Porcine Epidemic Diarrhea Virus Replication in Human Intestinal Cells Reveals Potential Susceptibility to Cross-Species Infection.

Various coronaviruses have emerged as a result of cross-species transmission among humans and domestic animals. Porcine epidemic diarrhea virus (PEDV; family Coronaviridae, genus Alphacoronavirus) causes acute diarrhea, vomiting, dehydration, and high mortality in neonatal piglets. Porcine small intestinal epithelial cells (IPEC-J2 cells) can be used as target cells for PEDV infection. However, the origin of PEDV in pigs, the host range, and cross-species infection of PEDV remain unclear. To determine whether PEDV has the ability to infect human cells in vitro, human small intestinal epithelial cells (FHs 74 Int cells) were inoculated with PEDV LJX and PEDV CV777 strains. The results indicated that PEDV LJX, but not PEDV CV777, could infect FHs 74 Int cells. Furthermore, we observed M gene mRNA transcripts and N protein expression in infected FHs 74 Int cells. A one-step growth curve showed that the highest viral titer of PEDV occurred at 12 h post infection. Viral particles in vacuoles were observed in FHs 74 Int cells at 24 h post infection. The results proved that human small intestinal epithelial cells are susceptible to PEDV infection, suggesting the possibility of cross-species transmission of PEDV.

Bioinformatic analysis of the S protein of human respiratory coronavirus.

The present study aimed to apply bioinformatic methods to analyze the structure of the S protein of human respiratory coronaviruses, including severe respiratory disease syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), human coronavirus HKU1 (HCoV-HKU1), and severe respiratory disease syndrome coronavirus type 2 (SARS-CoV-2). We predicted and analyzed the physicochemical properties, hydrophilicity and hydrophobicity, transmembrane regions, signal peptides, phosphorylation and glycosylation sites, epitopes, functional domains, and motifs of the S proteins of human respiratory coronaviruses. All four S proteins contain a transmembrane region, which enables them to bind to host cell surface receptors. All four S proteins contain a signal peptide, phosphorylation sites, glycosylation sites, and epitopes. The predicted phosphorylation sites might mediate S protein activation, the glycosylation sites might affect the cellular orientation of the virus, and the predicted epitopes might have implications for the design of antiviral inhibitors. The S proteins of all four viruses have two structural domains, S1 (C-terminal and N-terminal domains) and S2 (homology region 1 and 2). Our bioinformatic analysis of the structural and functional domains of human respiratory coronavirus S proteins provides a basis for future research to develop broad-spectrum antiviral drugs, vaccines, and antibodies.

Health-related quality of life of COVID-19 patients after discharge: A multicenter follow-up study.

AIMS AND OBJECTIVES: To determine the health-related quality of life (HRQoL) of COVID-19 patients after discharge and its predicting factors. BACKGROUND: COVID-19 has caused a worldwide pandemic and led a huge impact on the health of human and daily life. It has been demonstrated that physical and psychological conditions of hospitalised COVID-19 patients are impaired, but the studies focus on physical and psychological conditions of COVID-19 patients after discharge from hospital are rare. DESIGN: A multicentre follow-up study. METHODS: This was a multicentre follow-up study of COVID-19 patients who had discharged from six designated hospitals. Physical symptoms and HRQoL were surveyed at first follow-up (the third month after discharge). The latest multiple laboratory findings were collected through medical examination records. This study was performed and reported in accordance with STROBE checklist. RESULTS: Three hundred eleven patients (57.6%) were reported with one or more physical symptoms. The scores of HRQoL of COVID-19 patients at third month after discharge, except for the dimension of general health, were significantly lower than Chinese population norm (p < .001). Results of logistic regression showed that female (odds ratio (OR): 1.79, 95% confidence interval (CI): 1.04-3.06), older age (≥60 years) (OR: 2.44, 95% CI: 1.33-4.47) and the physical symptom after discharge (OR: 40.15, 95% CI: 9.68-166.49) were risk factors for poor physical component summary; the physical symptom after discharge (OR: 6.68, 95% CI: 4.21-10.59) was a risk factor for poor mental component summary. CONCLUSIONS: Health-related quality of life of discharged COVID-19 patients did not come back to normal at third month after discharge and affected by age, sex and the physical symptom after discharge. RELEVANCE TO CLINICAL PRACTICE: Healthcare workers should pay more attention to the physical and psychological rehabilitation of discharged COVID-19 patients. Long-term follow-up on COVID-19 patients after discharge is needed to determine the long-term impact of COVID-19.