ISOLATION OF MAJOR BACTERIAL SPECIES ASSOCIATED WITH EQUINE SKIN WOUND AND IN-VITRO ANTIBACTERIAL ACTIVITIES OF SELECTED MEDICINAL PLANTS AGAINST ISOLATED SPECIES IN MERTI DISTRICT, SOUTH EAST ETHIOPIA

Abstract

Wound is a disruption of the normal continuity of body structures by physical, chemical, thermal, microbial and immunological factors. Skin wounds are among one of the commonest health concerns that afflict working equine. Medicinal plants are traditionally used to treat different human and livestock ailments among that it is used to treat equine skin wounds. They have antimicrobial activities and effectiveness in controlling certain viral, bacterial and fungal diseases. In study district, there was no study conducted on evaluation of antimicrobial activities of traditionally used medicinal plants against common bacteria involved in wound infection. This study was aimed to evaluate in-vitro antibacterial activity of crude methanolic extracts of selected medicinal plants against isolated pathogens in Merti district. Agar well diffusion, disc diffusion and broth dilution methods were used to determine the antibacterial activity of selected medicinal plants. In present study, S. aureus was the most isolated bacteria from equine skin wound and all the tested medicinal plants like Z. officinale, A. sativum, C. macrostachyus and S. incanum were found to exhibit considerable antibacterial activity against S. aureus, P. aeruginosa, E. coli and K. pneumoniae. By agar well diffusion method, A. sativum and C. macrostachyus at 780 mg/ml concentration showed the highest zone of inhibition 28.9mm and 29.2mm, respectively against standard strains of S. aureus. By disc diffusion method, the extracts of combined Allium-zinger, Allium-croton and zinger-croton at 780 mg/ml concentration showed highest zone of inhibition 33.2mm, 33.2mm and 33.6mm, respectively on standard strain of S.aureus. The result of the MIC revealed that extracts of tested medicinal ranged from 12.18mg/ml for A. sativum against standard S. aureus to 390mg/ml for S. incanum against P.aeruginosa while MBC ranged from 24.38mg/ml for A. sativum against standard S. aureus to >390mg/ml for S. incanum against both standard and clinically isolated K. pneumoniae and P. aeruginosa. As conclusion, this study clearly indicates that all extracts of selected medicinal plants have a potential of antibacterial effects against standard strains and clinically isolated pathogens from skin wound of equine. Further study should be conducted on in-vivo antibacterial to confirm the in-vitro antibacterial activities of crude extracts against tested isolates to elucidate the safety of test plants on their use as treatments of equine skin wound