Erastin inhibits porcine epidemic diarrhea virus replication in Vero cells

Background Porcine epidemic diarrhea virus (PEDV), an intestinal pathogenic coronavirus, has caused significant economic losses to the swine industry worldwide. At present, there are several treatment methods, but there is still a lack of clinically effective targeted drugs, new antiviral mechanisms and drugs need to be explored. Methods In this study, we established a model of erastin versus ferrostatin-1 treatment of Vero cells, and then detected virus proliferation and gene expression by RT-qPCR through PEDV infection experiments. Results We demonstrated for the first time that erastin significantly inhibited the replication of PEDV upon entry into cells;Vero treated with erastin significantly regulated the expression of three genes, NRF2, ACSL4 and GPX4, notably erastin regulated the expression of these three genes negatively correlated with the expression induced by PEDV virus infection. Conclusions Since NRF2, ACSL4 and GPX4 are classical Ferroptosis genes, this study speculates that erastin may inhibit the replication of PEDV in Vero cells in part through the regulation of ferroptosis pathway, and erastin may be a potential drug for the treatment of PEDV infection.

Erastin inhibits porcine epidemic diarrhea virus replication in Vero cells.

Background: Porcine epidemic diarrhea virus (PEDV), an intestinal pathogenic coronavirus, has caused significant economic losses to the swine industry worldwide. At present, there are several treatment methods, but there is still a lack of clinically effective targeted drugs, new antiviral mechanisms and drugs need to be explored. Methods: In this study, we established a model of erastin versus ferrostatin-1 treatment of Vero cells, and then detected virus proliferation and gene expression by RT-qPCR through PEDV infection experiments. Results: We demonstrated for the first time that erastin significantly inhibited the replication of PEDV upon entry into cells; Vero treated with erastin significantly regulated the expression of three genes, NRF2, ACSL4 and GPX4, notably erastin regulated the expression of these three genes negatively correlated with the expression induced by PEDV virus infection. Conclusions: Since NRF2, ACSL4 and GPX4 are classical Ferroptosis genes, this study speculates that erastin may inhibit the replication of PEDV in Vero cells in part through the regulation of ferroptosis pathway, and erastin may be a potential drug for the treatment of PEDV infection.

Prevalence and genotypic diversity of Canine Coronavirus in Shandong Province

Objective: To learn the prevalence and genotypic diversity of canine coronavirus(CCoV)in healthy and diarrhea dogs in Shandong Province.

Research progress on mink Coronavirus

Mink coronavirus(MCoV),a member of Coronaviridae,Alphacoronavirus,is an important pathogenic agent of Mink epizootic catarrhal gastroenteritis(ECG), which is characterized by catarrhal diarrhea in minks. ECG has broken out in many mink farms in several countries and caused serious threats to minks. This article reviews the research progress on ECG reported since 1975, including the genomic structure, genetic evolution and receptor characteristics of MCoV,diagnosis, prevention and treatment of ECG. This review will provide reference for clinical prevention and treatment of ECG, and arouse people's attention to MCoV.

Recovery of Recombinant Canine Distemper Virus That Expresses CPV-2a VP2: Uncovering the Mutation Profile of Recombinant Undergoing 50 Serial Passages In Vitro

Canine distemper and canine parvoviral enteritis are infections caused by the canine distemper virus (CDV) and canine parvovirus type 2 (CPV-2), respectively. They are two common infectious diseases that cause high morbidity and mortality in affected dogs. Combination vaccines have been broadly used to protect dogs from infections of CDV, CPV-2, and other viruses. VP2 is the most abundant protein of the CPV-2 capsid. It elicits potent immunity in animals and, therefore, is widely used for designing subunit antigen-based vaccines. In this study, we rescued a recombinant CDV (QN vaccine strain) using reverse genetics. The recombinant CDV (rCDV-VP2) was demonstrated to express stably the VP2 in cells for at least 33 serial passages in vitro. Unfortunately, a nonsense mutation was initially identified in the VP2 open reading frame (ORF) at passage-34 (P34) and gradually became predominant in rCDV-VP2 quasispecies with passaging. Neither test strip detection nor indirect immunofluorescence assay demonstrated the expression of the VP2 at P50. The P50 rCDV-VP2 was subjected to next-generation sequencing, which totally identified 17 single-nucleotide variations (SNVs), consisting of 11 transitions and 6 transversions. Out of the 17 SNVs, 1 and 9 were identified as nonsense and missense mutations, respectively. Since the nonsense mutation arose in the VP2 ORF as early as P34, an earlier rCDV-VP2 progeny should be selected for the vaccination of animals in future experiments.

Rescue of recombinant canine distemper virus that expresses S1 subunit of SARS-CoV-2 spike protein in vitro.

