Current understanding of an Emerging Coronavirus using in silico approach: Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) / Compreensão atual de um coronavírus emergente usando abordagem in silico: síndrome respiratória aguda grave - coronavírus-2 (SARS-CoV-2)

Abstract Novel coronavirus (nCoV) namely "SARS-CoV-2" is being found responsible for current PANDEMIC commenced from Wuhan (China) since December 2019 and has been described with epidemiological linkage to China in about 221 countries and territories until now. In this study we have characterized the genetic lineage of SARS-CoV-2 and report the recombination within the genus and subgenus of coronaviruses. Phylogenetic relationship of thirty nine coronaviruses belonging to its four genera and five subgenera was analyzed by using the Neighbor-joining method using MEGA 6.0. Phylogenetic trees of full length genome, various proteins (spike, envelope, membrane and nucleocapsid) nucleotide sequences were constructed separately. Putative recombination was probed via RDP4. Our analysis describes that the "SARS-CoV-2" although shows great similarity to Bat-SARS-CoVs sequences through whole genome (giving sequence similarity 89%), exhibits conflicting grouping with the Bat-SARS-like coronavirus sequences (MG772933 and MG772934). Furthermore, seven recombination events were observed in SARS-CoV-2 (NC_045512) by RDP4. But not a single recombination event fulfills the high level of certainty. Recombination mostly housed in spike protein genes than rest of the genome indicating breakpoint cluster arises beyond the 95% and 99% breakpoint density intervals. Genetic similarity levels observed among "SARS-CoV-2" and Bat-SARS-CoVs advocated that the latter did not exhibit the specific variant that cause outbreak in humans, proposing a suggestion that "SARS-CoV-2" has originated possibly from bats. These genomic features and their probable association with virus characteristics along with virulence in humans require further consideration.

Resumo O novo coronavírus (nCoV), nomeadamente "SARS-CoV-2", foi considerado responsável pela pandemia atual iniciada em Wuhan (China) desde dezembro de 2019 e foi descrito com ligação epidemiológica à China em cerca de 221 países e territórios até agora. Neste estudo, caracterizamos a linhagem genética do SARS-CoV-2 e relatamos a recombinação dentro do gênero e subgênero dos coronavírus. A relação filogenética de 39 coronavírus pertencentes a seus quatro gêneros e cinco subgêneros foi analisada usando o método de Neighbour-joining usando MEGA 6.0. Árvores filogenéticas do genoma de comprimento total, várias proteínas (espícula, envelope, membrana e nucleocapsídeo), sequências de nucleotídeos foram construídas separadamente. A recombinação putativa foi testada via RDP4. Nossa análise descreve que o "SARS-CoV-2", embora mostre grande semelhança com as sequências de Bat-SARS-CoVs em todo o genoma (dando semelhança de sequência de 89%), exibe agrupamento conflitante com as sequências de coronavírus do tipo Bat-SARS (MG772933 e MG772934) Além disso, sete eventos de recombinação foram observados em SARS-CoV-2 (NC045512) por RDP4. Mas nem um único evento de recombinação preenche o alto nível de certeza. A recombinação está alojada mais em genes de proteína de pico, principalmente, do que no resto do genoma, indicando que o cluster de ponto de interrupção surge além dos intervalos de densidade de ponto de interrupção de 95% e 99%. Os níveis de similaridade genética observados entre "SARS-CoV-2" e Bat-SARS-CoVs defendem que o último não exibe a variante específica que causa surto em humanos, sugerindo que "SARS-CoV-2" tenha se originado possivelmente de morcegos. Essas características genômicas e sua provável associação com as características do vírus, juntamente com a virulência em humanos, requerem uma consideração mais aprofundada.

Genomic surveillance and sequencing of SARS-CoV-2 across South America / Vigilancia genómica y secuenciación del SARS-CoV-2 en América del Sur / Vigilância genômica e sequenciamento do SARS-CoV-2 na América do Sul

ABSTRACT After 2 years of the COVID-19 pandemic, the protocols used to control infection lack attention and analysis. We present data about deposits of complete genomic sequences of SARS-CoV-2 in the Global Initiative on Sharing All Influenza Data (GISAID) database made between January 2021 and May 31, 2022. We build the distribution profile of SARS-CoV-2 variants across South America, highlighting the contribution and influence of each variant over time. Monitoring the genomic sequences in GISAID illustrates negligence in the follow up of infected patients in South America and also the discrepancies between the number of complete genomes deposited throughout the pandemic by developed and developing countries. While Europe and North America account for more than 9 million of the genomes deposited in GISAID, Africa and South America deposited less than 400 000 genome sequences. Genomic surveillance is important for detecting early warning signs of new circulating viruses, assisting in the discovery of new variants and controlling pandemics.

