Methicilin-resistant Staphylococcus aureus (MRSA) infection is a major nosocomial infection that has emerged as community-acquired MRSA worldwide. The resistance of MRSA towards ß-lactam antibiotic had led to research on natural product as novel target for MRSA treatment. Canarium odontophyllum(CO) Miq.locally known as dabai has been considered as an alternative phytotherapeutic treatment against MRSA. The aim of this study is to determine the time-kill assay (TKA) and post-antibiotic effect (PAE) of acetone extract of C. odontophylum leaves in comparison to oxacillin against MRSA ATCC 33591. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of extract against MRSA were determined using broth microdilution method and streak-plate technique. Results showed that acetone extract of C. odontophylum leaves was bactericidal against MRSA ATCC 33591 with equal MIC and MBC value of 1250 µg/ml. As expected, oxacillin was also bactericidal with MIC value that equal MBC value of 7.81 µg/ml. From TKA analysis, acetone extract of C. odontophylum leaves did not display bactericidal effect against MRSA throughout the 24 hours incubation period. While, oxacillin has shown bactericidal activity by a reduction of ≥3 log in colony count at 2.6 hours. Interestingly, the acetone extract of C. odontophyllum leaves showed longer PAE time (0.85 ± 1.74 hour) against MRSA ATCC 33591 compared to oxacillin at 0.18± 2.43 hour. In conclusion, despite the bacteriostatic action of acetone extract for C. odontophyllum leaves it exhibited a prolonged and persistent antimicrobial effect. These findings indicated that acetone extract of C. odontophyllum could give some potential insight on pharmacodynamics information against MRSA.
