Imaging of Borrelia turicatae Producing the Green Fluorescent Protein Reveals Persistent Colonization of the Ornithodoros turicata Midgut and Salivary Glands from Nymphal Acquisition through Transmission
Imaging of Borrelia turicatae Producing the Green Fluorescent Protein Reveals Persistent Colonization of the Ornithodoros turicata Midgut and Salivary Glands from Nymphal Acquisition through Transmission
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DOI：
10.1128/aem.02503-16
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发表时间：
2017-03-01
影响因子：
4.4
通讯作者：
Lopez, Job E.
中科院分区：
文献类型：
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作者：
Krishnavajhala, Aparna;Wilder, Hannah K.;Lopez, Job E.
回归热（RF）螺旋体定殖并主要通过鸟虱属蜱传播给哺乳动物，关于病原体在载体中的生命周期知之甚少。为了进一步理解RF螺旋体的载体定殖和传播，将表达绿色荧光蛋白（GFP）标记物（B. turicatae-GFP）。在蜱-哺乳动物感染周期期间，从第三若虫龄到成虫阶段，评价转化体。B。turicatae-GFP在饥饿的第四阶段若虫蜱中保持存活至少18个月，并且研究表明螺旋体种群持续定殖于蜱中肠和唾液腺。我们这一代的B。turicatae-GFP还显示，在唾液腺内，螺旋体定位于腺泡的导管和管腔中，并且在蜱喂食后，组织仍然充满螺旋体。B。本研究中产生的turicatae-gfp是进一步理解和确定媒介定殖和传播机制的重要工具。重要性为了中断蜱传回归热螺旋体的感染周期，重要的是要加强我们对媒介定殖和传播的理解。为此，我们产生了一种组成型产生绿色荧光蛋白的疏螺旋体菌株，并在整个感染周期中评估了荧光螺旋体。我们确定，中肠和唾液腺的Ornithodoros turicata蜱保持病原体在整个载体的生命周期，并保持定殖与螺旋体至少18个月。我们还确定了蜱的唾液腺没有耗尽后，传输血液喂养。这些发现为进一步了解中肠和唾液腺定植的机制奠定了基础。
Relapsing fever (RF) spirochetes colonize and are transmitted to mammals primarily by Ornithodoros ticks, and little is known regarding the pathogen's life cycle in the vector. To further understand vector colonization and transmission of RF spirochetes, Borrelia turicatae expressing a green fluorescent protein (GFP) marker (B. turicatae-gfp) was generated. The transformants were evaluated during the tick-mammal infectious cycle, from the third nymphal instar to adult stage. B. turicatae-gfp remained viable for at least 18 months in starved fourth-stage nymphal ticks, and the studies indicated that spirochete populations persistently colonized the tick midgut and salivary glands. Our generation of B. turicatae-gfp also revealed that within the salivary glands, spirochetes are localized in the ducts and lumen of acini, and after tick feeding, the tissues remained populated with spirochetes. The B. turicatae-gfp generated in this study is an important tool to further understand and define the mechanisms of vector colonization and transmission.IMPORTANCE In order to interrupt the infectious cycle of tick-borne relapsing fever spirochetes, it is important to enhance our understanding of vector colonization and transmission. Toward this, we generated a strain of Borrelia turicatae that constitutively produced the green fluorescent protein, and we evaluated fluorescing spirochetes during the entire infectious cycle. We determined that the midgut and salivary glands of Ornithodoros turicata ticks maintain the pathogens throughout the vector's life cycle and remain colonized with the spirochetes for at least 18 months. We also determined that the tick's salivary glands were not depleted after a transmission blood feeding. These findings set the framework to further understand the mechanisms of midgut and salivary gland colonization.