Porcine deltacoronavirus infection: Etiology, cell culture for virus isolation and propagation, molecular epidemiology and pathogenesis

Abstract

Porcine deltacoronavirus (PDCoV) (family Coronaviridae, genus Deltacoronavirus) is a novel swine enteropathogenic coronavirus that causes acute diarrhea/vomiting, dehydration and mortality in seronegative neonatal piglets. PDCoV diarrhea was first reported in the US in early 2014, concurrently with co-circulation of porcine epidemic diarrhea virus (PEDV) (family Coronaviridae, genus Alphacoronavirus). The origin of PDCoV in pigs and also its sudden emergence or route of introduction into the US still remains unclear. In the US, since 2013-2014, the newly emerged PDCoV and PEDV have spread nationwide, causing a high number of pig deaths and significant economic impacts. The current US PDCoV strains are enteropathogenic and infect villous epithelial cells of the entire small and large intestines although the jejunum and ileum are the primary sites of infection. Similar to PEDV infections, PDCoV infections also cause acute, severe atrophic enteritis accompanied by transient viremia (viral RNA) that leads to severe diarrhea and/or vomiting, followed by dehydration as the potential cause of death in nursing piglets. At present, differential diagnosis of PDCoV, PEDV, and transmissible gastroenteritis virus (TGEV) is essential to control viral diarrheas in US swine. Cell culture-adapted US PDCoV (TC-PDCoV) strains have been isolated and propagated by us and in several other laboratories. TC-PDCoV strains will be useful to develop serologic assays and to evaluate if serial cell-culture passage attenuates TC-PDCoV as a potential vaccine candidate strain. A comprehensive understanding of the pathogenesis and epidemiology of epidemic PDCoV strains is currently needed to prevent and control the disease in affected regions and to develop an effective vaccine. This review focuses on the etiology, cell culture isolation and propagation, molecular epidemiology, disease mechanisms and pathogenesis of PDCoV infection.

Porcine Epidemic Diarrhea Virus Shedding and Antibody Response in Swine Farms: A Longitudinal Study

“…More than 80% of the sows showed detectable levels of PEDV at the first sampling but only the 30% showed diarrhea. The severity of clinical signs caused by PEDV is age-dependent (Jung et al, 2016). In adult animals, clinical signs are usually milder or completely absent.…”

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.…”

Porcine gastroenteric viruses: pathogenesis and protection

“…In contrast, apoptotic signals were found in PDCoV antigen-positive LLC-PK and ST cells that also showed cytopathic effects, such as cell rounding, detachment and clumping in clusters. Therefore, PDCoVinduces apoptosis in porcine cell cultures, but not in the infected intestinal enterocytes in vivo (Jung et al, 2016b).…”