Department of Biology, Long Island University, Brooklyn, NY, USA; Department of Biological Sciences, Fordham University, Bronx, NY, USA; Vector Ecology Laboratory, Louis Calder Center-Biological Field Station, Fordham University, Armonk, NY, USA.
New York State Department of Health, Louis Calder Center-Biological Field Station, Fordham University, Armonk, NY, USA.
Ticks Tick Borne Dis. 2018 Mar;9(3):563-572. doi: 10.1016/j.ttbdis.2018.01.007. Epub 2018 Jan 31.
Blacklegged ticks (Ixodes scapularis) spend the majority of their life cycle off host, typically in woodland habitat, but require a blood meal at each of three life stages (larva, nymph, adult) to reach maturity and reproduce. Blood feeding usually lasts for several days each time and as blood is imbibed, a range of known pathogens from the host may also be acquired. Using next generation sequencing of 16S rRNA gene amplicons, we examined the influence of host blood meal on the internal bacterial community within nymphal blacklegged ticks across host-seeking, feeding, blood meal digestion, and after molting into the adult stage. Results demonstrate bacterial community structuring across host and ticks with 287 taxa found exclusively in ticks, suggesting the field environment plays a significant role in shaping the internal tick microbiome. A decrease in bacterial diversity was noted from unfed nymphs through feeding/digestion and after molting into adults, suggesting that bacterial species are lost during the corresponding physiological changes. The similarity in biochemical pathways across the different tick categories suggests that the loss of bacterial taxa does not mirror a large change in microbial function. Ticks likely lose bacterial taxa after feeding, but continual exposure to bacteria from the field environment counters this loss.
黑腿蜱（Ixodes scapularis）在其生命周期的大部分时间都在宿主之外度过，通常在林地栖息地，但在三个生命阶段（幼虫、若虫、成虫）都需要一次血餐才能成熟和繁殖。每次吸血通常持续数天，当血液被吸收时，宿主身上的一系列已知病原体也可能被获得。我们使用 16S rRNA 基因扩增子的下一代测序技术，研究了宿主血液餐对寻宿主、吸血、消化血液餐以及蜕皮成成虫阶段的若虫黑腿蜱内部细菌群落的影响。结果表明，细菌群落结构在宿主和蜱虫之间存在差异，在蜱虫中发现了 287 种特有分类群，这表明野外环境在塑造内部蜱虫微生物组方面发挥了重要作用。从未进食的若虫到进食/消化以及蜕皮成成虫后，细菌多样性下降，这表明在相应的生理变化过程中细菌物种会丢失。不同蜱虫类群之间的生化途径相似性表明，细菌分类群的丢失并不反映微生物功能的巨大变化。蜱虫在进食后可能会失去细菌分类群，但持续暴露于野外环境中的细菌会抵消这种损失。
