Detection of a new emerging strain of rabbit haemorrhagic disease virus 2 (GI.2) in China
Data publikacji: 14 wrz 2022
Zakres stron: 289 - 295
Otrzymano: 10 mar 2022
Przyjęty: 30 sie 2022
DOI: https://doi.org/10.2478/jvetres-2022-0048
Słowa kluczowe
© 2022 W. Chen et al. published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
Introduction
In May 2020, an outbreak of rabbit haemorrhagic disease 2 (RHD2) caused by the rabbit haemorrhagic disease virus 2 (RHDV2, GI.2) occurred in Sichuan, China. The acute onset and short disease course resulted in rabbit mortality as high as 42.86%. Currently, basic research on the aetiology and genetic characteristics of GI.2 is lacking in China.
Material and Methods
Pathological changes in various tissues from infected rabbits were investigated and the viral genome was characterised. This study used RT-PCR, histopathology and scanning electron microscopy to identify the pathogen in samples from infected rabbits that had died. Phylogenetic trees were constructed based on whole genome sequence analysis, and recombination events were analysed.
Results
RT-PCR identified the presence of GI.2. Histopathology revealed liver cell necrosis and haemorrhaging into lung alveoli. Electron microscopy demonstrated spherical GI.2 particles that were 40 nm in size. The gene sequence length of the isolate was 7,445 bp (GenBank accession number MW178244). A phylogenetic analysis based on the genome of the isolated strain and 60 reference strains showed that the isolate was grouped together with GI.2 strain MT586027.1 in a relatively independent sub-branch. The results of the recombination analysis showed that the strain was recombined from the MT586027.1 (major parent) and MN90145.1 (minor parent) strains, and recombination breakpoints were at locations in the 2858–5137 nt range.
Conclusion
The results of this study extend our understanding of the molecular epidemiology of GI.2.