RESUMEN Tras dos años de pandemia del COVID-19, los protocolos empleados para controlar la infección carecen de atención y análisis. En este artículo se presentan datos sobre depósitos de secuencias genómicas completas del SARS-CoV-2 en la base de datos de secuenciación GISAID, la Iniciativa mundial para intercambiar todos los datos sobre la gripe aviar, realizadas entre enero del 2021 y el 31 de mayo del 2022. Se creó el perfil de distribución de las variantes del SARS-CoV-2 en América del Sur, en el que se destacaron la contribución y la influencia de cada variante a lo largo del tiempo. El monitoreo de las secuencias genómicas en GISAID ilustra la negligencia en el seguimiento de los pacientes infectados en América del Sur, así como las discrepancias entre el número de genomas completos depositados a lo largo de la pandemia por parte de los países desarrollados y los países en desarrollo. Mientras que Europa y América del Norte han depositado más de 9 millones de genomas en GISAID, África y América del Sur han aportado menos de 400 000 secuencias genómicas. La vigilancia genómica es importante para detectar los primeros signos de alerta de virus nuevos en circulación, ayudar en el descubrimiento de nuevas variantes y controlar las pandemias.

RESUMO Após 2 anos da pandemia de covid-19, os protocolos usados para controlar a infecção necessitam maior atenção e análise. Apresentamos dados sobre as sequências genômicas completas do SARS-CoV-2 depositadas no banco de dados do a iniciativa internacional para o intercâmbio de dados sobre os vírus da influenza (GISAID) entre janeiro de 2021 e 31 de maio de 2022. Construímos o perfil de distribuição das variantes do SARS-CoV-2 na América do Sul, destacando a contribuição e a influência de cada variante ao longo do tempo. O monitoramento das sequências genômicas do GISAID ilustra a negligência no acompanhamento de pacientes infectados na América do Sul e as discrepâncias entre os países desenvolvidos e em desenvolvimento com relação ao número de genomas completos depositados ao longo da pandemia. Enquanto a Europa e a América do Norte respondem por mais de 9 milhões dos genomas depositados no GISAID, a África e a América do Sul depositaram menos de 400 000 sequências genômicas. A vigilância genômica é importante para detectar sinais de alerta precoces de novos vírus circulantes, auxiliar na descoberta de novas variantes e controlar pandemias.

Optimización de unidades formadoras de colonias y detección del virus de papiloma humano en sangre de cordón umbilical / Colony-forming units optimization and human papillomavirus detection in umbilical cord blood

Resumen Introducción: Se requiere analizar diversos parámetros para el control de calidad adecuado de las unidades de sangre de cordón umbilical (USCU) cuando se utilizan con fines terapéuticos. Objetivo: Optimizar las unidades formadoras de colonias (UFC) de cultivos clonogénicos y detectar el genoma del virus del papiloma humano (VPH) en USCU. Métodos: Se incluyeron 141 muestras de sangre de cordón umbilical (SCU), de segmento y de UFC de cultivos clonogénicos de USCU. Se realizó extracción de ADN, cuantificación y amplificación por PCR del gen endógeno GAPDH. Se detectó el gen L1 del VPH con los oligonucleótidos MY09/MY11 y GP5/GP6+; los productos de PCR se migraron en electroforesis de agarosa. El ADN purificado de las UFC se analizó mediante electroforesis de agarosa y algunos ADN, con la técnica sequence specific priming. Resultados: La concentración de ADN extraído de UFC fue superior comparada con la de SCU (p = 0.0041) y la de segmento (p < 0.0001); así como la de SCU comparada con la de segmento (p < 0.0001). Todas las muestras fueron positivas para la amplificación de GAPDH y negativas para MY09/MY11 y GP5/GP6+. Conclusiones: Las USCU criopreservadas fueron VPH netativas; además, es factible obtener ADN en altas concentraciones y con alta pureza a partir de UFC de los cultivos clonogénicos.

Abstract Introduction: Analysis of several markers is required for adequate quality control in umbilical cord blood units (UCBU) when are used for therapeutic purposes. Objective: To optimize colony-forming units (CFU) from clonogenic cultures and to detect the human papillomavirus (HPV) genome in UCBU. Methods: One hundred and forty-one umbilical cord blood (UCB), segment or CFU samples from UCBU clonogenic cultures were included. DNA extraction, quantification and endogenous GAPDH gene PCR amplification were carried out. Subsequently, HPV L1 gene was detected using the MY09/MY11 and GP5/GP6+ oligonucleotides. PCR products were analyzed with electrophoresis in agarose gel. CFU-extracted purified DNA was analyzed by electrophoresis in agarose gel, as well as some DNAs, using the SSP technique. Results: CFU-extracted DNA concentration was higher in comparison with that of UCB (p = 0.0041) and that of the segment (p < 0.0001), as well as that of UCB in comparison with that of the segment (p < 0.0001). All samples were positive for GAPDH amplification and negative for MY09/MY11 and GP5/GP6+. Conclusions: Cryopreserved UCBUs were HPV-negative. Obtaining CFU DNA from clonogenic cultures with high concentrations and purity is feasible.

