The unfolded protein response components IRE1α and XBP1 promote human coronavirus infection.

The cellular processes that support human coronavirus replication and contribute to the pathogenesis of severe disease remain incompletely understood. Many viruses, including coronaviruses, cause endoplasmic reticulum (ER) stress during infection. IRE1α is a component of the cellular response to ER stress that initiates non-conventional splicing of XBP1 mRNA. Spliced XBP1 encodes a transcription factor that induces the expression of ER-related targets. Activation of the IRE1α-XBP1 pathway occurs in association with risk factors for severe human coronavirus infection. In this study, we found that the human coronaviruses HCoV-OC43 (human coronavirus OC43) and SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) both robustly activate the IRE1α-XBP1 branch of the unfolded protein response in cultured cells. Using IRE1α nuclease inhibitors and genetic knockdown of IRE1α and XBP1, we found that these host factors are required for optimal replication of both viruses. Our data suggest that IRE1α supports infection downstream of initial viral attachment and entry. In addition, we found that ER stress-inducing conditions are sufficient to enhance human coronavirus replication. Furthermore, we found markedly increased XBP1 in circulation in human patients with severe coronavirus disease 2019 (COVID-19). Together, these results demonstrate the importance of IRE1α and XBP1 for human coronavirus infection.IMPORTANCEThere is a critical need to understand the cellular processes co-opted during human coronavirus replication, with an emphasis on identifying mechanisms underlying severe disease and potential therapeutic targets. Here, we demonstrate that the host proteins IRE1α and XBP1 are required for robust infection by the human coronaviruses, SARS-CoV-2 and HCoV-OC43. IRE1α and XBP1 participate in the cellular response to ER stress and are activated during conditions that predispose to severe COVID-19. We found enhanced viral replication with exogenous IRE1α activation, and evidence that this pathway is activated in humans during severe COVID-19. Together, these results demonstrate the importance of IRE1α and XBP1 for human coronavirus infection.

Geraniin as a potential inhibitor of SARS-CoV-2 3CLpro.

Geraniin is a polyphenolic compound first isolated from Geranium thunbergii. The major protease (Mpro), namely 3 C-like protease (3CLpro), of coronaviruses is considered an attractive drug target as it is essential for the processing and maturation of viral polyproteins. Thus, our primary goal is to explore the efficiency of geraniin on 3CLpro of SARS-CoV-2 using the computational biology strategy. In this work, we studied the anti-coronavirus effect of geraniin in vitro and its potential inhibitory mode against the 3CLpro of SARS-CoV-2. We found that geraniin inhibited HCoV-OC43 coronavirus-infected cells during the attachment and penetration phases. Molecular docking and dynamics simulations exhibited that geraniin had a strong binding affinity and high stable binding to 3CLpro of SARS-CoV-2. Geraniin showed a strong inhibitory activity on coronavirus and may be a potential inhibitor of SARS-CoV-2 3CLpro.

Epidemiology of Non-SARS-CoV2 Human Coronaviruses (HCoVs) in People Presenting with Influenza-like Illness (ILI) or Severe Acute Respiratory Infections (SARI) in Senegal from 2012 to 2020.

In addition to emerging coronaviruses (SARS-CoV, MERS, SARS-CoV-2), there are seasonal human coronaviruses (HCoVs): HCoV-OC43, HCoV-229E, HCoV-NL63 and HCoV-HKU1. With a wide distribution around the world, HCoVs are usually associated with mild respiratory disease. In the elderly, young children and immunocompromised patients, more severe or even fatal respiratory infections may be observed. In Africa, data on seasonal HCoV are scarce. This retrospective study investigated the epidemiology and genetic diversity of seasonal HCoVs during nine consecutive years of influenza-like illness surveillance in Senegal. Nasopharyngeal swabs were collected from ILI outpatients or from SARI hospitalized patients. HCoVs were diagnosed by qRT-PCR and the positive samples were selected for molecular characterization. Among 9337 samples tested for HCoV, 406 (4.3%) were positive: 235 (57.9%) OC43, 102 (25.1%) NL63, 58 (14.3%) 229E and 17 (4.2%) HKU1. The four types circulated during the study period and a peak was noted between November and January. Children under five were the most affected. Co-infections were observed between HCoV types (1.2%) or with other viruses (76.1%). Genetically, HCoVs types showed diversity. The results highlighted that the impact of HCoVs must be taken into account in public health; monitoring them is therefore particularly necessary both in the most sensitive populations and in animals.

