Isolation, genomic characterization, and pathogenicity of a Chinese porcine deltacoronavirus strain CHN-HN-2014

Abstract

Porcine deltacoronavirus (PDCoV) is an emerging swine coronavirus that causes diarrhea in piglets. Since the first outbreak of PDCoV in the United States in 2014, this novel porcine coronavirus has been detected in South Korea, Canada, Mexico, Thailand, and China. In this study, a Chinese PDCoV strain, designated CHN-HN-2014, was isolated from piglets with severe diarrhea on a pig farm in Henan Province, China, and examined with a specific immunofluorescence assay and electron microscopy. Genomic analysis showed that CHN-HN-2014 shares 91.6%-99.4% nucleotide identity with other known PDCoV strains. The pathogenicity of CHN-HN-2014 was further investigated in 5-day-old and 21-day-old piglets. Both kinds of piglets developed clear clinical symptoms, including vomiting, anorexia, lethargy, and severe diarrhea, by 2days postinoculation (DPI), and diarrhea persisted for about 5-6 days. Viral shedding was detected in rectal swabs until 14 DPI in challenged 5-day-old pigs and until 18 DPI in challenged 21-day-old pigs. At necropsy at 4 DPI, macroscopic and microscopic lesions were observed and viral antigen was detected in the small intestines with immunohistochemical staining. These data demonstrate that Chinese PDCoV strain CHN-HN-2014 shares high nucleotide identity with previously reported PDCoV strains and is pathogenic in 5-day-old and 21-day-old piglets.

Porcine deltacoronavirus induces TLR3, IL-12, IFN-α, IFN-β and PKR mRNA expression in infected Peyer’s patches in vivo

“…Further, histology analysis exhibited acute diffuse, severe atrophic enteritis and mild vacuolation of superficial epithelial cells in cecum and colon (Kwonil et al, 2015). The pathogenicity of PDCoV in conventional pigs were also confirmed with the subsequent isolation (Chen et al, 2015;Dong et al, 2016;Ma et al, 2015;Xu et al, 2018). All these studies target suckling piglets, however, there are still sporadic outbreaks of diarrhea in weaned piglets with unknown reasons.…”

“…The clinical symptoms in newborn piglets by PDCoV infection are similar to that by other porcine enteric pathogens such as PEDV and TGEV, include diarrhea, vomiting, dehydration and lethal (Zhang, 2016). Currently a few studies have reproduced clinical diarrheal disease by experimentally infecting gnotobiotic and conventional pigs with the isolated PDCoV strains (Chen et al, 2015;Dong et al, 2016;Kwonil et al, 2015;Ma et al, 2015;Xu et al, 2018). As expected, the 11-14 day-old gnotobiotic pigs inoculated orally with PDCoV strain OH-FD22 and OH-FD100 showed severe diarrhea, vomiting, and atrophic enteritis (Kwonil et al, 2015).…”

Point‐of‐care diagnostic assay for rapid detection of porcine deltacoronavirus using the recombinase polymerase amplification method

“…Porcine deltacoronavirus (PDCoV), a new member of Deltacoronavirus , was firstly detected in pig faeces in the molecular investigation of CoV in Hong Kong in 2012 (Woo et al., ). Up to now, PDCoV has been detected/isolated in pigs across the world, including USA, Mexico, Canada, South Korea, China and Thailand (Dong et al., ; Fu et al., ; Janetanakit et al., ; Jang et al., ; Jung, Hu, & Saif, ; Lee & Lee, ; Mai et al., ; Song et al., ; Wang, Byrum, & Zhang, ; Xu et al., ). PDCoV has become a reportable disease in the United States by United States Department of Agriculture, and an infection case is published weekly at http://www.aphis.usda.gov.…”

Cryo-Electron Microscopy Structure of Porcine Deltacoronavirus Spike Protein in the Prefusion State

“…PdCoV from the ␦ genus is a highly lethal viral pathogen in piglets (39)(40)(41). Compared to the extensive studies on ␣and ␤-coronavirus spikes, much less is known about the structure and function of ␦-coronavirus spikes.…”