Isolation, identification and virulence factor detection of pathogenicAeromonas salmonicida from rainbow trout Oncorhynchus mykiss
DIAO Jing1,2, LI Le1,2, WANG Xiao-lu1,2, FAN Ying1,2, YU Xiao-qing1,2, XU La1,2, GAI Chun-lei1,2, WANG Yong-qiang3, YE Hai-bin1,2
1. Marine Biology Institute of Shandong Province, Qingdao 266104, China; 2. Key Laboratory for Disease Control in Mariculture in Shandong Province, Qingdao 266104, China; 3. Wanzefeng Fishery Limited Corporation，Rizhao 250000, China
Abstract: One dominant bacterial strain RBWF-1 was isolated from the skin ulcer lesion of diseased rainbow trout Oncorhynchusmykiss, and its virulence was proved to be high to healthy rainbow trout by artificial LD50 value of 5.5×106 CFU/mL infection test to elucidate the mechanism of Aeromonassalmonicida in rainbow thout. 16S rDNA gene of strain RBWF-1 was amplified and sequenced, and was highly homologous with Aeromonassalmonicida subsp. masoucidastrain NBRC 13748 and A.salmonicida subsp. achromogenes strain NCIMB 1110, with similarity of 99.6%. Phylogenetic tree based on 16S rDNA gene revealed that strain RBWF-1 clustered together with A.salmonicida subsp. salmonicida, A.salmonicida subsp. masoucida, A.salmonicida subsp. achromogenes and A.salmonicida subsp. smithia. Biolog’s identification system combined with physiological and biochemical test indicated that strain RBWF-1 had the highest similarity with those of A.salmonicida subsp. masoucida, and was identified to be A.salmonicida subsp. salmonicida. Meanwhile, 7 virulence-related genes including haemolysin, serine protease, lipase, DNases, aerolysin, zonula occludens toxin and S-layer protein, were all detected in the isolated strain. The enzymatic activity test showed that the extracellular products of strain RBWF-1 had the activities of protease, lipase, amylase, DNase and hemolysin. The findings provide the necessary data and information for the infectious characteristics, taxonomic identification and vaccine development of A.salmonicida in rainbow trout cultured in China.
刁菁, 李乐, 王晓璐, 樊英, 于晓清, 许拉, 盖春蕾, 王勇强, 叶海斌. 虹鳟致病性杀鲑气单胞菌的分离鉴定及其毒力因子的检测[J]. 大连海洋大学学报, 2018, 33(4): 435-443.
DIAO Jing, LI Le, WANG Xiao-lu, FAN Ying, YU Xiao-qing, XU La, GAI Chun-lei, WANG Yong-qiang, YE Hai-bin, . Isolation, identification and virulence factor detection of pathogenicAeromonas salmonicida from rainbow trout Oncorhynchus mykiss. Journal of Dalian Ocean University, 2018, 33(4): 435-443.
2018, Vol. 33 