Coronaviruses

The coronaviruses belong to the family Coronaviridae in the order Nidovirales. CoVs are found globally and infect a variety of animals, causing illnesses that range from gastrointestinal tract infections, encephalitis and demyelination;and can be fatal. Humans coronaviruses (hCoVs) have traditionally been associated with self-limiting upper respiratory tract infections and gastrointestinal tract infections. In recent years, however, it has become increasingly evident that the hCoVs can cause more severe lower respiratory tract infections such as bronchitis, pneumonia and even acute respiratory distress syndrome (ARDS), and can lead to death. Seven CoVs are known to infect humans, with the four "common cold” CoVs circulating globally on a yearly basis. The remaining three are more pathogenic and have resulted in outbreaks with high mortality rates. This review focussed on the three pathogenic CoVs. © 2022 Elsevier Inc. All rights reserved.

Household transmission of seasonal coronavirus infections: Results from the Flu Watch cohort study.

Background: In the context of the current coronavirus disease 2019 (COVID-19) pandemic, understanding household transmission of seasonal coronaviruses may inform pandemic control. We aimed to investigate what proportion of seasonal coronavirus transmission occurred within households, measure the risk of transmission in households, and describe the impact of household-related factors of risk of transmission. Methods: Using data from three winter seasons of the UK Flu Watch cohort study, we measured the proportion of symptomatic infections acquired outside and within the home, the household transmission risk and the household secondary attack risk for PCR-confirmed seasonal coronaviruses. We present transmission risk stratified by demographic features of households. Results: We estimated that the proportion of cases acquired outside the home, weighted by age and region, was 90.7% (95% CI 84.6- 94.5, n=173/195) and within the home was 9.3% (5.5-15.4, 22/195). Following a symptomatic coronavirus index case, 14.9% (9.8 - 22.1, 20/134) of households experienced symptomatic transmission to at least one other household member. Onward transmission risk ranged from 11.90% (4.84-26.36, 5/42) to 19.44% (9.21-36.49, 7/36) by strain. The overall household secondary attack risk for symptomatic cases was 8.00% (5.31-11.88, 22/275), ranging across strains from 5.10 (2.11-11.84, 5/98) to 10.14 (4.82- 20.11, 7/69). Median clinical onset serial interval was 7 days (IQR= 6-9.5). Households including older adults, 3+ children, current smokers, contacts with chronic health conditions, and those in relatively deprived areas had the highest transmission risks. Child index cases and male index cases demonstrated the highest transmission risks. Conclusion: Most seasonal coronaviruses appear to be acquired outside the household, with relatively modest risk of onward transmission within households. Transmission risk following an index case appears to vary by demographic household features, with potential overlap between those demonstrating the highest point estimates for seasonal coronavirus transmission risk and COVID-19 susceptibility and poor illness outcomes.

Aseptic meningitis caused by Coronavirus OC43 in a child: A case report

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses that cause the mild cold. On the other hand, extra-respiratory manifestations such as central nervous system infections with HCoV-OC43 are very rarely reported. We present a case of a previously healthy immunocompetent child with acute aseptic meningitis, as a result of HCoV-OC43 who admitted to the emergency department with a complaint of unconsciousness.. Respiratory tract and cerebrospinal fluid culture showed HCoV-OC43 in viral screening. During the follow-up period, the patient was completely asymptomatic, with normalized consciousness. The clinicians should keep in mind that HCoV-OC43 can be the etiological agent in the differential diagnosis of aseptic meningitis in immunocompetent individuals with reversible neurological symptoms.Copyright © 2022, Derman Medical Publishing. All rights reserved.

