College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
Insitutute for Translational Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China.
Viruses. 2021 Apr 15;13(4):679. doi: 10.3390/v13040679.
The ectoparasitic mite, , feeds directly on honey bees and serves as a vector for transmitting viruses among them. The mite causes relatively little damage to its natural host, the Eastern honey bee () but it is the most devastating pest for the Western honey bee (). Using Illumina HiSeq sequencing technology, we conducted a metatranscriptome analysis of the microbial community associated with mites. This study led to the identification of a new Chinese strain of virus-2 (VDV-2), which is a member of the family and was previously reported to be specific to mites. A subsequent epidemiological investigation of Chinese strain of VDV-2 (VDV-2-China) showed that the virus was highly prevalent among populations and was not identified in any of the adult workers from both and colonies distributed in six provinces in China, clearly indicating that VDV-2-China is predominantly a -adapted virus. While worker pupae exposed to less than two mites tested negative for VDV-2-China, VDV-2-China was detected in 12.5% of the worker pupae that were parasitized by more than 10 mites, bringing into play the possibility of a new scenario where VDV-2 could be transmitted to the honey bees during heavy infestations. Bioassay for the VDV-2-China infectivity showed that was not a permissive host for VDV-2-China, yet could be a biological host that supports VDV-2-China's replication. The different replication dynamics of the virus between the two host species reflect their variation in terms of susceptibility to the virus infection, posing a potential threat to the health of the Western honey bee. The information gained from this study contributes to the knowledge concerning genetic variabilities and evolutionary dynamics of Varroa-borne viruses, thereby enhancing our understanding of underlying molecular mechanisms governing honey bee Varroosis.
寄生在蜜蜂体外的节肢动物壁虱直接以蜜蜂为食，并且是在蜜蜂之间传播病毒的载体。壁虱对其天然宿主——东方蜜蜂（）的危害相对较小，但它是西方蜜蜂（）最具破坏性的害虫。本研究利用 Illumina HiSeq 测序技术对与壁虱相关的微生物群落进行了宏转录组分析。研究鉴定出了一种新型的中国株蜜蜂病毒-2（VDV-2），它是病毒科的一员，以前被报道专门寄生在壁虱上。对中国株 VDV-2（VDV-2-China）的后续流行病学调查显示，该病毒在中国流行率很高，在分布于中国六个省份的和 两个蜂群的成年工蜂中均未检测到该病毒，这清楚地表明 VDV-2-China 主要是一种适应壁虱的病毒。当 工蜂蛹暴露于不到 2 只壁虱时，对 VDV-2-China 检测呈阴性，但当 工蜂蛹被 10 多只壁虱寄生时，有 12.5%检测到 VDV-2-China，这提示了一种新的情况，即在严重的壁虱感染期间，VDV-2 可能会传播给蜜蜂。对 VDV-2-China 感染力的生物测定表明， 不是 VDV-2-China 的允许宿主，但 可能是支持 VDV-2-China 复制的生物宿主。两种宿主物种中病毒的不同复制动态反映了它们对病毒感染的敏感性差异，这对西方蜜蜂的健康构成了潜在威胁。本研究获得的信息有助于了解瓦螨传播病毒的遗传变异性和进化动态，从而增强我们对控制蜜蜂瓦螨病的潜在分子机制的理解。
