Distribution of <i>Clba</i> Gene and Its Correlation With Antimicrobial Resistance Patterns in MDR <i>E. coli</i> From Diverse Host Groups

Multidrug-resistant (MDR) Escherichia coli (E. coli) represents a significant public health concern, particularly when harboring virulence genes such as clbA, which encodes the genotoxin colibactin. This study assessed the distribution of the clbA gene among MDR E. coli isolates from normal individuals, cancer patients, and clinical patients, and examined its association with antimicrobial resistance patterns. A total of 115 MDR E. coli isolates were collected from January to December 2024 at two healthcare centers in Nepal. The clbA gene was detected in 13.0% (15/115) of isolates, 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 markedly increased resistance to critical 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 strains. These findings suggest that the presence of the colibactin-encoding clbA gene in MDR E. coli is linked to heightened antimicrobial resistance, especially in clinical settings, underscoring the need for targeted molecular surveillance and infection control strategies.