维氏气单胞菌TH0426株ndk基因缺失株的构建与生物学特性分析

Construction and biological characterizations of ndk gene mutant in Aeromonas veronii TH0426

为研究维氏气单胞菌ndk基因的功能,利用自杀性质粒pRE112通过同源重组的方法缺失ndk基因,然后对野生株和缺失株的生长能力、运动性、生物被膜形成能力及LD50等进行差异分析。经过PCR以及荧光定量PCR表达水平证明ndk基因缺失成功;生物学特性研究显示,缺失株的生长能力和泳动性均下降;生物被膜形成能力与野生株相比差异极显著(P<0.001);与野生株相比,LD50升高了5.5倍,且差异极显著(P<0.001)。由此可以推测,ndk基因与维氏气单胞菌的毒力及生物被膜形成密切相关。本研究结果为维氏气单胞菌致病机制的研究奠定了基础。

In order to study the function of ndk gene in Aeromonas veronii, the ndk gene mutant was constructed using suicide plasmid p RE112 by homologous recombination,then the differences between wild and mutant strains in growth ability,motility,biofilm formation and LD50 were analyzed.The results of PCR and expression of fluorescence quantitative PCR showed that ndk gene mutant was confirmed.The biological characteristics showed that the decrease of the growth ability and the migratory ability on the deleted strains.The formation ability of biofilm as well as the increased 5.5-fold of LD50 in the mutant strains were significantly different from the wild strain TH0426(P<0.001).The studies suggested that the ndk gene of A.veronii was closely related to the virulence and biofilm formation.The results laid the foundation for the study on pathogenesis of A.veronii.