Studies on phytochemical screening and antimicrobial potentials of Phyllanthus amarus against multiple antibiotic resistant bacteria

Summary: The phytochemical screening and antimicrobial potentiality of Phyllanthus amarus against multidrug resistant pathogens were investigated using standard microbiological techniques. The extracts were tested by agar well diffusion method for activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella Spp. isolated from clinical samples.The susceptibility patterns of the test isolates against the crude extract was determined at extract concentrations of 10 mg/ml, 50 mg/ml, 100 mg/ml and 150 mg/ml respectively. The results revealed that the extracts did not inhibit the growth of Escherichia coli, Pseudomonas Spp. and Klebsiella Spp. at 10mg/ml but the largest zones of growth inhibition for the ethanolic extract was recorded with Staphylococcus aureus, E. coli and Klebsiella Spp. with a mean zone diameter of 20 mm concentrations. However, the isolates were subjected to antibiotics susceptibility testing and found to be resistant to Gram negative and Gram positive antibiotics with little variations in sensitivity pattern. The minimum inhibitory concentration (MIC) of the ethanolic plant extracts on E. coli, S. aureus, P. aeruginosa and Klebsiella Spp. were at 10 mg/ml, 50 mg/ml, 150 mg/ml and 100 mg/ml while the MBC were at 50 mg/ml, 100 mg/ml, 150 mg/ml and 150 mg/ml respectively. The observed antibacterial effects were believed to be due to the presence of alkaloids, tannins, and flavonoids identified in the extracts. The results apparently justified their use in the treatment of infections. Industrial relevance: Phyllanthus amarus from this research has shown itself as highly promising source of potent antimicrobial drug. It is obviously worthy of large scale investment as the need for antimicrobials against multidrug resistant pathogens persist around the globe.