Bacteria and fungi isolates associated with harvested fish from Useh flood reservoir in Edo State

Abstract

This study was conducted to ascertain the presence of bacteria and fungi in fish samples harvested from Useh flood reservoir. A total of 15 samples of harvested fishes over a period of 3 months, were collected and transported with clean Ziplock© bags to the laboratory for microbiological quality analysis. Isolation of bacteria was done by pour plate method. The serial dilution method by Harrigan and McCance (1976) was aseptically carried out in sterile test tubes for the ten-fold dilution. Aliquots from each tube was used to inoculate the media for isolation of fungi using the pour plate method (Bourbonnais et al., 1995). The plates were then examined after incubation and the number of colony forming units (CFU) that developed were counted. All the samples were found to harbor bacteria and fungi up to a range of 106 cfu/g. The total viable bacteria count of 4.39 x 105cfu/g, 4.41 x 105cfu/g and 4.37 x 105cfu/g were recorded in the gills, colon and skin respectively. While the total viable count of fungi were 5.17 x 104cfu/g, 3.33 x 104cfu/g and 4.67 x 104cfu/g in the gills, colon and skin respectively. Escherichia coli were found in all samples as a specific bacteria pathogen. The bacteria isolates identified were Klebsiella Spp., Escherichia coli, Bacillus Spp., Staphylococcus aureus, Proteus Spp., Micrococcus Spp., Pseudomonas Spp., Bacillus subtilis, Staphylococcus epidermis and Pseudomonas aerogenosa. The fungi isolates identified in fish sample during the period of study were Cladosporium Spp., Saccharomyces Spp., Cryptomonas Spp., Aspergillus nidulans, Aspergillus niger, Penicillium Spp., Trichoderma viridi, Cryptomonas Spp., Mucor mucido, Mucor Spp., Botrydiplodia Spp., Aspergillus tamarii, Neurospora Spp., Cryptomonas neoformis and Helminthosporium Spp. It was therefore observed that bacteria and fungi above 105cfu/g were present in fishes harvested from Useh flood reservoir. Bacteria count of less than 105/g is indicative of good fish quality, there is therefore the likelihood of infestation of persons with these pathogenic bacteria in this environ that consume harvested fish or make contact with the fish from Useh flood reservoir.