Primeras seis secuencias del genoma completo de SARS-CoV-2 por NGS en El Salvador / First six sequences of the complete SARS-CoV-2 genome by NGS in El Salvador

En este trabajo se describen las primeras secuencias completas del genoma de SARS-CoV-2 a partir de muestras de pacientes salvadoreños. Objetivo. Reportar las primeras secuencias completas del genoma del SARS-CoV-2 de casos procedentes de El Salvador. Metodología. Se realizó una secuenciación masiva en la plataforma MiniSeq Illumina a partir de muestras de secreción nasofaríngea. Resultados. El análisis filogenético determinó que estas muestras pertenecen al clado 20C secundario de 20A que tiene en común la variante de la mutación D614G de la glicoproteína espícula. La mutación S: D614G fue encontrada en las seis secuencias de SARS-CoV-2. En la plataforma GISAID, las secuencias mostraron pertenecer al clado GH linaje pangolín B.1.2 y B.1.370; ambos linajes están presentes en Estados Unidos. Conclusión. El análisis filogenético evidenció que estas seis muestras pertenecen al clado 20C, clado secundario de 20A, que tiene en común la variante de la mutación D614G de la glicoproteína espícula

This work describes the first complete sequences of the SARS-CoV-2 genome from samples of Salvadoran patients. Objective. Report the first complete sequences of the SARS-CoV-2 genome from cases from El Salvador. Methodology. Massive sequencing was performed on the MiniSeq Illumina platform from samples of nasopharyngeal secretion. Results. Phylogenetic analysis determined that these samples belong to the secondary 20C clade of 20A which has in common the variant of the spike glycoprotein D614G mutation. The S: D614G mutation was found in all six SARS-CoV-2 sequences. In the GISAID platform, the sequences were shown to belong to the clade GH pangolin lineage B.1.2 and B.1.370; both lineages are present in the United States. Conclusion. Phylogenetic analysis showed that these six samples belong to clade 20C, a secondary clade of 20A, which has in common the variant of the spike glycoprotein D614G mutation

Análisis de la mutación D614G en secuencia del genoma completo de SARS-CoV-2 en El Salvador / Analysis of the D614G mutation in the sequence of the complete SARS-CoV-2 genome in El Salvador

El 18 de marzo se reporta el primer caso de infección por SARS- CoV-2 confirmado en El Salvador y durante el mes de octubre de 2020 se logra secuenciar el genoma de SARS-CoV-2 a partir de muestras obtenidas en el país. Objetivo. Analizar in silico las mutaciones detectadas en las secuencias aisladas en El Salvador. Metodología. Se utilizó la plataforma SOPHiA-DDM-V5.7.10., para la determinación de las variantes por mutaciones con sentido erróneo. Se utilizó la plataforma Nexclade beta v0.8.1.; se visualizó y comparó la proteína S silvestre (D614: PDB ID: 6VXX) y de la variante mutada (D614G: PDB ID: 6XS6). Para el modelamiento y generación de imágenes de los detalles moleculares de las proteínas se utilizó Pymol-v1.7.2.3. Resultados. Los cristales de la proteína S silvestre y mutada muestra diferencias a nivel molecular, incluyendo la pérdida de interacciones entre el residuo G614 del dominio S1 y la treonina 859 de dominio S2, favoreciendo de esta manera la conformación abierta de la proteína S, la cual es necesaria para la interacción de S con el receptor ACE2. Conclusión. Los hallazgos confirman el predominio de la variante D614G en este grupo de secuencias, lo cual probablemente favorece su transmisibilidad, que puede explicarse por la configuración de los sitios de unión con receptor ACE2. El predominio mundial de la D614G y las evidencias de laboratorio y bioinformáticas publicadas hasta la fecha, apuntan hacia una posible mayor infectividad y transmisibilidad

On March 18, the first confirmed case of SARS-CoV-2 infection was reported in El Salvador and during the month of October 2020, the SARS-CoV-2 genome was sequenced from samples obtained in the country. Objective. To analyze in silico the mutations detected in the sequences isolated in El Salvador. Methodology. The SOPHiA-DDM-V5.7.10. Platform was used for the determination of variants due to missense mutations. The Nexclade beta v0.8.1 platform was used; The wild-type protein S (D614: PDB ID: 6VXX) and the mutated variant (D614G: PDB ID: 6XS6) were visualized and compared. For the modeling and generation of images of the molecular details of the proteins, Pymol-v1.7.2.3 was used. Results. The crystals of wild and mutated protein S show differences at the molecular level, including the loss of interactions between residue G614 of domain S1 and threonine 859 of domain S2, thus favoring the open conformation of protein S, which is necessary for the interaction of S with the ACE2 receptor. Conclusion. The findings confirm the predominance of the D614G variant in this group of sequences, which probably favors its transmissibility, which can be explained by the configuration of the ACE2 receptor binding sites. The worldwide prevalence

