Comparative vector competence of the Afrotropical soft tick Ornithodoros moubata and Palearctic species, O. erraticus and O. verrucosus, for African swine fever virus strains circulating in Eurasia
Comparative vector competence of the Afrotropical soft tick Ornithodoros moubata and Palearctic species, O. erraticus and O. verrucosus, for African swine fever virus strains circulating in Eurasia
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DOI：
10.1371/journal.pone.0225657
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发表时间：
2019-11-27
期刊：
影响因子：
3.7
通讯作者：
Le Potier, Marie-Frederique
中科院分区：
文献类型：
--
作者：
de Oliveira, Remi Pereira;Hutet, Evelyne;Le Potier, Marie-Frederique
非洲猪瘟（African Swine Fever，ASF）是由非洲猪瘟病毒（African Swine Fever Virus，ASFV）引起的一种严重危害世界养猪业的致死性出血性疾病。在非洲本土的地方性疫源地，ASFV在鸟虱属软蜱之间自然传播，特别是在O。moubata组和野生水库猪，如疣猪（Phacochoerus spp.）它们被栖息在洞穴中的受感染的软蜱叮咬。虽然一些非洲热带软蜱传播和维持ASFV的能力已经得到了很好的证实，但目前在欧亚大陆流行的ASFV毒株的古北界软蜱种的媒介状态仍然很大程度上未知。例如，伊比利亚软蜱O。erraticus是已知的ASFV载体和储存库，但自2007年ASF在欧洲重新出现以来，尚未评估其传播不同ASFV毒株的能力。ASFV在其他物种中的感受态知之甚少，如O. verrucosus，发生在东欧南部，包括乌克兰和俄罗斯部分地区，以及高加索地区。因此，我们用两种古北界软蜱进行了传播试验。erraticus和O. verrucosus和非洲热带种O.穆巴塔我们检测了蜱传播强毒ASFV毒株的能力，包括一种直接来源于非洲的毒株（Liv 13/33）和三种来自欧亚大陆的毒株（OurT 88/1），以及目前的流行病（格鲁吉亚-2007/1和Ukr 12/Zapo）。实验结果表明，O. moubata能传播非洲和欧亚毒株，而O. erraticus和O. verrucosus未能传播欧亚ASFV毒株。然而，当用粉碎的O. erraticus和O.疣状蜱以病毒血症猪为食，证明蜱中所含ASFV具有感染性。这些结果证明O. erraticus和O. verrucosus不太可能是目前在欧亚大陆流行的ASFV毒株的载体。此外，软蜱感染持续数月再次证实，特定蜱种属的感染状态只是评估其ASFV载体能力所需数据的一部分。
African swine fever (ASF) is a lethal hemorrhagic disease in domestic pigs and wild suids caused by African swine fever virus (ASFV), which threatens the swine industry globally. In its native African enzootic foci, ASFV is naturally circulating between soft ticks of the genus Ornithodoros, especially in the O. moubata group, and wild reservoir suids, such as warthogs (Phacochoerus spp.) that are bitten by infected soft ticks inhabiting their burrows. While the ability of some Afrotropical soft ticks to transmit and maintain ASFV is well established, the vector status of Palearctic soft tick species for ASFV strains currently circulating in Eurasia remains largely unknown. For example, the Iberian soft tick O. erraticus is a known vector and reservoir of ASFV, but its ability to transmit different ASFV strains has not been assessed since ASF re-emerged in Europe in 2007. Little is known about vector competence for ASFV in other species, such as O. verrucosus, which occurs in southern parts of Eastern Europe, including Ukraine and parts of Russia, and in the Caucasus. Therefore, we conducted transmission trials with two Palearctic soft tick species, O. erraticus and O. verrucosus, and the Afrotropical species O. moubata. We tested the ability of ticks to transmit virulent ASFV strains, including one of direct African origin (Liv13/33), and three from Eurasia that had been involved in previous (OurT88/1), and the current epizooties (Georgia-2007/1 and Ukr12/Zapo). Our experimental results showed that O. moubata was able to transmit the African and Eurasian ASFV strains, whereas O. erraticus and O. verrucosus failed to transmit the Eurasian ASFV strains. However, naive pigs showed clinical signs of ASF when inoculated with homogenates of crushed O. erraticus and O. verrucosus ticks that fed on viraemic pigs, which proved the infectiousness of ASFV contained in the ticks. These results documented that O. erraticus and O. verrucosus are unlikely to be capable vectors of ASFV strains currently circulating in Eurasia. Additionally, the persistence of infection in soft ticks for several months reaffirms that the infectious status of a given tick species is only part of the data required to assess its vector competence for ASFV.