Anti-MRSA activity of sophoraflavanone G and synergism with other antibacterial agents

Anti-MRSA activity of sophoraflavanone G (SFG) and synergism between SFG and antibacterial agents against MRSA (methicillin-resistant Staphylococcus aureus) were evaluated by means of Minimal Inhibitory Concentrations (MIC). The MICs of SFG against 27 strains of MRSA ranged from 3.13 to 6.25 mu g ml(-1). Synergism between SFG and vancomycin hydrochloride (VCM) or fosfomycin (FOM) was observed (the fraction inhibitory concentration (FIC) indices were 0.16 and 0.48), while partial synergism was admitted between SFG and other antibacterial agents such as methicillin (DMPPC), cefzonam (CZON), gentamicin (GM), minocycline (MINO) and levofloxacin (LVFX) (the FIC indices were 0.71, 0.73, 0.69, 0.65 and 0.58, respectively). These findings suggest that SFG in combination with VCM or FOM: may be useful in controlling MRSA infections.