Fosfomycin- Is it a Drug of Choice in Multidrug Resistant Escherichia Coli?

Abstract

Introduction: Urinary Tract Infections (UTIs) caused by Multidrug-Resistant (MDR) gram-negative bacteria, specifically E. coli, are a growing concern because of limited therapeutic options. Fosfomycin as a novel oral therapeutic option against the MDR uropathogens has been widely discussed recently. Aim: To know the local antimicrobial susceptibilities and to evaluate the activity of fosfomycin against Extended-Spectrum Beta-Lactamase (ESBL) producing, Carbapenem-Resistant (CR) and MDR E. coli isolates in Southern India. Materials and Methods: A cross-sectional study was conducted in the Department of Microbiology of a tertiary care hospital from January to December 2019. Pathogenic organisms were identified from the urine samples by conventional biochemical tests. Antibiotic sensitivity testing and ESBL production was tested for E. coli strains. Minimum Inhibitory Concentration (MIC) was determined by E-test. Data were analysed using Microsoft Excel 2016. Frequencies and percentages were determined for categorical variables. Results: Out of the 118 positive isolates yielded after the urine culture, 81 (68.6%) were E. coli, 12 (10.16%) were Klebsiella spp., 7 (5.93%) were Acinetobacter spp, 8 (6.77%) were Pseudomonas spp., 5 (4.23%) were Proteus spp, and 5 (4.23%) were Citrobacter spp. Among 81 E. coli isolates, 33 (40.74%) were ESBL producers, 26 (32.09%) were CR, and 10 (12.34%) isolates were found to be MDR. However, all the isolates were found to be fosfomycin susceptible both by disc diffusion method and by E-strips. Conclusion: Fosfomycin might be a promising antibiotic for the treatment of uncomplicated UTIs due to E. coli. It has also shown good activity against ESBL-producing, CR, and MDR E. coli isolates.

Keywords

• antibiotics
• drug resistance
• urinary tract infection