鲍曼不动杆菌bauA与basD基因缺失株的构建及其生物学功能研究

Construction of bauA and basD gene deletion strains of Acinetobacter baumannii and its biological function

目的构建鲍曼不动杆菌bauA与basD基因缺失株,研究铁载体相关基因对鲍曼不动杆菌生存及致病性的影响。方法构建pMO130-Tel^(R)-bauA(Up/Down)及pMO130-Tel^(R)-basD(Up/Down)质粒,通过同源重组获得基因缺失株;通过基因缺失株生长曲线测定、运动能力比较、生物膜的形成及胞内存活能力测定等方法对缺失株的功能进行了测试。结果通过构建含同源片段的重组pMO130-Tel^(R)质粒,分别成功敲除鲍曼不动杆菌4294中的bauA基因和basD基因,突变株在缺铁条件下生长能力显著下降,运动能力、生物膜形成能力及胞内存活能力也有不同程度的下降。结论bauA基因和basD基因敲除对鲍曼不动杆菌生存有很大影响,提示铁载体相关基因在细菌致病中发挥重要作用。

Objective To construct Acinetobacter baumannii bauA and basD gene deletion strains respectively,and study the effects of siderophore-related genes on the survival and pathogenesis of A.baumannii.Methods Plasmids pMO130-Tel^(R)-bauA(Up/Down)and pMO130-Tel^(R)-basD(Up/Down)were constructed,and the gene deletion strains were obtained by homologous recombination.The function of the gene deletion strains was tested by measuring the growth curve of the deletions,comparing athletic ability,the formation of the biofilm and measuring the intracellular viability.Results By building restructuring pMO130-Tel^(R)plasmid containing homologous fragments,respectively on success in addition to basD and bauA genes in A.baumannii 4294,mutations in a significant reduction in the ability to grow under the condition of iron deficiency,athletic ability,the ability of biofilm formation and intracellular survival ability also had varying degrees of decline.Conclusion bauA gene and basD gene knockout have a great impact on the survival of A.baumannii,suggesting that siderophore-related genes play an important role in bacterial disease.