In vitro activity of minocycline combined with fosfomycin against clinical isolates of methicillin-resistant Staphylococcus aureus.

This study aimed to evaluate the in vitro activity of minocycline combined with fosfomycin against isolates of methicillin-resistant Staphylococcus aureus (MRSA). A total of 87 clinical isolates of MRSA collected from three Chinese hospitals were included in the study. The checkerboard method with determination of the fractional IC index (FICI) was used to determine whether antibiotic combinations act synergistically against these isolates. The susceptibility results for minocycline and fosfomycin were interpreted according to the most relevant criteria. The results demonstrated the following interactions: 76 isolates (87.4%) showed synergistic interactions (FICI0.5) and 11 isolates (12.6%) showed indifferent interactions (0.5<FICI<4). No antagonistic interactions (FICI4) were observed. The combination of minocycline and fosfomycin can be synergistic against MRSA. Further studies are required to determine the potential clinical role of this combination regimen as a therapeutic alternative for certain types of MRSA infections.