Isolation and Identification of Pathogenic Aeromonas hydrophila From Esox lucius Around Urumqi in Xinjiang

Abstract:

Northern pike (Esox lucius), one of the major indigenous economic fish in Xinjiang, belongs to the ferocious carnivorous cold-water fish family. With the fast development of artificial breeding, disease outbreak has raised. The outbreak of bacterial sepsis is one of the dominant diseases to Northern pike farming, causing huge economic losses in local aquaculture. In order to identify the etiology of the Northern pike, the liver and kidney samples of Northern pike were collected for the morphology observations, physiological and biochemical tests, and 16S rDNA sequence analysis. Nine dominant bacteria were separated, which belong to the Aeromonas hydrophila family (named PK001−PK009). The PCR specificity detection results indicated that the separated nine strains contained three mainly and widely studied virulence factors of A.hydrophila ahpA, hlyA and aerA with the frequency from zero to three, which leaded to the discrepancy of strains. The illness of artificial recurrent infection and natural case of E. lucius were similar, and the origin infection bacteria were separated and further confirmed with A. hydrophila infection. A. hydrophila is the main pathogenic bacteria that induce fish bacterial sepsis.