大菱鲆源鳗弧菌毒力基因的检测及序列分析

Detection and sequence analysis of virulence genes of Vibrio anguillarum isolated from turbot(Scophthalmus maximus)

采用PCR方法,对分离于大菱鲆的30株致病性鳗弧菌进行了溶血素vah1基因、鞭毛蛋白flaA基因、金属蛋白酶empA基因及外膜蛋白ompU基因的检测,选取3个代表菌株的相应基因序列通过Blast与GenBank中公布的参考菌株进行核苷酸同源性比较分析。结果表明,所检测的30株鳗弧菌均携带vah1、flaA、empA、ompU基因,携带率为100%;所测代表菌株的vah1、flaA、empA基因同参考菌株间均具有较高的同源性(93.9%～99.9%),而外膜蛋白ompU基因,3株代表菌间存在较大差异(86.0%～95.9%),其中的S010610-1株与其他2株代表菌及参考菌株均存在较大差异,在进化树中单独聚为一支。3株代表菌的其他基因(vah1、flaA、empA)均具有较高的同源性(94.2%～99.5%),但均存在一定的差异性。

Thirty pathogenicity Vibrio anguillarum strains isolated from turbot （Scophthalmus maximus ）were investigated for the presence of virulence genes including hemolysin（yah1）, flagellin（JlaA） ,metalloprotease（ernpA） and outer membrane protein（ornpU） using PCR methods in this study, and the homology of virulence genes from diverse representative V. anguillarum strains were compared with available sequences in the NCBI GenBank. The results showed that all the detected strains contained the vahl,flaA, ernpA and ornpU genes, the carrier rates were 100%. The vahl,jqaA and empA genes of three V. anguillarum strains were sequenced, sharing 93.9%-99.9o/oo nucleotide sequence homology with the reference strains. There is big difference （86. 0^-95. 9~） of ornpU gene in the three representative strains, the ompU gene of strain S010610-1 has significant difference with the sequences of reference strains in the NCBI GenBank and the other representative strains,and form a separated cluster in the phylogenetic tree. There are higher homology （ 94. 2 %-99. 5 %） among other genes （vahl,flaA, ern pA） of representative strains, but all exist some difference.