Pathogenicity of three isolates of porcine respiratory coronavirus in the USA

Abstract

The pathogenicity of three isolates of porcine respiratory coronavirus (AR310, LEPP and 1894) from the USA was assessed in specific pathogen-free pigs. Pigs inoculated with 1894 developed mild respiratory disease and pigs inoculated with AR310 and LEPP developed moderate respiratory disease from four to 10 days after they were inoculated, but all the pigs recovered fully by 14 days after inoculation. Gross and microscopic examination revealed mild (1894) to moderate (AR310 and LEPP) multifocal bronchointerstitial pneumonia from four to 10 days after inoculation. The lesions were characterised by necrotising bronchiolitis, septal infiltration with mononuclear cells, and a mixed alveolar exudate. No clinical signs or microscopic lesions were observed in control pigs that had not been inoculated.

Lung pathology of fatal severe acute respiratory syndrome

“…24 Although we did not find PCR evidence of a secondary viral infection, such as HMPV, in pigs infected with some isolates of porcine respiratory coronavirus, the respiratory lesions were severe enough to predispose the pigs to secondary bacterial or mycoplasmal infections or to lead to combined viral infections. 25 As we have already mentioned, the histological features of porcine reproductive and respiratory syndrome virus infection are similar to those of SARS-CoV infection; it is possible that SARS-CoV infection in human beings may "open the door" to secondary infections, as previously reported. 5 The patients who received ribavirin therapy still had PCR and electron-microscopic evidence of SARS-CoV in the lung.…”

Host-pathogen interactions during coronavirus infection of primary alveolar epithelial cells

“…The repiratory and enteric tracts are common targets for coronaviruses that infect animals and poultry, including pigs, cows, dogs, rodents, and chickens. Porcine respiratory coronavirus infects the epithelial cells of the lung, and disease ranges from subclinical infection to moderate bronchointerstitial pneumo-nia, depending on the virus strain [1,2]. Bovine coronavirus causes disease in the enteric tract and the upper and lower respiratory tracts, which has been associated with shipping fever [3].…”

Could Naturally Occurring Coronaviral Diseases in Animals Serve as Models for COVID-19? A Review Focusing on the Bovine Model

“…This mutation event has intrigued researchers for decades, but to the best of our knowledge, it does not reflect what is happening in COVID-19. PRCV also belongs to the genus Alphacoronavirus and causes mild respiratory signs in pigs [13]. This virus is a deletion mutant of the more pathogenic transmissible gastroenteritis virus (TGEV), and the spread of PRCV has provided a beneficial cross-protection in the pig population [14].…”

“…pleural and abdominal effusions, fever, lethargy, anorexia, and weight loss; fatal [11] Respiratory signs, incl. pneumonia, but most often mild to moderate clinical signs [13] Upper respiratory signs (part of the canine infectious respiratory disease complex); often mild [17] Diarrhea and respiratory signs; part of bovine respiratory disease complex and winter dysentery in adult cows can lead to severe signs [10,22] Upper respiratory signs, ranging from mild to severe (incl. acute respiratory distress); in severe cases multi-organ failure; gastrointestinal signs; occasionally, long-term effects [23,24] Genetic characteristics…”

“…HCoV OC43 [15,25] Genetically similar to bat SARS-like CoVs [26] Tropism Multiple, mainly monocytes/macrophages [11] Respiratory tract (epithelial cells and alveolar macrophages) [13,14] Mainly respiratory tract [17] Respiratory and gastrointestinal tract [10] Respiratory and gastrointestinal tract (incl. epithelial cells and alveolar macrophages) [23,24,27,28] Vaccine?…”