Evaluation of Four Indonesian Leaf Extracts for Their Antimicrobial Activity against Staphylococcus aureus (MRSA) & Escherichia coli (K-12)

Abstract

The prolonged use of synthetic pesticides can lead to adverse effects on both the environment and human health, manifesting in conditions such as organ dysfunction, hormonal disturbances, and even cancer. Thus, there is an imperative need to explore natural-based pesticides (biopesticides) that possess antimicrobial capabilities, are environmentally friendly, and are beneficial for health. Several plants, including Muntingia calabura, Mangifera indica, Psidium guajava, and Tithonia diversifolia, offer potential as sources for biopesticides. This research aims to assess the antimicrobial efficacy of extracts from these leaves with water-based solvent, evaluating their potential use as biopesticides. The plant samples were extracted using the maceration method with water as the solvent. Each extract was tested for its antimicrobial activity against Escherichia coli (K-12) and Staphylococcus aureus (MRSA). Antimicrobial efficacy was quantitatively measured by calculating the minimum inhibitory concentration (MIC) using the CLSI guidelines (M07-A13). The results demonstrated that the T. diversifolia leaf extract, with a 3-hour simplicia immersion duration, exhibited the most potent antimicrobial activity against the test bacterial strain E. coli, given its lowest MIC value of (7.03 ± 0.79 µg/ml). Hence, the T. diversifolia leaf extract holds significant promise for development into a biopesticide, owing to its superior antimicrobial capabilities.