Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado.
Minnesota Department of Health, St Paul.
Clin Infect Dis. 2018 Jun 1;66(12):1864-1871. doi: 10.1093/cid/cix1107.
Tick-transmitted Borrelia fall into 2 heterogeneous bacterial complexes comprised of multiple species, the relapsing fever (RF) group and the Borrelia burgdorferi sensu lato group, which are the causative agents of Lyme borreliosis (LB), the most common tickborne disease in the Northern Hemisphere. Geographic expansion of LB in the United States and discovery of emerging Borrelia pathogens underscores the importance of surveillance for disease-causing Borrelia.
De-identified clinical specimens, submitted by providers throughout the United States, for patients suspected of LB, anaplasmosis, ehrlichiosis, or babesiosis were screened using a Borrelia genus-level TaqMan polymerase chain reaction (PCR). Borrelia species and sequence types (STs) were characterized by multilocus sequence typing (MLST) utilizing next-generation sequencing.
Among 7292 specimens tested, 5 Borrelia species were identified: 2 causing LB, B. burgdorferi (n = 25) and B. mayonii (n = 9), and 3 RF borreliae, B. hermsii (n = 1), B. miyamotoi (n = 8), and Candidatus B. johnsonii (n = 1), a species previously detected only in the bat tick, Carios kelleyi. ST diversity was greatest for B. burgdorferi-positive specimens, with new STs identified primarily among synovial fluids.
These results demonstrate that broad PCR screening followed by MLST is a powerful surveillance tool for uncovering the spectrum of disease-causing Borrelia species, understanding their geographic distribution, and investigating the correlation between B. burgdorferi STs and joint involvement. Detection of Candidatus B. johnsonii in a patient with suspected tickborne disease suggests this species may be a previously undetected cause of illness in humans exposed to bat ticks.
蜱传伯氏疏螺旋体属于两个异质细菌复合体，包含多个种，即回归热（RF）组和伯氏疏螺旋体亚种组，它们是莱姆病（LB）的病原体，LB 是北半球最常见的蜱传疾病。LB 在美国的地理范围扩大以及新兴伯氏疏螺旋体病原体的发现突显了对致病伯氏疏螺旋体进行监测的重要性。
从美国各地的医疗服务提供者送检的疑似 LB、无形体病、埃立克体病或巴贝斯虫病的临床标本中，使用伯氏疏螺旋体属水平 TaqMan 聚合酶链反应（PCR）进行筛查。通过下一代测序利用多位点序列分型（MLST）对伯氏疏螺旋体种和序列型（ST）进行特征描述。
在 7292 个检测标本中，鉴定出了 5 种伯氏疏螺旋体：引起 LB 的 2 种，即伯氏疏螺旋体（n = 25）和马氏疏螺旋体（n = 9），以及 3 种 RF 伯氏疏螺旋体，即赫姆斯疏螺旋体（n = 1）、米氏疏螺旋体（n = 8）和候选伯氏疏螺旋体约翰逊亚种（n = 1），该种以前仅在蝙蝠蜱中被检测到。B. burgdorferi 阳性标本的 ST 多样性最大，主要在关节液中发现新的 ST。
这些结果表明，广泛的 PCR 筛查后进行 MLST 是一种强大的监测工具，可用于发现致病伯氏疏螺旋体的种类，了解其地理分布，并研究 B. burgdorferi ST 与关节受累之间的相关性。在疑似蜱传疾病患者中检测到候选伯氏疏螺旋体约翰逊亚种提示该种可能是以前未被发现的人类暴露于蝙蝠蜱后发病的病原体。
