Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, USA.
Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
Appl Environ Microbiol. 2018 Oct 17;84(21). doi: 10.1128/AEM.01505-18. Print 2018 Nov 1.
Vector competence refers to the ability of an arthropod to acquire, maintain, and successfully transmit a microbial pathogen. Tick-borne relapsing fever (TBRF) spirochetes are globally distributed pathogens, and most species are transmitted by argasid ticks of the genus A defining characteristic in vector competence is an apparent specificity of a species of TBRF spirochete to a given tick species. In arid regions of the southern United States, is the primary cause of TBRF. Interestingly, there are two populations of the tick vector distributed throughout this region. is a western population that ranges from California to Texas. There is a gap through Louisiana, Mississippi, and Alabama where the tick has not been identified. An isolated eastern population exists in Florida and was designated a subspecies, A knowledge gap that exists is the poor understanding of vector competence between western and eastern populations of ticks for In this study, we generated uninfected colonies of that originated in Texas and Kansas and of acquisition, maintenance through the molt, and subsequent transmission were evaluated. Our findings revealed significant differences in murine infection after feeding infected and ticks on the animals. Interestingly, the salivary glands of both tick populations were colonized with to similar densities. Our results suggest that the salivary glands of the tick colonies assessed in this study impact vector competence of the evaluated isolates. Several knowledge gaps exist in the vector competence of various geographical populations of that transmit A western population of this tick is distributed from California to Texas, and an eastern population exists in Florida. Utilizing western and eastern populations of the vector, we studied acquisition and transmission of two isolates. Regardless of the isolate used, infection frequencies were poor in mice after the eastern population feeding on them. Since salivary gland colonization is essential for transmission, these tissues were further evaluated. Interestingly, the salivary glands from the two populations were similarly colonized with These findings suggest the role of tick saliva in the establishment of infection and that the salivary glands may be a bottleneck for successful transmission.
媒介能力是指节肢动物获取、维持和成功传播微生物病原体的能力。蜱传回归热（TBRF）螺旋体在全球范围内分布，大多数物种由属的蜱传播 蜱类媒介能力的一个定义特征是 TBRF 螺旋体的一个物种对特定的蜱种明显具有特异性。在美国南部的干旱地区， 是 TBRF 的主要原因。有趣的是，该地区分布着两种蜱虫媒介种群。 是从加利福尼亚到德克萨斯的西部种群。在路易斯安那州、密西西比州和阿拉巴马州没有发现这种蜱虫。在佛罗里达州存在一个孤立的东部种群，并被指定为一个亚种， 存在的知识差距是对西部和东部种群的蜱对 的媒介能力了解甚少。在这项研究中，我们生成了起源于德克萨斯州和堪萨斯州的未感染的 和 种群，评估了它们的获取、通过蜕皮维持以及随后的传播。我们的发现表明，在用感染了 的 和 喂食动物后，感染鼠的差异显著。有趣的是，两种蜱种群的唾液腺都以相似的密度定植了 。我们的研究结果表明，在这项研究中评估的蜱虫种群的唾液腺影响了评估的 分离株的媒介能力。 在传播 的各种地理种群的媒介能力方面存在几个知识差距。这种蜱的西部种群分布从加利福尼亚到德克萨斯，东部种群存在于佛罗里达州。利用该媒介的西部和东部种群，我们研究了两种 分离株的获取和传播。无论使用哪种分离株，在用东部种群喂养后，感染鼠的感染频率都很差。由于唾液腺定植对于 传播至关重要，因此进一步评估了这些组织。有趣的是，来自两个种群的唾液腺都以相似的密度定植了 。这些发现表明了蜱唾液在建立感染中的作用，并且这些组织可能是成功传播的瓶颈。
