布鲁氏菌vjbR突变株的构建及其毒力表型分析

Construction of the vjbR Mutant Strain and Analysis of Its Virulence Phenotypes

摘要:

为分析vjbR在布鲁氏菌毒力中的作用, 构建了vjbR的突变株和互补株, 并分析了它们在巨噬细胞和小鼠体内的存活能力。利用同源重组的方法, 用卡那抗性基因替换了16M的vjbR (BMEII1116)基因, 得到了vjbR的缺失突变株16MΔvjbR。将vjbR基因的ORF克隆到pMD18-T载体中, 然后将其转入到突变株16MΔvjbR中得到互补株16MΔvjbR-C。用16M、16MΔvjbR和16MΔvjbR-C侵染巨噬细胞和感染小鼠, 比较分析它们在巨噬细胞内的生存能力及小鼠毒力。研究结果表明vjbR突变株在巨噬细胞和小鼠体内的毒力减弱, 存活能力下降, 说明vjbR基因是布鲁氏菌16M的毒力相关基因, 对于布鲁氏菌建立慢性感染是必要的。

关键词:布鲁氏菌, vjbR, QS系统, 毒力

Abstract:

To evaluate the virulence roles of vjbR, the mutant and complementary strains of vjbR were constructed, and their survival capabilities in macrophage and mice were assayed. By using homologous recombination, the vjbR (BMEII1116) was replaced by kanamycin gene, resulting the deletion mutant 16MΔvjbR. The ORF was PCR amplified and cloned into pMD-18T, which was transformed into mutant strain to generate the complementary strain 16MΔvjbR-C. The three strains, 16M, 16MΔvjbR and 16MΔvjbR-C, were used to infect macrophage and mice, and their survival capability were assayed and compared. The vjbR mutant strain16MΔvjbR showed reduced survival in macrophage and mice, indicating that vjbR is a virulence gene of Brucella, and is essential for establishment of choronic infection.

Key words:Brucella, vjbR, quorum sensing system, virulence