Fosfomycin an Alternative for the Treatment of Methicillin Resistant Staphylococcus aureus (MRSA)

Abstract

Introduction: Fosfomycin an antibiotic having unique chemical structure possess broad-spectrum activity against numerous pathogenic organisms including both gram negative and gram positive bacteria including multi-resistant strains. In early 1970 this antibiotic was accepted in clinical practice, but for several years the use of fosfomycin was limited for treating uncomplicated lower urinary tract infections. However, fosfomycin achieves clinically relative concentrations in serum, cerebrospinal fluid, other body fluids, lung, kidney, bladder wall, prostate gland, heart valve tissues, other inflamed tissues, abscess, and bone as well and has shown the good activity in treating severe infections caused by multi-resistant pathogens at various body sites. The objective of the study was to evaluate fosfomycin as an alternative treatment against methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary care hospital. Materials and Methods: The Prospective Descriptive cross-sectional study was conducted at the Department of Clinical Microbiology Laboratory at the Sindh Institute of Urology and Transplantation (SIUT) Hospital, Karachi, June 2017 till January 2018. A total of 147 specimens were collected from various body sites include blood, fluids like pleural fluid, synovial fluids, broncho-alveolar lavage, urine, pus and tissues were identified to genus level by a routine biochemical test. Antimicrobial sensitivity was determined by Kirby-Bauer disk diffusion method. All fosfomycin susceptible isolates i.e. Zone size of ≥16 mm and resistant isolates as zone size <16 mm were evaluated. Results: Out of 147 isolates 113 (76.9%) isolates were from blood, 12 (8.2%) were from other body fluids, 14(5%) were from pus and 8 (4%) from Urine. All 147 isolates were resistant to methicillin. Out of 147 isolates of MRSA 143(97.3%) were sensitive to fosfomycin and only 4 (2.7%) were found to be resistant. Conclusion: Fosfomycin proved to be a very good alternative for treating MRSA because of good activity against this pathogen as well as good penetration of fosfomycin in serum; tissues, cerebrospinal fluid and other body fluids make this drug effective in treating infections at various body sites.