Phylogenetic analysis, biofilm formation, antimicrobial resistance and relationship between these characteristics in Uropathogenic Escherichia coli.

Background: In the present study, we examine the prevalence of phylogenetic groups, O-serogroups, adhesin genes, antimicrobial resistance, the level of gene expression associated with biofilm formation, and the presence of extended-spectrum beta-lactamase (ESBL) in UPEC strains isolated from both pediatric and adult patients.
Methods: In this cross-sectional study, 156 UPEC isolates were collected from UTI patients. ESBL-producing isolates were detected using the double-disc synergy (DDS) method, and biofilm formation was assessed through a microplate assay. The presence of O-serogroups, adhesion factors and resistance genes, including ESBLs and PMQR genes, was detected by PCR, and isolates were categorized into phylogenetic groups using multiplex PCR. Additionally, the quantitative real-time PCR method was also used to determine the expression level of genes related to biofilm.
Results: During the study period, 50.6% (79/156) of the samples were obtained from children, and 49.4% (77/156) were from adults. The highest rate of resistance was to NA (91.7%), while FM (10.9%) had the lowest rate of antibiotic resistance. In addition, 67.9% (106/156) of UPEC isolates were ESBL producers. Most of UPEC isolates belonged to phylogenetic group B ₂ (37.1%). This study revealed that bla _CTX-M and qnrS are widely distributed among UPEC isolates. The mean expression levels of fimA genes were significantly higher in non-biofilm producers than in biofilm producers (p < 0.01).
Conclusions: The high antibiotic resistance rates in this study highlight the significance of local resistance monitoring and investigating underlying mechanisms. Our findings indicate the dominance of phylogroup B ₂ and group D as the prevailing phylogenetic groups. Consequently, it is imperative to investigate the epidemiological aspects and characterize UPEC isolates across diverse regions and time frames.
(© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)