Origin and evolution of pathogenic coronaviruses

Nucleocapsid Protein Recruitment to Replication-Transcription Complexes Plays a Crucial Role in Coronaviral Life Cycle

CoVs have long been regarded as relatively harmless pathogens for humans. Severe respiratory tract infection outbreaks caused by severe acute respiratory syndrome CoV and Middle East respiratory syndrome CoV, however, have caused high pathogenicity and mortality rates in humans. These outbreaks highlighted the relevance of being able to control CoV infections. We used a model CoV, MHV, to investigate the importance of the recruitment of N protein, a central component of CoV virions, to intracellular platforms where CoVs replicate, transcribe, and translate their genomes. By identifying the principal binding partner at these intracellular platforms and generating a specific mutant, we found that N protein recruitment to these locations is crucial for promoting viral RNA synthesis. Moreover, blocking this recruitment strongly inhibits viral infection. Thus, our results explain an important aspect of the CoV life cycle and reveal an interaction of viral proteins that could be targeted in antiviral therapies.

Coronavirus (CoV) nucleocapsid (N) proteins are key for incorporating genomic RNA into progeny viral particles. In infected cells, N proteins are present at the replication-transcription complexes (RTCs), the sites of CoV RNA synthesis. It has been shown that N proteins are important for viral replication and that the one of mouse hepatitis virus (MHV), a commonly used model CoV, interacts with nonstructural protein 3 (nsp3), a component of the RTCs. These two aspects of the CoV life cycle, however, have not been linked. We found that the MHV N protein binds exclusively to nsp3 and not other RTC components by using a systematic yeast two-hybrid approach, and we identified two distinct regions in the N protein that redundantly mediate this interaction. A selective N protein variant carrying point mutations in these two regions fails to bind nsp3 in vitro, resulting in inhibition of its recruitment to RTCs in vivo. Furthermore, in contrast to the wild-type N protein, this N protein variant impairs the stimulation of genomic RNA and viral mRNA transcription in vivo and in vitro, which in turn leads to impairment of MHV replication and progeny production. Altogether, our results show that N protein recruitment to RTCs, via binding to nsp3, is an essential step in the CoV life cycle because it is critical for optimal viral RNA synthesis.

IMPORTANCE CoVs have long been regarded as relatively harmless pathogens for humans. Severe respiratory tract infection outbreaks caused by severe acute respiratory syndrome CoV and Middle East respiratory syndrome CoV, however, have caused high pathogenicity and mortality rates in humans. These outbreaks highlighted the relevance of being able to control CoV infections. We used a model CoV, MHV, to investigate the importance of the recruitment of N protein, a central component of CoV virions, to intracellular platforms where CoVs replicate, transcribe, and translate their genomes. By identifying the principal binding partner at these intracellular platforms and generating a specific mutant, we found that N protein recruitment to these locations is crucial for promoting viral RNA synthesis. Moreover, blocking this recruitment strongly inhibits viral infection. Thus, our results explain an important aspect of the CoV life cycle and reveal an interaction of viral proteins that could be targeted in antiviral therapies.

The Extent of Transmission of Novel Coronavirus in Wuhan, China, 2020

A cluster of pneumonia cases linked to a novel coronavirus (2019-nCoV) was reported by China in late December 2019. Reported case incidence has now reached the hundreds, but this is likely an underestimate. As of 24 January 2020, with reports of thirteen exportation events, we estimate the cumulative incidence in China at 5502 cases (95% confidence interval: 3027, 9057). The most plausible number of infections is in the order of thousands, rather than hundreds, and there is a strong indication that untraced exposures other than the one in the epidemiologically linked seafood market in Wuhan have occurred.

A bibliometric analysis of Pubmed literature on coronavirus: All time period

In late December 2019, there are several reported pneumonia-liked cases with the new strain coronavirus in China. The World Health Organization then assigned this new disease with COVID-19. Coronavirus has been declared as the most responsible agent for a recent public health emergency (PHEIC) in early 2020. The need for further research regarding coronavirus is essential, considering its high threat of public health without any available specific antiviral or vaccine yet. The growth and development of coronavirus related research and thematic trends are still unknown. This study aimed to depict the bibliographic trend of coronavirus all time and pictured the coronavirus research patterns and dynamics throughout the years. Therefore, the objective of this study was aimed to generate a comprehensive bibliometric analysis of coronavirus infection, research topic dynamic and the development of Medical subject heading (MeSH). The study retrieved data from PubMed for the source. Pubmed is chosen because it is the biggest freely available health and medicine electronic database. The R software and Microsoft Excel used for the data analysis. For data visualization, it extracted from VOS viewer. The graph from VOS viewer used as a source for social network analysis.

Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR

BACKGROUND

The ongoing outbreak of the recently emerged novel coronavirus (2019-nCoV) poses a challenge for public health laboratories as virus isolates are unavailable while there is growing evidence that the outbreak is more widespread than initially thought, and international spread through travellers does already occur.

AIM

We aimed to develop and deploy robust diagnostic methodology for use in public health laboratory settings without having virus material available.

METHODS

Here we present a validated diagnostic workflow for 2019-nCoV, its design relying on close genetic relatedness of 2019-nCoV with SARS coronavirus, making use of synthetic nucleic acid technology.

RESULTS

The workflow reliably detects 2019-nCoV, and further discriminates 2019-nCoV from SARS-CoV. Through coordination between academic and public laboratories, we confirmed assay exclusivity based on 297 original clinical specimens containing a full spectrum of human respiratory viruses. Control material is made available through European Virus Archive - Global (EVAg), a European Union infrastructure project.

CONCLUSION

The present study demonstrates the enormous response capacity achieved through coordination of academic and public laboratories in national and European research networks.

