Antimicrobial Resistance, Biofilm Formation, and Phylogenetic Grouping of Uropathogenic Escherichia coli Isolates in Egypt: The Role of Efflux Pump-Mediated Resistance

Background: Urinary tract infections are the most commonly encountered infections in clinics and outpatient settings and are mainly caused by Uropathogenic Escherichia coli (UPEC). Multidrug-resistant bacteria (MDR) have become a major public health threat, worldwide. Objectives: This study aimed to investigate the prevalence of the MDR phenotype, efflux pump-mediated resistance, and the ability for in vitro biofilm formation among UPEC clinical isolates from Egypt. Methods: Uropathogenic E. coli isolates were collected from two Egyptian governorates, identified, and classified to their corresponding phylogenetic group by the polymerase chain reaction (PCR). Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method. AcrAB-TolC efflux pump major genes were detected by PCR; efflux pump-mediated resistance was determined by the efflux pump inhibitor microplate-based assay. The ability for in-vitro biofilm formation was also tested. Results: The phylogenetic analysis of the UPEC isolates revealed that most of the isolates belonged to groups B2 and D. The MDR phenotype was detected in 90.8% of UPEC isolates; efflux pump-mediated resistance was detected in all MDR isolates. The acrA, acrB, and tolC were detected in 74.84% of MDR isolates. The ability for in-vitro biofilm formation was recorded in 76.5% of the UPEC isolates. Conclusions: The MDR phenotype and the ability for in-vitro biofilm formation were predominant among UPEC in Egypt. The high prevalence of MDR efflux pumps necessitates the application of new treatment strategies to inhibit this phenomenon.