Genetic Characterization of ESBL-Producing Escherichia coli Isolates from Nosocomial Infections, Healthcare Workers, and Sewage in a Tertiary Hospital: Insights into the Emergence of the High-Risk Clone ST8881

Objectives Extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) poses a significant clinical challenge due to its resistance to commonly used beta-lactam antibiotics. Recent studies have highlighted the emergence of high-risk clones, particularly ST8881, in both hospital settings and among healthcare workers. This study aimed to investigate the genetic features and molecular epidemiology of ESBL-producing E. coli within a healthcare environment, focusing on the high-risk ST8881 clone. Methods A descriptive cross-sectional study was conducted from June 2021 to October 2021, involving 371 E. coli isolates from hospitalized patients (n = 246), healthcare workers' feces (n = 100), and hospital wastewater (n = 25). ESBL production was screened using the combination and double disk methods. Genotypic characterization included multilocus sequence typing (MLST) for sequence type identification and PCR detection of ESBL resistance genes ( CTX-M , shv , and tem ). Results ESBL-producing E. coli was isolated from 20% of samples, with the highest prevalence in hospital wastewater (60%), followed by healthcare workers (25%) and hospitalized patients (14.2%). MLST revealed that ST8881 was the predominant strain. Notably, the ctx-M gene was detected in 97% of ESBL-producing isolates. Conclusions Our study highlights the widespread distribution of ESBL-producing E. coli , particularly the high-risk ST8881 clone, in a healthcare environment, including hospital workers and wastewater. The high prevalence of ctx-M and other ESBL genes underscores the need for enhanced infection control measures and targeted antibiotic stewardship strategies.