Sialoglycovirology of Lectins: Sialyl Glycan Binding of Enveloped and Non-enveloped Viruses

On the cell sur "face", sialoglycoconjugates act as receptionists that have an important role in the first step of various cellular processes that bridge communication between the cell and its environment. Loss of Sia production can cause the developmental of defects and lethality in most animals; hence, animal cells are less prone to evolution of resistance to interactions by rapidly evolved Sia-binding viruses. Obligative intracellular viruses mostly have rapid evolution that allows escape from host immunity, leading to an epidemic variant, and that allows emergence of a novel strain, occasionally leading to pandemics that cause health-social-economic problems. Recently, much attention has been given to the mutual recognition systems via sialosugar chains between viruses and their host cells and there has been rapid growth of the research field "sialoglycovirology." In this chapter, the structural diversity of sialoglycoconjugates is overviewed, and enveloped and non-enveloped viruses that bind to Sia are reviewed. Also, interactions of viral lectins-host Sia receptors, which determine viral transmission, host range, and pathogenesis, are presented. The future direction of new therapeutic routes targeting viral lectins, development of easy-to-use detection methods for diagnosis and monitoring changes in virus binding specificity, and challenges in the development of suitable viruses to use in virus-based therapies for genetic disorders and cancer are discussed.

A guide to laboratory diagnosis of Corona Virus Disease-19 for the gastroenterologists

The outbreak of Corona Virus Disease-19 (COVID-19), caused by Severe Acute Respiratory Syndrome Corona Virus - 2 (SARS-CoV-2), a global pandemic, is having a significant impact on healthcare, especially the clinical microbiology laboratories all around the world. There are many reports which suggest that the disease can present with gastrointestinal symptoms such as nausea, vomiting, diarrhea, and loss of appetite, which the gastroenterologists may have to deal with. Hence, knowledge about the diagnosis of COVID-19 is important to gastroenterologists as well. The current review therefore covers the challenges faced while choosing appropriate sample collection, transport, and tests for SARS-CoV-2 infection. The right sample at the right time from the right anatomical site with the proper precautions is crucial in prompt and accurate diagnosis of COVID-19. The tests can be divided into direct, indirect, and complementary tests. In the direct test, real-time polymerase chain reaction (RT-PCR) assays are the molecular tests of choice for the diagnosis of COVID-19. Other direct tests include GeneXpert and TrueNAT. In indirect testing, antigen-antibody-based techniques are recommended for surveillance for the disease, which may help to formulate the control measures. Finally, the additional tests help in assessing the disease severity and evaluating the prognosis. All the above tests are important not only for diagnosis but also for management strategy and prognosis.

COVID-19, Virology and Geroscience: A Perspective

A new coronavirus, called SARS-CoV-2, was identified in Wuhan, China, in December 2019. The SARS-CoV-2 spread very rapidly, causing a global pandemic, Coronavirus Disease 2019 (COVID-19). Older adults have higher peak of viral load and, especially those with comorbidities, had higher COVID-19-related fatality rates than younger adults. In this Perspective paper, we summarize current knowledge about SARS-CoV-2 and aging, in order to understand why older people are more affected by COVID-19. We discuss about the possibility that the so-called "immunosenescence" and "inflammaging" processes, already present in a fraction of frail older adults, could allow the immune escape of SARS-CoV-2 leading to COVID-19 serious complications. Finally, we propose to use geroscience approaches to the field of COVID-19.

Coronaviruses' sugar shields as vaccine candidates

A successful global healthcare response relies on versatile vaccines and production of broadly virus-neutralizing antibodies by the immune system to protect us from emerging infectious diseases. The present 2019 severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic highlights the urgent need for development of anti-viral biodefense. Due to the genetic and proteomic diversities of viral pathogens, establishing versatile anti-viral vaccines or therapeutic agents is highly challenging. Carbohydrate antigens represent an important class of immunological targets for vaccine development and immunotherapy against microbial infections. In this mini review, some concepts and strategies for exploring the potential of immunogenic sugar moieties as CoV vaccine candidates are presented.

Salient Conclusive Remarks on Epidemiology and Clinical Manifestations of Pediatric COVID-19: Narrative Review

The ongoing pandemic of COVID-19, which is caused by the novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), constituted significant public health concerns and impacted the human populations with massive economic and social burdens worldwide. The disease is known to infect people of all ages, including children, adults, and the elderly. Although several reports about pediatric COVID-19 were seen in the literature, we believe that the epidemiology and pathology of the infection described in these reports are not conclusive. Therefore, in this scientific communication, a narrative review study was performed to shed some light on the characteristic epidemiological features and clinical phenotypes of pediatric COVID-19. In this report, we had compiled and presented the different epidemiological features of the disease related to the age of infection, virus acquisition, explanations of the low infectivity rates, and consequences of infections. The discriminatory clinical manifestations of the disease in children were also addressed and discussed in this review. The search included the data published from the date of the start of the pandemic in December 2019 up to October 2020. Our literature search revealed that children of all ages, including neonates, had been infected by the virus. Despite the fact that pediatric COVID-19 is less common to occur, as compared to the disease in adults, the infected children usually manifest the disease symptomatology in benign form. Asymptomatic and symptomatic adult patients are the primary source of the virus to the children. Intrauterine transmission of the virus and breastfeeding infections to the neonates were hypothesized in some studies but ruled out since they were not confirmed. Intensive review and discussion warranting the low infection rates and benign conditions of COVID-19 in children were also made in this study. As documented in many studies, the infectivity, morbidity, and mortality rates of the disease among the children populations are much lower than those in adults. They also seem to be lower than those observed during SARS-CoV and MERS-CoV epidemics. The described clinical phenotypes of COVID-19 in children do not differ much from those of adults, and complications of the disease seem to be associated with comorbidities.

