The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum).
The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum).
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DOI：
10.1371/journal.pone.0146651
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
DeBruyn JM
中科院分区：
文献类型：
--
作者：
Trout Fryxell RT;DeBruyn JM
孤星星蜱，Amblyomma americanum，传播几种细菌病原体，包括无形体属和埃立克体属。Amblyomma americanum也是许多非致病性细菌内共生体的宿主。最近对其他节肢动物和昆虫媒介的研究表明，蜱虫微生物区系可以影响媒介传播的病原体的传播;然而，对蜱虫微生物群及其对蜱虫传播疾病的可能影响知之甚少。我们的目的是比较与A. americanum，比较无形体/埃立克体感染和未感染的蜱。现场采集的调查标本（n = 50）用于分析，其中17个被确定为无形体/埃里希体感染的基础上PCR扩增和groEL基因测序。使用16 S rRNA基因扩增子文库的Illumina测序来表征来自每个标本的细菌群落。样本之间的多样性范围很广，逆辛普森多样性指数从1.28-89.5不等。PCR诊断的无形体/埃立克体阳性蜱和阴性蜱的总体微生物群落结构无统计学差异，但基于采集方法（P <0. 05）、采集地点（P <0. 05）和性别（P <0. 1）的差异表明环境因素可能构成A.美洲微生物群有趣的是，Illumina测序和PCR诊断之间并不总是一致的：在三个PCR阴性标本的16 S rRNA基因文库中鉴定出埃里希体;相反，在六个PCR阳性蜱的文库中没有发现埃里希体。Illumina测序还有助于识别合并感染，例如，一个标本同时具有埃里希体和无形体。这些标本中的其他感兴趣的分类群包括Coxiella，Borrelia和Rickettsia。从一个单一的地理位置的一个蜱物种的标本之间的细菌群落差异的鉴定表明，种内微生物组的差异不仅仅是由于病原体的存在/不存在，但也可能是由媒介生活史因素，包括环境，生活阶段，人口结构，和主机的选择。
The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.