我国脑膜炎奈瑟菌中nalP基因的分布特征

Distribution characteristics of nalP gene of Neisseria meningitidis in China

目的了解我国脑膜炎奈瑟菌(Nm)菌株的nal P基因分布特征,为其功能和作用机制研究提供依据。方法采用多位点序列分型方法对187株分离自我国的Nm菌株进行分子分型。利用菌株全基因组框架图获得nal P基因及其两侧序列,对基因序列进行同源性比对及聚类分析。结果 178株Nm携带nal P基因;Nm中nal P基因与淋病奈瑟菌(Ng)中nal P基因的同源性为95%~96%,但系统进化分析明显分为两支,两侧间隔区同源性>85%。9株无nal P基因菌株中6株为?nal P2型,新发现3种排布方式。C群患者和健康携带者来源phase on菌株数差异有统计学意义。结论 Nm中nal P基因可能由Ng获得后各自独立进化,无nal P基因菌株可能是nal P基因丢失,能够表达Nal P的C群患者来源菌株可能缺失Nal P的补偿机制。

Objective To investigate the distribution characteristics of the nal P gene of Neisseria meningitides in China.Methods Multi locus Sequence Typing was used to analyze the molecular subtyping of the 187 N. meningitides isolates.Homologous comparison and clustering analysis were conductexd after obtaining the nal P gene and its flanking sequences from the whole genome sequences. Results A total of 178 isolates of N. meningitides were nal P positive. The homology of nal P gene of N. meningitides and N. gonorrhoeae was 95%–96%, but they were split in two disparate branch, the homology of the flanking region of nal P was more than 85%. Six of the 9 nal P– negative strains were ？nal P2 and 3 new type of arrangement were found. The difference in phase on number between invasive N. meningitides C strains and healthy carriage strains was statistically significant. Conclusion The nal P gene of N. meningitides might be obtained from N. gonorrheae and then has evolution independently. It is possibly that nal P negative strain has lost nal P gene. The invasive N. meningitides C strains which could express nal P might be in deficiency of the compensating mechanism.