Study on the characteristics and pathogenicity of Staphylococcus lugdunensis isolated from sturgeon, Acipenser schrencki

This study described the first isolation of Staphylococcus lugdunensis from sturgeon, Acipenser schrencki, in Taiwan. The pathogenicity experiments were performed by immersion challenge in juvenile sturgeons. Fish were received 8.1×108CFU/mL, 1.95×109CFU/mL and 1.95×109CFU/mL of bascterial suspension and triple duplicate, and the cumulative mortality was 83%, 66.6％and 33.3％, respectively. It revealed chronic pathogenicity of S. lugdunensis for sturgeons. During the necropsy, the body of dead fish appeared curved shape, discorolation and mucus secretion. The congestion and hemorrhage were present on the base of operculum, the surface of abdmenal skin, and the skin of scraping area. The growth character, morphology and biochemical properties of S. lugdunensis isolated from sturgeons were similar to the reference strain of S. lugdunensis. The 16S rDNA sequence of 1320bp amplicon from isolates has shown 99% identify with S. lugdunensis. The S. lugdunensis hemolysin (SLUSH) sequence of 1011bp amplicon also has shown 99% identify with S. lugdunensis hemolysin gene. The results of this study revealed pathologenicitic and hemorrhagic of S. lugdunensis in sturgeons. This was the first report of S. lugdunensis in sturgeon cases.