RESUMEN
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.
Asunto(s)
Nucleoproteínas/genética , Orthohantavirus/clasificación , Orthohantavirus/genética , Roedores/virología , Proteínas Virales/genética , Animales , Teorema de Bayes , Brasil , Evolución Molecular , Variación Genética , Humanos , Tasa de Mutación , Filogenia , FilogeografíaRESUMEN
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.
Asunto(s)
Antígenos Virales , Síndrome Pulmonar por Hantavirus/diagnóstico , Proteínas de la Nucleocápside , Orthohantavirus/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , Proteínas de la Cápside/inmunología , Ensayo de Inmunoadsorción Enzimática , Escherichia coli , Vectores Genéticos , Humanos , Inmunoglobulina G/inmunología , Proteínas de la Nucleocápside/genética , Proteínas de la Nucleocápside/inmunología , Proteínas del Núcleo Viral/inmunologíaRESUMEN
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.
Asunto(s)
Animales Salvajes/virología , Anticuerpos Antivirales/sangre , Infecciones por Hantavirus/veterinaria , Orthohantavirus/inmunología , Enfermedades de los Roedores/epidemiología , Sigmodontinae/virología , Animales , Animales Salvajes/clasificación , Brasil/epidemiología , Ensayo de Inmunoadsorción Enzimática , Orthohantavirus/clasificación , Orthohantavirus/genética , Orthohantavirus/aislamiento & purificación , Infecciones por Hantavirus/epidemiología , Infecciones por Hantavirus/virología , Inmunoglobulina G/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Enfermedades de los Roedores/virología , Sigmodontinae/clasificaciónRESUMEN
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.
Asunto(s)
Humanos , Antígenos Virales , Síndrome Pulmonar por Hantavirus/diagnóstico , Orthohantavirus/inmunología , Proteínas de la Nucleocápside , Antígenos Virales/genética , Antígenos Virales/inmunología , Proteínas de la Cápside/inmunología , Ensayo de Inmunoadsorción Enzimática , Escherichia coli , Vectores Genéticos , Inmunoglobulina G/inmunología , Proteínas de la Nucleocápside/genética , Proteínas de la Nucleocápside/inmunología , Proteínas del Núcleo Viral/inmunologíaRESUMEN
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.
Asunto(s)
Infecciones por Flavivirus/virología , Flavivirus/aislamiento & purificación , Macrófagos Peritoneales/virología , Animales , Brasil , Efecto Citopatogénico Viral , Retículo Endoplásmico/ultraestructura , Flavivirus/fisiología , Infecciones por Flavivirus/sangre , Infecciones por Flavivirus/patología , Macrófagos Peritoneales/ultraestructura , Ratones , Microscopía Electrónica , Ribosomas/ultraestructuraRESUMEN
A prospective study of cytomegalovirus (CMV) infection was carried out on 34 renal transplant recipients managed at a General Hospital in Ribeirão Preto, SP, Brazil. Serologic tests showed that all patients were infected with CMV before renal transplantation. Two nested-PCR techniques with primers that recognize sequences of the glycoprotein B (gB) and H (gH) genes were used for CMV detection in blood and urine samples during the post-transplantation period. CMV was detected more frequently in blood samples than in urine samples (P<0.001). Thirty-three patients had CMV detected at least once in blood and/or urine samples. Seven of these patients (21.2 percent) were diagnosed as having symptomatic CMV infection and showed a worse clinical outcome, with a higher death rate (P = 0.03). No association between CMV viremia and graft rejection was observed. Nested-PCR was not useful to identify patients at risk for symptomatic CMV infection since only 21.2 percent of the patients with CMV infection were symptomatic
Asunto(s)
Humanos , Infecciones por Citomegalovirus/diagnóstico , Trasplante de Riñón , Reacción en Cadena de la Polimerasa/métodos , Secuencia de Bases , Infecciones por Citomegalovirus/sangre , Infecciones por Citomegalovirus/orina , Cartilla de ADN , Inmunoglobulina G/aislamiento & purificación , Inmunoglobulina M/aislamiento & purificación , Estudios Prospectivos , Proteínas del Envoltorio Viral/genéticaRESUMEN
Cytomegalovirus (CMV) is the single most important infectious agent affecting recipients of organ transplants. To evaluate the incidence and the clinical importance of CMV infection in renal transplants in Brazil, 37 patients submitted to renal allograft transplants were tested periodically for the presence of cytomegalovirus DNA in urine using the polymerase chain reaction (PCR), and for the presence of IgM and IgG antibodies against CMV by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF). The PCR-amplified products were detected by gel electrophoresis and confirmed by dot-blot hybridization with oligonucleotide probes. Thirty-two of the 37 patients (86.4 percent) were positive by at least one of the three methods. In six patients, PCR was the only test which detected the probable CMV infection. Ten patients had a positive result by PCR before transplantation. In general, the diagnosis was achieved earlier by PCR than by serologic tests. Active infection occurred more frequently during the first four months after transplantation. Sixteen of the 32 patients (50 percent) with active CMV infection presented clinical symptoms consistent with CMV infection. Five patients without evidence of active CMV infection by the three tests had only minor clinical manifestations during follow-up. Our results indicate that PCR is a highly sensitive procedure for the early detection of CMV infection and that CMV infection in renal transplant patients is a frequent problem in Brazil
Asunto(s)
Humanos , Infecciones por Citomegalovirus/diagnóstico , Infecciones por Citomegalovirus/epidemiología , Citomegalovirus/aislamiento & purificación , Trasplante de Riñón , Reacción en Cadena de la Polimerasa , Complicaciones Posoperatorias , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/virología , Ensayo de Inmunoadsorción Enzimática , Incidencia , Prevalencia , Estudios Prospectivos , Pruebas SerológicasRESUMEN
Two patients receiving the same cadaver kidney graft were investigated prospectively for cytomegalovirus (CMV) infection using the polymerase chain reaction (PCR) and serologic tests (ELISA and IFI). The data indicate that a strain of CMV was probably transmitted from the same donor to both kidney recipients including one who was seropositive for CMV