Evaluation of antimicrobial properties of Coscinium fenestratum methanol fraction on Enterococcus raffinosus.

Common infections are becoming increasingly harder to treat due to bacteria developing higher antimicrobial resistance. Among these, the multidrug-resistant ESKAPE pathogens — Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp have been listed as serious threats to human life by the Center for Disease Control and Prevention, which shows the urgency of finding new antimicrobial drugs. Enterococcus faecium is one of the commonly isolated pathogens from hospital-acquired infections and has shown to be resistant to many antibiotics available. Cocoscinium fenestratum is a large woody vine found in Southeast Asia, known for having medicinal properties that have treated wounds, skin diseases, and infections. In this study, we extracted secondary metabolites from C. fenestratum using methanol and tested its antimicrobial properties on Enterococci using E. raffinosus, a non-pathogenic relative of E. faecium. We used the disk diffusion method where the diameter of the inhibition zones was measured to determine antibacterial susceptibility. The average diameter of the inhibition zone for 800 µg and 1600 µg of methanol extract of C. fenestratum and 30 µg of chloramphenicol (positive control) was 7.22±0.44 mm, 8.78±0.83 mm, and 23.67±2.06 mm respectively. The experiments to determine the minimum inhibitory concentration (MIC), bactericidal concentration, and to identify the compound responsible for observed antimicrobial effects are in progress. Our results provide evidence for the potential use of C. fenestratum as a source of new therapeutics to treat Enterococci. Further studies are required to understand the mode of action of antimicrobial drugs from the C. fenestratum plant.