Prevalence of Aeromonas species in Clarias gariepinus and water from different culture facilities in fish farms in Kwara State, Nigeria

Abstract

Aeromonas species are associated with diseases on fish farms leading to mortality and economic losses. In order to determine the prevalence and diversity of Aeromonas species from water and Clarias gariepinus cultured in the different holding facilities; five hundred and seventy six Clarias gariepinus fish and one hundred and eight water samples were randomly sampled from fish farms in Kwara State. The samples were clinically and bacteriologically examined and confirmed using Oxiod rapid microbat identification test kits for Gram-negative bacteria, Microbact 24E (MB24E). The overall prevalence of Aeromonas species from water from the different cultured facilities revealed water sampled from earthen ponds had the highest prevalence of 66.67 % followed by concrete tanks with a prevalence of 41.66 % and the least prevalence of 30.56 % was recorded for water in plastic tanks. A similar pattern was recorded in Clarias gariepinus from the different holding facilities showing that earthen ponds had the highest prevalence of 40.10 % when compared with concrete tanks 28.65%, and to plastic tanks 20.83 %. Four varying diversities of Aeromonas species comprising of Aeromonas hydrophila, Aeromonas caviae, Aeromonas veronii biovar sobria, and Aeromonas veronii biovar veronii were isolated from both water and fish from the different holding facilities. From this study, cultured Clarias gariepinus were susceptible to Aeromonas species irrespective of the culture facilities. Therefore, there is need for proper management practices and adherence to biosecurity measures to prevent the outbreak and spread of diseases on the farms.