First isolation and identification of Aeromonas veronii and Chryseobacterium joostei from reared sturgeons in Fars province, Iran

The purpose of the present study was to isolate and identify the pathogenic agents in Acipenser stellatus (Pallas, ۱۷۷۱) and Huso huso, (Linnaeus, ۱۷۵۸) reared in the south of Fars province, Iran which have shown infectious disease signs. Samples from spleen and kidney of ۳۲ fishes showing septicemia symptoms such as decreasing of appetite, unbalanced swimming, expanded wounds, and petechia on the body surfaces, pectoral fins rot, visceral hemorrhage, bleeding on the spleen, and heart ascites were collected. Then samples were cultured on brain heart infusion agar growth media, stain and biological and biochemical tests on purified bacteria were performed. On the other hand, ۱۶S rDNA region of the isolated organism was amplified using PCR. The amplified gene fragment was sequenced and evolutionary history was inferred by phylogenetic tree construction using neighbor-joining method. Results indicated that two bacterial species including Chryseobacterium joostei which isolated from the kidney of stellate sturgeon (۴۳.۰۰%), and Aeromonas veronii which isolated from the spleen of both sturgeon species (۷۵.۰۰% and ۳۱.۰۰% from beluga and stellate sturgeon, respectively), were recognized. Phylogenetic tree analysis showed that Fars isolated organisms including A. veronii and C. joostei had highest similarity with A. veronii bv veronii and C. joostei isolated from France, respectively.

کلیدواژه ها:

<i>Acipenser stellatus</i> ، <i>Aeromonas veronii</i> ، <i>Chryseobacterium joostei</i> ، Fars province ، <i>Huso ‎huso</i>