RESUMO
An unprecedented global health crisis has been caused by a new virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We performed experiments to test if a hypertonic saline solution was capable of inhibiting virus replication. Our data show that 1.2% NaCl inhibited virus replication by 90%, achieving 100% of inhibition at 1.5% in the nonhuman primate kidney cell line Vero, and 1.1% of NaCl was sufficient to inhibit the virus replication by 88% in human epithelial lung cell line Calu-3. Furthermore, our results indicate that the inhibition is due to an intracellular mechanism and not to the dissociation of the spike SARS-CoV-2 protein and its human receptor. NaCl depolarizes the plasma membrane causing a low energy state (high ADP/ATP concentration ratio) without impairing mitochondrial function, supposedly associated with the inhibition of the SARS-CoV-2 life cycle. Membrane depolarization and intracellular energy deprivation are possible mechanisms by which the hypertonic saline solution efficiently prevents virus replication in vitro assays.
RESUMO
We followed the presence of Zika virus (ZIKV) in four healthy adults (two men and two women), for periods ranging from 78 to 298 days post symptom onset. The patients were evaluated regarding the presence of the virus in different body fluids (blood, saliva, urine and semen), development of immune responses (including antibodies, cytokines and chemokines), and virus genetic variation within samples collected from semen and urine during the infection course. The analysis was focused primarily on the two male patients who shed the virus for up to 158 days after the initial symptoms. ZIKV particles were detected in the spermatozoa cytoplasm and flagella, in immature sperm cells and could also be isolated from semen in cell culture, confirming that the virus is able to preserve integrity and infectivity during replication in the male reproductive system (MRS). Despite the damage caused by ZIKV infection within the MRS, our data showed that ZIKV infection did not result in infertility at least in one of the male patients. This patient was able to conceive a child after the infection. We also detected alterations in the male genital cytokine milieu, which could play an important role in the replication and transmission of the virus which could considerably increase the risk of ZIKV sexual spread. In addition, full genome ZIKV sequences were obtained from several samples (mainly semen), which allowed us to monitor the evolution of the virus within a patient during the infection course. We observed genetic changes over time in consensus sequences and lower frequency intra-host single nucleotide variants (iSNV), that suggested independent compartmentalization of ZIKV populations in the reproductive and urinary systems. Altogether, the present observations confirm the risks associated with the long-term replication and shedding of ZIKV in the MRS and help to elucidate patterns of intra-host genetic evolution during long term replication of the virus
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Interações Hospedeiro-Patógeno , Zika virusRESUMO
Abstract Objective: Characterize the role of human parainfluenza virus and its clinical features in Brazilian children under 2 years of age presenting with acute lower respiratory tract infections. Methods: Real-time assays were used to identify strains of human parainfluenza virus and other common respiratory viruses in nasopharyngeal aspirates. One thousand and two children presenting with acute lower respiratory tract illnesses were enrolled from February 2008 to August 2010. Results: One hundred and four (10.4%) patients were human parainfluenza virus positive, of whom 60 (57.7%) were positive for human parainfluenza virus-3, 30 (28.8%) for human parainfluenza virus-4, 12 (11.5%) for human parainfluenza virus-1, and two (1.9%) for human parainfluenza virus-2. Seven (6.7%) patients had more than one strain of human parainfluenza virus detected. The most frequent symptoms were tachypnea and cough, similar to other viral respiratory infections. Clinical manifestations did not differ significantly between human parainfluenza virus-1, -2, -3, and -4 infections. Human parainfluenza virus-1, -3, and -4 were present in the population studied throughout the three years of surveillance, with human parainfluenza virus-3 being the predominant type identified in the first two years. Conclusion: Human parainfluenza viruses contribute substantially to pediatric acute respiratory illness (ARI) in Brazil, with nearly 30% of this contribution attributable to human parainfluenza virus-4.
