Bacterial composition isolated from ulcers “ba dau” of soft-shelled turtles (Pelodiscus sinensis) in Nam Dinh farm and characterization of Aeromonas spp. virulence

Pelodiscus sinensis is a widespread species of soft-shelled turtle that commercially cultured in freshwater and prominently exploited as speciality food Vietnam. During the cultivation, there are distinctly recurrent epidemic diseases causing economically vast damage for farmers. In this research, we carried out isolation microorganisms from typical ulcers “ba dau” presenting on taken Nam Dinh farm. The samples were inoculated common media used bacteria, actinomyces, fungus yeast. Only bacteria grew culture medium. Fifteen bacterial strains isolated identified by 16S rRNA sequence analysis. They belonged to genera such Acidovorax (n=1), Acinetobacter Aeromonas (n=8), Citrobacter Chryseobacterium Moraxella Paludibacterium (n=1) Parabacteroides (n=1). which, eight spp. selected further research virulence characterization. PCR results showed these possessed at least 4/7 genes including aer (75%), alt (37.5%), ast (50%), ela (87.5%), exu ( 100%), hlyA (37.5%) ser (100%). With additional tests, confirmed virulent expression haemolysin (100%), protease DNAase elastase (25%) cytotoxicity (62.5%). These scientific basis establish develop practical methods controlling preventing "ba dau" disease future.