Isolation,identification and drug-resistance genes detection of Acinetobacter junii from fish

In this study,two bacteria strains SX01 and SX02 were isolated from diseased Acipenser schrenckii and the carps(Carassais auratus gibelio)were artificially challenged to test the pathogenicity of the strains.Morphology profiles were observed,physical and biochemical characteristics were tested,and molecular analysis was combined to identify the isolated strains,also antibiotics drug resistance genes were detected.The results showed,the strains were pathogenic to the carps,with the 96 h LD₅₀=1.02×10⁹cells/mL.The strains were Gram negative,short rods,nearly sphere,oxidation test and motility negative,catalase positive,showed the profiles of Acinetobacter genus.16S rRNA gene sequence of the strains shared 100% identity with those published data of A.junii in GenBank,and rpoB sequence of SX01 showed 99% identity with those of A.junii,were well identified the strains to A.junii.A β-lactam enzyme coding gene TEM-1 and acetamide transferase gene Aac(3)Ⅱ were detected in the strains,suggesting possible clinical contamination.Enough attention must be paid to guard against the drug-resistant A.junii in aquaculture and food sanitation.