Abstract:
Water is a valued natural resource for the existence of all living organisms. Management of the quality of this precious resource is, therefore, of special importance. Andrographis paniculata (Kalmegh) has been demonstrated to be a plant of medicinal importance. This study was aimed at determining the antibacterial activities of A. paniculata on methicillin and vancomycin resistant enteric bacteria isolated from River Owena. Water samples were collected from Owena River in Owena, Osun State, Nigeria.The bacteriological evaluation of the water samples was carried out using standard microbiological method. A. paniculata leaf and stem extracts were prepared using the polar (i.e., methanol) and nonpolar (i.e., n-hexane) solvents. The phytochemical constituents and antibacterial activity of all the extracts of A. paniculata leaf and stem were investigated using standard methods. Results revealed that methanol extracts from A. paniculata contained the higher amount of phytochemicals when compared to that of the n- hexane extracts.Salmonella and Shigella were both resistant to vancomycin, while they were only susceptible to methicillin once throughout the sampling week. The methanol extracts from A. paniculata showed higher antibacterial activity against the targeted bacterial isolates of enteric origin which include E.coli, faecalcoliforms, Shigella, Salmonella and intestinalenterococci. The methanol leaf extract of A. paniculata showed the maximum antibacterial activity against E.coli, Salmonella, Shigella, Intestinal enterococci and faecal coliformwith zones of inhibition 29.0 mm, 26.00 mm, 21.3mm, 21mm and 19mm respectively. The methanollic stem extract of A. paniculatashowed a maximum antibacterial activity againstSalmonellawith zone of inhibition of 25mm while n-hexane stem extractexhibited a maximum zone inhibition of 17.6 mm againstSalmonella. The minimum inhibitory concentration (MIC) value for all the A. paniculata extracts was at a concentration of 12.5– 50ml. The pH of the water ranged from 6.50 to 6.90, temperature ranged of 26 to 31oC. Thefindings from this study demonstrated that River Owena is highly contaminated with faecal materials and that leaf and stem extracts ofA. paniculatamay be used as antibacterial agents against methicillin and vancomycin resistant bacteria of enteric origin.
