Calves are susceptible to infection with the newly emerged porcine deltacoronavirus, but not with the swine enteric alphacoronavirus, porcine epidemic diarrhea virus

Abstract

Fecal virus shedding, seroconversion and histopathology were evaluated in 3-7-year-old gnotobiotic calves orally inoculated with porcine deltacoronavirus (PDCoV) (9.0-9.6 log genomic equivalents [GE] of OH-FD22-P5; n=4) or porcine epidemic diarrhea virus (PEDV) (10.2-12.5 log GE of PC21A; n=3). In PDCoV-inoculated calves, an acute but persisting fecal viral RNA shedding and PDCoV-specific serum IgG antibody responses were observed, but without lesions or clinical disease. However, no fecal shedding, seroconversion, histological lesions, and clinical disease were detected in PEDV-inoculated calves. Our data indicate that calves are susceptible to infection by the newly emerged PDCoV, but not by the swine coronavirus, PEDV.

Broad receptor engagement of an emerging global coronavirus may potentiate its diverse cross-species transmissibility

“…Our observations collectively reveal the multihost potential of PDCoV. A broad host range of PDCoV is also suggested by the reported susceptibility of germ-free calves to experimental PDCoV infection (67), as well as by the identification of a highly similar virus-at the time not yet recognized as a deltacoronavirus-in Chinese ferret badgers and Asian leopard cats at live-animal markets in southern China (68). As opposed to the repeated identification and isolation of PDCoV from swine, the incidental identification of viruses in both cat and badger with identical sequences seem to argue against a role for these animals as a potential reservoir (13).…”

Emerging and re-emerging coronaviruses in pigs

“…Currently, disease control and prevention mainly depend on swine farm management, focusing on high biosecurity measures and disease containment within and among farms. Coronaviruses often spill over to other species: PEDV and PDCoV can infect cells from different species, and PDCoV can also infect calves [111]. Currently, these emerging porcine CoVs are only known to infect pigs, but not humans [48,53 ].…”

Detection and spike gene characterization in porcine deltacoronavirus in China during 2016–2018

“…Because it has a non-swine ancestor, PDCoV may not yet be fully adapted to pigs, and it appears to continue to undergo genetic drift to become more adapted to pigs, even if pigs are considered the initial susceptible hosts (Jung et al, 2017). The S protein of the coronavirus is the main determinant of viral host range and tissue tropism; thus, substitutions in the S protein are critical for analysing the evolution, infectivity and pathogenicity of PDCoV.…”