Histopathological Analysis of Striped Catfish, Pangasianodon hypophthalmus (Sauvage, 1878) Spontaneously Infected with Aeromonas hydrophila

Abstract

Mass mortality of Pangasianodon hypophthalmus in cultured earthen pond was investigated. Infected P. hypophthalmus were characterized by number of clinical signs such as abnormal swimming behaviour, skin lesion, and local hemorrhages. Moribund samples were collected from Karnataka to investigate the etiological as well as histopathological changes. The causative agents of the diseased pangasius were identified as Aeromonas hydrophila using specific selective media, polymerase chain reaction (PCR) technique and through scanning electron microscopy (SEM). The amplified DNA product was 130bp for haemolysin genes of A. hydrophila. Scanning electron microscopy revealed straight rods with single polar flagellum of A. hydrophila. Histopathogical studies of different organs of diseased P. hypothalamus revealed cellular alteration such as necrosis and hemorrhages in the gill and liver, tubular degenerations in the kidneys, splenitis accompanied with hemosiderosis in spleen. Additionally, there was sloughed necrotic debris in intestinal lumen with increase in goblet cell number.