Experiência do laboratório central de Saúde Pública da Bahia no enfrentamento da pandemia da Covid-19 / Experience of the central laboratory of Public Health of Bahia in coping with the Covid-19 pandemic / Experiencia del laboratorio central de Salud Pública de Bahía en el afrontamiento de la pandemia Covid-19

A Covid-19 é uma doença infecciosa causada pelo novo coronavírus, denominado SARS-CoV-2, que causou um surto de pneumonia viral incomum em pacientes em Wuhan, na China, no final do ano de 2019. O vírus se disseminou pelo mundo em grandes proporções, atingindo o status epidemiológico de pandemia. Diante desse cenário, que afetou toda a Federação brasileira, o Laboratório Central de Saúde Pública Professor Gonçalo Moniz (Lacen-BA) tem exercido papel fundamental no diagnóstico da Covid-19 e na vigilância genômica do SARS-CoV-2. Nesse sentido, este estudo tem como objetivo descrever as estratégias implementadas pelo Lacen-BA para ampliar a capacidade diagnóstica e atender a demanda da rede SUS-BA no contexto da pandemia da Covid-19. Trata-se de um estudo descritivo-observacional, orientado por um modelo lógico sustentado em quatro dimensões: parque tecnológico, metodologias analíticas, descentralização do exame e monitoramento de indicadores de resultados. As iniciativas de gestão possibilitaram ampliação da capacidade instalada e operacional, mediante modernização da estrutura física, renovação do parque tecnológico, reorganização dos fluxos e processos de trabalho, aporte de novas tecnologias analíticas e estruturação de dashboard para monitorar indicadores e subsidiar o processo decisório. O Lacen-BA, enquanto coordenador da Rede Estadual de Laboratórios de Saúde Pública e sistema de apoio da Rede de Atenção à Saúde (RAS), constitui-se então em estruturas policêntricas essenciais para o diagnóstico descentralizado e regionalizado da Covid-19, contribuindo para a integração sistêmica das ações e serviços no contexto da regionalização da saúde, de modo a garantir a universalidade do acesso e integralidade dos cuidados aos usuários do SUS.

Covid-19 is an infectious disease caused by the new coronavirus, called SARS-CoV-2, which caused an outbreak of unusual viral pneumonia in patients in Wuhan, China, at the end of 2019 and spread across the world, in large proportions, reaching the epidemiological status of a pandemic. Considering this epidemiological scenario that affected the entire Brazilian Federation, the Central Laboratory of Public Health Professor Gonçalo Moniz (Lacen-BA) has played a fundamental role in the diagnosis of Covid-19 and the genomic surveillance of SARS-CoV-2. In this sense, this study aims at describing the strategies implemented by Lacen-BA to expand the diagnostic capacity to meet the demand of the SUS-BA network, in the context of the Covid-19 pandemic. This is a descriptive-observational study, guided by a logical model based on four dimensions: technological park, analytical methodologies, decentralization of the exam and monitoring of result indicators. The management initiatives enabled the expansion of the installed and operational capacity by modernizing the physical structure, renewing the technological park, reorganizing workflows and processes, providing new analytical technologies, structuring the dashboard to monitor indicators and support the decision-making process. The Lacen-BA, as coordinator of the State Public Health Laboratory Network and support system of the Health Care Network (RAS), constitutes essential polycentric structures for the decentralized and regionalized diagnosis of Covid-19, which can contribute to the systemic integration of actions and services in the context of regionalization of health to guarantee the universality of access and comprehensive care to SUS users.

El covid-19 es una enfermedad infecciosa causada por el nuevo coronavirus, llamado SARS-CoV-2, que provocó un brote de neumonía viral inusual en pacientes en Wuhan, China, a fines de 2019, y que se extendió por el mundo, en grandes proporciones hasta alcanzar el estado epidemiológico de pandemia. Ante este escenario epidemiológico que afectó a Brasil, el Laboratorio Central de Salud Pública Profesor Gonçalo Moniz (Lacen-BA) ha jugado un papel fundamental en el diagnóstico del covid-19 y la vigilancia genómica del SARS-CoV-2. En este sentido, este estudio tiene como objetivo describir las estrategias implementadas por Lacen-BA para ampliar la capacidad de diagnóstico y atender la demanda de la red SUS-BA, en el contexto de la pandemia del Covid-19. Este estudio es descriptivo-observacional, guiado por un modelo lógico con base en cuatro dimensiones: parque tecnológico, metodologías analíticas, descentralización del examen y seguimiento de indicadores de resultado. Las iniciativas de gestión permitieron ampliar la capacidad instalada y operativa al modernizar la estructura física, renovar el parque tecnológico, reorganizar los flujos y procesos de trabajo, brindar nuevas tecnologías analíticas y estructuración del cuadro de mando para monitorear indicadores, y apoyar la toma de decisiones. Lacen-BA, como coordinador de la Red Estadual de Laboratorios de Salud Pública y sistema de apoyo de la Red de Atención a la Salud (RAS), constituye estructuras policéntricas imprescindibles para el diagnóstico descentralizado y regionalizado del Covid-19, que pueden contribuir a la integración sistémica de acciones y servicios en el contexto de la regionalización de la salud, a fin de garantizar la universalidad del acceso y la atención integral a los usuarios del SUS.

