A Relapsing Fever Group Spirochete Transmitted by Ixodes scapularis Ticks
A Relapsing Fever Group Spirochete Transmitted by Ixodes scapularis Ticks
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一种由蜱传播的复发性热群螺旋体
DOI：
10.1089/153036601750137624
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发表时间：
2001-03-01
影响因子：
2.1
通讯作者：
Fish, Durland
中科院分区：
文献类型：
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作者：
Scoles, Glen;Papero, Michele;Fish, Durland
一种以前在北美未知的疏螺旋体螺旋体已被发现由肩突硬蜱传播。受感染的蜱对疏螺旋体属呈阳性。通过DFA试验，但通过聚合酶链反应（PCR），使用16 S rDNA、外表面蛋白A、外表面蛋白C和鞭毛蛋白基因的种特异性引物，对伯氏疏螺旋体呈阴性。一个1,347 bp的16 S rDNA的一部分，从池感染，测序，并与同源片段从其他26种疏螺旋体进行比较。分析显示与B的成对差异为4.6%。burgdorferi，与日本全沟硬蜱报道的Borrelia miyamotoi（99.3%相似性）最近的亲缘关系。系统发育分析表明，未知的疏螺旋体与回归热组螺旋体而不是莱姆病螺旋体聚类。鞭毛蛋白基因的764-bp的片段也进行了比较，从其他24种疏螺旋体的同源片段。B的鞭毛蛋白序列。与已知疏螺旋体的同源性为19.5%，与B的同源性为98.6%。宫本井。设计一对PCR引物，从该螺旋体中扩增出219 bp的鞭毛蛋白基因片段，并对现场采集的I.产自东北部五个州（康涅狄格州、罗得岛、纽约、新泽西和马里兰州）的肩胛草。从四个州采集的712只蜱虫中有1.9-2.5%获得阳性结果，但从马里兰州采集的162只蜱虫中无一获得阳性结果。经卵传播表现为感染的女性与子代感染率从6%到73%的幼虫后代的PCR。从幼虫到成虫都发生了跨海鞘的传播。脊椎动物感染通过在白足鼠上喂食受感染的幼虫并在7-21天后从喂食的未感染的异种诊断幼虫中回收生物体来证明。考虑到我和你之间接触的频率。肩胛骨蜱和人类的传播，需要进一步的工作来确定由这种蜱传播的另一种人畜共患病病原体的潜在公共卫生意义。
A species of Borrelia spirochetes previously unknown from North America has been found to be transmitted by Ixodes scapularis ticks. Infected ticks are positive for Borrelia spp. by DFA test but negative for Borrelia burgdorferi by polymerase chain reaction (PCR) using species-specific primers for 16S rDNA, outer surface protein A, outer surface protein C, and flagellin genes. A 1,347-bp portion of 16S rDNA was amplified from a pool of infected nymphs, sequenced, and compared with the homologous fragment from 26 other species of Borrelia. The analysis showed 4.6% pairwise difference from B. burgdorferi, with the closest relative being Borrelia miyamotoi (99.3% similarity) reported from Ixodes persulcatus in Japan. Phylogenetic analysis showed the unknown Borrelia to cluster with relapsing fever group spirochetes rather than with Lyme disease spirochetes. A 764-bp fragment of the flagellin gene was also compared with the homologous fragment from 24 other Borrelia species. The flagellin sequence of B. burgdorferi was 19.5% different from the unknown Borrelia and showed 98.6% similarity with B. miyamotoi. A pair of PCR primers specifically designed to amplify a 219-bp fragment of the flagellin gene from this spirochete was used to survey field-collected I. scapularis nymphs from five northeastern states (Connecticut, Rhode Island, New York, New Jersey, and Maryland). Positive results were obtained in 1.9-2.5% of 712 nymphs sampled from four states but in none of 162 ticks collected from Maryland. Transovarial transmission was demonstrated by PCR of larval progeny from infected females with filial infection rates ranging from 6% to 73%. Transstadial passage occurred from larvae through adults. Vertebrate infection was demonstrated by feeding infected nymphs on Peromyscus leucopus mice and recovering the organism from uninfected xenodiagnostic larvae fed 7-21 days later. Considering the frequency of contact between I. scapularis and humans, further work is needed to determine the potential public health significance of yet another zoonotic agent transmitted by this tick species.