Dealing with "Coronavirus Pandemic": A Dental Outlook

An emergent pneumonia outbreak, denoted as coronavirus disease-2019 (COVID-19) by the World Health Organization (WHO) originated in Wuhan City, in late December 2019 and spread at an alarming rate to become a pandemic affecting more than 200 countries. The COVID-19 is caused by a novel coronavirus (2019-nCoV), which is highly contagious and is associated with a high mortality rate. The current COVID-19 outbreak has created a major havoc among every strata of the society with a detrimental impact on healthcare professionals, including dentists limiting their capabilities at large. The transmission of virus through aerosols produced by high- and low-speed handpieces, ultrasonic scalers, air/water syringes, or an infected patient coughing, and even when taking intraoral radiographs has made it difficult for dental personnel to provide even the most basic services to the needful. The virus survives on environmental surfaces for extended periods of time, including metal and plastic surfaces commonly found in dental offices making it utmost necessary to follow the precautions and recommendations issued by various organizations in order to contain its spread. This article aims to provide the latest knowledge encompassing the various aspects of COVID-19 to pediatric dentists in India.

How to cite this article

Goswami M, Sharma S, Kumar G, et al. Dealing with "Coronavirus Pandemic": A Dental Outlook. Int J Clin Pediatr Dent 2020;13(3):269-278.

Computational analysis of the SARS-CoV-2 and other viruses based on the Kolmogorov's complexity and Shannon's information theories

This paper tackles the information of 133 RNA viruses available in public databases under the light of several mathematical and computational tools. First, the formal concepts of distance metrics, Kolmogorov complexity and Shannon information are recalled. Second, the computational tools available presently for tackling and visualizing patterns embedded in datasets, such as the hierarchical clustering and the multidimensional scaling, are discussed. The synergies of the common application of the mathematical and computational resources are then used for exploring the RNA data, cross-evaluating the normalized compression distance, entropy and Jensen-Shannon divergence, versus representations in two and three dimensions. The results of these different perspectives give extra light in what concerns the relations between the distinct RNA viruses.

SFED recommendations for IBD endoscopy during COVID-19 pandemic: Italian and French experience

The current coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has required a complete change in the management of patients with inflammatory bowel disease (IBD) who need to undergo endoscopic procedures. Several preventive measures must be taken to avoid the spread of infection among health-care professionals and patients with IBD, including the use of personal protective equipment, greater attention to endoscopic room hygiene and rescheduling of non-urgent procedures. This Perspective aims to provide a guide based on the Italian and French experience to better face the difficulties encountered by endoscopists during this global health emergency. In particular, recommendations regarding the use of personal protective equipment to prevent COVID-19 transmission, both for patients and health-care professionals, are proposed and different scenarios in endoscopic IBD management are evaluated to suggest when endoscopy could be rescheduled and replaced by alternative biomarkers.

Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR

BACKGROUND

The ongoing outbreak of the recently emerged novel coronavirus (2019-nCoV) poses a challenge for public health laboratories as virus isolates are unavailable while there is growing evidence that the outbreak is more widespread than initially thought, and international spread through travellers does already occur.

AIM

We aimed to develop and deploy robust diagnostic methodology for use in public health laboratory settings without having virus material available.

METHODS

Here we present a validated diagnostic workflow for 2019-nCoV, its design relying on close genetic relatedness of 2019-nCoV with SARS coronavirus, making use of synthetic nucleic acid technology.

RESULTS

The workflow reliably detects 2019-nCoV, and further discriminates 2019-nCoV from SARS-CoV. Through coordination between academic and public laboratories, we confirmed assay exclusivity based on 297 original clinical specimens containing a full spectrum of human respiratory viruses. Control material is made available through European Virus Archive - Global (EVAg), a European Union infrastructure project.

CONCLUSION

The present study demonstrates the enormous response capacity achieved through coordination of academic and public laboratories in national and European research networks.

Three Novel Real-Time RT-PCR Assays for Detection of COVID-19 Virus

What is already known on this topic?

A novel human coronavirus, known as SARS-CoV-2 or 2019-nCoV, is the causative agent of the coronavirus disease 2019 (COVID-19). We have released the primers and probes of real-time reverse transcription polymerase chain reaction (rRT-PCR) assays for the laboratory detection of COVID-19 infection.

What is added by this report?

Here we provide detailed technical data and evaluate the performance of three novel rRT-PCR assays targeting the ORF1ab, N, and E genes for detection of COVID-19 infection. The application of rRT-PCR assays among four types of specimens (alveolar lavage, sputum, throat swabs, and stool) from patients with COVID-19 indicated that the mean viral loads detected in sputum were higher than other specimens.

What are the implications for public health practice?

These rRT-PCR assays reported here could be used for laboratory diagnosis of COVID-19 infection with high sensitivity, specificity, and applicability. Sputum rather than throat swabs and stool should be a priority for specimen collection for laboratory detection of COVID-19.

Current understanding, knowledge gaps and a perspective on the future of COVID-19 Infections: A systematic review

A novel coronavirus infection, which began as an outbreak of unusual viral pneumonia in Wuhan, a central city in China, has evolved into a global health crisis. The outbreak is an unembellished reminder of the hazard coronaviruses pose to public health. Government and researchers around the world have been taking swift measures to control the outbreak and conduct aetiological studies to understand the various facets of the outbreak. This review is an attempt at providing an insight about the current understanding, knowledge gaps and a perspective on the future of coronavirus disease 2019 (COVID-19) infections. All the authentic data published so far on COVID-19 has been systematically analysed. PubMed, NCBI, World Health Organisation, Ministry of Health and Family Welfare (India), and Centers for Disease Control and Prevention databases and bibliographies of relevant studies up to 22nd June 2020 have been included. The Wuhan outbreak is a stark reminder of the continuing threat posed by zoonotic diseases to global health. Despite an armamentarium of Government officials, researchers and medical fraternity working towards the containment of this novel coronavirus viral pneumonia continues to spread at an alarming rate infecting multitudes and claiming hundreds of lives.