Saliva as a promising biofluid for SARS-CoV-2 detection during the early stages of infection / La saliva como biofluido promisorio para la detección del SARS-CoV-2 durante las primeras etapas de la infección

Abstract Background: Diagnostic testing for coronavirus disease (COVID)-19 is performed using nasopharyngeal swabs. This type of sampling is uncomfortable for the patient, dangerous for health workers, and its high demand has led to a global shortage of swabs. One of the alternative specimens is saliva. However, the optimal conditions for the test have not been established. Methods: Reverse transcription-polymerase chain reaction was used to detect the viral genome in saliva samples kept at room temperature, in the fridge or frozen for 2 days. In addition, the influence of brushing teeth and feeding on the detection of the virus in saliva was addressed. Finally, the efficiency of saliva in revealing the presence of the virus during the hospitalization period was determined in children. Results: The viral genome was consistently detected regardless of the storage conditions of saliva samples. Brushing teeth and feeding did not influence the sensitivity of the test. In hospitalized children, positive results were obtained only during the early days. Conclusions: These results support the idea of the use of saliva as an alternative specimen for diagnostic testing for COVID-19. The viral genome is stable and endures perturbations in the oral cavity. However, clearance of the virus from the mouth during the infection may limit the use of the test only to the early stages of the disease.

Resumen Introducción: El diagnóstico de COVID-19 (enfermedad por coronavirus 2019) se realiza con un hisopado nasofaríngeo. El procedimiento de toma de muestra es molesto para el paciente y peligroso para el personal de salud, y la alta demanda de análisis ha conducido a la escasez de hisopos. Una alternativa es el uso de saliva, pero las condiciones óptimas para realizar el estudio no han sido establecidas. Métodos: Se usó la reacción en cadena de la polimerasa con transcriptasa reversa para detectar el genoma viral en muestras de saliva mantenidas a temperatura ambiente, en refrigeración o congeladas. Además, se evaluó la influencia del aseo bucal y de la ingesta de alimento en la detección del virus. Finalmente, se determinó el desempeño de la saliva para reportar la presencia del virus durante el periodo de hospitalización en niños. Resultados: El genoma viral fue estable durante 2 días a las diferentes temperaturas ensayadas. El aseo bucal y la ingesta de alimento no influyeron en la detección del virus. En los niños hospitalizados solo se obtuvieron resultados positivos durante los primeros días. Conclusiones: Los resultados coinciden con la idea del uso de la saliva como biofluido alternativo para el diagnóstico de COVID-19. El genoma viral es estable y no se ve afectado por perturbaciones en la cavidad oral; sin embargo, la dinámica de la infección puede provocar que el ensayo solo sea útil durante las primeras etapas de la enfermedad.

Aspectos generales sobre la estructura del coronavirus del síndrome respiratorio agudo grave 2 (SARS-CoV-2) / General aspects about the structure of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Introduction: In late 2019, a new coronavirus named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that causes respiratory-related illness was reported in Wuhan, China. This virus can attack human lung cells causing a disease called coronavirus disease 2019 (COVID-19), which can lead to pneumonia and acute respiratory distress syndrome. Objective: Describe the structural characteristics of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Methods: A review was written from 47 bibliographic references. Articles and information from national and international journals available in the PubMed, Scopus, Medline, SciELO databases were used. The quality, reliability and validity of the selected articles were analyzed to carry out an adequate review. Analysis-synthesis and logical deduction methods were applied. Development: An introduction to the general aspects of the structure of SARS-CoV-2 is provided by stating the characteristics of the structural and non-structural proteins encoded by the viral genome, which provides the basis for understanding viral entry mechanisms to the host cell, and may be useful to stimulate the search for novel insights and possible therapeutic targets to fight the infection. Conclusions: Knowledge of the structure of the SARS-CoV-2 virus and the characteristics of the structural and non-structural proteins provides the basis for understanding the viral mechanisms of infection and the strategies for developing effective therapeutics(AU)

