Terminalia ferdinandiana Fruit and Leaf Extracts Inhibit Methicillin-Resistant Staphylococcus aureus Growth.

The development of multiple antibiotic-resistant bacteria has vastly depleted our repertoire of effective antibiotic chemotherapies. The development of multi--lactam-resistant strains are particularly concerning due to our previous reliance on this class of antibiotics because of their initial efficacy and broad-spectrum activity. With increases in extended-spectrum -lactam-resistance and an expanded resistance to other classes of antibiotics, there is an urgent need for the development of effective new antibiotic therapies. is an endemic Australian plant known for its high antioxidant and tannin contents. fruit and leaf extracts have strong antibacterial activity against a wide variety of bacterial pathogens. However, extracts have not been tested against ESBL and MRSA antibiotic-resistant pathogens. An objective of this study was to screen fruit and leaf extracts for bacterial growth inhibitory activity by disc diffusion assay against -lactam-sensitive and -resistant strains and against methicillin-sensitive and -resistant . The minimum inhibitory concentration (MIC) was quantified by liquid dilution techniques. The fruit methanolic extract, as well as the methanolic, aqueous, and ethyl acetate leaf extracts strongly inhibited the growth of the MRSA, with MICs as low as 223 µg/mL. In contrast, the extracts were ineffective inhibitors of ESBL growth. Metabolomic fingerprint analysis identified a diversity and relative abundance of tannins, flavonoids, and terpenoids, several of which have been reported to inhibit MRSA growth in isolation. All extracts were nontoxic in the nauplii and HDF toxicity assays, further indicating their potential for medicinal use.