Phylogenetic characterization of UPEC and its relation with serotyping, distribution of virulence factors, antimicrobial resistance pattern and biofilm formation ability: An apparent elucidation of the bacterial nature

Abstract Extensive heterogeneity in O-serogroups, phylogenetic types, possession of plethora resistance mechanisms, and virulence factors have all accreted Uropathogenic Escherichia coli (UPEC) to achieve a landmark as an attractive pathogen and a survival advantage. The present research aimed at a comprehensive approach investigating antibiotic susceptibility, biofilm capability, serotyping, phylogenetic typing, and virulence factors of 102 UPEC isolates. O-serotyping and virulence genotyping was conducted to detect 14 serogroups and 8 virulence genes including molecular predictors of UPEC strains. Phylogenetic groups were identified at molecular level and analyzed to evaluate whether these strains belonged to one lineage or extended widely among hospital patients. The analysis revealed that the majority of the strains belonged to the phylogenetic groups B2, D/E and serotype O25. The number of virulence factors and antibiotic resistance exhibited was significantly high in groups B2 and serogroup O25/O15 compared to other groups. Among the 74 multidrug-resistant isolates, 56.7% belonged to the phylogenetic group B2. Significantly, isolates belonging to phylogroup B2, serogroup O25 and those harbored fimH and papE/F virulence factors formed biofilm. In conclusion, our study observed the dissemination of UPEC among several serotypes and phylogenetic groups. Strong biofilm index suggests a characteristic feature of UPEC isolates.