Porcine Epidemic Diarrhea Virus and Its nsp14 Suppress ER Stress Induced GRP78.

Porcine epidemic diarrhea virus (PEDV), a member of the α-coronavirus genus, can cause vomiting, diarrhea, and dehydration in piglets. Neonatal piglets infected with PEDV have a mortality rate as high as 100%. PEDV has caused substantial economic losses to the pork industry. Endoplasmic reticulum (ER) stress, which can alleviate the accumulation of unfolded or misfolded proteins in ER, involves in coronavirus infection. Previous studies have indicated that ER stress could inhibit the replication of human coronaviruses, and some human coronaviruses in turn could suppress ER stress-related factors. In this study, we demonstrated that PEDV could interact with ER stress. We determined that ER stress could potently inhibit the replication of GⅠ, GⅡ-a, and GⅡ-b PEDV strains. Moreover, we found that these PEDV strains can dampen the expression of the 78 kDa glucose-regulated protein (GRP78), an ER stress marker, while GRP78 overexpression showed antiviral activity against PEDV. Among different PEDV proteins, PEDV non-structural protein 14 (nsp14) was revealed to play an essential role in the inhibition of GRP78 by PEDV, and its guanine-N7-methyltransferase domain is necessary for this role. Further studies show that both PEDV and its nsp14 negatively regulated host translation, which could account for their inhibitory effects against GRP78. In addition, we found that PEDV nsp14 could inhibit the activity of GRP78 promotor, helping suppress GRP78 transcription. Our results reveal that PEDV possesses the potential to antagonize ER stress, and suggest that ER stress and PEDV nsp14 could be the targets for developing anti-PEDV drugs.

Clinical practice guidelines and expert consensus statements on rehabilitation for patients with COVID-19: protocol for a systematic review.

INTRODUCTION: COVID-19 is a highly infectious disease, characterised by respiratory, physical and psychological dysfunctions. Rehabilitation could effectively alleviate the symptoms and promote recovery of the physical and mental health of patients with COVID-19. Recently, rehabilitation medical institutions have issued clinical practice guidelines (CPGs) and expert consensus statements involving recommendations for rehabilitation assessments and rehabilitation therapies for COVID-19. This systematic review aims to assess the methodological quality and reporting quality of the guidance documents, evaluate the heterogeneity of the recommendations and summarise the recommendations with respect to rehabilitation assessments and rehabilitation therapies for COVID-19 to provide a quick reference for front-line clinicians, therapists and patients as well as reasonable suggestions for future guidelines. METHODS AND ANALYSIS: The electronic databases including PubMed, Embase, Chinese Biomedical Literature Database (CBM), Chinese Science and Technology Periodical Database (VIP), Wanfang Database and China National Knowledge Infrastructure (CNKI) and websites of governments or organisations (eg, National Guideline Clearinghouse, Guidelines International Network, National Institute for Health and Clinical Excellence, Scottish Intercollegiate Guidelines Network and WHO) will be searched for eligible CPGs and expert consensus statements from inception to August 2022. CPGs and expert consensus statements published in Chinese or English and presenting recommendations for modern functional rehabilitation techniques and/or traditional Chinese medicine rehabilitation techniques for COVID-19 will be included. Reviews, interpretations, old versions of CPGs and expert consensus statements and those for the management of other diseases during the pandemic will be excluded. Two reviewers will independently review each article, extract data, appraise the methodological quality following the Appraisal of Guidelines for Research & Evaluation II tool and assess the reporting quality with the Reporting Items for Practice Guidelines in Healthcare statement. The Measurement Scale of Rate of Agreement will be used to evaluate the heterogeneity of the recommendations in different CPGs and expert consensus statements. Agreement between reviewers will be calculated using the intraclass correlation coefficient. We will also summarise the recommendations for rehabilitation in patients with COVID-19. The results will be narratively described and presented as tables or figures. ETHICS AND DISSEMINATION: Ethics approval is not needed for this systematic review because information from published documents will be used. The findings will be submitted for publication in a peer-reviewed journal and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PROSPERO REGISTRATION NUMBER: CRD42020190761.

Lack of viable severe acute respiratory coronavirus virus 2 (SARS-CoV-2) among PCR-positive air samples from hospital rooms and community isolation facilities.

