Antibacterial Effect of Nymphaea lotus (Linn) Extracts on Enteric Bacteria Isolated from River Ogbese, Nigeria

Abstract
The increase in multidrug resistance pathogenic bacteria and decrease in efficiency of existing antibiotics is a serious global health concern which call for development of new alternative medicine and continuous research for new classes of antimicrobial agents that can be effective in destroying these multidrug resistant pathogens without or with minimal side effect and at an affordable cost. N. lotus has been reported to possess some amount of phytochemicals such as phenols, tannins, saponins, steroids, proanthocyanidins and flavanols which may serve as an effective antimicrobial agent. This study was aimed at determining the antibacterial effect of Nymphaea lotus (Linn) extracts on enteric bacteria isolated from River Ogbese, Nigeria. Water samples were collected every week for a period of sixteen (16) weeks aseptically and transported to the laboratory for microbiological and physicochemical examinations; enteric bacteria were isolated from the water samples using membrane filtration method. Bioactive components of N. lotus were extracted using Ethanol, water and N-Hexane solvents. In-vitro antibacterial effect of N. lotus extracts was assayed using agar well diffusion technique. Results showed Shigella and faecal coliforms had the highest occurrence in the water samples at (30.19%) followed by Salmonella (20.76%) and Escherichia coli (18.87%). Physicochemical characteristics of water samples from River Ogbese showed that water temperature ranged from 22.00 to 28.10 ℃, turbidity ranged from 2.00 to 33.80 NTU and phosphate ranged from 5.45 to 68.57 mg/L respectively. Whilst the isolates had the highest total percentage resistance to Augmentin at 20.03 %, ethanol extract of N. lotus exhibited the highest mean zone of inhibition of 24.67±0.67 mm against the isolates at 100 mg/mL respectively. The findings from this study suggest N. lotus extracts to be effective in the treatment of enteric infections that may occur as a result of consumption or contact with faecal impacted water.