RESUMO
Hantavirus (Family Bunyaviridae) are mostly associated to rodents and transmitted to man by inhalation of aerosolized infected excreta of these animals. The human infection by hantaviruses can lead to severe diseases such as hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe, and pulmonary syndrome (HPS) in the Americas. To determine the origin, spreading and evolutionary dynamics of rodent-borne hantaviruses, 190 sequences of nucleoprotein (N) of hantaviruses identified in 30 countries, from 1985 to 2010, were retrieved from the GenBank and analyzed using the BEAST program. Our evolutionary analysis indicates that current genetic diversity of N gene of rodent-borne hantaviruses probably was originated around 2000 years ago. Hantavirus harbored by Murinae and Arvicolinae subfamilies, probably, were originated in Asia 500-700 years ago and later spread toward Siberia, Europe, Africa and North America. Hantavirus carried by Neotominae subfamily, probably, emerged 500-600 years ago in Central America and spread toward North America. Finally, hantaviruses associated to Sigmodontinae occurred in Brazil 400 years ago and were, probably, originated from Neotominae-associated virus from northern South America. These data offer subsidies to understand the time-scale and worldwide dissemination dynamics of rodent-borne hantaviruses.
Assuntos
Nucleoproteínas/genética , Orthohantavírus/classificação , Orthohantavírus/genética , Roedores/virologia , Proteínas Virais/genética , Animais , Teorema de Bayes , Brasil , Evolução Molecular , Variação Genética , Humanos , Taxa de Mutação , Filogenia , FilogeografiaRESUMO
Hantavirus cardiopulmonary syndrome (HCPS) has been recognized as an important public heath problem. Five hantaviruses associated with HCPS are currently known in Brazil: Juquitiba, Araraquara, Laguna Negra-like, Castelo dos Sonhos, and Anajatuba viruses. The laboratory diagnosis of HCPS is routinely carried out by the detection of anti-hantavirus IgM and/or IgG antibodies. The present study describes the expression of the N protein of a hantavirus detected in the blood sample of an HCPS patient. The entire S segment of the virus was amplified and found to be 1858 nucleotides long, with an open reading frame of 1287 nucleotides that encodes a protein of 429 amino acids. The nucleotide sequence described here showed a high identity with the N protein gene of Araraquara virus. The entire N protein was expressed using the vector pET200D and the Escherichia coli BL21 strain. The expression of the recombinant protein was confirmed by the detection of a 52-kDa protein by Western blot using a pool of human sera obtained from HCPS patients, and by specific IgG detection in five serum samples of HCPS patients tested by ELISA. These results suggest that the recombinant N protein could be used as an antigen for the serological screening of hantavirus infection.
Assuntos
Antígenos Virais , Síndrome Pulmonar por Hantavirus/diagnóstico , Proteínas do Nucleocapsídeo , Orthohantavírus/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Ensaio de Imunoadsorção Enzimática , Escherichia coli , Vetores Genéticos , Humanos , Imunoglobulina G/imunologia , Proteínas do Nucleocapsídeo/genética , Proteínas do Nucleocapsídeo/imunologia , Proteínas do Core Viral/imunologiaRESUMO
Sera from 269 rodents obtained during the routine surveillance operations in plague areas of Rio de Janeiro and Pernambuco states, Brazil were tested by ELISA for specific IgG antibodies against a recombinant nucleocapsid (N) protein of Araraquara hantavirus. ELISA-positive sera were submitted to reverse transcriptase-polymerase chain reaction (RT-PCR) for amplification of the virus genome and later sequencing for identification of the viral variant. The samples from the state of Pernambuco were antibody negative, and although four from Rio de Janeiro were ELISA-positive, they failed to yield viral cDNA by RT-PCR. This is the first report of the presence of antibodies to a hantavirus among rodents from Rio de Janeiro and suggests the possibility of human cases of hantavirus pulmonary syndrome (HPS) in that state, although no case has yet been reported.