Introducción: A finales de 2019 se informó el brote de un nuevo coronavirus en Wuhan, China, llamado Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) que causa alteraciones en el aparato respiratorio. Este virus puede atacar las células humanas del pulmón causando una enfermedad denominada enfermedad por coronavirus 2019 (COVID-19), que puede producir neumonía y un síndrome de dificultad respiratoria aguda. Objetivo: Describir las características estructurales del virus SARS-CoV-2. Métodos: Se realizó una revisión bibliográfica a partir de 47 referencias. Se utilizaron artículos e información de revistas nacionales e internacionales disponibles en las bases de datos PubMed, Scopus, Medline, SciELO. Para llevar a cabo una revisión adecuada, se analizaron la calidad, fiabilidad y validez de los artículos seleccionados. Se aplicaron métodos de análisis-síntesis y deducción lógica. Desarrollo: Se proporciona una introducción de los aspectos generales de la estructura del SARS-CoV-2. Se enuncian las características de las proteínas estructurales y no estructurales codificadas por el genoma viral, lo que provee la base para comprender los mecanismos virales de entrada a la célula huésped. El artículo resulta de utilidad para estimular la búsqueda de nuevos conocimientos y posibles objetivos terapéuticos para combatir la infección. Conclusiones: El conocimiento sobre la estructura del virus SARS-CoV-2 y las características de las proteínas estructurales y no estructurales que lo forman ampara significativamente las bases para entender los mecanismos virales de la infección y las estrategias para el desarrollo terapéutico efectivo(AU)

Genómica de rotavirus. Impacto en salud pública / Rotavirus genomics. Public health impact

Resumen: Con la introducción de las vacunas de rotavirus Rotarix (RV1) o RotaTeq (RV5) en programas nacionales de vacunación de diversos países, surgió la preocupación de que la presión inmune generada condujera al aumento en la prevalencia de genotipos virales no incluidos en las vacunas, o bien del surgimiento de nuevas cepas que pudieran escapar a la respuesta inmune protectora inducida por la vacunación. La variación natural de los rotavirus ha hecho que sea muy difícil distinguir si el cambio en las cepas circulantes se debe a la presión selectiva impuesta por las vacunas o bien a la fluctuación natural de las cepas. Si acaso ha habido una presión selectiva, ésta ha sido hasta ahora baja. Sin embargo, es importante mantener la vigilancia epidemiólogica y poner atención al surgimiento de cepas resistentes a la inmunidad, en particular en países en desarrollo en los que se ha descrito una mayor diversidad viral.

Abstract: With the introduction of rotavirus vaccines Rotarix (RV1) or RotaTeq (RV5) in the immunization programs of an increasing number of countries, there is concern that the immune selection pressure induced will cause an increase in the prevalence of virus genotypes not included in the vaccine formulation, or to the appearance of novel rotavirus strains that could evade the protective immune response. The natural fluctuation of rotaviruses makes it difficult to distinguish if the change in the circulating strains is due to the vaccine selective pressure or to the natural diversity fluctuation of viruses. If there has been a selective pressure, it has been low so far. However, it is important to keep an epidemiological surveillance and pay attention to the emergence of strains that are resistant to the vaccine, in particular in those countries where the viral diversity has been shown to be higher.

As descobertas genômicas do SARS-CoV-2 e suas implicações na pandemia de COVID-19 / The genomic discoveries of SARS-CoV-2 and their implications for the COVID-19 pandemic

Objetivo: Auxiliar no entendimento da COVID-19 em relação à origem do SARS-CoV-2, suas descobertas genômicas, patogenia, possíveis hospedeiros primários e intermediários, além da comparação com outros coronavírus. Metodos: foram utilizadas as bases de dados Scientific Eletronic Library Online e PubMed, com artigos de revisão e originais, em língua portuguesa e inglesa, pesquisados no período de 05 de março a 10 de abril de 2020, adotando os seguintes descritores: SARS-CoV, COVID-19, coronavirus, Wuhan, genome, structure, origin, transmission, evolution, zoonotic. Os artigos originais identificados foram incluídos nesta revisão, juntamente com artigos de suporte referenciados por estes. Resultados: As características genômicas descritas até o momento podem explicar, em parte, a infectividade e a transmissibilidade do SARS-CoV-2 em humanos. Devido aos notáveis recursos de SARS-CoV-2, incluindo o local otimizado do domínio de ligação ao receptor (RBD) e de clivagem polibásica, é pouco provável um cenário laboratorial para a origem do SARS-CoV-2. Conclusão: Para o presente, é de extrema importância obter mais dados genéticos e funcionais sobre o SARS-CoV-2, incluindo estudos em animais, sequenciamento do vírus em casos muito precoces e identificação dos parentes virais mais próximos do SARS-CoV-2 que circulam em animais.(AU)

