Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a global health threat, highlighting the urgent need for new treatments as antibiotic effectiveness wanes. Marine microbes are valuable sources of potential anti-MRSA com-pounds. In this study, marine bacteria were isolated, cultured in marine broth, and extracted with ethyl acetate. The extracts were tested against clinical MRSA 142. Among four bacteria isolated from sponges and sediment, isolates S6.2 (sponge-derived) and SK3 (sediment-derived actinobacteria) showed the strongest anti-MRSA activity, with MIC values of 0.156 mg/mL and 0.078 mg/ mL, respectively. HPLC analysis revealed key peaks at Rt 25.58 and 29.02 minutes for S6.2 and a prominent peak at Rt 29.18 minutes for SK3. The SK3 iso-late exhibited robust growth and high metabolite production on marine agar, ISP no. 2, 5, and 7, indicating it a promising candidate for anti-MRSA compound production.