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.

Background: Staphylococcus aureus is a prevalent opportunistic pathogen which is increasingly associated with various equine dermatological afflictions. The burgeoning issue of antibacterial resistance against this bacterium necessitates novel therapeutic approaches. This study, executed from May to November (2022) at the National Research Centre on Equine, Equine Production Centre, Bikaner, aimed to isolate and identify S. aureus from equine dermal lesions and to assess the in vitro efficacy of both organic (methanolic, aqueousand ethanolic) and inorganic (chloroform and petroleum ether) phytoextracts from Calotropis gigentean, Capparis decidua, Leptadenia pyrotechnica, Aerva javanica, Azadirachta indica, Aloe vera and Eucalyptus camaldulensis. Method: The study utilised agar well diffusion and broth dilution techniques to assess the antimicrobial efficacy of these extracts against S. aureus. Result: Microscopic analysis of gram-stained smears from cultures, alongside a suite of biochemical assays and polymerase chain reaction (PCR), corroborated the presence of S. aureus. The antimicrobial screening disclosed that both organic and inorganic extracts of E. camaldulensis manifested the most pronounced antibacterial activity, exhibiting zones of inhibition ranging from 15 mm to 21 mmand minimum inhibitory concentrations between 1.56 to 3.13 mg/mL. Furthermore, extracts from A. indica (chloroform, methanolicand ethanolic) and A. vera (methanolic and ethanolic) also demonstrated antibacterial effectiveness against this pathogen, with inhibition zones extending from 15 mm to 17.33 mm (MIC: 3.13 to 25 mg/mL) and 9 mm to 12 mm (MIC: 12.5 to 25 mg/mL), respectively. Moreover, the outcomes of this investigation substantiate the antibacterial capabilities of E. camaldulensis, A. indica and A. vera against dermatological pathogens, advocating their inclusion in topical antibacterial formulations as a strategic countermeasure to the escalating challenge of drug resistance.