Assuntos
Animais Selvagens/virologia , Anticorpos Antivirais/sangue , Infecções por Hantavirus/veterinária , Orthohantavírus/imunologia , Doenças dos Roedores/epidemiologia , Sigmodontinae/virologia , Animais , Animais Selvagens/classificação , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Orthohantavírus/classificação , Orthohantavírus/genética , Orthohantavírus/isolamento & purificação , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/virologia , Imunoglobulina G/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Doenças dos Roedores/virologia , Sigmodontinae/classificaçãoRESUMO
Hantavirus cardiopulmonary syndrome (HCPS) has been recognized as an important public heath problem. Five hantaviruses associated with HCPS are currently known in Brazil: Juquitiba, Araraquara, Laguna Negra-like, Castelo dos Sonhos, and Anajatuba viruses. The laboratory diagnosis of HCPS is routinely carried out by the detection of anti-hantavirus IgM and/or IgG antibodies. The present study describes the expression of the N protein of a hantavirus detected in the blood sample of an HCPS patient. The entire S segment of the virus was amplified and found to be 1858 nucleotides long, with an open reading frame of 1287 nucleotides that encodes a protein of 429 amino acids. The nucleotide sequence described here showed a high identity with the N protein gene of Araraquara virus. The entire N protein was expressed using the vector pET200D and the Escherichia coli BL21 strain. The expression of the recombinant protein was confirmed by the detection of a 52-kDa protein by Western blot using a pool of human sera obtained from HCPS patients, and by specific IgG detection in five serum samples of HCPS patients tested by ELISA. These results suggest that the recombinant N protein could be used as an antigen for the serological screening of hantavirus infection.
Assuntos
Humanos , Antígenos Virais , Síndrome Pulmonar por Hantavirus/diagnóstico , Orthohantavírus/imunologia , Proteínas do Nucleocapsídeo , Antígenos Virais/genética , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Ensaio de Imunoadsorção Enzimática , Escherichia coli , Vetores Genéticos , Imunoglobulina G/imunologia , Proteínas do Nucleocapsídeo/genética , Proteínas do Nucleocapsídeo/imunologia , Proteínas do Core Viral/imunologiaRESUMO
Scanning and transmission electron microscopy were used to analyse the ultrastructure of peritoneal mouse macrophage cells infected with Brazilian flavivirus (yellow fever, Rocio, Bussuquara and Saint Louis encephalitis viruses). Macrophage cells collected 3 days after viral infection had a flattened shape, with an increased number of large spikes of cytoplasm prolongations, giving an appearance of hairy cells. Cytopathological changes to the macrophage cells were similar regardless of the infecting flavivirus. Rough and smooth endoplasmic reticulum of the macrophage cells infected with flavivirus were abundant, hypertrophic and enlarged. A large number of free ribosomes were seen in the cytoplasm of these infected cells. Spherical particles approximately 50-70 nm in diameter, some of which were empty, were observed in the cytoplasm, generally inside vesicles. These particles probably correspond to viral particles.
Assuntos
Infecções por Flavivirus/virologia , Flavivirus/isolamento & purificação , Macrófagos Peritoneais/virologia , Animais , Brasil , Efeito Citopatogênico Viral , Retículo Endoplasmático/ultraestrutura , Flavivirus/fisiologia , Infecções por Flavivirus/sangue , Infecções por Flavivirus/patologia , Macrófagos Peritoneais/ultraestrutura , Camundongos , Microscopia Eletrônica , Ribossomos/ultraestruturaRESUMO
We described here the complete nucleotide sequence of the L RNA segment of Oropouche virus (genus Orthobunyavirus, family Bunyaviridae). We found the L RNA segment is 6846 nucleotides long and encodes a putative RNA polymerase of 2250 amino acids. Phylogenetic analysis showed that ORO virus cluster to the Orthobunyavirus genus confirming the serological classification. It also showed that Bunyamwera and California viruses, from the Orthobunyavirus genus, are more closely related to each other than to ORO virus. Sequence comparisons performed between the L proteins of 15 bunyaviruses and the PB1 proteins of 3 influenza viruses revealed that ORO L protein contains the 3 regions characteristic of arenaviruses and bunyaviruses. These comparisons also showed the existence of an additional fourth conserved region in the L protein of bunyaviruses that contains at least two active sites.
Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , RNA Viral/química , Proteínas Virais/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Sequência de Bases , Sequência Conservada , RNA Polimerases Dirigidas por DNA/genética , Vírus da Encefalite da Califórnia/química , Vírus da Encefalite da Califórnia/genética , Genoma Viral , Vírus La Crosse/química , Vírus La Crosse/genética , Dados de Sequência Molecular , Fases de Leitura Aberta , Orthomyxoviridae/química , Orthomyxoviridae/genética , Filogenia , RNA Viral/classificação , RNA Viral/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Proteínas Virais/classificação , Proteínas Virais/genéticaRESUMO
Thirty one infective endocarditis (IE) fatal cases whose diagnosis was first obtained at autopsy were studied. The clinical data of these patients (Group 1) showed significant differences compared to other 141 IE cases (Group 2). The average age of 53 years in Group 1 patients was 18 years higher than that of Group 2. The Group 1 patients had a low frequency of IE predisposing heart disease. Both patient groups presented fever (about 87%), but a significant low frequency of cardiac murmur (25.8%) was observed in Group 1 patients and echocardiography tests were performed in only 16.1%, suggesting that IE diagnosis was not suspected. Likewise, although most Group 1 patients appeared with severe acute illness, they did not present the classic IE clinical presentation. Blood cultures were performed in only 64.5% of the Group 1 patients. However, bacteria were isolated in 70% of these blood cultures and Staphylococcus aureus was isolated in 71.4%. The bacteria attacked mitral and aortic valves. Complications such as embolizations and cardiac failure occurred in almost half of the cases and they also presented with infections of the lungs, urinary tract, and central nervous system. Medical procedures were performed in practically all fatal cases whose diagnosis was first obtained at autopsy. Sepsis occurred in about half of the patients and it was followed by shock in more than 25%. This form of IE must be suspected in mature and in old febrile hospitalized patients having infection predisposing diseases, embolization, and suffering medical procedures.