Objective: To assist in the understanding of COVID-19 in relation to the origin of SARS-CoV-2, its genomic discoveries, pathogenesis, possible primary and intermediate hosts, in addition to comparison with other coronaviruses. Methods: the Scientific Electronic Library Online and PubMed databases were used, with review articles and originals, in Portuguese and English, researched from March 5 to April 10, 2020, adopting the following descriptors: SARS-CoV , COVID-19, coronavirus, Wuhan, genome, structure, origin, transmission, evolution, zoonotic. The original articles identified were included in this review, along with supporting articles referenced by them. Results: The genomic characteristics described so far may partly explain the infectivity and transmissibility of SARS-CoV-2 in humans. Due to the remarkable resources of SARS-CoV-2, including the optimized site of the receptor binding domain (RBD) and polybasic cleavage, a laboratory scenario for the origin of SARS-CoV-2 is unlikely. Conclusion: For the present, it is extremely important to obtain more genetic and functional data on SARS-CoV-2, including studies on animals, sequencing of the virus in very early cases and identification of the closest viral relatives of SARS-CoV-2 that circulate in animals.(AU)

Genomic surveillance of the Chikungunya Virus (CHIKV) in Northeast Brazil after the first outbreak in 2014

Abstract INTRODUCTION: We performed an epidemiological surveillance of the Chikungunya (CHIKV) lineages in Bahia after the 2014 East/Central/South African (ECSA) genotype outbreak. METHODS: Reverse-transcription polymerase chain reaction (RT-PCR), viral isolation, and phylogenetic analyses were conducted on serum samples from 605 patients with CHIKV-like symptoms during 2014-2018. RESULTS: Of the 605 samples, 167 were CHIKV-positive. Viral isolation was achieved for 20 samples; their phylogenetic analysis (E2 protein) revealed the presence of ECSA lineage and reinforced the phylogenetic relationship between ECSA and Indian Ocean lineages. CONCLUSIONS: The genomic surveillance of CHIKV showed that only ECSA lineage circulated in Bahia since the 2014 outbreak.

Genomic and phylogenetic characterisation of an imported case of SARS-CoV-2 in Amazonas State, Brazil

A new coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] is currently causing a life-threatening pandemic. In this study, we report the complete genome sequencing and genetic characterisation of a SARS-CoV-2 detected in Manaus, Amazonas, Brazil, and the protocol we designed to generate high-quality SARS-CoV-2 full genome data. The isolate was obtained from an asymptomatic carrier returning from Madrid, Spain. Nucleotide sequence analysis showed a total of nine mutations in comparison with the original human case in Wuhan, China, and support this case as belonging to the recently proposed lineage A.2. Phylogeographic analysis further confirmed the likely European origin of this case. To our knowledge, this is the first SARS-CoV-2 genome obtained from the North Brazilian Region. We believe that the information generated in this study may contribute to the ongoing efforts toward the SARS-CoV-2 emergence.

In silico analysis of mismatches in RT-qPCR assays of 177 SARS-CoV-2 sequences from Brazil

Abstract INTRODUCTION: Quantitative reverse transcription polymerase chain reaction (RT-qPCR) can detect the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) in a highly specific manner. However, a decrease in the specificity of PCR assays for their targets may lead to false negative results. METHODS: Here, 177 high-coverage complete SARS-CoV-2 genome sequences from 13 Brazilian states were aligned with 15 WHO recommended PCR assays. RESULTS: Only 3 of the 15 completely aligned to all Brazilian sequences. Ten assays had mismatches in up to 3 sequences and two in many sequences. CONCLUSION: These results should be taken into consideration when using PCR-based diagnostics in Brazil.

Effect of encephalomyocarditis virus 3'Untranslated region on GFP transient expression: implications in recombinant protein production / Efecto de la Región 3'-no traducida del virus de la encefalomiocarditis sobre la expresión transitoria de GFP: implicaciones en la producción de proteínas recombinantes

The enrichment of therapeutic protein production yield in mammalian cell cultures by modulating mRNA stability is a fairly new strategy in biotechnological applications. Here, we describe the application of 3'-untranslated region (3'UTR) from RNA viral genome to modulate mRNA stability.The data obtained showed that the use of the 3 'UTR sequence of the encephalomyocarditis virus (EMCV 3'UTR) downstream of the target gene was not able to significantly modulate the free energy density indicators of the RNA. However, the sequence influenced the stability of the mRNA (and, therefore, the amount of protein production) in a cell type and time-dependent manner, indicating a central role of mRNA-stabilizing binding sites/cellular factors in this process. Our data might be of interest for the biotechnology community to improve recombinant protein production in mammalian cell cultures and RNA-based therapy/vaccination approaches.