Development of a TaqMan-probe-based multiplex real-time PCR for the simultaneous detection of emerging and reemerging swine coronaviruses

With the outbreak of the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019, coronaviruses have become a global research hotspot in the field of virology. Coronaviruses mainly cause respiratory and digestive tract diseases, several coronaviruses are responsible for porcine diarrhea, such as porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and emerging swine acute diarrhea syndrome coronavirus (SADS-CoV). Those viruses have caused huge economic losses and are considered as potential public health threats. Porcine torovirus (PToV) and coronaviruses, sharing similar genomic structure and replication strategy, belong to the same order Nidovirales. Here, we developed a multiplex TaqMan-probe-based real-time PCR for the simultaneous detection of PEDV, PDCoV, PToV, and SADS-CoV for the first time. Specific primers and TaqMan fluorescent probes were designed targeting the ORF1a region of PDEV, PToV, and SADS-CoV and the ORF1b region of PDCoV. The method showed high sensitivity and specificity, with a detection limit of 1 × 102 copies/μL for each pathogen. A total of 101 clinical swine samples with signs of diarrhea were analyzed using this method, and the result showed good consistency with conventional reverse transcription PCR (RT-PCR). This method improves the efficiency for surveillance of these emerging and reemerging swine enteric viruses and can help reduce economic losses to the pig industry, which also benefits animal and public health.

Medical Students and COVID-19: Knowledge, Attitudes, and Precautionary Measures. A Descriptive Study From Jordan

The recent coronavirus disease (COVID-19) pandemic is associated with increasing morbidity and mortality and has impacted the lives of the global populations. Human behavior and knowledge assessment during the crisis are critical in the overall efforts to contain the outbreak. To assess knowledge, attitude, perceptions, and precautionary measures toward COVID-19 among a sample of medical students in Jordan. This is a cross-sectional descriptive study conducted between the 16th and 19th of March 2020. Participants were students enrolled in different levels of study at the six medical schools in Jordan. An online questionnaire which was posted on online platforms was used. The questionnaire consisted of four main sections: socio-demographics, sources of information, knowledge attitudes, and precautionary measures regarding COVID-19. Medical students used mostly social media (83.4%) and online search engines (84.8%) as their preferred source of information on COVID-19 and relied less on medical search engines (64.1%). Most students believed that hand shaking (93.7%), kissing (94.7%), exposure to contaminated surfaces (97.4%), and droplet inhalation (91.0%) are the primary mode of transmission but were indecisive regarding airborne transmission with only 41.8% in support. Participants also reported that elderly with chronic illnesses are the most susceptible group for the coronavirus infection (95.0%). As a response to the COVID-19 pandemic more than 80.0% of study participants adopted social isolation strategies, regular hand washing, and enhanced personal hygiene measures as their first line of defense against the virus. In conclusion, Jordanian medical students showed expected level of knowledge about the COVID-19 virus and implemented proper strategies to prevent its spread.

New coronavirus: what does nursing have to learn and teach in times of a pandemic?

ABSTRACT Objective: To promote a theoretical reflective analysis of what nursing has to learn and teach to global society in times of OVID-19 pandemic. Methods: Reflective theoretical essay aimed at contributing new knowledge and raising new questions, based on the assumptions of Edgar Morin’s complexity thinking, subsidized by readings of texts extracted from electronic databases, as well as speeches by health professionals available in open communication tools. Results: COVID-19 reiterates that the biological warfare of the current pandemic is not fought with nuclear or fire weapons, but with care in its multiple dimensions: physical, emotional, spiritual, family, social, political and economic. Final considerations: Nursing has to learn and teach global society that its main object of work, care, is related to the expansion of systemic interactions and associations and the capacity to strengthen the interlocution with complex reality.

Natural Plant Products: A Less Focused Aspect for the COVID-19 Viral Outbreak

The sudden emergence of COVID-19 caused by a novel coronavirus (nCoV) led the entire world to search for relevant solutions to fight the pandemic. Although continuous trials are being conducted to develop precise vaccines and therapeutic antibodies, a potential remedy is yet to be developed. Plants have largely contributed to the treatment of several human diseases and different phytoconstituents have been previously described to impede the replication of numerous viruses. Despite the previous positive reports of plant-based medications, no successful clinical trials of phyto-anti-COVID drugs could be conducted to date. In this article, we discuss varying perspectives on why phyto-anti-viral drug clinical trials were not successful in the case of COVID-19. The issue has been discussed in light of the usage of plant-based therapeutics in previous coronavirus outbreaks. Through this article, we aim to identify the disadvantages in this research area and suggest some measures to ensure that phytoconstituents can efficiently contribute to future random viral outbreaks. It is emphasized that if used strategically phyto-inhibitors with pre-established clinical data for other diseases can save the time required for long clinical trials. The scientific community should competently tap into phytoconstituents and take their research up to the final stage of clinical trials so that potential phyto-anti-COVID drugs can be developed.

[The SARS-CoV-2, a new pandemic zoonosis that threatens the world]

On December 31, 2019, an outbreak of pneumonia of unknown etiology was detected in the city of Wuhan (China). A week later, a new coronavirus was isolated in these patients, initially designated as 2019-nCoV and subsequently SARS-CoV-2. This is a new virus that is much closer genetically to the coronavirus of bats than to human SARS. The new virus infects and replicates in the lung parenchyma pneumocytes and macrophages in which the ACE-2 cell receptor resides. He has now infected many more people than his predecessors (> 85,000). From the clinical point of view, those infected have an average age of 55 years; the main symptoms are fever, dry cough, lymphopenia, dyspnea, and pneumonia in its severe form. The overall lethality rate is 2-3% in China and 0.1% in cases detected outside of this country. The incubation period has been set at about 3 days (0-24 days). There are no specific antivirals or vaccines.

