Pathogenic bacteria associated with cultured American eels, Anguilla rostrata Le Sueur

American eels, Anguilla rostrata , obtained from an aquaculture facility in South Carolina were examined for diseases and bacterial pathogens were isolated and identified. During the first year of culture, only a small number of bacterial pathogens and diseases were detected in glass and elver stages. This observation appears to be associated with a natural immunity to disease and/or administering the antibacterial compound, nitrofurazone. There was also a positive correlation between the use of nitrofurazone and the isolation of nitrofurazone resistant strains of Aeromonas hydrophila . A higher incidence of bacterial pathogens and/or disease occurred during the process of culling and in older eels during warmer months. The primary aetiological agent of disease of cultured eels was A. hydrophila . Other potential pathogens isolated included A. salmonicida, Vibrio spp. and Pseudomonas spp.