BACKGROUND: Understanding the extent of aerosol-based transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important for tailoring interventions for control of the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have reported the detection of SARS-CoV-2 nucleic acid in air samples, but only one study has successfully recovered viable virus, although it is limited by its small sample size. OBJECTIVE: We aimed to determine the extent of shedding of viable SARS-CoV-2 in respiratory aerosols from COVID-19 patients. METHODS: In this observational air sampling study, air samples from airborne-infection isolation rooms (AIIRs) and a community isolation facility (CIF) housing COVID-19 patients were collected using a water vapor condensation method into liquid collection media. Samples were tested for presence of SARS-CoV-2 nucleic acid using quantitative real-time polymerase chain reaction (qRT-PCR), and qRT-PCR-positive samples were tested for viability using viral culture. RESULTS: Samples from 6 (50%) of the 12 sampling cycles in hospital rooms were positive for SARS-CoV-2 RNA, including aerosols ranging from <1 µm to >4 µm in diameter. Of 9 samples from the CIF, 1 was positive via qRT-PCR. Viral RNA concentrations ranged from 179 to 2,738 ORF1ab gene copies per cubic meter of air. Virus cultures were negative after 4 blind passages. CONCLUSION: Although SARS-CoV-2 is readily captured in aerosols, virus culture remains challenging despite optimized sampling methodologies to preserve virus viability. Further studies on aerosol-based transmission and control of SARS-CoV-2 are needed.

Environmental contamination in a coronavirus disease 2019 (COVID-19) intensive care unit-What is the risk?

BACKGROUND: The risk of environmental contamination by severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in the intensive care unit (ICU) is unclear. We evaluated the extent of environmental contamination in the ICU and correlated this with patient and disease factors, including the impact of different ventilatory modalities. METHODS: In this observational study, surface environmental samples collected from ICU patient rooms and common areas were tested for SARS-CoV-2 by polymerase chain reaction (PCR). Select samples from the common area were tested by cell culture. Clinical data were collected and correlated to the presence of environmental contamination. Results were compared to historical data from a previous study in general wards. RESULTS: In total, 200 samples from 20 patient rooms and 75 samples from common areas and the staff pantry were tested. The results showed that 14 rooms had at least 1 site contaminated, with an overall contamination rate of 14% (28 of 200 samples). Environmental contamination was not associated with day of illness, ventilatory mode, aerosol-generating procedures, or viral load. The frequency of environmental contamination was lower in the ICU than in general ward rooms. Eight samples from the common area were positive, though all were negative on cell culture. CONCLUSION: Environmental contamination in the ICU was lower than in the general wards. The use of mechanical ventilation or high-flow nasal oxygen was not associated with greater surface contamination, supporting their use and safety from an infection control perspective. Transmission risk via environmental surfaces in the ICUs is likely to be low. Nonetheless, infection control practices should be strictly reinforced, and transmission risk via droplet or airborne spread remains.

Clinical and radiographic characteristics, management and short-term outcomes of patients with COVID-19 in Wenzhou, China.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an emerging viral disease. Here, we report the clinical features, management, and short-term outcomes of COVID-19 patients in Wenzhou, China, an area outside Wuhan. METHODS: Patients admitted to the Infectious Diseases Department of Ruian People's Hospital in Wenzhou, from January 21 to February 7, 2020, were recruited. Medical data on epidemiological history, demographics, clinical characteristics, laboratory tests, chest computerized tomography (CT) examination, treatment, and short-term outcomes were retrospectively reviewed. Blood biochemistry and routine tests were examined using standard methods and automatic machines. CT examination was performed several times during hospitalization as necessary. RESULTS: A total of 67 confirmed COVID-19 cases were diagnosed; 64 (95.4%) were common cases and three (4.5%) were severe cases. The most common symptoms at admission were fever (86.6%), cough (77.6%), productive cough (52.2%), chest distress (17.9%), and sore throat (11.9%), followed by diarrhea (7.4%), headache (7.4%), shortness of breath (6.0%), dizziness (4.5%), muscular soreness (4.5%), and running nose (4.5%). Thirty patients (47.8%) had increased C-reactive protein levels. The CT radiographs at admission showed abnormal findings in 54 (80.6%) patients. The patients were treated mainly by oxygen therapy and antiviral drugs. By March 3, 2020, all 67 patients completely recovered and had negative nucleic acid tests. The patients were discharged from the hospital and transferred to a medical observation isolation center for further observation. CONCLUSION: Cases of COVID-19 in Wenzhou are milder and have a better prognosis, compared to those in Wuhan. Timely and appropriate screening, diagnosis, and treatment are the key to achieve good outcomes.

