First Report of Two Bacterial Diseases from the Freshwater Fishes of the Andaman Islands, India

Background: Studies on the bacterial diseases from the Andaman and Nicobar Islands are scanty and have only two reports recorded during 1996 and 1999. A case of emaciation and abdominal dropsy caused by different strains of Aeromonas hydrophila was recorded by earlier workers in the Andaman, Islands. In the present work, a similar disease syndrome was recorded in Barbonymus gonionotus and Cyprinus carpio var. Koi. The present study served to investigate the disease’s cause and the pathogen associated with it. Methods: This study details the isolation, biochemical and molecular characterization of three bacterial pathogens associated with emaciated, tail rot syndrome (ETS) and big belly syndrome (BBS) in B. gonionotus and C. carpio var. Koi respectively. Histology and re-infectivity study was also done for the infected host tissues and with Catla catla fingerlings. Result: This study constitutes the first report of three bacterial pathogens from the Andaman Islands, India viz., Aeromonas veronii, Aeromonas sp. and Pseudomonas alcaligenes causing emaciation and abdominal dropsy, with biochemical, molecular, histopathological and experimental challenge study evidence.