Navegando por Assunto "Virologia"

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Acesso aberto (Open Access)
Análise crítica dos achados hematológicos e sorológicos de pacientes com suspeita de Dengue
(2008-10) BARROS, Lilian Patrícia Souza; IGAWA, Sônia E. S.; JOCUNDO, Susana Y.; BRITO JUNIOR, Lacy Cardoso de
The increase in the number of more serious forms of dengue fever among cases in the city of Belém, Brazil has astounded local authorities. The objective of this study was to conduct a critical analysis of hematologic and serologic findings of patients with clinical suspicion of dengue seen at a clinical laboratory in Belém in Pará State. This retrospective study involved 210 patients who were referred to the Laboratory of Clinical Pathology Dr. Paulo C. Azevedo in Belém, in the period of February and March of 2007, with requests for a complete blood count and serological test for IgM to confirm the diagnosis of dengue. Of the cases studied, 51/210 (24.3%) presented with thrombocytopenia and 53/210 (25.2%) leukopenia. The serologic test for IgM was positive in 47.1% (99/210) of cases. A statistically significant association (p<0.05) was observed only among patients who presented with thrombocytopenia (33/99) and positive serology for dengue, suggesting that the hematological alterations of leukopenia and thrombocytopenia, frequently associated with this illness, may not be present at the beginning of the infection. It is therefore essential to carry out a serologic test for IgM to confirm a diagnosis of dengue.
Acesso aberto (Open Access)
Caracterização genotípica do Vírus Varicela-Zoster em casos de varicela e Herpes zoster em Belém-Pará, Brasil
(Universidade Federal do Pará, 2013) COSTA, Marcos Rogério Menezes da; MONTEIRO, Talita Antônia Furtado; http://lattes.cnpq.br/4592027736583434; SOUSA, Rita Catarina Medeiros; http://lattes.cnpq.br/3560941703812539
Varicella zoster virus (VZV) can cause chickenpox during primary infection, subsequently establishing a latent infection. In case of reactivation of the virus, the herpes zoster may occur. Analysis of the presence of IgG and IgM is critical to determine the prevalence of this virus in the Metropolitan Region of Belém. The study of specific nucleotide polymorphisms is used to define the genotypes of VZV. Analysis of ORFs 22, 38 and 54 identified genotypes of VZV according to the classification established in conference July 25, 2008 in Whitechapel, London / UK, where the strains of VZV detected and characterized by sequencing of SNPs were grouped into classes 1 through 5. To evaluate the prevalence of antibodies and describe the circulating genotypes was the aim of this study. The frequency of IgM and IgG antibodies in cases of chickenpox was 68.2% and 48.2%, respectively. Cases of herpes zoster showed prevalence of anti-VZV IgG and IgM of 87.5% and 12.5%, respectively. The genotypes 1 or 3 and 5 were present in 13 samples sequenced, and the European strain (class 1 or 3) was found in samples from all the cities studied. The identification of strains circulating VZV is extremely important because of the association of specific genotypes with clinical harshest and to assess the implementation of the vaccine in the National Immunization Program.
Acesso aberto (Open Access)
Caracterização molecular dos vírus do grupo Gamboa (Bunyaviridae, Orthobunyavirus) isolados nas américas e infecção experimental em pintos (Gallus gallus domesticus) com o vírus Gamboa cepa Be AN 439546
(Universidade Federal do Pará, 2010-03-31) CHIANG, Jannifer Oliveira; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564
Presently, little information on Gamboa serogroup viruses (Bunyaviridae, Orthobunyavirus) is available. Thus, in this work, it was performed a comparative phylogenetic study on the members of the Gamboa serogroup and with other orthobunyaviruses to the level of the gene Gn (M-RNA); an experimental infections in the domestic bird (Gallus domesticus) using the strain Be AN 439546 of the Gamboa Virus (GAMV); and a serologic study using the Hemagglutination Inhibition (HI) test in serum samples of wild animals and humans collected in Tucuruí - Pará. The phylogenetic analysis of Gamboa group viruses demonstrated that they are genetically closely related to group Turlock viruses and less related to the Simbu group viruses. The group Gamboa viruses were distributed in two clades (I and II), that it is in agreement with the current serologic classification; the clade I correspond to the Gamboa complex and the clade II to the Alajuela complex. The strain Be AN 439546 presented tropism for chikens lung and liver, with viral replication in this organs confirmed by detection of viral antigens by immunohistochemistry. These results, demonstrate that this bird species is a susceptible host for GAMV replication. The detection of HI antibodies against GAMV, confirmed by neutralization tests were found in wild bird plasmas and reinforces the hypothesis that these animals constitute the main amplification hosts in the maintenance cycle of GAMV. Full length genome studies of the Gamboa serogroup viruses, as well as on the ecoepidemiology of their vectors and potential vertebrate hosts are needed to generate new data and to reinforce the understanding of the information already existent on those viruses.