Evaluation of Environmental Stability and Disinfectant Effectiveness for Human Coronavirus OC43 on Human Skin Surface.

The environmental stability of human coronavirus OC43 (HCoV-OC43) on the surface of human skin and the effectiveness of disinfectant against HCoV-OC43, which are important to prevent contact transmission, have not been clarified in previous studies. Using previously generated models, we evaluated HCoV-OC43 stability and disinfection effectiveness. Then we compared the results with those for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The median survival time of HCoV-OC43 on the surface of human skin was 24.6 h (95% confidence interval, 19.7 to 29.6 h), which was higher than that of SARS-CoV-2 (10.8 h). Although the in vitro disinfectant effectiveness evaluation showed that HCoV-OC43 has a higher ethanol resistance than SARS-CoV-2, HCoV-OC43 on the skin surface was completely inactivated by a minimum of 50% ethanol within 5 s (the log reduction values were >4.0). Moreover, 1.0% chlorhexidine gluconate and 0.2% benzalkonium chloride showed relatively high disinfectant effectiveness, and the log reduction values when these disinfectants were applied for 15 s were >3.0. HCoV-OC43 is highly stable on the skin surface, which may increase the risk of contact transmission. Although HCoV-OC43 has relatively high ethanol resistance, appropriate hand hygiene practices with current alcohol-based disinfectants sufficiently reduce the risk of contact transmission. IMPORTANCE This study revealed the environmental stability of HCoV-OC43 and disinfectant effectiveness against HCoV-OC43, which had not been demonstrated in previous studies. HCoV-OC43 is highly stable on the surface of human skin, with a survival time of approximately 25 h. High stability of HCoV-OC43 may increase the risk of contact transmission. Furthermore, the in vitro disinfectant effectiveness evaluation showed that HCoV-OC43, which is classified as an envelope virus, has a relatively high ethanol resistance. This finding suggests that disinfectant effectiveness may vary greatly depending on the virus and that each virus targeted for infection control should be evaluated individually. HCoV-OC43 on the skin surface was rapidly inactivated by 50% ethanol, which suggests that appropriate hand hygiene practices with current alcohol-based disinfectants can sufficiently reduce the risk of HCoV-OC43 contact transmission.

Evaluation of Broad Anti-Coronavirus Activity of Autophagy-Related Compounds Using Human Airway Organoids.

To deal with the broad spectrum of coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that threaten human health, it is essential to not only drugs develop that target viral proteins but also consider drugs that target host proteins/cellular processes to protect them from being hijacked for viral infection and replication. To this end, it has been reported that autophagy is deeply involved in coronavirus infection. In this study, we used airway organoids to screen a chemical library of autophagic modulators to identify compounds that could potentially be used to fight against infections by a broad range of coronaviruses. Among the 80 autophagy-related compounds tested, cycloheximide and thapsigargin reduced SARS-CoV-2 infection efficiency in a dose-dependent manner. Cycloheximide treatment reduced the infection efficiency of not only six SARS-CoV-2 variants but also human coronavirus (HCoV)-229E and HCoV-OC43. Cycloheximide treatment also reversed viral infection-induced innate immune responses. However, even low-dose (1 µM) cycloheximide treatment altered the expression profile of ribosomal RNAs; thus, side effects such as inhibition of protein synthesis in host cells must be considered. These results suggest that cycloheximide has broad-spectrum anti-coronavirus activity in vitro and warrants further investigation.

Heparan Sulfate and Enoxaparin Interact at the Interface of the Spike Protein of HCoV-229E but Not with HCoV-OC43.

