Abstract：
A Borrelia miyamotoi gene with partial homology to bipA of relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae was identified by a GenBank basic alignment search analysis. We hypothesized that this gene product may be an immunogenic antigen as described for other relapsing fever Borrelia (RFB) and could serve as a serological marker for B. miyamotoi infections. The B. miyamotoi gene was a truncated version about half the size of the B. hermsii and B. turicatae bipA with a coding sequence of 894 base pairs. The gene product had a calculated molecular size of 32.7 kDa (including the signal peptide). Amino acid alignments with B. hermsii and B. turicatae BipA proteins and with other B. miyamotoi isolates showed conservation at the carboxyl end. We cloned the B. miyamotoi bipA-like gene (herein named bipM) and generated recombinant protein for serological characterization and for antiserum production. Protease protection analysis demonstrated that BipM was surface exposed. Serologic analyses using anti-B. miyamotoi serum samples from tick bite-infected and needle inoculated mice showed 94 % positivity against BipM. The 4 BipM negative serum samples were blotted against another B. miyamotoi antigen, BmaA, and two of them were seropositive resulting in 97 % positivity with both antigens. Serum samples from B. burgdorferi sensu stricto (s.s.)-infected mice were non-reactive against rBipM by immunoblot. Serum samples from Lyme disease patients were also serologically negative against BipM except for 1 sample which may have indicated a possible co-infection. A recently published study demonstrated that B. miyamotoi BipM was non-reactive against serum samples from B. hermsii, Borrelia parkeri, and B. turicatae infected animals. These results show that BipM has potential for a B. miyamotoi-infection specific and sensitive serodiagnostic to differentiate between Lyme disease and various RFB infections.
摘要：
通过GenBank基本比对搜索分析，鉴定了与复发性发热螺旋体的bipA具有部分同源性的miyamotoi基因。我们假设该基因产物可能是其他复发性发热疏螺旋体（RFB）所述的免疫原性抗原，并且可以作为B.miyamotoi感染的血清学标志物。B.miyamotoi基因是截短的版本，约为B.hermsii和B.turicataebipA大小的一半，编码序列为894个碱基对。基因产物具有32.7kDa的计算分子大小(包括信号肽)。与B.hermsii和B.turicataeBipA蛋白以及与其他B.miyamotoi分离物的氨基酸比对显示在羧基末端的保守性。我们克隆了B.miyamotoibipA样基因(本文称为bipM),并产生用于血清学表征和抗血清产生的重组蛋白。蛋白酶保护分析表明BipM是表面暴露的。使用抗B.来自蜱叮咬感染和针头接种的小鼠的miyamotoi血清样品对BipM的阳性率为94％。将4份BipM阴性血清样品用另一种B.miyamotoi抗原印迹，BmaA,其中两个为血清阳性，导致两种抗原的阳性率为97％。来自B.burgdorferisensustricto（s.s.）感染的小鼠的血清样品通过免疫印迹对rBipM无反应。来自莱姆病患者的血清样品对BipM也是血清学阴性的,除了1个样品可能表明可能的共感染。最近发表的一项研究表明，B.miyamotoiBipM对来自B.hermsii的血清样本无反应，Parkeri疏螺旋体,以及感染了绿藻芽孢杆菌的动物。这些结果表明，BipM具有用于区分莱姆病和各种RFB感染的特异性和敏感性血清诊断的潜力。
