Evaluation of bacteria pathogens with zoonotic potentials in catfish and pond water from selected fish farms, Ebonyi State, Nigeria

Fish, renowned for being a rich source of vital nutrients such as high-quality protein, polyunsaturated fatty acids, and essential minerals, can also act as a reservoir for zoonotic bacterial pathogens. These pathogens often indicate the level of environmental contamination in aquatic ecosystems. The study evaluated zoonotic bacterial pathogens in catfish and pond water samples from selected fish farms in Ebonyi State, Nigeria. A total of 72 samples, including catfish (48 samples) and pond water (24 samples), were collected from three locations: Abakaliki, Afikpo, and Ngbo. Standard microbiological and biochemical methods were employed to isolate, enumerate, and identify bacterial species. Morphological and biochemical analyses revealed the presence of Aeromonas sp., Vibrio sp., and Streptococcus sp. in both catfish and pond water samples. The biochemical analysis showed that Streptococcus sp. were positive to oxidase, lactase, glucose, sucrose, methyle red and catalase tests but showed negative result with Voges-Proskauer (VP) and citrate tests. However, Aeromonas species were positive to lactase, glucose, sucrose, methyl red, catalase, oxidase, indole and methyl red tests while Vibro species revealed to be variable to methyl red and VP-negative but positive to oxidase, lactase, glucose, sucrose, catalase and indole-negative, which were the same for both catfish and pond water samples. According to the distribution pattern of these microbes in the test samples, Aeromonas sp showed the highest prevalence (13.9%) in both test samples, while (18.75%) and (25%) were recorded in catfish and pond water respectively; their distribution across the three locations within the test samples were not statistically significant (p > 0.05), followed by Vibrio spp. (12.5%) in both samples while (18.75%) and (25%) were recorded in catfish and pond water respectively which their distribution were significant (p<0.05) and Streptococcus sp showed 8.3% in both samples while (12.5%) and (12.5%) were recorded in catfish and pond water respectively and the distribution pattern in the samples were not significant. The findings indicated compromised water quality in fish farms which is evident in the increased bacteria load, were likely influenced by environmental conditions and management practices.