Antibacterial Activity of Leaf Extracts from Blumea balsamifera, Morus alba and Limnocharis flava Against Skin Pathogenic Bacteria

<b>Background and Objective:</b> <i>Blumea balsamifera</i>, <i>Morus alba</i> and <i>Limnocharis flava</i> are rich in bioactive compounds. However, reports on their antibacterial activity against antibiotic-resistant bacteria remain limited, prompting this study to evaluate the efficacy of their leaf extracts against skin infection-causing bacteria, including multidrug-resistant <i>Klebsiella pneumoniae</i>, <i>Acinetobacter baumannii</i> and <i>Bacillus subtilis</i> 101 and two reference strains: <i>Staphylococcus epidermidis</i> TISTR518 and <i>Klebsiella pneumoniae</i> TISTR1383. <b>Materials and Methods:</b> Plant samples were extracted using solvents of varying polarity. The preliminary assessment of antibacterial activity was done using the disc diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were established using the broth microdilution assay. The diameters of the inhibition zones (mm) were statistically analyzed using Duncan's Multiple Range Test (DMRT) implemented in SPSS software. <b>Results:</b> The <i>B. balsamifera</i> leaf extracts, utilizing ethanol and ethyl acetate, exhibited the largest inhibition zone of 20 mm against <i>B. subtilis</i> 101. The lowest MIC value, 0.098 mg/mL, was observed in <i>B. balsamifera</i> leaf extracts with ethanol and ethyl acetate against<i> B. subtilis</i> 101. Additionally, the lowest MBC value, 0.78 mg/mL, was obtained from <i>B. balsamifera</i> leaf extracts with ethyl acetate against <i>A. baumannii</i>. <b>Conclusion:</b> This study is the first to report the potential of <i>B. balsamifera</i> extracts against antibiotic-resistant bacteria, including multidrug-resistant <i>K. pneumoniae</i> and <i>A. baumannii</i>. These findings suggest that <i>B. balsamifera</i> extracts could be developed as natural antibacterial agents to combat antibiotic-resistant infections.