The coronavirus disease 2019 (COVID-19), as an unprecedented pandemic, has rapidly spread around the globe. Its etiological agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), belongs to the genus Betacoronavirus in the family Coronaviridae. The viral S1 subunit has been demonstrated to have a powerful potential in inducing protective immune responses in vivo. Since April 2020, farmed minks were frequently reported to be infected with the SARS-CoV-2 in different countries. Unfortunately, there has been no available veterinary vaccine as yet. In this study, we used reverse genetics to rescue a recombinant canine distemper virus (CDV) that could express the SARS-CoV-2 S1 subunit in vitro. The S1 subunit sequence was demonstrated to be relatively stable in the genome of recombinant CDV during twenty serial viral passages in cells. However, due to introduction of the S1 subunit sequence into CDV genome, this recombinant CDV grew more slowly than the wild-type strain did. The genomic backbone of recombinant CDV was derived from a virulence-attenuating strain (QN strain). Therefore, if able to induce immune protections in minks from canine distemper and COVID-19 infections, this recombinant would be a potential vaccine candidate for veterinary use.

Decontamination of face masks with steam for mask reuse in fighting the pandemic COVID-19: Experimental supports.

The coronavirus disease 2019 pandemic caused by the novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has claimed many lives worldwide. Wearing medical masks (MMs) or N95 masks ([N95Ms] namely N95 respirators) can slow the virus spread and reduce the infection risk. Reuse of these masks can minimize waste, protect the environment, and help solve the current imminent shortage of masks. Disinfection of used masks is needed for their reuse with safety, but improper decontamination can damage the blocking structure of masks. In this study, we demonstrated using the avian coronavirus of infectious bronchitis virus to mimic SARS-CoV-2 that MMs and N95Ms retained their blocking efficacy even after being steamed on boiling water for 2 hours. We also demonstrated that three brands of MMs blocked over 99% viruses in aerosols. The avian coronavirus was completely inactivated after being steamed for 5 minutes. Altogether, this study suggested that MMs are adequate for use on most social occasions and both MMs and N95Ms can be reused for a few days with steam decontamination between use.

Potential utilities of mask-wearing and instant hand hygiene for fighting SARS-CoV-2.

The surge of patients in the pandemic of COVID-19 caused by the novel coronavirus SARS-CoV-2 may overwhelm the medical systems of many countries. Mask-wearing and handwashing can slow the spread of the virus, but currently, masks are in shortage in many countries, and timely handwashing is often impossible. In this study, the efficacy of three types of masks and instant hand wiping was evaluated using the avian influenza virus to mock the coronavirus. Virus quantification was performed using real-time reverse transcription-polymerase chain reaction. Previous studies on mask-wearing were reviewed. The results showed that instant hand wiping using a wet towel soaked in water containing 1.00% soap powder, 0.05% active chlorine, or 0.25% active chlorine from sodium hypochlorite removed 98.36%, 96.62%, and 99.98% of the virus from hands, respectively. N95 masks, medical masks, and homemade masks made of four-layer kitchen paper and one-layer cloth could block 99.98%, 97.14%, and 95.15% of the virus in aerosols. Medical mask-wearing which was supported by many studies was opposed by other studies possibly due to erroneous judgment. With these data, we propose the approach of mask-wearing plus instant hand hygiene (MIH) to slow the exponential spread of the virus. This MIH approach has been supported by the experiences of seven countries in fighting against COVID-19. Collectively, a simple approach to slow the exponential spread of SARS-CoV-2 was proposed with the support of experiments, literature review, and control experiences.

Deep learning-based model for detecting 2019 novel coronavirus pneumonia on high-resolution computed tomography: a prospective study in 27 patients (preprint)

Background: Computed tomography (CT) is the preferred imaging method for diagnosing 2019 novel coronavirus (COVID19) pneumonia. Our research aimed to construct a system based on deep learning for detecting COVID-19 pneumonia on high resolution CT, relieve working pressure of radiologists and contribute to the control of the epidemic. Methods: For model development and validation, 46,096 anonymous images from 106 admitted patients, including 51 patients of laboratory confirmed COVID-19 pneumonia and 55 control patients of other diseases in Renmin Hospital of Wuhan University (Wuhan, Hubei province, China) were retrospectively collected and processed. Twenty-seven consecutive patients undergoing CT scans in Feb, 5, 2020 in Renmin Hospital of Wuhan University were prospectively collected to evaluate and compare the efficiency of radiologists against 2019-CoV pneumonia with that of the model. Findings: The model achieved a per-patient sensitivity of 100%, specificity of 93.55%, accuracy of 95.24%, PPV of 84.62%, and NPV of 100%; a per-image sensitivity of 94.34%, specificity of 99.16%, accuracy of 98.85%, PPV of 88.37%, and NPV of 99.61% in retrospective dataset. For 27 prospective patients, the model achieved a comparable performance to that of expert radiologist. With the assistance of the model, the reading time of radiologists was greatly decreased by 65%. Conclusion: The deep learning model showed a comparable performance with expert radiologist, and greatly improve the efficiency of radiologists in clinical practice. It holds great potential to relieve the pressure of frontline radiologists, improve early diagnosis, isolation and treatment, and thus contribute to the control of the epidemic.