Molecular Detection of Quinolone and Aminoglycoside-Resistant Genes in Multidrug-Resistant Uropathogenic Escherichia coli Isolated from Diabetic Patients with Urinary Tract Infection in Bauchi Metropolis

Abstract

Background: Urinary tract infection (UTI) is one of the most common medical conditions associated with diabetes mellitus across all age groups. Most cases are caused by uropathogenic E. coli (UPEC). Inappropriate antibiotic use has contributed to the emergence of multidrug-resistant strains. The increasing emergence of multidrug-resistant uropathogenic E. coli, particularly strains resistant to quinolones and aminoglycosides, poses a significant public health concern. Aims: This study aimed to investigate the molecular characterisation of quinolone- and aminoglycoside-resistance genes in MDR UPEC isolates from diabetic patients with urinary tract infections in Bauchi metropolis. Study design: This was a cross-sectional, laboratory-based study conducted on clinical isolates of aminoglycoside- and quinolone-resistant uropathogenic E. coli obtained from diabetic patients in Bauchi metropolis. Place and Duration of Study: The study was conducted at Abubakar Tafawa Balewa University, Bauchi (ATBU), from November 2025 to May 2026. Methodology: Ten (10) MDR uropathogenic E. coli isolates resistant to two or more aminoglycoside and quinolone antibiotics were included. Genotypic detection was performed to confirm aminoglycoside- and quinolone-resistance genes among the isolates. The MDR isolates were subjected to polymerase chain reaction (PCR) to detect the aminoglycoside-resistance genes aph(2″)-Ib and aph(3′)-IIIa and the quinolone-resistance genes qnrS and qnrD. Results: PCR analysis revealed that aph(2″)-Ib was the most prevalent aminoglycoside-resistance gene and was detected in all isolates; the coexistence of aph(3′)-IIIa and aph(2″)-Ib was detected in one isolate. Among the quinolone-resistance genes, qnrD was present in all isolates, whereas the coexistence of qnrS and qnrD was detected in one isolate. Conclusion: The presence and coexistence of aminoglycoside- and quinolone-resistance genes were identified in this study. These findings suggest that the detected resistance genes may contribute to the dissemination of antibiotic resistance among MDR UPEC isolates resistant to aminoglycosides and quinolones, highlighting the potential role of horizontal gene transfer in the spread of antimicrobial resistance among bacteria.