Abstract
Context: The emergence of resistant strains of microorganisms has undermined the effectiveness of existing antimicrobial agents and hence renewed the interests in the discovery of new plant derived antimicrobial compounds. When some compounds are added to the common antibiotics used, it can enhance the inhibitory effect on microbial growth. Objectives: The study was conducted with objectives like biochemical profiling of the extract, inhibitory effect against gram positive and negative, drug resistant and clinical strains of microorganisms and also to understand the synergistic effect between the extract and antibiotics against microorganisms. Materials and methods: Plant leaves were collected from different geographical locations and extract was prepared. The inhibitory effect against different microorganism were tested using micro dilution method. The synergistic effect of the extract along with standard antibiotics were also tested against gram positive and negative microorganisms. Results and discussion: The MIC values against bacterial ranged from 150 to 350 μg/ ml for the aqueous extract. The MIC of the methanol extract was 280μg/ml against both Staphylococcus aureus and Klebsiella pneumonia. It showed significant activity against the clinical strain with a minimum MIC value of 120 μg /ml. Aqueous extract was found to more effective than methanol extract against most of the standard strains tested. Extract has shown additive effect when used with the antibiotics - gentamicin and penicillin, against E.coli and S. aureus respectively. Conclusions: We can conclude that Moringa oleifera has the potential source to develop into an antimicrobial agent.