Acesso aberto (Open Access)
Caracterização morfológica e antigênica do vírus Juruaçá, isolado de morcego no estado do Pará
(Universidade Federal do Pará, 2006) ARAÚJO, Tais Pinheiro de; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564
Juruaçá virus (BE AN 401933) was isolated from pooled organs of an unidentified bat captured during field work in Porto Trombetas, Oriximiná, Pará State, in 1982, and remains unclassified/ungrouped. The aims of this work were to classify Juruaçá virus in a viral taxon taking in account its morphological, physicochemical, antigenic and molecular properties, as well as, to describe the pathological alterations. This agent is pathogenic only for infant mice, and the animal’s death occurs with eight days post-inoculation. It’s not related to any of the arthropod borne viruses with which it has been tested by serological tests, such as complement fixation (CF) and hemagglutination inhibition (HI). Positive reactions were only observed with its homologous serum. Juruaçá virus is not sensitive to sodium desoxicolate and can hemagglutinate goose cells at pH 5.75. The virus didn’t show any cytophatic effect and immunofluorescence was negative in Vero and C6/36 cell lines, but it replicates in brain tissue primary culture cell line (astrocytes and microglias), confirmed by immunofluorescent assay (IFA). Culture of neuronal cells appears not to be infected by Juruaçá virus; however, infection of these cells was confirmed by imunohistochemistry. By transmission electron microscopy and negative stain, the virus is a spherical particle, with mean diameter of 23-30nm. Pathological alterations were observed mainly in the central nervous system of newborn mice experimentally infected with Juruaçá virus. The molecular results of RT-PCR suggest that Juruaçá virus is a possible new virus belonging to the family Picornaviridae, genus Enterovirus.
Acesso aberto (Open Access)
Detecção de vírus Influenza A em aves migratórias capturadas em regiões litorâneas dos estados da Bahia, Pará e Pernambuco
(Universidade Federal do Pará, 2014) FERREIRA, Deimy Lima; MELLO, Wyller Alencar de; http://lattes.cnpq.br/1784167608719139; SOUSA, Rita Catarina Medeiros; http://lattes.cnpq.br/3560941703812539
The Influenza virus is known for its ability to infect a wide variety of animals, such as mammals (humans, pigs, horses, whales), domestic birds (chicken [Gallus gallus], goose, turkey [Meleagris ocellata]) beyond wild birds of the orders Anseriformes (duck, wild goose and swan) and Charadriiformes (seagulls, swallows, aquatic birds and sandpipers) these being its natural host. Comprehend the movement of long distance migratory wild birds is crucial to explain the movement of avian influenza viruses. This event causes movement of the birds are acting as an important means of spreading the virus along a migratory route, a fact widely accepted. During the period 2006 and 2007, samples were collected 2,252 samples from a variety of bird species captured in locations which are part of the Atlantic migration route and Mississippi, in the states of Bahia, Para and Pernambuco for epidemiological surveillance of West Nile virus and influenza. The objective of this study was to investigate the circulation of influenza virus among migratory birds that use the routes that pass the above states. For this, the samples were analyzed by means of molecular biological techniques, which comprised two main steps: a) extraction of DNA / RNA from the biological specimen; b) amplification of the gene encoding cytochrome oxidase control of by the technical Polymerase Chain Reaction (PCR) and amplification of the vRNA by Real time Reverse Transcripition polimerase chain reaction (RT-qPCR). The results obtained showed that the total samples tested, 7.2% (n = 158) were positive by RT-qPCR for Influenza A virus. We observed a difference in positivity for the virus among bird species analyzed, which is 3.58% for Charadriformes order, 26.3% among the birds of the order Anseriformes, 5.3% of birds belonging to the order Pelecaniformes and 10.9% for those order Suliformes. Among the samples of the orders Passeriformes and Columbiformes, no sample was positive for Influenza Virus. The data suggest variation among the sampling sites, and the state of Para with the lowest percentage of positivity, the second highest rate with Bahia and Pernambuco finally presenting higher prevalence of absolute value. This study shows that although rare investigations in Brazilian territory, there has been movement of Influenza A viruses among several species of migratory birds that utilize the states of Para, Bahia and Pernambuco as stopping places and reproduction of their species. These findings justify further investigations to understand the dynamics of avian influenza viruses circulating in the population of wild birds in Brazil, and its role as a potential source of infection for other animals, including humans.
