Herbal disinfection against Rhodococcus equi

Rhodococcus equi is an important bacterial respiratory pathogen of young foals. Prevention of R. equi depends on early detection, environmental management and chemoprophylaxis. Aerosol infection via soil is the most important route of infection to the foals and effective management of land by reducing aerosol exposure can reduce incidence of R. equi. We found that leaves of Tamarindus indica (Tamarind; Imli) and Eucalyptus globulus (Eucalyptus; Safeda) have potential in vitro antibacterial activity against R. equi. Both the plants are widely available, so leaves of these plants were tested for their disinfectant activity against R. equi present in farm soil. Study was carried out to find an herbal disinfectant for farm soil against R. equi and its active principle. Aqueous extracts of leaves of T. indica and E. globulus were fractioned on silica column by using ethanol methanol and water serially. Different fractions were tested against pure colonies of R. equi in vitro to find out active principle. To find out disinfectant property of leaves in the presence of farm soil, pure colonies of R. equi were mixed in soil and efficacy of leaves boiled water was tested against control. Water boiled with plant leaves in the concentration of 10% and above, was found effective against R. equi present in the farm soil. Active principal of T. indica was matching with the previous reports while active principle of E. globulus could not be matched with previous reports, however, it was found that active principle of E. globulus is a very polar compound.