Resumo Objetivo: Caracterizar o papel do VPH-4 e suas características clínicas em crianças brasileiras com menos de dois anos de idade com infecções agudas do trato respiratório inferior. Métodos: Ensaios em tempo real foram utilizados para identificar tipos de VPH e outros vírus respiratórios comuns em aspirados nasofaríngeos. Mil e duas crianças com doença aguda do trato respiratório inferior foram inscritas para participar de fevereiro de 2008 a agosto de 2010. Resultados: 104 (10,4%) pacientes eram VPH positivos, dos quais 60 (57,7%) eram positivos para VPH-3, 30 (28,8%) para VPH-4, 12 (11,5%) para VPH-1 e dois (1,9%) para VPH-2. Sete (6,7%) pacientes apresentaram mais de um tipo de VPH detectado. Os sintomas mais frequentes foram tosse e taquipneia, semelhantes a outras infecções respiratórias virais. As manifestações clínicas não diferiram de forma significativa entre as infecções por VPH-1, -2, -3 e -4. Os VPH-1, -3 e -4 estavam presentes na população estudada ao longo dos três anos de vigilância, e o VPH-3 foi o tipo predominante identificado nos primeiros dois anos. Conclusão: Os VPHs contribuem substancialmente para a DRA pediátrica no Brasil com quase 30% dessa contribuição atribuível ao VPH-4.
Assuntos
Humanos , Recém-Nascido , Lactente , Pré-Escolar , Infecções Respiratórias/virologia , Vírus da Parainfluenza 4 Humana/genética , Estações do Ano , Nasofaringe/virologia , Vigilância da População , Doença Aguda , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vírus da Parainfluenza 4 Humana/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo RealRESUMO
OBJECTIVE: To characterize and compare clinical, epidemiological, and laboratory aspects ofinfants with acute lower respiratory infection (ALRI) associated with the detection of adenovirus(ADV) or respiratory syncytial virus (RSV). METHODS: A preliminary respiratory infection surveillance study collected samples of nasopharyngeal aspirate (NPA) for viral research, linked to the completion of a standard protocol, from children younger than two years admitted to a university hospital with ALRI, between March of 2008 and August of 2011. Polymerase chain reaction (PCR) was used for eight viruses: ADV, RSV, metapneumovirus, Parainfluenza 1, 2, and 3, and Influenza A and B. Cases with NPA collectedduring the first 24 hours of admission, negative results of blood culture, and exclusive detection of ADV (Gadv group) or RSV (Grsv group) were selected for comparisons. RESULTS: The preliminary study included collection of 1,121 samples of NPA, 813 collected in thefirst 24 hours of admission, of which 50.3% were positive for at least one virus; RSV was identifiedin 27.3% of cases surveyed, and ADV was identified in 15.8%. Among the aspects analyzed inthe Gadv (n = 58) and Grsv (n = 134) groups, the following are noteworthy: the higher meanage, more frequent prescription of antibiotics, and the highest median of total white blood cellcount and C-reactive protein values in Gadv. CONCLUSIONS: PCR can detect persistent/latent forms of ADV, an aspect to be considered wheninterpreting results. Additional studies with quantitative diagnostic techniques could elucidatethe importance of the high frequency observed. .
OBJETIVO: Caracterizar e comparar aspectos clínicos, epidemiológicos e laboratoriais delactentes com evidências de infecção aguda do trato respiratório inferior (IATRI) associada à detecção do adenovírus (ADV) ou do vírus sincicial respiratório (VSR). MÉTODOS: Um estudo preliminar de vigilância de infecções respiratórias desenvolveu coleta de aspirado nasofaríngeo (ANF) para pesquisa viral, vinculada ao preenchimento de protocolo padrão, de menores de dois anos internados com quadro de IATRI em hospital universitário, entre março de 2008 e agosto de 2011. Utilizou-se técnica da reação em cadeia da polimerase (PCR) para oito vírus: ADV, VSR, metapneumovírus, parainfluenza 1, 2 e 3 e influenza A e B. Foram selecionados para comparações os casos com ANF coletado nas primeiras 24 horas da admissão, resultado de hemocultura negativo e detecção exclusiva de ADV (grupo Gadv) ou VSR (grupo Gvsr). RESULTADOS: O estudo preliminar incluiu coleta de 1.121 amostras de ANF, sendo 813 coletadas nas primeiras 24 h da admissão, das quais 50,3% foram positivas para ao menos um dos vírus, com VSR em primeiro lugar, em 27,3%, e ADV em segundo, em 15,8% dos casos pesquisados. Dentre os aspectos analisados nos grupos Gadv (n = 58) e Gvsr (n = 134), destacaram-se a média da idade mais elevada, maior frequência da prescrição de antibióticos e medianas mais elevadas para contagem total de leucócitos e valores da proteína C-reativa no Gadv. CONCLUSÕES: A PCR utilizada pode detectar formas persistentes/latentes de ADV, aspecto aser considerado ao interpretar os resultados. Estudos complementares com técnicas diagnósticas quantitativas, por exemplo, poderiam evidenciar a importância da elevada frequência verificada. .