EN
During the summer heat wave of July 2004, a large number of mallard ducks (Anas platyrhynchos) were found dead in Skaryszewski Park in Warsaw. Simultaneously, in the parks lake a massive wave of dead fish were discovered. Gram negative oxydase positive rods were isolated from the following organs of the dead ducks: kidneys, liver, pancreas and intestine, as well as in a pure culture. These bacteria caused a strong haemolyis on blood agar plates. Using API, NE test isolates were identified as Aeromonas hydrophila. The tested strain was proven susceptible, among others, to neomycine, streptomycine, gentamycine, tetracycline, flumequine, and norfloxacine, but resistant to amoxycillne, amoxycillin and clavulanic acid as well as to polimyxin.