Prospective Molecular and Phenotypic Characterization of blaCTX-M and blaTEM ESBL Genes in Uropathogenic Escherichia coli from ICU Patients at Three Tertiary-Care Hospitals in Tabriz, Iran

Background

Urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli have become a major therapeutic challenge worldwide, especially in intensive care units. In northwestern Iran, the molecular epidemiology of the key resistance genes blaCTX-M and blaTEM, along with their potential co-carriage on plasmids, remains poorly understood. This gap limits the development of effective local empirical treatment guidelines and infection control strategies.