Integrons and Efflux Pump‐Mediated Antibiotic Resistance in Multidrug‐Resistant (MDR) Uropathogenic Escherichia coli

OBJECTIVE: Integrons facilitate the acquisition and expression of antibiotic resistance genes, with Classes 1 and 2 commonly found in clinical E. coli. The AcrAB-TolC efflux pump is a major RND system that expels diverse antimicrobial agents and contributes to resistance. This study is aimed at determining the prevalence of Class 1/2 integrons and the AcrAB-TolC efflux pump in UPEC isolates from UTI patients in Babol, Iran. METHODS: This cross-sectional study analyzed 155 UPEC isolates collected from UTI patients in Babol, northern Iran (2021-2023). Isolates were identified using standard biochemical and genotypic methods. Antimicrobial susceptibility was assessed by disk diffusion. Polymerase chain reaction (PCR) was used to detect the presence of integron and efflux pump genes. Statistical analysis was performed using SPSS (Version 16), with significance defined at p value < 0.05. RESULTS: Findings revealed that 85.2% of the isolates carried Class 1 integrons, whereas 23.2% contained Class 2 integrons. Integron-positive isolates presented an increased level of antibiotic resistance, particularly to trimethoprim-sulfamethoxazole (75% and 88.9%) and nalidixic acid (90.9% and 91.7%). Additionally, over 88% of the isolates had AcrAB-TolC efflux pump genes. MDR rates were 75% among intI1-positive isolates and 83.3% among intI2-positive isolates. CONCLUSION: In conclusion, integrons contribute to the spread of antibiotic resistance among UPEC isolates, whereas the AcrAB-TolC efflux pump contributes to the ability of bacteria to expel toxic substances. There is a need for effective infection management policies and proper application of antibiotics to limit the dissemination of resistance genes.