Investigation of the relationship between some virulence genes and biofilm formation in uropathogenic escherichia coli isolates using pcr method

Objective: This study aimed to investigate the presence of certain virulence genes in uropathogen Escherichia coli (E. coli) isolates using the polymerase chain reaction (PCR) method and to determine the phenotypic biofilm production of these isolates. Methods: In our study, an automated system and disk diffusion method were used for antibiotic susceptibility testing. The molecular similarities of isolates obtained from urine samples of the same patient were investigated using PCR-based methods. Recurrent UTI (rUTI) and non-recurrent UTI (nrUTI) groups were formed with the strains in our study. The phylogenetic classification of the strains and the presence of fimH, papC, sfa, csgA, csgD, afa, flu, bcsA, pgaA, pgaC, fliCH4, and fliCH7 genes were investigated using PCR. The expression levels of pgaA and bcsA genes were determined by measuring mRNA quantities using real-time PCR (RT-PCR). Phenotypic biofilm production of the strains was determined using both Congo red agar (CRA) and the microtiter plate method (MPM). Results and Conclusion: A total of 108 strains were included in the study, with 54 strains in the rUTI group and 54 strains in the nrUTI group. A positive correlation was found between resistance to ceftriaxone (CRO), cefixime (CFM), ciprofloxacin (CIP), levofloxacin (LEV), extended-spectrum beta-lactamase (ESBL) production, and the recurrence of UTIs (p< 0.05). In both groups, the majority of the strains belonged to phylogroup B2, followed by phylogroup D. The virulence genes fimH, csgA, and csgD were found to be positive in all strains, while afa was the least prevalent gene in both groups. The prevalence of bcsA and pgaC genes was higher in the rUTI group, and the expression level of the pgaA gene was higher in the nrUTI group (p< 0.05). Most strains in both groups produced biofilm by the CRA method and they were low level biofilm producer by the MPM. No significant difference was found in biofilm production between the two groups.