Diversity of ACE2 and its interaction with SARS-CoV-2 receptor binding domain (preprint)

COVID-19, the clinical syndrome caused by the SARS-CoV-2 virus, has rapidly spread globally causing millions of infections and hundreds of thousands of deaths. The potential animal reservoirs for SARS-CoV-2 are currently unknown, however sequence analysis has provided plausible potential candidate species. SARS-CoV-2 binds to the angiotensin I converting enzyme 2 (ACE2) to enable its entry into host cells and establish infection. We analyzed the binding surface of ACE2 from several important animal species to begin to understand the parameters for the ACE2 recognition by the SARS-CoV-2 spike protein receptor binding domain (RBD). We employed Shannon entropy analysis to determine the variability of ACE2 across its sequence and particularly in its RBD interacting region, and assessed differences between various species ACE2 and human ACE2. As cattle are a known reservoir for coronaviruses with previous human zoonotic transfer, and has a relatively divergent ACE2 sequence, we compared the binding kinetics of bovine and human ACE2 to SARS-CoV-2 RBD. This revealed a nanomolar binding affinity for bovine ACE2 but an approximate ten-fold reduction of binding compared to human ACE2. Since cows have been experimentally infected by SARS-CoV-2, this lower affinity sets a threshold for sequences with lower homology to human ACE2 to be able to serve as a productive viral receptor for SARS-CoV-2.

The Fc-mediated effector functions of a potent SARS-CoV-2 neutralizing antibody, SC31, isolated from an early convalescent COVID-19 patient, are essential for the optimal therapeutic efficacy of the antibody (preprint)

SARS-CoV-2-neutralizing antibodies are promising therapeutics for COVID-19. However, little is known about the mechanisms of action of these antibodies or their effective dosing windows. We report the discovery and development of SC31, a potent SARS-CoV-2 neutralizing IgG1 antibody, originally isolated from a convalescent patient at day 27 after the onset of symptoms. Neutralization occurs via a binding epitope that maps within the ACE2 interface of the SARS-CoV-2 Spike protein, conserved across all common circulating SARS-CoV-2 mutants. In SARS-CoV-2 infected K18-human ACE2 transgenic mice, SC31 demonstrated potent survival benefit by dramatically reducing viral load concomitant with attenuated pro-inflammatory responses linked to severe systemic disease, such as IL-6. Comparison with a Fc-null LALA variant of SC31 demonstrated that optimal therapeutic efficacy of SC31 requires intact Fc-mediated effector functions that can further induce an IFN{gamma}-driven anti-viral immune response. Dose-dependent efficacy for SC31 was observed down to 5mg/kg when dosed before the activation of lung inflammatory responses. Importantly, despite Fc{gamma}R binding, no evidence of antibody dependent enhancement was observed with the Fc-competent SC31 even at sub-therapeutic doses. Therapeutic efficacy was confirmed in SARS-CoV-2-infected hamsters, where SC31 again significantly reduced viral load, decreased lung lesions and inhibited progression to severe disease manifestations. This study underlines the potential for significant COVID-19 patient benefit for the SC31 antibody that justifies rapid advancement to the clinic, as well as highlighting the importance of appropriate mechanistic and functional studies during development. One Sentence SummaryAnti-SARS-CoV-2 IgG1 antibody SC31 controls infection in vivo by blocking SP:ACE2 binding and triggering a Fc-mediated anti-viral response.

Prevention program for the COVID-19 in a children's digestive endoscopy center.

The pneumonia caused by the coronavirus disease-2019 (COVID-19) outbreak in Wuhan, China constitutes a public health emergency of international concern. The gastrointestinal symptoms of vomiting, diarrhea and abdominal pain and the detection of COVID-19 nucleic acid from fecal specimens in a small number of patients suggest the possibility of transmission via the gastrointestinal tract. People of all ages are vulnerable to this virus, including children. Digestive endoscopy is an invasive procedure during which children cannot wear masks; therefore, they have higher risks of exposure to COVID-19, and the digestive endoscopy center is a relatively high-risk area for COVID-19 infection. Based on these factors and in combination with related policies and regulations, a prevention and control program for the COVID-19 pneumonia in a children's digestive endoscopy center was established to prevent the COVID-19 nosocomial infection.