Molecular Monitoring of Fosfomycin Resistance in Escherichia coli Strains Isolated from Patients with Urinary Catheters in north-east of Iran

Introduction: Urinary tract infection is a common nosocomial infection that has recently become difficult to treat because of the increased emergence of multi-drug resistant strains. This study aims to determine the minimum inhibitory concentration, and molecular pattern of resistance to fosfomycin in Escherichia coli isolates originated from patients hospitalized with urinary tract infection in the intensive care unit (ICU) and coronary care unit (CCU) in three hospitals of Gorgan, northeast of Iran. Methods: Urine samples were obtained from ۱۰۶ patients in three hospitals of Gorgan, northeast of Iran. After isolation and identification of E. coli isolates, the Kirby-Bauer disk diffusion test was performed to evaluate the antibiotic susceptibility pattern. Minimum inhibitory concentrations (MICs) of isolates to fosfomycin were determined using the agar dilution method over a concentration range of ۰.۵-۱۰۲۴ μg/mL. Also, the presence of murA and glpT genes were investigated using polymerase chain reaction with specific primers. Results: Frequency of E. coli isolates was ۶۲.۳%, most of which originated from ICU patients (۵۶.۵%). The rate of susceptibility to fosfomycin was ۸۵%. Moreover, the MIC of ۸۰.۳% of the isolates was less than or equal to ۶۴ μg/mL. We also detected the murA and glpT genes in ۷۷.۸% and ۲۲.۲% of fosfomycin-resistant isolates, respectively. Conclusion: Our results indicated a high bactericidal activity of fosfomycin against uropathogenic E. coli isolates. In agreement with similar studies, we concluded that the presence of murA is significantly associated with the development of resistance to fosfomycin.

کلیدواژه ها:

Fosfomycin ، Uropathogenic Escherichia coli ، Coronary Care Units ، PCR