Distribution of clbA gene and its correlation with antimicrobial resistance patterns in MDR E. coli from diverse host groups

Author : Soma Kanta Baral

Abstract :Introduction: Multidrug-resistant (MDR) Escherichia coli poses a significant threat to public health, particularly when harboring virulence genes such as clbA, which encodes the genotoxin colibactin. This study aimed to investigate the distribution of the clbA gene among MDR E. coli isolates from different host groups (normal individuals, cancer patients, and clinical patients) and to evaluate its association with antimicrobial resistance patterns. Methods: A cross-sectional study was conducted over a twelve-month period (January 2024–December 2024) at Manmohan Memorial Institute of Health Sciences and its Teaching Hospital in Kathmandu, as well as at Capital Reference Laboratory in Bharatpur, Chitwan, Nepal. Samples were collected from diverse host groups and processed using standard microbiological techniques to isolate E. coli. The clbA gene was detected via PCR, and antimicrobial susceptibility was assessed using standard Kirby-Bauer disk diffusion method. Statistical analyses were performed to determine associations between clbA status, host group, and resistance profiles. Results: The clbA gene was detected in 15 of 115 MDR E. coli isolates (13.0%), with a significantly higher prevalence in clinical patients (25.0%) compared to cancer patients (8.6%) and normal individuals (5.0%) (p = 0.0105). clbA positive isolates exhibited significantly higher resistance rates to key antibiotics, including imipenem (100% vs. 15.0%, p = 0.003), meropenem (100% vs. 12.5%, p = 0.001) and amikacin (100% vs. 10.0%, p = 0.050) compared to clbA negative isolates. Conclusions: The presence of the clbA gene in MDR E. coli is significantly associated with enhanced resistance to multiple critical antibiotics, particularly among clinical patient isolates. These findings suggest a potential link between colibactin-producing E. coli and elevated antimicrobial resistance, highlighting the need for integrated surveillance and molecular monitoring strategies to better manage and contain these high-risk strains.

Keywords :Antimicrobial resistance, clbA gene, MDR E. coli, virulence.

Conference Name :International Conference on Health and Medicine(ICHM-25)

Conference Place Chennai India

Conference Date 27th Jul 2025