Pasteurella piscicida is a bacterium that lacks taxonomic validity. In this study, strains coming from all over the world have been tested in order to compare their biochemical reaction-profile and to determine the most distinguishing characteristics that can be used for the fast identification of this organism. The strains had all a similar reaction profile, being positive for arginine dihydrolase, oxidase, catalase, VP and MR reactions, lipase, amylase and DNase. They could ferment glucose, levulose, galactose and mannose with acid production, and could grow on McConkey agar plates, at salinity 0.5-3%, but not at 0% or 8%. No growth was observed on TCBS plates. All strains, except from the Japanese ones, were very sensitive to antibiotics, but none of them was sensitive to Oxacillin and 75% of them were resistant to Streptomycin. Sections from fish tissues, infected with Pasteurella piscicida, were examined to locate the bacterium and to discuss its pathology. |
