RESUMEN
The bacterial strain CSS-4-2 isolated from the spleen of Carassius auratus of penze(♀) ? Cyprinus acutidorsalis (♂) with septicemia was proved to b e a pathogen by artificial infection. This bacteria has short rod-shaped cells , Gram negative and motile, with single polar flagellum, and with not capsule. No spore was formed , and it was resistant to 0/129. It could utilize glucose, mal t ose ,mannite, sucrose and inositol, but could not utilize malonate, lactose, xyl ose, raffinose, sorbin and adonitol. Oxidase and arginine dihydrolase was posit ive.While urease, lysine decarboxylase and ornthine decarboxylase was negative .Bacteriological identification by VITEK-AMS-60 showed the strain CSS-4-2 w as Aeromonas caviae. Drug sensitivity assay showed that this strain was sen sitive to s treptomycin, tobramycin, chloromycetin, rifampicin, norfloxacin and nitrofuranto in, but resistant to penicillin G.