Association of Aeromonas hydrophila with epizootic ulcerative syndrome (EUS) of freshwater fish in Sri Lanka

Abstract

Aeromonas hydrophila was the predominant bacteria isolated from the haemorrhagic lesions and necrotic ulcers in the seven species of fish, Etroplus suratensis, Ophicephalus striatus, Puntius sarana, Rasbora danicornius, Trichogaster pectoralis, Tor khudree lonispinnis and Wallago attu affected by eizootic ulcerative syndrome(EUS), during the 1990 and 1991 disease outbreaks in Sri Lanka. Severely affected fish were truly septicemic, as A. hydrophila was recovered from their internal organs. A. hydrophila isolated from diseased fish and injected intramuscularly into healthy E. suratensis and O. striatus induced dermonecrotic lesions resemblin EUS. The results suggests that A. hydrophila is consistently associated with EUS in Sri Lanka anf may play an important role in the patlogenesis of the disease.