Determination of virulence and quinolone resistance genes and biofilm production among uropathogenic Escherichia coli strains isolated from clinical specimens in Iran

Background: Uropathogenic Escherichia coli (UPEC) is the main cause of nosocomial urinary tract infections. The high rates of antimicrobial resistance among UPEC have markedly reduced the remedial options and raised the therapeutic costs and fatality rates. This study analyzed the ability of extended spectrum beta-lactamase (ESBL) production and the presence of plasmid-mediated quinolone resistance genes among UPEC isolates. It also assessed the correlation between plasmid-mediated quinolone resistance genes, biofilm production, and virulence factors among these isolates. Materials and methods: A number of 300 UPEC isolates were recovered from patients with typical clinical signs and symptoms of cystitis, and pyelonephritis, as well as those with asymptomatic bacteriuria. Hemolysis assay, antimicrobial susceptibility testing, and biofilm production were investigated among these isolates. These samples were analyzed by multiplex PCR on genes encoding the pursuits among the virulence factors: type 1 fimbrial adhesin (FimH), pyelonephritis-associated pili (PaP), S fimbriae (Sfa), afimbrial adhesin I (AfaI), hemolysin (hly), aerobactin (Aer), flagelares de la fase 1 (FliC), cytotoxic necrotizing factor 1 (Cnf1), IroN-uptake systems of E. coli D (IucD), cytolethal distending toxin (CDT), and uropathogenic-specific protein (Usp) operon. Results: The current study showed that the presence of virulence genes render the UPEC isolates higher resistance to antibiotics and a higher ability of biofilm production. Conclusion: The fact that the infection can be highly affected by virulence factors of E. coli, let us to conclude that in the case of signs and symptoms of urinary tract infection, it is better to avoid wide use of antibiotics.