Molecular biology of coronaviruses: an overview of virus-host interactions and pathogenesis / Biología molecular de los coronavirus: una visión panorámica de las interacciones virus-hospedero y de la patogénesis

Abstract Coronaviruses (CoV) are enveloped, plus-strand RNA viruses that have the largest known RNA genomes and infect birds and mammals, causing various diseases. Human coronaviruses (HCoVs) were first identified in the mid-1960s and have been known to cause enteric or respiratory infections. In the last two decades, three HCoVs have emerged, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initiated the ongoing pandemic. SARS-CoV-2 causes a respiratory illness that presents as a mild upper respiratory disease but may result in acute respiratory distress syndrome, multi-organ failure and can be fatal, especially when underlying comorbidities are present. Children account for a low percentage of coronavirus disease 2019 (COVID-19) cases, with seemingly less severe disease. Most pediatric patients present mild or moderate symptoms or are asymptomatic. However, some cases may be severe. Therefore, SARS-CoV-2 infection and COVID-19 in pediatric patients must be studied in detail. This review describes general features of the molecular biology of CoVs and virus-host interactions that may be implicated in the pathogenesis of SARS-CoV-2.

Resumen Los coronavirus son virus envueltos de ARN de polaridad positiva, con los genomas más grandes que se conocen. Infectan aves y mamíferos, y causan una amplia variedad de enfermedades. Los coronavirus humanos se identificaron a mediados de la década de 1960 y se sabe que causan infecciones entéricas y respiratorias. En las últimas dos décadas han emergido tres coronavirus humanos pandémicos, incluido el coronavirus 2 del síndrome agudo respiratorio grave (SARS-CoV-2) que ha causado la pandemia actual. El SARS-CoV-2 produce enfermedad respiratoria que se presenta con padecimientos moderados de las vías respiratorias altas, pero puede resultar en síndrome respiratorio agudo, falla multiorgánica y muerte, en especial en casos con morbilidad subyacente. Los casos de COVID-19 en niños representan un porcentaje bajo y con síntomas menos graves de la enfermedad. La mayoría de los pacientes pediátricos son asintomáticos o presentan enfermedad leve o moderada; sin embargo, también en niños la enfermedad puede ser grave, por lo que la infección con SARS-CoV-2 y la COVID-19 en pacientes pediátricos deben estudiarse con detalle. En esta revisión se describen las características generales de la biología molecular de los coronavirus y de las interacciones virus-hospedero que se conocen para los coronavirus humanos identificados previamente, y que podrían estar implicados en la patogénesis del SARS-CoV-2.

Características de los coronavirus, origen del SARS-CoV-2, características estructurales, proteínas y factores de virulencia, variantes genéticas / Characteristics of coronaviruses, origin of SARS-CoV-2, characteristics structural, proteins and factors of virulence, genetic variants

Coronaviruses (CoVs) were identified in 1937, they were considered innocuous viruses until the appearance of three highly pathogenic variants, SARS-CoV, MERS-CoV and SARS-CoV-2 causing the current pandemic of Covid-19, so far it is known that its origin is zoonotic, the main reservoir could be bats considering the high homology of CoVs that inhabit this species. Its transmissibility is much higher than that of previous CoVs, possibly in the process of natural selection; it has acquired some or all the mutations necessary for a much more efficient transmission in our species. This condition is specifically attributed to unique characteristics of the SARS-CoV-2 Spike protein that allow it greater affinity and therefore greater infectivity by binding to the angiotensin receptor 2 (ACE-2) present in the host cells. Since the Covid-19 outbreak began at the end of 2019, more than 1,500 mutations have been detected throughout the SARS-CoV-2 genome, however the most significant are those that occur near or in the receptor binding domain (RBD) that could provide variations between 4x to 100x greater infectivity, such is the case of the new variants identified in the United Kingdom, South Africa, Brazil and Japan that force us to take extreme preventive measures and continue research to elucidate strategies to combat the current crisis. (AU)

Coronaviruses: a review of their properties and diversity

Human coronaviruses, which hitherto were causative agents of mild respiratory diseases of man, have recently become one of the most important groups of pathogens of humans the world over. In less than two decades, three members of the group, severe acute respiratory syndrome (SARS) coronavirus (CoV), Middle East respiratory syndrome (MERS)-CoV, and SARS-COV-2, have emerged causing disease outbreaks that affected millions and claimed the lives of thousands of people. In 2017, another coronavirus, the swine acute diarrhea syndrome (SADS) coronavirus (SADS-CoV) emerged in animals killing over 24,000 piglets in China. Because of the medical and veterinary importance of coronaviruses, we carried out a review of available literature and summarized the current information on their properties and diversity. Coronaviruses are single-stranded RNA viruses with some unique characteristics such as the possession of a very large nucleic acid, high infidelity of the RNA-dependent polymerase, and high rate of mutation and recombination in the genome. They are susceptible to a number of physical agents and several chemical agents used for disinfection procedures in hospitals and laboratories. They exhibit considerable genetic and host diversity, causing diseases of gastrointestinal and respiratory system in a wide range of vertebrate hosts including humans. The high prevalence of coronaviruses in domestic and wild animals, especially bats and birds, and the propensity for their genomes to undergo mutation and recombination may lead to emergence of new coronaviruses that could pose a serious threat to human and animal health

