Anti-methicillin-resistant Staphylococcus aureus activities of three main components of azalomycin F / 中国药学杂志

ABSTRACT

OBJECTIVE: To research the anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activities of azalomycins F5a, F4a and F3a and their potential synergistic anti-MRSA activities combined with other compounds. METHODS: Against a reference strain MRSA ATCC 33592 and eight clinical isolates MRSA 01-08, the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of three main components of azalomycin F were determined by broth microdilution method, and daptomycin was used as positive control. The anti-MRSA effects of them combined with carnosic acid or trimethylhydroquinone were designed with checkerboard method, and determined by broth microdilution method. RESULTS: Their MICs of azalomycins F5a, F4a and F3a against all nine MRSA strains were successively 4-8, 4 and 4-8 μg · mL-1, and all their MBCs were 8-16 μg · mL-1. All the fractional inhibitory concentration indices (FICIs) of them combined with carnosic acid or trimethylhydroquinone were 0.75-1.25 (indifference) or 0.25-0.50 (synergism). CONCLUSION: Three main compounds of azalomycin F have remarkable anti-MRSA activities, and the anti-MRSA effect of azalomycins F5a, F4a or F3a combined with trimethylhydroquinone was synergistic. As new anti-MRSA macrocyclide, azalomycin F is worthy of further research and development.