Fish ponds with poor water quality will cause fish mortality and outbreak of diseases to fish consumers. Evaluation of physicochemical, bacteriological and parasitological parameters of selected fish pond water samples in Awka and its environment was conducted to determine their quality and suitability for fish farming. Physicochemical analysis was done using standard analytical methods. The total bacterial count, and parasitological analysis were done by serial dilution and centrifugation method respectively. Molecular identification was done according to Maldi-Tof mass spectrometry. Antibacterial activity of the antibiotics and extracts was done using disc diffusion method (Kirby-Bauer). Some of the physicochemical parameters exceeded their recommended limits. The bacterial counts ranged from (3.49 to 3.88) logcfu/ml for the inlets and (3.60 to 4.12) logcfu/ml for the outlets. Twelve bacterial species namely Klebsiella pneumoniae, Acinetobacter calcoaceticus, Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Pseudomonas fluorescens, Pseudomonas aeruginosa, Proteus mirabilis, Vibrio parahaemolyticus, Bacillus subtilis, Shigella flexineri and Salmonella typhi were isolated and identified. Seven genera of parasites namely Ichthyobodo, Myxobolus, Chilodonella, Ambiphrya (protozoans) Diplostomum, Leech and Bothriocephalus (helminths) were isolated from the fish ponds. Isolation of bacteria and parasites were more in the fish pond outlets. The antibiotics, garlic and ginger showed variable susceptibility to the isolates. The extracts inhibited the isolates in this descending order ginger ethanol > ginger methanol > garlic methanol > ginger hot water > garlic ethanol > garlic hot water. The MIC and MBC for ethanol, methanol and hot water extracts ranged from 31.25mg/ml to 62.5mg/ml and 62.5mg/ml to 125mg/ml respectively. The use of ginger and garlic for control of fish pathogens appears to be justified. The presence of these bacteria and parasites above admissible limits showed paucity of proper fish pond management services. There is therefore a need to monitor fish ponds water quality so as to prevent an epidemic.
Keywords: Sanitary risk assessment, Physicochemical, Bacteriological, Parasitological, Conventional antibiotics, Garlic, Ginger, Minimum inhibitory and bactericidal concentrations