Infectio: contribución al conocimiento de las enfermedades infecciosas en Colombia / Infectio: Contribution to the knowledge of infectious diseases in Colombia

El campo de las enfermedades infecciosas ha tenido un crecimiento acelerado en el mundo en las últimas 3 décadas. La emergencia o el descubrimiento de múltiples agentes infecciosos, como el del virus de la inmunodeficiencia humana, los priones asociados con la enfermedad de Creutzfeldt-Jakob y otras enfermedades del ser humano, los coronavirus causantes del síndrome respiratorio agudo grave o el de Plasmodium knowlesi, quinta especie causal de malaria en humanos, son tan solo algunos ejemplos de los nuevos retos a los que se enfrentan los profesionales que trabajan en el campo de la infectología y disciplinas relacionadas. Para afrontarlos, la investigación y la difusión del conocimiento científico en aspectos epidemiológicos, diagnósticos, terapéuticos y preventivos han tenido que incrementarse.

The field of infectious diseases has seen an accelerated growth in the world over the last 3 decades. The emergence or discovery of multiple infectious agents, such as the human immunodeficiency virus, prions associated with Creutzfeldt-Jakob disease and other human diseases, coronaviruses causing severe acute respiratory syndrome or Plasmodium knowlesi, the fifth species causing malaria in humans, are just some examples of the new challenges faced by professionals working in the field of infectious diseases and related disciplines. To face them, research and dissemination of scientific knowledge in epidemiological, diagnostic, therapeutic and preventive aspects have had to increase.

A coronavirus detected in the vampire bat Desmodus rotundus

This article reports on the identification of a group 2 coronavirus (BatCoV DR/2007) in a Desmodus rotundus vampire bat in Brazil. Phylogenetic analysis of ORF1b revealed that BatCoV DR/2007 originates from a unique lineage in the archetypical group 2 coronaviruses, as described for bat species elsewhere with putative importance in Public Health.

Evaluation of Seeplex(TM) RV Detection Kit for Detecting Rhinovirus, Human Metapneumovirus, and Coronavirus / 대한진단검사의학회지

BACKGROUND: Direct antigen test (DAT) and culture are primary tests to diagnose infections by respiratory viruses, but are mainly available for the traditional viral pathogens such as respiratory syncytial virus (RSV), influenza virus, parainfluenza virus (PIV), and adenovirus in clinical laboratories. The objective of this study was to evaluate a multiplex reverse transcriptase-PCR method using Seeplex(TM) RV Detection kit (Seegene, Korea) for the detection of rhinovirus, coronavirus, and human metapneumovirus (hMPV). METHODS: From January to May 2007, nasopharyngeal aspirates (NPAs) from pediatric patients negative for culture and DAT of traditional viral pathogens were tested with Seeplex(TM). All the amplicons were directly sequenced and homology of the sequences was searched in the National Center for Biotechnology Information (NCBI) database. Patients' medical records were reviewed for clinical and demographic features. RESULTS: Forty-seven (26.4%) of 178 NPAs were positive: 18 rhinovirus, 15 hMPV, 4 RSV A, 3 coronavirus OC43, 3 influenza virus A, 2 adenovirus, 1 coronavirus NL63, and 1 RSV B. Based on maximum identity, each of the sequences indicating rhinovirus, hMPV, and coronavirus OC43 matched to the corresponding viruses with homology of 94-98%, 96-99%, and 98-100%, respectively. Seeplex(TM) positive patients were 0-11 yr old with a male:female ratio of 1.5:1. Clinical diagnoses included 9 pneumonia, 6 bronchiolitis, 2 cold, 1 asthma exacerbation for rhinovirus; 10 pneumonia, 4 bronchiolitis, and 1 clinical sepsis for hPMV; and 1 pneumonia, 2 croup, and 1 cold for coronavirus. CONCLUSIONS: Multiplex reverse transcriptase-PCR method using Seeplex(TM) RV Detection kit is a reliable test to detect rhinovirus, hMPV, and coronavirus. It may improve the diagnostic sensitivity for RSV, influenza virus, PIV, and adenovirus.