Evaluating the Antibacterial Activity of Moringa oleifera Leaves Extracts against Pathogenic Bacterial Isolates

Abstract

Multi-drug resistant (MDR) bacterial infections pose a major threat to global health. The emergence of antibiotic resistance is due to the overuse and misuse of antibiotics. To overcome this problem, phytochemicals extracted from medicinal plants present an attractive alternative. This study was designed to evaluate the antibacterial and antibiofilm activities of Moringa oleifera leaves extracts against human pathogens. Moringa oleifera leaves were collected and their extracts were prepared in methanol, ethanol, water, and dimethyl sulfoxide solvents. Human pathogenic bacteria were isolated from the urine, sputum, and blood samples of patients from a tertiary care hospital in Lahore. Bacterial isolates were characterized based on their morphological, biochemical, and physiological characteristics. Antibacterial activity of antibiotics was checked through the disc diffusion method. Furthermore, the ability of bacterial strains to form biofilms was observed using qualitative ring test and quantitative microtiter plate assay. Bacterial strains were identified as Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Antibacterial activity of Moringa oleifera leaves extracts, checked by agar well diffusion assay, displayed maximum inhibitory effect (25 mm) in aqueous extract against the strain E2. All of the bacterial strains were found resistant to almost all tested antibiotics, except fosfomycin and amikacin. All bacterial isolates exhibited the potential of biofilm formation. Among all isolates, E2 and E3 bacterial strains appeared as strong slime producers. It was concluded that the significant antibacterial and antibiofilm activity of Moringa oleifera leaves extracts present it as a potential source for novel therapeutic compounds. So, it should be purified and characterized further by using advanced techniques.