Fathima Rasli C.H., Shainy N.K., Neja C. and Kunhi. A. A. M. 2016. Antibacterial and synergistic effects of leaf extracts of Chromolaena odorata and Hyptis suaveolens against multi drug resistant strain Staphylococcus aureus. BIOSPARK’16, National Symposium on ‘Nanotechnology Meets Microbiology’, Dept. of Microbiology, EMEA College of Arts & Science, Kondotty, Malappuram, Kerala. 17-18, Feb. 2016.



Emerging resistance among pathogenic bacteria towards various antibiotics has prompted researchers to look for alternatives such as plant-derived antimicrobial compounds. In the present study antimicrobial activity of leaf extracts of Chromolaena odorata and Hyptis suaveolens made in acetone, chloroform, petroleum ether, and water, separately was tested against a multidrug resistant strain of Staphylococcus aureus. All the extracts exhibited growth inhibition of the test organism, acetone extract being the most potent. Phytochemical analysis of acetone extracts of both the plants showed the presence 4 different phyto constituents, which may be responsible for the antibacterial activity. The minimum inhibitory concentrations (MIC) of chloroform and acetone extracts of C. odorata leaves were found to be 250 and 200 ul, respectively whereas similar extracts of H. suaveolens showed MIC values of 350 and 300 ul, respectively. Synergy of the antibacterial activity of the leaf extracts of the two plants was tested by checkerboard assay. Among the different extracts only the acetone extract exhibited synergy in the growth inhibition, the FIC value being 0.468. Chloroform extracts showed a FIC value of 0.567, which is slightly higher than the value of synergy of ≤ 0.5. This clearly indicated the potential use of a combination of acetone extracts of C. odorata and H. suaveolens for the treatment of multidrug resistant S. aureus infections.