Convalescent plasma appears efficacious and safe in COVID-19

A cluster of pneumonia cases of unknown etiology associated with pyrexia and acute respiratory distress was identified in Southern China. Links between the previous severe acute respiratory syndrome (SARS) cases and the region's seafood market were noted with the possibility of a new zoonosis and SARS-CoV-2 was identified as the responsible agent. Currently, there are no effective prophylactic or therapeutic options to deal with coronavirus disease-19 (COVID-19) or any other human coronavirus (HCoV) infections. Convalescent plasma (CP) therapy is a classic adaptive immunotherapy which has been in use for more a century to prevent and treat infections including SARS, Middle East respiratory syndrome (MERS), and H1N1 pandemic. Moreover, the World Health Organization regarded CP transfusion as the most promising therapy to treat MERS-CoV. This review was undertaken to demonstrate the potential of CP in the treatment of the pandemic COVID-19 disease. A total of eight studies conducted on CP therapy in patients with COVID-19 were reviewed wherein 25,028 patients above 18 years of age were involved. The vast majority of patients reported favorable outcomes when treated with CP with <1% serious adverse events. Despite its promising beneficial effects in patients severely ill with COVID-19, CP therapy requires further evaluation in randomized clinical trials (RCTs) as a lack of satisfactory efficacy data from this area certainly enhances the hesitancy with regard to employing this treatment. In the present circumstances of unsatisfactory pharmacological therapy and the urgent need for a successful curative remedy, considering the use of CP therapy is reasonable provided RCTs confirm its safety, efficacy, and tolerability.

Relationship of chest CT score with clinical characteristics of 108 patients hospitalized with COVID-19 in Wuhan, China

BACKGROUND

In December 2019, the outbreak of a disease subsequently termed COVID-19 occurred in Wuhan, China. The number of cases increased rapidly and spread to six continents. However, there is limited information on the chest computed tomography (CT) results of affected patients. Chest CT can assess the severity of COVID-19 and has sufficient sensitivity to assess changes in response to glucocorticoid therapy.

OBJECTIVE

Analyze COVID-19 patients to determine the relationships of clinical characteristics, chest CT score, and levels of inflammatory mediators.

METHODS

This retrospective, single-center case series of 108 consecutive hospitalized patients with confirmed COVID-19 at Tongji Hospital, Tongji Medical College of HUST (Wuhan, China) examined patients admitted from January 28 to February 20, 2020. Patient demographics, comorbidities, clinical findings, chest CT results, and CT scores of affected lung parenchyma were recorded. The relationships between chest CT score with levels of systemic inflammatory mediators were determined.

RESULTS

All patients exhibited signs of significant systemic inflammation, including increased levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin, chest CT score, and a decreased lymphocyte (LY) count. Chest CT score had positive associations with white blood cell (WBC) count, CRP, ESR, procalcitonin, and abnormal coagulation function, and a negative association with LY count. Treatment with a glucocorticoid increased the LY count, reduced the CT score and CRP level, and improved coagulation function.

CONCLUSIONS

COVID-19 infection is characterized by a systemic inflammatory response that affects the lungs, blood, digestive system, and circulatory systems. The chest CT score is a good indicator of the extent of systemic inflammation. Glucocorticoid treatment appears to reduce systemic inflammation in these patients.

The novel coronavirus 2019-nCoV: Its evolution and transmission into humans causing global COVID-19 pandemic

A novel coronavirus strain 2019-nCoV has caused a rapid global pandemic-COVID-19. Scientists have taken onto the task of characterizing this new virus and understanding how this virus has transmitted to humans. All preliminary studies have found some striking similarities between this new virus and the SARS-CoV that caused a similar kind of epidemic in 2002-2003. Through bioinformatics tools, a great deal of information has been gathered about the origin, evolution and zoonosis of this virus. We, in this review, report the symptoms, mode of transmission and available and putative treatments to tackle 2019-nCoV infections. We also comprehensively summarize all the information so far made available regarding the genome, evolution and zoonosis of this virus.

Zoonoses

The selection of papers included in this issue of Microbiology Australia present a broad brush of zoonotic diseases, from those known or described in ancient times such as rabies, first described in the Eshnunna cuneiform law tablets from ancient Mesopotamia dating back to the 18th–19th centuries BC, and glanders, thought to be first described in donkeys by Aristotle in Ancient Greece in 420–450 BC and subsequently by the Romans, to some discovered or recognised as zoonotic within the past 30 years, such as the recently described zoonotic bat-borne pathogens in Australia, and Clostridium difficile, only recently recognised as a zoonotic pathogen. The selection of papers also demonstrates the wide range of zoonotic origins, including arthropod-borne viruses and potentially seafood-borne parasites.

Artificial Light at Night (ALAN): A Potential Anthropogenic Component for the COVID-19 and HCoVs Outbreak

The origin of the coronavirus disease 2019 (COVID-19) pandemic is zoonotic. The circadian day-night is the rhythmic clue to organisms for their synchronized body functions. The "development for mankind" escalated the use of artificial light at night (ALAN). In this article, we tried to focus on the possible influence of this anthropogenic factor in human coronavirus (HCoV) outbreak. The relationship between the occurrences of coronavirus and the ascending curve of the night-light has also been delivered. The ALAN influences the physiology and behavior of bat, a known nocturnal natural reservoir of many Coronaviridae. The "threatened" and "endangered" status of the majority of bat species is mainly because of the destruction of their proper habit and habitat predominantly through artificial illumination. The stress exerted by ALAN leads to the impaired body functions, especially endocrine, immune, genomic integration, and overall rhythm features of different physiological variables and behaviors in nocturnal animals. Night-light disturbs "virus-host" synchronization and may lead to mutation in the genomic part of the virus and excessive virus shedding. We also proposed some future strategies to mitigate the repercussions of ALAN and for the protection of the living system in the earth as well.

Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR

BACKGROUND

The ongoing outbreak of the recently emerged novel coronavirus (2019-nCoV) poses a challenge for public health laboratories as virus isolates are unavailable while there is growing evidence that the outbreak is more widespread than initially thought, and international spread through travellers does already occur.

AIM

We aimed to develop and deploy robust diagnostic methodology for use in public health laboratory settings without having virus material available.

METHODS

Here we present a validated diagnostic workflow for 2019-nCoV, its design relying on close genetic relatedness of 2019-nCoV with SARS coronavirus, making use of synthetic nucleic acid technology.