It is known that the spike protein of human coronaviruses can bind to a secondary receptor, or coreceptor, to facilitate the virus entry. While HCoV-229E uses human aminopeptidase N (hAPN) as a receptor, HCoV-OC43 binds to 9-O-acetyl-sialic acid (9-O-Ac-Sia), which is linked in a terminal way to the oligosaccharides that decorate glycoproteins and gangliosides on the surface of the host cell. Thus, evaluating the possible inhibitory activity of heparan sulfate, a linear polysaccharide found in animal tissues, and enoxaparin sodium on these viral strains can be considered attractive. Therefore, our study also aims to evaluate these molecules' antiviral activity as possible adsorption inhibitors against non-SARS-CoV. Once the molecules' activity was verified in in vitro experiments, the binding was studied by molecular docking and molecular dynamic simulations confirming the interactions at the interface of the spike proteins.

Human coronavirus 3CL proteases cleave septins and disrupt Hedgehog signaling, causing ciliary dysfunction.

Coronaviruses target ciliate cells causing the loss of cilia, acute rhinorrheas, and other ciliopathies. The loss of ciliary function may help the virus infect, replicate, and spread. However, the molecular mechanisms by which coronaviruses cause ciliary defects are still unclear. Herein we demonstrate how coronavirus infection and severe acute respiratory syndrome coronavirus2 3CL protease induce cilia dysfunction by targeting a host protein septin that is required for the structure and function of cilia. Further, we demonstrate that coronaviruses and 3CL protease lead to the cleavage of several septin proteins (SEPT2, -6, and -9), producing cleaved obstructive fragments. Furthermore, ectopic expression of cleaved SEPT2 fragments shows defective ciliogenesis, disoriented septin filaments, and ablated Sonic Hedgehog (SHH) signaling in a protease activity-dependent manner. We present that the 3CLpro inhibitors are potent and prevent abnormal ciliary structures and SHH signaling. These results provide useful insights into the general mechanisms underlying ciliary defects caused by coronaviruses, which, in turn, facilitate virus spread and prove that preclinical and clinical 3CL protease inhibitors may prove useful as therapeutics for treating ciliary defects of coronaviruses.

Cardamonin as a p38 MAPK Signaling Pathway Activator Inhibits Human Coronavirus OC43 Infection in Human Lung Cells.

A natural chalcone, cardamonin (2',4'-dihydroxy-6'-methoxychalcone; CDN) was isolated from the seeds of Alpinia katsumadai Hayata, which has been traditionally used to treat stomach aches. CDN has been reported to possess various pharmacological properties, including anticancer and anti-inflammatory effects. This study evaluated the antiviral activity of CDN against human coronavirus HCoV-OC43 and determined the mode of action in HCoV-OC43-infected human lung cell lines (MRC-5 and A549 cells). CDN significantly inhibited HCoV-OC43-induced cytopathic effects with an IC50 of 3.62 µM and a CC50 of >50 µM, resulting in a selectivity index of >13.81. CDN treatment reduced the level of viral RNA and the expression of spike and nucleocapsid proteins in HCoV-OC43-infected cells as determine through qRT-PCR and Western blot analysis. Additionally, the activation of p38 mitogen-activated protein kinase (MAPK) by anisomycin decreased viral protein expression, whereas an inhibitor of p38 MAPK signaling, SB202190, increased viral protein expression. CDN also amplified and extended the p38 MAPK signaling pathway in HCoV-OC43-infected cells. In conclusion, CDN inhibited HCoV-OC43 infection by activating the p38 MAPK signaling pathway and has potential as a therapeutic agent against human coronavirus.

Respiratory viruses in medicolegal autopsies during the winter season 2021/2022: observations after reduction of coronavirus disease-19 (COVID-19) pandemic restrictions.

