空肠弯曲菌cheA基因插入突变及其对小鼠空肠定植能力的影响

Construction of cheA insertion mutant of Campylobacter jejuni and the effect of its adhesion on mice jejunum

【目的】构建空肠弯曲菌(Campylobacter jejuni)cheA基因插入突变株,了解CheA与空肠弯曲菌小鼠体内定植的相关性。【方法】运用同源重组的原理构建空肠弯曲菌cheA基因突变株,采用PCR技术检测cheA突变株的构建情况。通过基因回补试验构建cheA基因回补株。空肠弯曲菌感染小鼠,运用小鼠空肠内容物涂板计数的方法检测cheA突变株、cheA基因回补株和野生株定植小鼠能力的差异。【结果】PCR检测显示成功构建cheA基因突变株。空肠弯曲菌cheA基因突变株定植小鼠空肠的数量明显减少(P<0.05);cheA基因回补株定植小鼠空肠的数量跟野生株相比无明显差异(P>0.05)。【结论】本研究成功构建cheA基因突变株及其回补株。cheA基因可能参与空肠弯曲菌在小鼠体内定植的过程。

[Objective]To construct cheA（chemotaxis,che） insertion mutant of Campylobacter jejuni and to observe the role of cheA gene in adhesion of Campylobacter jejuni on mice jejunum.[Methods]We generated cheA gene insertion mutant of C.jejuni NCTC11168 based on homologous recombination.The cheA mutant was checked by PCR and sequencing.We detected the difference in mice jejunal adhesion between cheA mutant and wild-type of C.jejuni NCTC11168 by CFU（Colony-Forming Units） counting of C.jejuni in jejunal content.We confirmed the of role cheA gene plays in mice jejunal adhesion of Campylobacter jejuni by complementation analysis.[Results]PCR results reveal that we have successfully constructed cheA insertion mutant of C.jejuni NCTC11168.The cheA mutant displayed significantly attenuated colonization on jejunal mucosa of mice compared to wild-type strain（P 0.05）.Complementation analysis shows that the complementation of cheA mutant regained its ability in colonization on jejunal mucosa of mice.[Conclusion]The cheA mutant and its complementation were successfully constructed.The cheA gene may play an important role in colonization of C.jejuni on jejunal mucosa of mice.