RESULTS

The workflow reliably detects 2019-nCoV, and further discriminates 2019-nCoV from SARS-CoV. Through coordination between academic and public laboratories, we confirmed assay exclusivity based on 297 original clinical specimens containing a full spectrum of human respiratory viruses. Control material is made available through European Virus Archive - Global (EVAg), a European Union infrastructure project.

CONCLUSION

The present study demonstrates the enormous response capacity achieved through coordination of academic and public laboratories in national and European research networks.

Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR

BACKGROUND

The ongoing outbreak of the recently emerged novel coronavirus (2019-nCoV) poses a challenge for public health laboratories as virus isolates are unavailable while there is growing evidence that the outbreak is more widespread than initially thought, and international spread through travellers does already occur.

AIM

We aimed to develop and deploy robust diagnostic methodology for use in public health laboratory settings without having virus material available.

METHODS

Here we present a validated diagnostic workflow for 2019-nCoV, its design relying on close genetic relatedness of 2019-nCoV with SARS coronavirus, making use of synthetic nucleic acid technology.

RESULTS

The workflow reliably detects 2019-nCoV, and further discriminates 2019-nCoV from SARS-CoV. Through coordination between academic and public laboratories, we confirmed assay exclusivity based on 297 original clinical specimens containing a full spectrum of human respiratory viruses. Control material is made available through European Virus Archive - Global (EVAg), a European Union infrastructure project.

CONCLUSION

The present study demonstrates the enormous response capacity achieved through coordination of academic and public laboratories in national and European research networks.

Global efforts on vaccines for COVID-19: Since, sooner or later, we all will catch the coronavirus

COVID-19 is an emerging infectious disease that has turned into a pandemic. It spreads through droplet transmission of the new coronavirus SARS-CoV-2. It is an RNA virus displaying a spike protein as the major surface protein with significant sequence similarity to SARS-CoV which causes severe acute respiratory syndrome. The receptor binding domain of the spike protein interacts with the human angiotensin converting enzyme 2 and is considered as the antigenic determinant for stimulating an immune response. While multiple candidate vaccines are currently under different stages of development, there are no known therapeutic interventions at the moment. This review describes the key genetic features that are being considered for generating vaccine candidates by employing innovative technologies. It also highlights the global efforts being undertaken to deliver vaccines for COVID-19 through unprecedented international cooperation and future challenges post development.

Coronaviruses: a paradigm of new emerging zoonotic diseases

A novel type of coronavirus (2019-nCoV) infecting humans appeared in Wuhan, China, at the end of December 2019. Since the identification of the outbreak the infection quickly spread involving in one month more than 31,000 confirmed cases with 638 death. Molecular analysis suggest that 2019-nCoV could be originated from bats after passaging in intermediate hosts, highlighting the high zoonotic potential of coronaviruses.

Development and Validation of a S1 Protein-Based ELISA for the Specific Detection of Antibodies against Equine Coronavirus

Equine coronavirus (ECoV) is considered to be involved in enteric diseases in foals. Recently, several outbreaks of ECoV infection have also been reported in adult horses from the USA, France and Japan. Epidemiological studies of ECoV infection are still limited, and the seroprevalence of ECoV infection in Europe is unknown. In this study, an indirect enzyme-linked immunosorbent assay (ELISA) method utilizing ECoV spike S1 protein was developed in two formats, and further validated by analyzing 27 paired serum samples (acute and convalescent sera) from horses involved in an ECoV outbreak and 1084 sera of horses with unknown ECoV exposure. Both formats showed high diagnostic accuracy compared to virus neutralization (VN) assay. Receiver-operating characteristic (ROC) analyses were performed to determine the best cut-off values for both ELISA formats, assuming a test specificity of 99%. Employing the developed ELISA method, we detected seroconversion in 70.4% of horses from an ECoV outbreak. Among the 1084 horse sera, seropositivity varied from 25.9% (young horses) to 82.8% (adult horses) in Dutch horse populations. Further, sera of Icelandic horses were included in this study and a significant number of sera (62%) were found to be positive. Overall, the results demonstrated that the ECoV S1-based ELISA has reliable diagnostic performance compared to the VN assay and is a useful assay to support seroconversion in horses involved with ECoV outbreaks and to estimate ECoV seroprevalence in populations of horses.

Should pulmonologists be gatekeepers or supporters for preoperative patients?

Postoperative pulmonary complications (PPCs) are considered as a leading cause of poor surgical outcomes, and occur frequently even in non-cardiothoracic surgery. Several multifactorial risk indices show potential effectiveness in identification of patients at high risk of developing PPCs. In preoperative consultation from surgeons, pulmonologists often act as gatekeepers for indication of surgery. With regard to preventive strategy for PPCs, recent reports have suggested the usefulness of preoperative interventions, such as smoking cessation, inhalation therapy, medications, pulmonary rehabilitation, and sleep study followed by continuous positive airway pressure therapy. Now, pulmonologists have an important role as supporters for preoperative patient care.

Influences of cyclosporin A and non-immunosuppressive derivatives on cellular cyclophilins and viral nucleocapsid protein during human coronavirus 229E replication

The well-known immunosuppressive drug cyclosporin A inhibits replication of various viruses including coronaviruses by binding to cellular cyclophilins thus inactivating their cis-trans peptidyl-prolyl isomerase function. Viral nucleocapsid proteins are inevitable for genome encapsidation and replication. Here we demonstrate the interaction between the N protein of HCoV-229E and cyclophilin A, not cyclophilin B. Cyclophilin inhibitors abolish this interaction. Upon infection, cyclophilin A stays evenly distributed throughout the cell, whereas cyclophilin B concentrates at ER-bleb-like structures. We further show the inhibitory potential of non-immunosuppressive CsA derivatives Alisporivir, NIM811, compound 3 on HCoV-229E-GFP and -Luciferase replication in human Huh-7.5 hepatoma cells at 18 and 48 h time points post infection with EC₅₀ s at low micromolar ranges. Thus, non-immunosuppressive CsA derivatives effectively inhibit HCoV-229E replication suggesting them as possible candidates for the treatment of HCoV infection. The interruption of interaction between CypA and N protein by CsA and its derivatives suggest a mechanism how CypA inhibitors suppress viral replication.

