Antibiotic Resistance and Integron Distribution in Escherichia coli Isolated from Urine Samples

Background and Aims: Antimicrobial resistance among uropathogenic Escherichia coli represents a growing global health concern and is largely driven by the dissemination of resistance genes through mobile genetic elements such as integrons. This study aimed to investigate antimicrobial resistance patterns and determine the prevalence of class 1 and class 2 integrons among E. coli isolates recovered from patients with urinary tract infections (UTIs).

Methods: A total of 100 non-duplicate E. coli isolates were obtained from urine samples collected from hospitalized patients at Al-Hilla Teaching Hospital, Babylon, Iraq. Antimicrobial susceptibility testing was performed using standard methods, and the presence of intI1 and intI2 genes was determined by polymerase chain reaction (PCR).

Findings: High resistance rates were observed to ampicillin (75%), nalidixic acid (69%), and co-trimoxazole (52%), whereas gentamicin (67%) and amikacin (69%) showed the highest susceptibility rates. Multidrug resistance was detected in 65% of the isolates. PCR analysis revealed that 75% of isolates carried the intI1 gene, while intI2 was detected in 5%. The presence of intI1 was significantly associated with resistance to ampicillin, ciprofloxacin, and co-trimoxazole (P < 0.05).

Conclusions: The high prevalence of integron-associated multidrug resistance among E. coli isolates underscores the need for continuous surveillance and strengthened antimicrobial stewardship programs to optimize the management of UTIs.