Assuntos
Endocardite Bacteriana/diagnóstico , Adulto , Autopsia , Brasil/epidemiologia , Distribuição de Qui-Quadrado , Intervalos de Confiança , Endocardite Bacteriana/mortalidade , Endocardite Bacteriana/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The frequency and severity of infections caused by respiratory syncytial virus (RSV) were assessed in children <2 years of age seen at the emergency department. The frequency of RSV detection in the clinical virology laboratory during the past 3 years was also analyzed retrospectively. RSV was found in 21.6% (188/869) of the samples collected from children seen at the emergency department and was found to be more frequent during the autumn, being less frequent or negligible by midwinter. RSV subgroups A and B co-circulated within the same time period in children seen at the emergency department, with varying predominance of either subgroup. There was no significant association of RSV subgroup with disease severity, but only a trend for RSV subgroup B being more frequent in children with risk factors for severe disease.
Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sinciciais Respiratórios/isolamento & purificação , Doença Aguda , Adolescente , Brasil/epidemiologia , Criança , Pré-Escolar , Hospitais Pediátricos , Hospitais Universitários , Hospitais Urbanos , Humanos , Lactente , Estudos Prospectivos , Estudos Retrospectivos , Estações do AnoRESUMO
A rapid test for the diagnosis of congenital CMV infection is still needed. This study evaluated the usefulness of dried blood and urine samples collected on filter paper for detecting cytomegalovirus (CMV) by the polymerase chain reaction (PCR) assay compared with the use of liquid urine. Samples were obtained from 332 infants aged 1-7 days. Liquid urine samples were collected into bags, cultured in human fibroblasts, and processed using a multiplex PCR technique. Dried urine samples were obtained by placing a piece of filter paper in contact with the infant's genitals. The heels of neonates were punctured and capillary blood was blotted onto filter paper and dried. Dried blood and urine specimens were analyzed by multiplex PCR and nested-PCR assays. A diagnosis of congenital CMV infection was established by isolating the virus, and by detecting viral DNA in the liquid urine. Of the 332 liquid urine samples collected from 332 neonates, seven (2.1%) were positive for CMV and 325 were negative, by both cell culture and PCR assay. In dried samples, CMV DNA was detectable only with a nested PCR assay. Compared with known CMV infection status, 5/7 (71.4%) neonates were positive for congenital CMV infection using dried blood samples. All 325 uninfected neonates were negative. In the dried urine samples, 4/4 CMV-infected infants gave positive tests, and all 262 uninfected infants were negative. Although further improvements in sample collection and/or processing are still needed, PCR testing on dried urine or blood collected on filter paper is a promising approach in the diagnosis of neonatal CMV infection.
Assuntos
Coleta de Amostras Sanguíneas/métodos , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/urina , Citomegalovirus/isolamento & purificação , Filtros Microporos/virologia , Linhagem Celular Transformada , Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , DNA Viral/análise , DNA Viral/genética , Filtração , Humanos , Lactente , Reação em Cadeia da Polimerase , Sensibilidade e EspecificidadeRESUMO
The Hantavirus pulmonary and cardiovascular syndrome (HPCVS) is an emerging disease in Brazil. In this study, eight confirmed cases of HPCVS were studied. All the patients presented fever and dyspnea as well as thrombocytopenia and hypoxemia. Tachycardia, malaise, hypotension and lung rales occurred in 75 to 87.5% of the cases. Hemoconcentration, blood cell count increased and immature neutrophils, and high levels of creatinine were observed in 75 to 87.5%. Intravenous liquid infusion, the use of drugs for increasing systemic vascular resistance and inotropism, and mechanic ventilation were used for the patients. Mechanical ventilation and volume administration should be started precociously, preferable in intensive care units employing recommended universal and respiratory precautions. Careful volume administration should be limited if signs of pulmonary edema develop. Mortality (50%) is high and probably related to the severity of the disease as well as to a delayed attending of the patients for intensive management. It is important to report hantaviruses and HPCVS to the Brazilian medical community considering that many cases could be undiagnosed.