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HCoV-229E replication is inhibited by Alisporivir, NIM811 and other non-immunosuppressive Cyclosporin A derivatives.

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HCoV-229E N protein interacts with cyclophilin A.

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Cyclophilin A is required for coronavirus replication.

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Cyclophilin B concentrates in bleb-like structures of the ER in HCoV-infected Huh7 cells.

Novel 2019-coronavirus on new year's Eve

An ongoing apocalyptic outbreak of a new virus causing pneumonia-like clusters in Wuhan city, China, has gleamed the world. The outbreak, confirmed on the New Year's Eve 2020, has known no boundaries since then. The number has surpassed that of Severe Acute Respiratory Syndrome (SARS) and Middle East respiratory syndrome (MERS), and is uninterruptedly escalating. Being an RNA virus, it has a propensity to mutate due to the low proofreading capacity of RNA-dependent RNA polymerase. Step-wise mutations have led to the gradual spillover of virus and after crossing the inter-species interface, the virus has adapted itself for a stable human-to-human transmission. The disease caused by severe acute respiratory syndrome coronavirus (CoV)-2 (SARS-CoV-2) can prove deadlier if the so-called 'super-spreading events' emerge with time. Recent research has shown the maximum homology of 99% of SARS-CoV-2 to pangolins associated coronavirus, owing to which these can serve as potential intermediate host. India is responding swiftly to the emergency situation, and the whole of the country is under lockdown since 25 March 2020, to ensure social distancing. All the international flights are padlocked and the travellers are being screened at airports and seaports via thermal sensors, and quarantine for a period of 14 days is recommended. Three hundred and forty-five patients across the country tested positive with six fatalities as of 22 March 2020. No specific anti-CoV drugs are currently available. Patients are being treated with protease drugs are inhibitors, remdesivir, chloroquine, angiotensin-converting enzyme 2 inhibitors, ivermectin, sarilumab and tocilizumab, though none of these is Food and Drug Administration approved and are undergoing trials. Preventive measures such as social distancing, quarantine, cough etiquettes, proper hand washing, cleaning and decontaminating the surfaces are the mainstay for curbing the transmission of this virus. The present review highlights the update of novel SARS-CoV-2 in context to the Indian scenario.

Genetically Engineering a Susceptible Mouse Model for MERS-CoV-Induced Acute Respiratory Distress Syndrome

Since 2012, monthly cases of Middle East respiratory syndrome coronavirus (MERS-CoV) continue to cause severe respiratory disease that is fatal in ~35% of diagnosed individuals. The ongoing threat to global public health and the need for novel therapeutic countermeasures have driven the development of animal models that can reproducibly replicate the pathology associated with MERS-CoV in human infections. The inability of MERS-CoV to replicate in the respiratory tracts of mice, hamsters, and ferrets stymied initial attempts to generate small animal models. Identification of human dipeptidyl peptidase IV (hDPP4) as the receptor for MERS-CoV infection opened the door for genetic engineering of mice. Precise molecular engineering of mouse DPP4 (mDPP4) with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology maintained inherent expression profiles, and limited MERS-CoV susceptibility to tissues that naturally express mDPP4, notably the lower respiratory tract wherein MERS-CoV elicits severe pulmonary pathology. Here, we describe the generation of the 288-330^+/+ MERS-CoV mouse model in which mice were made susceptible to MERS-CoV by modifying two amino acids on mDPP4 (A288 and T330), and the use of adaptive evolution to generate novel MERS-CoV isolates that cause fatal respiratory disease. The 288-330^+/+ mice are currently being used to evaluate novel drug, antibody, and vaccine therapeutic countermeasures for MERS-CoV. The chapter starts with a historical perspective on the emergence of MERS-CoV and animal models evaluated for MERS-CoV pathogenesis, and then outlines the development of the 288-330^+/+ mouse model, assays for assessing a MERS-CoV pulmonary infection in a mouse model, and describes some of the challenges associated with using genetically engineered mice.

Antibodies and vaccines against Middle East respiratory syndrome coronavirus

The Middle East respiratory syndrome coronavirus (MERS-CoV) has spread through 27 countries and infected more than 2,200 people since its first outbreak in Saudi Arabia in 2012. The high fatality rate (35.4%) of this novel coronavirus and its persistent wide spread infectiousness in animal reservoirs have generated tremendous global public health concern. However, no licensed therapeutic agents or vaccines against MERS-CoV are currently available and only a limited few have entered clinical trials. Among all the potential targets of MERS-CoV, the spike glycoprotein (S) has been the most well-studied due to its critical role in mediating viral entry and in inducing a protective antibody response in infected individuals. The most notable studies include the recent discoveries of monoclonal antibodies and development of candidate vaccines against the S glycoprotein. Structural characterization of MERS-CoV S protein bound with these monoclonal antibodies has provided insights into the mechanisms of humoral immune responses against MERS-CoV infection. The current review aims to highlight these developments and discuss possible hurdles and strategies to translate these discoveries into ultimate medical interventions against MERS-CoV infection.

Human-animal interactions and bat coronavirus spillover potential among rural residents in Southern China

Human interaction with animals has been implicated as a primary risk factor for several high impact zoonoses, including many bat-origin viral diseases. However the animal-to-human spillover events that lead to emerging diseases are rarely observed or clinically examined, and the link between specific interactions and spillover risk is poorly understood. To investigate this phenomenon, we conducted biological-behavioral surveillance among rural residents in Yunnan, Guangxi, and Guangdong districts of Southern China, where we have identified a number of SARS-related coronaviruses in bats. Serum samples were tested for four bat-borne coronaviruses using newly developed enzyme-linked immunosorbent assays (ELISA). Survey data were used to characterize associations between human-animal contact and bat coronavirus spillover risk. A total of 1,596 residents were enrolled in the study from 2015 to 2017. Nine participants (0.6%) tested positive for bat coronaviruses. 265 (17%) participants reported severe acute respiratory infections (SARI) and/or influenza-like illness (ILI) symptoms in the past year, which were associated with poultry, carnivore, rodent/shrew, or bat contact, with variability by family income and district of residence. This study provides serological evidence of bat coronavirus spillover in rural communities in Southern China. The low seroprevalence observed in this study suggests that bat coronavirus spillover is a rare event. Nonetheless, this study highlights associations between human-animal interaction and zoonotic spillover risk. These findings can be used to support targeted biological behavioral surveillance in high-risk geographic areas in order to reduce the risk of zoonotic disease emergence.

