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【目的和方法】鳗弧菌是一种嗜盐的革兰氏阴性细菌,也是鱼类弧菌病的主要病原。对斑马鱼的半数致死量研究结果表明,鳗弧菌菌株VIB72具有较高的毒力,而菌株CW1的毒力较低。本文利用抑制性消减杂交(SSH)技术对这两个菌株的遗传差异进行了研究。【结果】通过对差减文库筛选,分离到59个对菌株VIB72的阳性克隆,并对这些克隆的DNA序列进行了测定。17个基因片断与其它细菌的已知功能的基因有较高的同源性,其中包括可溶性溶胞壁质转糖基酶、转移蛋白MobA和MobC、转座子IS66、抑制相关蛋白(金属β-内酰胺酶和乙酰转移酶家族)、毒素蛋白(DT-201和alveicin A免疫蛋白)、与OLD家族相似的ATP依赖性核酸内切酶以及SocE和GTP结合蛋白HflX(有高频率的溶原化)。这些基因片断有可能是鳗弧菌毒力岛的一部分。其他的基因片断与其它的已知基因没有明显的相关性。【结论】这些结果表明,SSH技术成功地鉴定了不同致病性的鳗弧菌菌株的基因差异及潜在的毒力基因。
【Objective and Methods】 Vibrio anguillarum is a halophilic gram-negative bacteria, is also the major pathogen of fish vibriosis. The median lethal dose of zebrafish showed that V. anguillarum strain VIB72 had higher virulence and strain CW1 had lower virulence. In this paper, SSH was used to study the genetic differences between these two strains. 【Result】 By screening the subtractive library, 59 positive clones of VIB72 were isolated and the DNA sequences of these clones were determined. The 17 gene fragments shared high homology with known functions of other bacteria, including soluble lysosomal glycosylase, MobA and MobC transfer proteins, transposon IS66, and the inhibition of related proteins (metal beta - lactamase and acetyltransferase families), toxin proteins (DT-201 and alveicin A immune proteins), ATP-dependent endonucleases similar to the OLD family, and SocE and GTP binding proteins HflX Change). These gene fragments may be part of Vibrio anguillarum virulence islands. Other gene fragments and other known genes have no obvious relevance. [Conclusion] These results indicate that the SSH technique has successfully identified the genetic differences and potential virulence genes of different pathogenic V. anguillarum strains.