Investigating the antimicrobial effect of methanol extract of Coscinium fenestratum on Acinetobacter baylyi

Abstract

Many microbial pathogens have developed resistance to the antimicrobial drugs available, which has led to an urgency in discovering and developing new therapeutic agents. Among these pathogens are the ESKAPE pathogens, which include Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. ESKAPE pathogens are widely known to be multidrug resistant. Acinetobacter baumannii, a gram-negative bacterium, is particularly concerning because of its association with nosocomial infections, including ventilator-associated pneumonia, bloodstream infections, and urinary tract infections. Acinetobacter baumannii is responsible for 7300 cases of infection and 500 deaths each year. In addressing this public health threat, the WHO In 2017 classified Acinetobacter baumannii as a high-priority pathogen for new antibiotic development. Coscinium fenestratum, a medicinal plant predominantly found in the Western Ghats of India and Sri Lanka, is a potential source of a novel antimicrobial agent. Previous studies have shown that Coscinium fenestratum has antimicrobial, antidiabetic, anti-inflammatory, and antioxidant properties. In this study we investigated the antimicrobial effect of methanol extract of Coscinium fenestratum on Acinetobacter baylyi, which is the non-pathogenic relative of Acinetobacter baumannii. The antimicrobial effect was assessed using the disc diffusion assay, where inhibition zones were measured to ascertain the antimicrobial susceptibility. The average inhibition zone for 80 mg/ml of methanol extract of Coscinium fenestratum and 30 µg of chloramphenicol (positive control) was 7.3 ± 0.7 mm and 25.1 ± 1.2 mm, respectively. Experiments to determine the minimum inhibitory concentration (MIC) and identify the compound associated with Coscinium fenestratum's antimicrobial effect are underway. Our findings suggest that Coscinium fenestratum is a potential source of new therapeutics to combat Acinetobacter baumannii infections. Further studies to determine the mechanism of action and its potency are crucial in the development of antimicrobial drugs from the Coscinium fenestratum plant.