English

Abstract

BACKGROUND Escherichia coli is one of the most important causes of urinary tract infections (UTIs). Increased antibiotic resistance may limit the therapeutic options for the treatment of these infections. Fosfomycin trometamol is a phosphonic acid derivative, which acts primarily by interfering with bacterial peptidoglycan synthesis with broad spectrum of activity against agents causing urinary tract infection with good antibiofilm activity and limited reports of resistance and hence is increasingly called upon for the treatment of multi drug resistant (MDR) organisms causing UTI. There are limited studies from India regarding the efficacy of this drug; so, the study was conducted to determine the in vitro efficacy of fosfomycin against uropathogenic MDR E. coli. METHODS This was a prospective study done in the Department of Microbiology, Government T.D. Medical College, Alappuzha, over a period of 1 year from April 2018 to March 2019. A total of 150 MDR urine samples were processed by routine microbiological methods and after identification of E. coli urinary isolates, antibiotic susceptibility testing was performed and results were interpreted following the Clinical and Laboratory Standards Institute guidelines (CLSI). Fosfomycin sensitivity was tested by the Kirby-Bauer disc diffusion method. RESULTS Among the 150 MDR urinary E. coli isolates, 148 (98 %) were sensitive to fosfomycin in our study. The susceptibility rate of fosfomycin was clearly higher than other commonly used drugs for UTI. All extended-spectrum beta-lactamases (ESBL) producing E. coli were sensitive to this drug. The susceptibility for nitrofurantoin was fair, whereas for ampicillin, norfloxacin, cefotaxime and trimethoprim / sulphamethoxazole was found poor. Relatively better rates of resistance were observed for parenteral antibiotics. CONCLUSIONS With an enormous increase in the bacterial pathogens resistant to first-line antibiotics, there has been a revival in the use of fosfomycin. The convenience of a single dose regimen, a good activity proven invitro, and minimal propensity for development of resistance pathogens makes fosfomycin an attractive regimen for the treatment of uncomplicated community and hospital acquired UTIs. In this regard, with the existing limited options for treating MDR organisms, fosfomycin finds its utility acting as an effective and promising option in the treatment of UTIs due to MDR pathogens in the future.