嗜水气单胞菌气溶素和溶血素基因的克隆与结构预测

从患出血病草鱼体上分离出1个菌株,传统分类学及16SrRNA基因鉴定其为嗜水气单胞菌,人工感染实验显示该分离菌株为强毒株。克隆该菌株的气溶素(aerolysin,aerA)基因和溶血素(hemolysin,hlyA)基因,序列分析显示这2个基因只有46.7%的同源性。Blast分析显示,hlyA基因与GenBank上已登录的hlyA序列具有较高的同源性,而aerA基因与已登录的aerA基因以及一些hlyA序列也具有较高的同源性。对与aerA基因同源性较高的这些hlyA序列进行结构域预测,发现它们均具有APT结构域和气溶素结构域,说明它们实际上应是aerA基因,只是命名上与hlyA基因混淆。用DNAstar软件预测aerA和hlyA的抗原区,显示它们均具有很好的抗原性。用特异性引物检测菌株的aerA基因和hlyA基因,结果显示2株毒力株均有特异条带,而无毒株则未扩增到特异条带,说明aerA和hlyA有可能作为鉴定嗜水气单胞菌毒力菌株的标记。

Cloning and Structure Prediction of aerA Gene and hlyA Gene of Aeromonas hydrophila

A bacteria strain was isolated from grass carp which suffered from hemorrhage.The bacteria strain was identified as Aeromonas hydrophila by both traditional taxonomic method and 16s rRNA identification,and it was identified as a virulent strain by artifical infection experiment.Aerolysin (aerA) gene and hemolysin (hlyA) gene of the strain were cloned.Sequence analysis showed that these two genes shared lower similarity (46.7%).Blast analysis showed that hlyA genes had higher similarities with their counterp...