Quercus infectoria: a candidate for the control of methicillin-resistant Staphylococcus aureus infections

Acetone, ethyl acetate, 95% ethanol and aqueous extracts of Quercus infectoria (Q. infectoria) demonstrated significant antibacterial activities against all strains of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Inhibition zones were in the range 11.75-16.82 mm. Both MRSA and MSSA strains exhibited minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values at 0.13 and 0.13-1.00 mg/mL, respectively. At 2 MIC, the growth of two representative MRSA strains was continually inhibited for at least 20 h. Surviving MRSA cells were not detected within 12-14 h after treatment with the extract at 4 MIC concentration. Staphylococcus aureus ATCC 25923 demonstrated similar results.