El enriquecimiento de la producción terapéutica de proteínas en cultivos de células de mamíferos mediante la modulación de la estabilidad del ARNm es una estrategia nueva en aplicaciones biotecnológicas. Se describe la aplicación de la región 3'-no traducida (3'UTR) del genoma viral ARN para modular la estabilidad del ARNm. Los datos obtenidos mostraron que el uso de la secuencia 3'UTR del virus de la encefalomiocarditis (EMCV 3'UTR) aguas abajo del gen objetivo no pudo modular significativamente los indicadores de densidad de energía libre del ARN. Sin embargo, la secuencia influyó en la estabilidad del ARNm (y, por lo tanto, en la cantidad de producción de proteínas) dependiente de la célula y del tiempo, lo que indica un papel central de los sitios de unión estabilizadores de ARNm/factores celulares en este proceso. Nuestros datos podrían ser de interés para la comunidad biotecnológica para mejorar la producción de proteínas recombinantes en cultivos de células de mamíferos y en enfoques de terapia/vacunación basados en ARN.

Description of a human Bocavirus recombinant strain in the Americas

Human bocaviruses (HBoV) are mainly associated with respiratory and gastroenteric infections. These viruses belong to the family Parvoviridae, genus Bocaparvovirus and are classified in four subtypes (HBoV1-4). Recombination and point mutation have been described as basis of parvovirus evolution. In this study three viral sequences were obtained from positives HBoV sewage samples collected in two Uruguayan cities and were characterised by different methods as recombinant strains. This recombination event was localised in the 5' end of VP1 gene and the parental strains belonged to subtypes 3 and 4. These three Uruguayan strains are identical at the nucleotide sequences in the analysed genome region of the virus. As far as we known, this study represents the first detection of HBoV recombinants strains in the Americas.

Molecular characterization of feline calicivirus variants from multicat household and public animal shelter in Rio de Janeiro, Brazil

ABSTRACT The aim of this study was to perform the molecular characterization of conserved and variable regions of feline calicivirus capsid genome in order to investigate the molecular diversity of variants in Brazilian cat population. Twenty-six conjunctival samples from cats living in five public short-term animal shelters and three multicat life-long households were analyzed. Fifteen cats had conjunctivitis, three had oral ulceration, eight had respiratory signs (cough, sneeze and nasal discharge) and nine were asymptomatic. Feline calicivirus were isolated in CRFK cells and characterized by reverse transcription PCR target to both conserved and variable regions of open reading frame 2. The amplicons obtained were sequenced. A phylogenetic analysis along with most of the prototypes available in GenBank database and an amino acid analysis were performed. Phylogenetic analysis based on both conserved and variable region revealed two clusters with an aLTR value of 1.00 and 0.98 respectively and the variants from this study belong to feline calicivirus genogroup I. No association between geographical distribution and/or clinical signs and clustering in phylogenetic tree was observed. The variants circulating in public short-term animal shelter demonstrated a high variability because of the relatively rapid turnover of carrier cats constantly introduced of multiple viruses into this location over time.

Optimización de una técnica de PCR convencional para detección de virus de papiloma humano tipo 16 y 18 / Optimization of a conventional PCR technique for detection of human papillomavirus type 16 and 18

El cáncer de cuello uterino es el segundo cáncer femenino más común a nivel mundial. El agente causal es el virus de papiloma humano (VPH). Se han identificado 13 tipos de virus de papiloma humano de alto riesgo oncogénico (VPH-AR), entre los cuales el VPH 16 y VPH 18 son los más frecuentemente detectados en cáncer de cuello uterino, siendo en Paraguay detectados en el 70% de casos de cáncer invasor. Por ello, el objetivo fue estandarizar y determinar el límite de detección de una técnica de PCR convencional para la detección de VPH 16 y 18. Para la detección de ADN de VPH 16 y 18, se observaron mejores resultados con 2mM de MgCl2 y 60°C para la temperatura de alineamiento. El límite de detección para las PCR fue de 14,6x10-11ng/µL para VPH 16 y 21,7x10-12ng/µL para VPH 18. Este trabajo servirá de base a otros estudios de detección e identificación de estos tipos virales por PCR, con miras a identificar un grupo de mujeres positivas para VPH-AR que poseen mayor riesgo de desarrollo de lesión y cáncer de cuello uterino y precisan de un seguimiento más cercano(AU

Cervical cancer is the second most common female cancer worldwide. It is caused by the human papilloma virus (HPV). Thirteen genotypes of high oncogenic risk human papilloma viruses (HPV-HR) have been identified, among which types 16 and 18 are the most frequently detected in cervical cancer. In Paraguay, they are detected in 70% of the invasive cancer cases. Therefore, the objective was to standardize and determine the detection limit of a conventional PCR technique for the detection of HPV 16 and 18. Better results were observed with 2mM MgCl2 and 60°C for the alignment temperature in detection of HPV 16 and 18 DNA. The limit of detection was 14.6x10-11ng/µL for HPV 16 and 21.7x10-12ng/µL for HPV 18. This work will help other studies for the detection and identification of these viral types by PCR in order to identify a group of HPV-HR positive women who have higher risk for the development of lesions and cervical cancer and need a closer follow-up(AU)