Cumbie Alexandra N, Trimble Rebecca N, Eastwood Gillian
Department of Entomology, College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA 24061, USA.
Department of Biochemistry, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA 24061, USA.
Pathogens. 2022 Apr 10;11(4):454. doi: 10.3390/pathogens11040454.
(Neumann, 1901) (Acari: Ixodidae), the Asian longhorned tick, is an invasive tick species present in the USA since at least 2017 and has been detected in one-third of Virginia counties. While this species is associated with the transmission of multiple pathogens in its native geographical range of eastern Asia, little is known about its ability to acquire and transmit pathogens in the USA, specifically those that are transmissible to humans, although from an animal health perspective, it has already been shown to vector Ikeda strains. Emerging tick-borne viruses such as Bourbon virus (genus: ) are of concern, as these newly discovered pathogenic agents have caused fatal clinical cases, and little is known about their distribution or enzootic maintenance. This study examined collected within Virginia (from ten counties) for Bourbon and Heartland viruses using PCR methods. All ticks tested negative for Heartland virus via qRT-PCR (S segment target). Bourbon-virus-positive samples were confirmed on two different gene targets and with Sanger sequencing of the PB2 (segment 1) gene. Bourbon virus RNA was detected in one nymphal stage from Patrick County, one nymph from Staunton City, and one larval pool and one adult female tick from Wythe County, Virginia. An additional 100 (Linnaeus 1758; lone star tick) collected at the same Patrick County site revealed one positive nymphal pool, suggesting that Bourbon virus may have spilled over from the native vector, potentially by co-feeding on a shared Bourbon-virus-infected vertebrate host. Blood tested from local harvested deer revealed a 11.1% antibody seroprevalence against Bourbon virus, exposure which further corroborates that this tick-borne virus is circulating in the southwest Virginia region. Through these results, it can be concluded that can carry Bourbon virus and that pathogen spillover may occur from native to invasive tick species.
（纽曼，1901年）（蜱螨亚纲：硬蜱科），即亚洲长角蜱，是一种至少自2017年起就已在美国出现的入侵性蜱种，在弗吉尼亚州三分之一的县被发现。虽然该物种在其东亚原生地理范围内与多种病原体的传播有关，但在美国其获取和传播病原体的能力，特别是那些可传播给人类的病原体的能力，人们了解甚少，尽管从动物健康角度来看，它已被证明可传播池田株。诸如波旁病毒（属： ）等新出现的蜱传病毒令人担忧，因为这些新发现的病原体已导致致命临床病例，且对其分布或动物疫源性维持了解甚少。本研究使用PCR方法检测了在弗吉尼亚州（来自十个县）采集的蜱中是否存在波旁病毒和哈特兰病毒。通过qRT-PCR（S片段靶点）检测，所有蜱对哈特兰病毒检测均为阴性。波旁病毒阳性样本在两个不同基因靶点上得到确认，并对PB2（第1片段）基因进行了桑格测序。在弗吉尼亚州帕特里克县的一只若虫、斯汤顿市的一只若虫以及怀斯县的一个幼虫池和一只成年雌蜱中检测到波旁病毒RNA。在同一帕特里克县地点采集的另外100只美洲钝眼蜱（林奈，1758年；孤星蜱）中，发现一个阳性若虫池，这表明波旁病毒可能已从本地媒介溢出，可能是通过共同取食受波旁病毒感染的共享脊椎动物宿主。对当地猎获鹿的血液检测显示，针对波旁病毒的抗体血清阳性率为11.1%，这种暴露进一步证实了这种蜱传病毒在弗吉尼亚州西南部地区传播。通过这些结果可以得出结论，美洲钝眼蜱可携带波旁病毒，病原体可能从本地蜱种溢出到入侵蜱种。
