Fosfomycin for the treatment of infections caused by Gram-positive cocci with advanced antimicrobial drug resistance: a review of microbiological, animal and clinical studies

Abstract

Background: The advancing antimicrobial drug resistance in Gram-positive cocci complicates the selection of appropriate therapy. The re-evaluation of older antibiotics may prove useful in expanding relevant therapeutic options. Objective: We sought to evaluate fosfomycin for the treatment of infections caused by methicillin-resistant staphylococci, vancomycin-resistant enterococci, and penicillin-non-susceptible pneumococci. Methods: We searched in PubMed, Scopus, and the Cochrane Library for studies evaluating the antimicrobial activity of fosfomycin against the above-mentioned pathogens, or the in vivo or clinical effectiveness of fosfomycin for the treatment of infections caused by these pathogens. Results/conclusions: As reported in the identified studies, the susceptibility rate of methicillin-resistant Staphylococcus aureus to fosfomycin was ≥ 90% in 12/22, and 50 – 90% in 7/22 studies; the cumulative susceptibility rate was 87.9% (4240/4892 isolates). The cumulative susceptibility rate of vancomycin-resistant enterococci to fosfomycin was 30.3% (183/604 isolates), and that of penicillin-non-susceptible pneumococci was 87.2% (191/219 isolates). Clinical data show that fosfomycin, primarily in combination regimens, has been associated with clinical success in 28/29 (96.6%) cases of infection (mainly pneumonia, bacteremia, and meningitis) by fosfomycin-susceptible isolates of methicillin-resistant S. aureus. The above data support further research on the role of fosfomycin against infections caused by Gram-positive cocci with advanced antimicrobial drug resistance.

Keywords::

• drug evaluation
• Enterococcus faecium
• microbial sensitivity tests
• Panton–Valentine leukocidin
• Staphylococcus epidermidis
• Streptococcus pneumoniae
• treatment outcome