莱姆病螺旋体中国分离株外膜蛋白C基因的克隆与序列分析

Molecular cloning and DNA sequencing of OspC gene of two strains Borrelia burgdorferi isolated in China

目的了解引起我国莱姆病的伯氏疏螺旋体外膜蛋白Ｃ（ＯｓｐＣ）基因变异情况。方法应用聚合酶链反应从２株莱姆病螺旋体中国分离株ＢＴ０１和ＢＪ－９０１１全基因组ＤＮＡ中将ＯｓｐＣ基因调出，并插入质粒ｐＧＥＭ－３ＺＦ（＋）中，构建重组质粒ｐＧＥＭ－３ＺＦ（＋）－ＯｓｐＣ，经Ｓａｎｇｅｒ双脱氧末端终止法测序，并将之与国外其它分离株进行同源性比较。结果除信号肽序列外，２株莱姆病螺旋体分离株ＢＴ０１和ＢＪ－９０１１的ＯｓｐＣ基因依次为５７９ｂｐ和５７６ｂｐ，分别编码１９３和１９２氨基酸，两者核苷酸和氨基酸序列的同源性分别为８６％和８３％，与国外分离株（ＰＢｉ、ＰＫｏ及Ｂ３１）的同源性均较高，其中ＢＪ－９０１１株与国际标准株Ｂ３１株之间核苷酸及氨基酸同源性达９９％。结论伯氏疏螺旋体Ｏｓ－ｐＣ基因在国内２个分离株之间存在一定差异。

Objective To investigate the variation of OspC gene in two Chinese isolates of Borrelia burgdorferi. Methods PCR technique was used to amplify the OspC gene from the whole cellular DNA of isolates BT01 and BJ 9011. The amplified products were inserted into plasmid pGEM 3ZF(+) and sequenced. Results Except the signal peptide, the OspC genes of the two isolates BT01 and BJ 9011 were 579bp and 576bp which encode 193,192 amino acids respectively. The nucleotide and amino acids sequence identity between the two strains was 86% and 83%. High homology exists between these Chinese isolates and several foreign isolates (PBi, PKo, B31), especially in BJ 9011. It had 99% nucleotide and amino acid sequence identitfied with B31. Conclusion Variations in OspC genes are noted between the two Chinese Borrelia burgdorferi isolates and foreign isolates.