Synergistic Antibacterial Effect of Ethyl Acetate Fraction of Delile Leaves with Tetracycline against Clinical Isolate Methicillin-Resistant (MRSA) and .

Multidrug-resistant bacteria have raised global concern about the inability to fight deadly infectious diseases. Methicillin-resistant (MRSA) and are the most common resistant bacteria that are causing hospital infections. The present study was undertaken to investigate the synergistic antibacterial effect of the ethyl acetate fraction of Delile leaves (EAFVA) with tetracycline against the clinical isolates MRSA and . Microdilution was used to establish the minimum inhibitory concentration (MIC). A checkerboard assay was conducted for the interaction effect. Bacteriolysis, staphyloxanthin, and a swarming motility assay were also investigated. EAFVA exhibited antibacterial activity against MRSA and with a MIC value of 125 g/mL. Tetracycline showed antibacterial activity against MRSA and with MIC values of 15.62 and 31.25 g/mL, respectively. The interaction between EAFVA and tetracycline showed a synergistic effect against MRSA and with a Fractional Inhibitory Concentration Index (FICI) of 0.375 and 0.31, respectively. The combination of EAFVA and tetracycline induced the alteration of MRSA and , leading to cell death. Moreover, EAFVA also inhibited the quorum sensing system in MRSA and The results revealed that EAFVA enhanced the antibacterial activity of tetracycline against MRSA and . This extract also regulated the quorum sensing system in the tested bacteria.