Vol. 11, Issue 10 (2022)

The experiment was conducted to evaluation of in vitro antibacterial properties of ethanolic, chloroformic and Sequentially Extracted Water Extract (SEWE) leaves extract of Thespesia populnea, Pongamia pinnata (L.) Pierre, Albizia lebbeck (L.) Benth., Delonix regia (Hook.) Raf., Cordia dichotoma and Dalbergia sissoo against Vap A and Vap C positive Rhodococcus equi. In initial screening using disc diffusion method ethanolic leaves extract of Thespesia populnea, Pongamia pinnata (L.) Pierre, Albizia lebbeck (L.) Benth. and Delonix regia (Hook.) Raf. Were found non-active against R. equi while ethanolic leaves extract of Cordia dichotoma and Dalbergia sissoo were showed good in vitro antibacterial against R. equi. On polarity based fractionation, only chloroformic leaves extract of Dalbergia sissoo was showed good in vitro antibacterial activity against R. equi using disc diffusion method. Further, solubility based fractionations of chloroformic leaves extract of Dalbergia sissoo sequentially extracted in petroleum ether, ethyl acetate, chloroform, acetone & ethanol, were found non active against R. equi using agar well diffusion method. On comparison with currently used antibiotics (azithromycin and rifampicin), required concentration of the chloroformic leaves extract of Dalbergia sissoo was too high for their possibilities of in vivo use. However, abundant availability of Dalbergia sissoo leaves and their antibacterial activity against R. equi suggests their potential for use as disinfectant against R. equi and further more investigation will be require phytochemical analysis for isolation of bioactive constituents responsible for their antimicrobial activity.