CSIRO, Acton, ACT, Australia.
Invasive Animals Cooperative Research Centre, University of Canberra, Bruce, ACT, Australia.
Transbound Emerg Dis. 2018 Apr;65(2):e444-e456. doi: 10.1111/tbed.12779. Epub 2017 Dec 10.
Rabbit haemorrhagic disease virus (RHDV, or GI.1) is a calicivirus in the genus Lagovirus that has been widely utilized in Australia as a biological control agent for the management of overabundant wild European rabbit (Oryctolagus cuniculus) populations since 1996. Recently, two exotic incursions of pathogenic lagoviruses have been reported in Australia; GI.1a-Aus, previously called RHDVa-Aus, is a GI.1a virus detected in January 2014, and the novel lagovirus GI.2 (previously known as RHDV2). Furthermore, an additional GI.1a strain, GI.1a-K5 (also known as 08Q712), was released nationwide in March 2017 as a supplementary tool for wild rabbit management. To discriminate between these lagoviruses, a highly sensitive strain-specific multiplex RT-PCR assay was developed, which allows fast, cost-effective and sensitive detection of the four pathogenic lagoviruses currently known to be circulating in Australia. In addition, we developed a universal RT-qPCR assay to be used in conjunction with the multiplex assay that broadly detects all four viruses and facilitates quantification of viral RNA load in samples. These assays enable rapid detection, identification and quantification of pathogenic lagoviruses in the Australian context. Using these assays, a novel recombinant lagovirus was detected in rabbit tissue samples, which contained the non-structural genes of GI.1a-Aus and the structural genes of GI.2. This variant was also recovered from the liver of a European brown hare (Lepus europaeus). The impact of this novel recombinant on Australian wild lagomorph populations and its competitiveness in relation to circulating field strains, particularly GI.2, requires further studies.
兔出血症病毒（RHDV，或 GI.1）是杯状病毒属中的一种 calicivirus，自 1996 年以来，已在澳大利亚被广泛用作管理过度繁殖的野生欧洲兔（Oryctolagus cuniculus）种群的生物控制剂。最近，澳大利亚报告了两种外来致病性杯状病毒的入侵；GI.1a-Aus，以前称为 RHDVa-Aus，是 2014 年 1 月检测到的 GI.1a 病毒，而新型 lagovirus GI.2（以前称为 RHDV2）。此外，于 2017 年 3 月在全国范围内释放了另一种 GI.1a 株，GI.1a-K5（也称为 08Q712），作为野生兔管理的补充工具。为了区分这些杯状病毒，开发了一种高度敏感的针对特定毒株的多重 RT-PCR 检测方法，该方法能够快速、经济高效且灵敏地检测目前在澳大利亚流行的四种致病性杯状病毒。此外，我们开发了一种通用的 RT-qPCR 检测方法，与多重检测方法结合使用，可广泛检测到这四种病毒，并促进对样本中病毒 RNA 载量的定量。这些检测方法能够在澳大利亚背景下快速检测、鉴定和定量致病性杯状病毒。使用这些检测方法，在兔组织样本中检测到了一种新型重组杯状病毒，该病毒包含 GI.1a-Aus 的非结构基因和 GI.2 的结构基因。该变体还从欧洲野兔（Lepus europaeus）的肝脏中分离出来。这种新型重组病毒对澳大利亚野生兔形目种群的影响及其与循环田间株，特别是 GI.2 的竞争力，需要进一步研究。