In the context of the coronavirus disease (COVID-19) pandemic, measures were taken to protect the population from infection. These were almost completely lifted in several countries in the spring of 2022. To obtain an overview of the spectrum of respiratory viruses encountered in autoptical routine case work, and their infectivity, all autopsy cases at the Institute of Legal Medicine in Frankfurt/M. with flu-like symptoms (among others) were examined for at least 16 different viruses via multiplex PCR and cell culture. Out of 24 cases, 10 were virus-positive in PCR: specifically, 8 cases with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), 1 with respiratory syncytial virus (RSV), and 1 with SARS-CoV-2 and the human coronavirus OC43 (HCoV-OC43), as a double infection. The RSV infection and one of the SARS-CoV-2 infections were only detected due to the autopsy. Two SARS-CoV-2 cases (postmortem interval of 8 and 10 days, respectively) showed infectious virus in cell culture; the 6 other cases did not show infectious virus. In the RSV case, virus isolation by cell culture was unsuccessful (Ct value of 23.15 for PCR on cryoconserved lung tissue). HCoV-OC43 was measured as non-infectious in cell culture, with a Ct value of 29.57. The detection of RSV and HCoV-OC43 infections may shed light on the relevance of respiratory viruses other than SARS-CoV-2 in postmortem settings; however, further, more extensive studies are needed for a robust assessment of the hazard potential due to infectious postmortem fluids and tissues in medicolegal autopsy settings.

Coronavirus infection in chemosensory cells.

Clinical manifestations of human coronavirus (HCoV)-related diseases are mostly related to the respiratory system, although secondary complications such as headache, anosmia, ageusia, and myalgia have been reported. HCoV infection and replication in chemosensory cells associated with ageusia and anosmia is poorly understood. Here, we characterized HCoV-OC43 and SARS-CoV-2 infection in two types of chemosensory cells, olfactory and taste cells, with their unique molecular and histological characteristics. We first assessed HCoV-OC43 infection in in vitro cultured human olfactory epithelial cells (hOECs) and fungiform taste papilla (HBO) cells. Interestingly, while both cell types were susceptible to HCoV-OC43 infection, viral replication rates were significantly reduced in HBO cells compared to hOECs. More interestingly, while culture media from hOECs was able to produce secondary infection in Vero cells, there was very limited secondary infection from HBO cells, suggesting that HBO cells may not be able to release infectious virus. On the other hand, unlike HCoV-OC43, SARS-CoV-2 showed comparable levels of viral infection rates in both hOECs and HBO cells. Furthermore, our RT-qPCR-based gene array studies revealed that several key genes involved in taste and olfactory functions were significantly altered by SARS-CoV-2 infection. These results may suggest a possible mechanism associated with chemosensory symptoms, such as anosmia and ageusia in patients infected with SARS-CoV-2.

Synthesis of Novel 1-Oxo-2,3,4-trisubstituted Tetrahydroisoquinoline Derivatives, Bearing Other Heterocyclic Moieties and Comparative Preliminary Study of Anti-Coronavirus Activity of Selected Compounds.

A series of novel 1-oxo-2,3,4-trisubstituted tetrahydroisoquinoline (THIQ) derivatives bearing other heterocyclic moieties in their structure were synthesized based on the reaction between homophthalic anhydride and imines. Initial studies were carried out to establish the anti-coronavirus activity of some of the newly obtained THIQ-derivatives against two strains of human coronavirus-229E and OC-43. Their antiviral activity was compared with that of their close analogues, piperidinones and thiomorpholinones, previously synthesized in our group, with aim to expand the range of the tested representative sample and to obtain valuable preliminary information about biological properties of a wider variety of compounds.

Aseptic meningitis caused by Coronavirus OC43 in a child: A case report

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses that cause the mild cold. On the other hand, extra-respiratory manifestations such as cen-tral nervous system infections with HCoV-OC43 are very rarely reported. We present a case of a previously healthy immunocompetent child with acute aseptic meningitis, as a result of HCoV-OC43 who admitted to the emergency department with a complaint of unconsciousness.. Respiratory tract and cerebrospinal fluid culture showed HCoV-OC43 in viral screening. During the follow-up period, the patient was completely asymptomatic, with normalized consciousness. The clinicians should keep in mind that HCoV-OC43 can be the etiological agent in the differential diagnosis of aseptic meningitis in immunocompetent individuals with reversible neurological symptoms.

