic regions in different decades, with genes present in more than 20 E. coli serotypes [14,16,20]. As described in Salmonella, Pil possibly display a significant function in conjugation mechanisms in E. coli, since insertional inactivation of pilS reduced conjugal transfer of the carrying plasmid by four orders of magnitude, and its presence was detected in conjugative transfer in the majority of EPEC strains [14,20]. Its role was further associated to biofilm formation on abiotic surfaces and the adherence process, where an E. coli K12 derivative carrying a plasmid encoding pil gene became an adherent strain, displaying a specific adherence pattern of EAEC pathotype, and inactivation of pilS led to almost 75% of adherence reduction to HT29 cells [20].…”