Antimicrobial activity and synergism of Sami-Hyanglyun-Hwan with ciprofloxacin against methicillin-resistant Staphylococcus aureus

ABSTRACT

OBJECTIVE@#To investigate the antibacterial activity of SHH extracted with either water or ethanol against methicillin-resistant Staphylococcus aureus (MRSA) and combinatory antimicrobial effect with ciprofloxacin (CIP) by time kill assay and checkerboard dilution test.@*METHODS@#The antibacterial activity determined by broth dilution method indicated that the antibacterial activity of Sami-Hyanglyun-Hwan (SHH) water extract (SHHW) and SHH ethanol extract (SHHE) ranged from 250 to 2000 μg/mL and 125 to 1000 μg/mL against MRSA, respectively.@*RESULTS@#In the checkerboard method, the combinations of SHHE with CIP had a partial synergistic or synergistic effect against MRSA. The time-kill curves showed that a combined SHHE and CIP treatment reduced the bacterial counts dramatically after 24 h.@*CONCLUSIONS@#The present study demonstrates the therapeutic ability of SHHE against MRSA infections.