SARS-CoV-2 mitochondriopathy in COVID-19 pneumonia exacerbates hypoxemia.

RATIONALE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 pneumonia. We hypothesize that SARS-CoV-2 causes alveolar injury and hypoxemia by damaging mitochondria in airway epithelial cells (AEC) and pulmonary artery smooth muscle cells (PASMC), triggering apoptosis and bioenergetic impairment, and impairing hypoxic pulmonary vasoconstriction (HPV), respectively. OBJECTIVES: We examined the effects of: A) human betacoronaviruses, SARS-CoV-2 and HCoV-OC43, and individual SARS-CoV-2 proteins on apoptosis, mitochondrial fission, and bioenergetics in AEC; and B) SARS-CoV-2 proteins and mouse hepatitis virus (MHV-1) infection on HPV. METHODS: We used transcriptomic data to identify temporal changes in mitochondrial-relevant gene ontology (GO) pathways post-SARS-CoV-2 infection. We also transduced AECs with SARS-CoV-2 proteins (M, Nsp7 or Nsp9) and determined effects on mitochondrial permeability transition pore (mPTP) activity, relative membrane potential, apoptosis, mitochondrial fission, and oxygen consumption rates (OCR). In human PASMC, we assessed the effects of SARS-CoV-2 proteins on hypoxic increases in cytosolic calcium, an HPV proxy. In MHV-1 pneumonia, we assessed HPV via cardiac catheterization and apoptosis using the TUNEL assay. RESULTS: SARS-CoV-2 regulated mitochondrial apoptosis, mitochondrial membrane permeabilization and electron transport chain (ETC) GO pathways within 2 hours of infection. SARS-CoV-2 downregulated ETC Complex I and ATP synthase genes, and upregulated apoptosis-inducing genes. SARS-CoV-2 and HCoV-OC43 upregulated and activated dynamin-related protein 1 (Drp1) and increased mitochondrial fission. SARS-CoV-2 and transduced SARS-CoV-2 proteins increased apoptosis inducing factor (AIF) expression and activated caspase 7, resulting in apoptosis. Coronaviruses also reduced OCR, decreased ETC Complex I activity and lowered ATP levels in AEC. M protein transduction also increased mPTP opening. In human PASMC, M and Nsp9 proteins inhibited HPV. In MHV-1 pneumonia, infected AEC displayed apoptosis and HPV was suppressed. BAY K8644, a calcium channel agonist, increased HPV and improved SpO2. CONCLUSIONS: Coronaviruses, including SARS-CoV-2, cause AEC apoptosis, mitochondrial fission, and bioenergetic impairment. SARS-CoV-2 also suppresses HPV by targeting mitochondria. This mitochondriopathy is replicated by transduction with SARS-CoV-2 proteins, indicating a mechanistic role for viral-host mitochondrial protein interactions. Mitochondriopathy is a conserved feature of coronaviral pneumonia that may exacerbate hypoxemia and constitutes a therapeutic target.

The inhibitory activity of methoxyl flavonoids derived from Inula britannica flowers on SARS-CoV-2 3CLpro.

In our ongoing efforts to identify effective natural antiviral agents, four methoxy flavonoids (1-4) were isolated from the Inula britannica flower extract. Their structures were elucidated using nuclear magnetic resonance. Flavonoids 1-4 exhibited inhibitory activity against SARS- CoV-2 3CLpro with IC50 values of 41.6 ± 2.5, 35.9 ± 0.9, 32.8 ± 1.2, and 96.6 ± 3.4 µM, respectively. Flavonoids 1-3 inhibited 3CLpro in a competitive manner. Based on molecular simulations, key amino acids that form hydrogen bond with inhibitor 3 were identified. Finally, we found that inhibitors (1-3) suppressed HCoV-OC43 coronavirus proliferation at micromole concentrations.

