Isolation and characterization of a variant duck orthoreovirus causing spleen necrosis in Peking ducks, China

Abstract

Since December 2017, an infectious disease has caused economic hardship for duck farms and breeding ducks in many regions of China. This disease characterized by spleen necrosis and swelling, is due to a variant strain of duck orthoreovirus (DRV) (Duck/N‐DRV‐XT18/China/2018), which we isolated from the spleen of diseased ducks. After isolating the virus, we used next‐generation sequencing technology to determine the entire genomic of the virus. Our phylogenetic analysis of 10 genomic segments showed that the N‐DRV‐XT18 strain is closely related to orthoreovirus isolates derived from ducks and geese, with nucleotide sequence identities for 10 genomic fragments ranging between 49.8% and 99.3%. In contract, the nucleotide sequence of N‐DRV‐XT18 genomic fragments are only 38.6% to 78.8% similar to the chicken orthoreovirus isolate. Therefore, we determined that this pathogen, causing duck spleen necrosis, is a new variant of a duck orthoreovirus that is significantly different from any previously reported waterfowl‐derived othoreovirus.

Rapid and Visual Detection of the Emerging Novel Duck Reovirus by Using a Specific and Sensitive Reverse Transcription Recombinase Polymerase Amplification Method

“…An emerging novel duck reovirus (NDRV) disease, called Duck Spleen Necrosis Disease, was recently found in China and the pathogen, distinct from the MDRV isolates previous, was identi ed to be a Orthoreovirus [1,3].…”

“…Importantly, Wang et al recently report that the emerging NDRV XT18 has extensive tissue tropism and could cause severe damage to the immune organs [3,8]. Furthermore, the NDRV co-infection with other pathogens can result in serious duck diseases [4].…”

“…Novel duck reovirus (NDRV), an avian Orthoreovirus, is an emerging important viral pathogen causing Duck Spleen Necrosis Disease (DSND) and infecting a variety of duck species recently [1][2][3][4]. The emerging NDRV can cause severe damage to the immune organs, and co-infected with Salmonella spp.…”

A TaqMan-based real-time PCR assay for specific detection of novel duck reovirus in China

“…The results showed that the primers and probes failed to align with sequences of other poultry reoviruses. Also, primers and probe were verified by the Basic Local Alignment Search Tool (BLAST, https://blast.ncbi.nlm.nih.gov/Blast.cgi) for specificity analysis [18].…”

“…Thus, to distinguish it from the "classical" MDRV, the reovirus has been categorized as "novel" duck reovirus (NDRV) [15,17]. Recently, Related research found that a new variant of a duck orthoreovirus that is significantly different from any previously reported waterfowl-derived othoreovirus, causing duck spleen necrosis [18]. The complete sequences of the 10 genome segments of NDRV have been completely determined [11].…”