Porcine hemagglutinating encephalomyelitis virus infection in vivo and ex vivo

Porcine hemagglutinating encephalomyelitis virus (PHEV) is a Betacoronavirus that causes vomiting and wasting disease and/or encephalomyelitis in suckling pigs. This study characterized PHEV infection, pathogenesis, and immune response in caesarean-derived, colostrum-deprived (CDCD) neonatal pigs. Infected animals developed mild respiratory, enteric, and neurological clinical signs between 2 to 13 days post oronasal inoculation (dpi). PHEV did not produce viremia, but virus shedding was detected in nasal secretions (1-10 dpi) and feces (2-7 dpi) by RT-qPCR. Viral RNA was detected in all tissues except liver, but the detection rate and RT-qPCR Ct values decreased over time. The highest concentration of virus was detected in inoculated piglets necropsied at 5 dpi in turbinate and trachea, followed by tonsils, lungs, tracheobronchial lymph nodes, and stomach. The most representative microscopic lesions were gastritis lymphoplasmacytic, moderate, multifocal, with perivasculitis, and neuritis with ganglia degeneration. A moderate inflammatory response, characterized by increased levels of IFN-α in plasma (5 dpi) and infiltration of T lymphocytes and macrophages was also observed. Increased plasma levels of IL-8 were detected at 10 and 15 dpi, coinciding with the progressive resolution of the infection. Moreover, a robust antibody response was detected by 10 dpi. An ex vivo air-liquid CDCD-derived porcine respiratory cells culture (ALI-PRECs) system showed virus replication in ALI-PRECs and cytopathic changes and disruption of ciliated columnar epithelia, thereby confirming the tracheal epithelia as a primary site of infection for PHEV. IMPORTANCE Among the ∼46 virus species in the Family Coronaviridae (2019), many of which are important pathogens of humans and 6 of which are commonly found in pigs, porcine hemagglutinating encephalomyelitis remains one of the least researched. The present study provided a comprehensive characterization of the PHEV infection process and immune responses using CDCD neonatal pigs. Moreover, we used an ex vivo porcine respiratory cells culture (ALI-PRECs) system resembling the epithelial lining of the tracheobronchial region of the porcine respiratory tract to demonstrate that the upper respiratory tract is a primary site of PHEV infection. This study provides a platform for further multidisciplinary studies of coronavirus infections.

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The Upper Respiratory Tract of Felids Is Highly Susceptible to SARS-CoV-2 Infection

International Journal of Molecular Sciences ◽

10.3390/ijms221910636 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10636

Author(s):

Nadine Krüger ◽

Cheila Rocha ◽

Sandra Runft ◽

Johannes Krüger ◽

Iris Färber ◽

...

Keyword(s):

Respiratory Tract ◽

Cell Cultures ◽

Ex Vivo ◽

Virus Transmission ◽

Upper Respiratory Tract ◽

Pathological Changes ◽

Domestic Cats ◽

Changes Detection ◽

Upper Respiratory ◽

Air Liquid Interface

Natural or experimental infection of domestic cats and virus transmission from humans to captive predatory cats suggest that felids are highly susceptible to SARS-CoV-2 infection. However, it is unclear which cells and compartments of the respiratory tract are infected. To address this question, primary cell cultures derived from the nose, trachea, and lungs of cat and lion were inoculated with SARS-CoV-2. Strong viral replication was observed for nasal mucosa explants and tracheal air–liquid interface cultures, whereas replication in lung slices was less efficient. Infection was mainly restricted to epithelial cells and did not cause major pathological changes. Detection of high ACE2 levels in the nose and trachea but not lung further suggests that susceptibility of feline tissues to SARS-CoV-2 correlates with ACE2 expression. Collectively, this study demonstrates that SARS-CoV-2 can efficiently replicate in the feline upper respiratory tract ex vivo and thus highlights the risk of SARS-CoV-2 spillover from humans to felids.

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The Betacoronavirus PHEV Replicates and Disrupts the Respiratory Epithelia and Upregulates Key Pattern Recognition Receptor Genes and Downstream Mediators, Including IL-8 and IFN-λ

mSphere ◽

10.1128/msphere.00820-21 ◽

2021 ◽

Vol 6 (6) ◽

Author(s):

Rahul K. Nelli ◽

Juan Carlos Mora-Díaz ◽

Luis G. Giménez-Lirola

Keyword(s):

Upper Respiratory Tract ◽

Immune Genes ◽

Tissue Sections ◽

Respiratory Epithelia ◽

Encephalomyelitis Virus ◽

Innate Immune Genes ◽

Air Liquid Interface ◽

Porcine Respiratory

The neurotropic betacoronavirus porcine hemagglutinating encephalomyelitis virus (PHEV) primarily infects and replicates in the swine upper respiratory tract, causing vomiting and wasting disease and/or encephalomyelitis in suckling pigs. This study investigated the modulation of key early innate immune genes at the respiratory epithelia in vivo, on tracheal tissue sections from experimentally infected pigs, and in vitro , on air-liquid interface porcine respiratory cell cultures.

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Vinegar and Its Active Component Acetic Acid Inhibit SARS-CoV-2 Infection In Vitro and Ex Vivo

10.1101/2020.07.08.193193 ◽

2020 ◽

Author(s):

Isabel Pagani ◽

Silvia Ghezzi ◽

Massimo Clementi ◽

Guido Poli ◽

Mario Bussi ◽

...

Keyword(s):

Acetic Acid ◽

Antiviral Activity ◽

Respiratory Tract ◽

Active Component ◽

Ex Vivo ◽

Vero Cells ◽

Nasopharyngeal Swab ◽

Upper Respiratory Tract ◽

Upper Respiratory

AbstractEffective and economical measures are needed to either prevent or inhibit the replication of SARS-CoV-2, the causative agent of COVID-19, in the upper respiratory tract. As fumigation of vinegar at low concentration (0.34%) ameliorated the symptoms of mild SARS-CoV-2 infection, we tested in vitro the potential antiviral activity of vinegar and of its active component, acetic acid. We here demonstrate that both vinegar and acetic acid indeed strongly inactivate SARS-CoV-2 infectivity in Vero cells. Furthermore, vinegar treatment caused a 90% inhibition of the infectious titer when directly applied to a nasopharyngeal swab transfer medium of a COVID-19 patient. These effects were potentiated if conduced at a temperature of 45 °C vs. 37 °C, a condition that is transiently generated in the upper respiratory tract during fumigation. Our findings are consistent and extend the results of studies performed in the early and mid-20th century on the disinfectant capacity of organic acids and can provide an affordable home-made aid to prevent or contain SARS-CoV-2 infection of the upper respiratory tract.

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