Hendson M, Lane R S
Division of Insect Biology, University of California, Berkeley, California 94720, USA.
J Clin Microbiol. 2000 Jul;38(7):2678-82. doi: 10.1128/JCM.38.7.2678-2682.2000.
Two Borrelia isolates (CA434 and CA435) cultured from the soft tick Ornithodoros coriaceus were analyzed by contour-clamped homogeneous electric field gel electrophoresis of unrestricted and ApaI-restricted DNA, standard electrophoresis of BamHI- and HindIII-restricted DNA, Southern hybridization, restriction fragment length polymorphism and sequencing of the 16S rRNA gene, and amplification of the 5S-23S intergenic spacer region. These isolates were compared with Borrelia coriaceae type strain Co53, B. burgdorferi sensu stricto strain CA4, and the relapsing-fever spirochete B. parkeri (undesignated). The 16S rRNA region of CA434 and CA435 differed from that of B. coriaceae type strain Co53 by the presence of 1 base (C) at position 367 (GenBank accession no. U42286). The linear plasmid profile of CA434 was similar to that of Co53, and the ApaI, BamHI, and HindIII restriction fingerprints of the total cellular DNA of CA434 and Co53 were similar. In contrast, CA435 differed somewhat from CA434 and Co53, which demonstrates that B. coriaceae is genetically diverse. Southern hybridization showed that the DNAs of CA434 and CA435 hybridized strongly with the digoxigenin-labeled DNA of Co53. Low homology was found between the DNA of Co53 and that of B. parkeri. The 16S rRNA sequence of B. parkeri was identical to previously published results for B. parkeri strain M3001 (GenBank accession number U42296). CA434 and CA435 represent only the second and third isolates of B. coriaceae obtained from any source since its initial isolation from an O. coriaceus tick in 1985. All three B. coriaceae isolates were derived from adult ticks collected from the same locality in northwestern California. Difficulties encountered in detecting B. coriaceae in, and isolating this spirochete from, the tissues of O. coriaceus are discussed. The lack of concordance between different detection or isolation methods suggests that reliance upon a single technique may grossly underestimate the true prevalence of spirochetal infection in wild-caught O. coriaceus ticks.
对从软蜱科氏钝缘蜱（Ornithodoros coriaceus）培养出的两株疏螺旋体（CA434和CA435），通过非限制型和ApaI酶切型DNA的轮廓夹恒定电场凝胶电泳、BamHI和HindIII酶切型DNA的标准电泳、Southern杂交、限制性片段长度多态性分析、16S rRNA基因测序以及5S - 23S基因间隔区扩增进行分析。将这些分离株与科氏疏螺旋体（Borrelia coriaceae）模式菌株Co53、狭义伯氏疏螺旋体（B. burgdorferi sensu stricto）菌株CA4以及回归热螺旋体帕克疏螺旋体（B. parkeri，未命名）进行比较。CA434和CA435的16S rRNA区域与科氏疏螺旋体模式菌株Co53的不同之处在于，在第367位存在1个碱基（C）（GenBank登录号U42286）。CA434的线性质粒图谱与Co53相似，并且CA434和Co53的总细胞DNA的ApaI、BamHI和HindIII酶切指纹图谱相似。相比之下，CA435与CA434和Co53有所不同，这表明科氏疏螺旋体在基因上具有多样性。Southern杂交显示，CA434和CA435的DNA与地高辛标记的Co53 DNA强烈杂交。在Co53的DNA与帕克疏螺旋体的DNA之间发现低同源性。帕克疏螺旋体的16S rRNA序列与先前发表的帕克疏螺旋体菌株M3001（GenBank登录号U42296）的结果相同。CA434和CA435是自1985年首次从科氏钝缘蜱中分离出科氏疏螺旋体以来，从任何来源获得的该菌的第二株和第三株分离株。所有三株科氏疏螺旋体分离株均来自从加利福尼亚州西北部同一地点采集的成年蜱。讨论了在科氏钝缘蜱组织中检测科氏疏螺旋体以及从该组织中分离这种螺旋体时遇到的困难。不同检测或分离方法之间缺乏一致性表明，仅依赖单一技术可能会严重低估野生捕获的科氏钝缘蜱中螺旋体感染的真实流行率。
