Abstract:
This study was aimed at determining the antibacterial effect of Nymphaea lotus (Linn) and
Allium sativum (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. Ethanol, water and N-Hexane
were used as solvent to extract the bioactive components of N. lotus and A. sativum, phytochemical
constituents and chemical compositions of the extracts were evaluated using standard methods. In-
vitro and in-vivo antibacterial efficacy of N. lotus and A. sativum extracts were assayed using agar
well diffusion technique and Swiss albino mice respectively. Results showed Shigella and faecal
coliforms had the highest occurrence (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 °C, 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 and water extract of A.
sativum exhibited the highest mean zone of inhibition of 24.67±0.67 mm and 22.00±1.16 mm
against the isolates at 100 mg/mL respectively. The histological effects of treatment with water
extract of A. sativum, ethanol extract of N. lotus and combination of water extract of A. sativum
and ethanol extract of N. lotus at ratio 1:1 on organs invasion of Salmonella showed that major
pathological effects were exerted on the liver and kidney of mice. The findings for this study
suggests that the extracts of N. lotus and A. sativum may be used as antibacterial agents in the
management of infections that may occur as a result of consumption or contact with faecally
impacted surface waters.