Roles of Sialyl Glycans in HCoV-OC43, HCoV-HKU1, MERS-CoV and SARS-CoV-2 Infections.

Ongoing seasonal HCoV-OC43 and HCoV-HKU1 (common cold), an ongoing zoonotic infection of highly lethal MERS-CoV in humans (MERS disease), and an ongoing pandemic SARS-CoV-2 (COVID-19) with high mutability giving some variants causing severe illness and death have been reported to attach to sialyl receptors via their spike (S) glycoproteins and via additional short spikes, hemagglutinin-esterase (HE) glycoproteins, for HCoV-OC43 and HCoV-HKU1. There is lack of zoonotic viruses that are origins of HCoV-HKU1 and the first recorded pandemic CoV (SARS-CoV-2) for studies. In this chapter, we review current knowledge of the roles of sialyl glycans in infections with these viruses in distinct infection stages. Determination of the similarities and differences in roles of sialyl glycans in infections with these viruses could lead to a better understanding of the pathogenesis and transmission that is essential for combating infections with CoVs that recognize sialyl glycans.

Phylogenetic characteristics of Non-SARS human coronavirus in southern Taiwan, 2012-2013.

This study characterizes the phylogenetic relatedness of non-SARS human coronaviruses (HCoVs) in southern Taiwan by sequencing the nucleocapsid (N), spike (S), and RNA-dependent RNA polymerase (RdRp) genes directly from ten HCoV PCR-positive respiratory samples collected during 2012-2013. In the N, S1, and RdRp phylogeny, HCoV-OC43 in one and three samples was clustered with genotypes F and G, respectively, and HCoV-OC43 in sample YC101/TWN/2013 represented a recombination event between genotypes F and G. Amino acid substitutions in the S1 protein of HCoV-OC43 were also identified. In the N phylogeny, HCoV-HKU1 in one and two samples clustered with genotypes A and B, respectively, and HCoV-229E in two samples was clustered with genogroup 6. The genotypes and genogroup detected here were in line with the prevalent phylogenetic lineages reported outside of Taiwan during the contemporary period. In summary, three species of non-SARS HCoVs with different genotypes cocirculated in the community, with genetic evolution observed in HCoV-OC43.

Surface Inactivation of Human Coronavirus by MACOMA™ UVA-TiO 2 Coupled Photocatalytic Disinfection System

There is an immense healthcare challenge and financial pressure due to the COVID-19 pandemic caused by a newly identified human coronavirus, SARS-CoV-2. Effective COVID-19 prevention efforts in healthcare, home, and community settings highlight the need for rapid, efficient, and no-contact SARS-CoV-2 inactivation strategies. Here, we examined the photocatalytic and virucidal activity of the MACOMA™ TiO2 photocatalytic film activated by an UVA-LED-12V-367 nm (MA-717836-1) lamp against the HCoV-OC43, a member of the beta coronaviruses family, like SARS-CoV-2, using quantitative RT-qPCR and virus infectivity assays. The UVA radiation-responsive TiO2 film accelerated virus inactivation (decreased viral titer) compared to the uncoated glass surface when placed at a vertical distance of 1.2 feet (~14 inches) from virus samples for 10, 30, and 60 min. UVA-LED exposure for both 10 and 30 min effectively reduced the viral RNA copies and the infectious virus in samples on TiO2-coated surfaces compared to the control surfaces. Importantly, a 60 min exposure of samples on the TiO2 completely eliminated HCoV-OC43. These results confirmed that the MACOMA™ UVA/TiO2-based disinfection system provides a rapid and complete surface inactivation of tested human coronavirus in a human-safe manner and has great potential for limiting the virus spread in poorly ventilated as well as high-traffic public places. [ FROM AUTHOR] Copyright of Catalysts (2073-4344) is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)