Activity of Fosfomycin against the Spectrum of Uropathogens Causing Cystitis

Abstract

Background: Urinary tract infections (UTIs) are the most frequent bacterial infections commonly seen in females. A high degree of antimicrobial resistance in uropathogens has challenged the use of therapeutic agents. Fosfomycin, which is an old antibiotic with distinctive characteristics, seems to be a promising novel therapeutic agent with a good bactericidal activity towards multi-drug resistant (MDR) uropathogens. Objective: The main objective of the study is to evaluate the antibacterial activity of fosfomycin among uropathogens causing cystitis. Methods: The study was carried out between 2017-2018. A total of 2060 UTI suspects from outpatient departments (OPDs) and inpatient departments (IPDs) were screened. Out of 2060 screened patients, 1658 were IPD patients, and 402 were OPD patients. The patient’s midstream urine samples were collected aseptically and processed according to standard protocols. The frequency of extendedspectrum- beta lactamases (ESBLs) producer and carbapenem resistance were estimated, respectively. Cultures with significant growth of uropathogens were identified, and minimum inhibitory concentration (MIC) to fosfomycin was determined by agar dilution (AD) and by E-test methods. Results: 184 out of 2060 (8.9%) urine samples showed significant growth of uropathogens. Uropathogenic Escherichia coli (UPEC) (64%, 118/184) was found to be the most isolated uropathogen. Among these Gram-negative uropathogens, 80% were ESBLs producers, 43.2% were carbapenemresistant, and 78% isolates were found to be MDR. The fosfomycin susceptibility for UPEC was 95% by the AD method. Conclusions: This study suggests that fosfomycin is reasonably effective and can be used in the treatment of MDR uropathogens along with uncomplicated UTIs.