Abstract
The object of this study was to formulate new, cost effective antimicrobial combination for multidrug resistant diseases based on the synergistic activity of oxytetracycline with methanolic extract of Thespesia populnea (Malvaceae) a medicinal plant common in South India. The minimum inhibitory concentration (MIC) of methanolic extracts in combination with oxytetracycline using 12 different Gram positive and Gram negative bacteria was found to be around (62.5 mu g/mL to 1000 mu g/mL). The synergistic activity was verified using Kirby and Bauer techniques. 83.3% shows synergistic activity against all 12 different bacteria both Gram positive and Gram negative species. The highest synergism rate was attained against Shigella boydii (ATCC8700).