Adaptive Mutations in Replicase Transmembrane Subunits Can Counteract Inhibition of Equine Arteritis Virus RNA Synthesis by Cyclophilin Inhibitors

Previously, the cyclophilin inhibitors cyclosporine (CsA) and alisporivir (ALV) were shown to inhibit the replication of diverse RNA viruses, including arteriviruses and coronaviruses, which both belong to the order Nidovirales In this study, we aimed to identify arterivirus proteins involved in the mode of action of cyclophilin inhibitors and to investigate how these compounds inhibit arterivirus RNA synthesis in the infected cell. Repeated passaging of the arterivirus prototype equine arteritis virus (EAV) in the presence of CsA revealed that reduced drug sensitivity is associated with the emergence of adaptive mutations in nonstructural protein 5 (nsp5), one of the transmembrane subunits of the arterivirus replicase polyprotein. Introduction of singular nsp5 mutations (nsp5 Q21R, Y113H, or A134V) led to an ∼2-fold decrease in sensitivity to CsA treatment, whereas combinations of mutations further increased EAV's CsA resistance. The detailed experimental characterization of engineered EAV mutants harboring CsA resistance mutations implicated nsp5 in arterivirus RNA synthesis. Particularly, in an in vitro assay, EAV RNA synthesis was far less sensitive to CsA treatment when nsp5 contained the adaptive mutations mentioned above. Interestingly, for increased sensitivity to the closely related drug ALV, CsA-resistant nsp5 mutants required the incorporation of an additional adaptive mutation, which resided in nsp2 (H114R), another transmembrane subunit of the arterivirus replicase. Our study provides the first evidence for the involvement of nsp2 and nsp5 in the mechanism underlying the inhibition of arterivirus replication by cyclophilin inhibitors.IMPORTANCE Currently, no approved treatments are available to combat infections with nidoviruses, a group of positive-stranded RNA viruses, including important zoonotic and veterinary pathogens. Previously, the cyclophilin inhibitors cyclosporine (CsA) and alisporivir (ALV) were shown to inhibit the replication of diverse nidoviruses (both arteriviruses and coronaviruses), and they may thus represent a class of pan-nidovirus inhibitors. In this study, using the arterivirus prototype equine arteritis virus, we have established that resistance to CsA and ALV treatment is associated with adaptive mutations in two transmembrane subunits of the viral replication machinery, nonstructural proteins 2 and 5. This is the first evidence for the involvement of specific replicase subunits of arteriviruses in the mechanism underlying the inhibition of their replication by cyclophilin inhibitors. Understanding this mechanism of action is of major importance to guide future drug design, both for nidoviruses and for other RNA viruses inhibited by these compounds.

Onward transmission of viruses: how do viruses emerge to cause epidemics after spillover?

The critical step in the emergence of a new epidemic or pandemic viral pathogen occurs after it infects the initial spillover host and then is successfully transmitted onwards, causing an outbreak chain of transmission within that new host population. Crossing these choke points sets a pathogen on the pathway to epidemic emergence. While many viruses spill over to infect new or alternative hosts, only a few accomplish this transition—and the reasons for the success of those pathogens are still unclear. Here, we consider this issue related to the emergence of animal viruses, where factors involved likely include the ability to efficiently infect the new animal host, the demographic features of the initial population that favour onward transmission, the level of shedding and degree of susceptibility of individuals of that population, along with pathogen evolution favouring increased replication and more efficient transmission among the new host individuals. A related form of emergence involves mutations that increased spread or virulence of an already-known virus within its usual host. In all of these cases, emergence may be due to altered viral properties, changes in the size or structure of the host populations, ease of transport, climate change or, in the case of arboviruses, to the expansion of the arthropod vectors. Here, we focus on three examples of viruses that have gained efficient onward transmission after spillover: influenza A viruses that are respiratory transmitted, HIV, a retrovirus, that is mostly blood or mucosal transmitted, and canine parvovirus that is faecal:oral transmitted. We describe our current understanding of the changes in the viruses that allowed them to overcome the barriers that prevented efficient replication and spread in their new hosts. We also briefly outline how we could gain a better understanding of the mechanisms and variability in order to better anticipate these events in the future.

This article is part of the theme issue ‘Dynamic and integrative approaches to understanding pathogen spillover’.

The re-emerging of SADS-CoV infection in pig herds in Southern China

A new highly virulent swine acute diarrhoea syndrome coronavirus (SADS‐CoV) emerged in Guangdong province in 2017 followed by fatal diarrhoea that involved the death of 24,693 piglets. And yet from May 2017 to January 2019, there were no new SADS cases arising in pig herds in Guangdong. In this study, we reported the recent diarrhoea outbreak of SADS‐CoV in Southern China on February 2019. Intestinal samples collected from diarrhoeal piglets were detected for common swine virus and confirmed that SADS‐CoV was responsible for the diarrhoea case. Meanwhile, serological investigation of sows’ sera implied that SADS‐CoV has existed in the farm and PEDV antibody may not directly contribute to the amplification of SADS‐CoV. Homology and phylogenetic analysis of the whole genome showed that the re‐emerging SADS‐CoV strain shared high sequence identities with existing SADS‐CoV strains and all strains clustered together in Alpha coronavirus. All in all, the report herein emphasized the re‐emerging of SADS‐CoV and highlights continuous monitoring for this virus.