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

## TL;DR

This study found that the clbA gene, linked to a harmful toxin, is more common in drug-resistant E. coli from clinical patients and is associated with higher antibiotic resistance.

## Contribution

The study reveals a novel correlation between clbA gene presence and increased antimicrobial resistance in MDR E. coli from clinical patients.

## Key findings

- The clbA gene was detected in 13.0% of MDR E. coli isolates, with the highest prevalence in clinical patients (25.0%).
- clbA-positive isolates showed 100% resistance to imipenem, meropenem, and amikacin, compared to clbA-negative isolates.
- The presence of clbA in MDR E. coli is linked to heightened antimicrobial resistance, especially in clinical settings.

## Abstract

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.

The clbA gene, encoding the genotoxin colibactin, was present in 13.0% of Multidrug‐resistant (MDR) E. coli isolates, with a significantly higher prevalence observed in clinical patients (25.0%) compared to other host groups. clbA‐positive isolates demonstrated a markedly enhanced resistance profile, including 100% resistance to critical antibiotics such as meropenem, imipenem, and amikacin. These findings underscore the dual threat posed by clbA ‐positive MDR E. coli: genotoxicity and enhanced antimicrobial resistance, warranting targeted surveillance in clinical settings.