Clinical and Pathological Investigation of Citrobacter freundii in Rainbow Trout (Oncorhynchus mykiss, Walbaum)

Authors: Seyit AYDIN, Selahattin ÇELEBİ, İhsan AKYURT

Abstract: The bacterium, Citrobacter freundii was isolated from naturally infected aquarium fish species (Poecilia sp., Xiphophorus demenciare, Xiphophorus pygmaeus, Carassius auratus and Astronotus ocellatus), and its pathogenicity was tested using healty 1.5-year-old rainbow trout. The infection caused gross clinical symptoms such as ulcerative lesions on skin, distended abdoman, pale liver, darkened spleen, watery kidney, bloody exudate in gastro-intestinal system too. Histopathological abnormalities were observed in tissues of skin, gills, liver, kidney, spleen and intestine. In a therapeutic experiment injection with oxytetracycline controlled the infection.

Keywords: Fish diseases, Rainbow trout, Aquarium fish, Citrobacter freundii.