Acesso aberto (Open Access)
Detecção e genotipagem de norovírus em diferentes amostras de água e esgoto não tratado na cidade de Belém, Pará, Brasil, 2008 a 2010
(Universidade Federal do Pará, 2014) TEIXEIRA, Dielle Monteiro; GABBAY, Yvone Benchimol; http://lattes.cnpq.br/1579859438466504
Enteric viruses excreted in feces from infected individuals dispersed in aquatic environments by sewage discharge. Among these viruses, the norovirus (NoV) is actually considered the main cause of gastroenteritis outbreaks worldwide, resulting from the ingestion of contaminated food and water as well as is also associated with hospitalizations. This research aimed to detect and partially characterize the human NoV (GI/GII) in different water matrices and in untreated sewage from Metropolitan Region of Belem. The study involved superficial waters from bay (Ver-o-Peso), river (Acai’s Port), stream (Tucunduba) and two lakes (Bolonha and Agua Preta), as well as treated water (WTP-Bolonha) and untreated sewage (SLP-UNA), monthly collected over two years . The water and sewage (2 liters) were initially concentrated on filtering membranes to obtain a final volume of 2 mL. The nucleic acid was extracted by silica method and submitted to semi nested RT-PCR (reverse transcription Polymerase chain reaction) using NoV GI and GII specific primers. The cDNA obtained after reverse transcription was also used to investigate the GI/GII by TaqMan® real time PCR. The positive samples for both molecular methods were analyzed for 5’end ORF2 by nested (for GI) and semi nested (for GII) in order to obtain amplicon for identification of circulating strains, being further purified using a commercial kit and submitted to molecular characterization in the automated sequencer. The obtained sequences were edited, aligned and compared to others available in gene bank (NCBI) and in the site NoV genotyping tool. In the period of November 2008 to October 2010, 168 water and sewage samples were collected and analyzed for NoV presence, obtaining a positivity of 33.9% (57/168) of which 21.1% (12/57) were positive only by TaqMan® real time PCR, 19.3% (11/57) only by semi nested and 59.6% (34/57) for both. Considering the two methodologies used, in the positive cases GI (82.5% - 47/57) was most frequent than GII (79.0% - 45/57). However, in most samples there was coexistence of the two genogroups (61.4% - 35/57), mainly in the Tucunduba and SLP-UNA samples, considered the most NoV contaminated sites. On the other hand, in WTP-Bolonha this agent was not found. Of 57 positive samples by TaqMan® real time PCR and/or semi nested RT-PCR, 53 were retested for 5’end ORF2, since four samples showed insufficient quantity of material which allowed a new analyze, so, in 47.2% (25/53) the NoV genome was detected, of these 12% (3/25) belonging to GI, 24% (6/25) to GII and 64% (16/25) for both. The most frequent GI and GII genotypes were GI.8 (n=8) and GII.4 (n=12), respectively, but others genotypes were also observed with lower incidence as GII.6 (n=3), GII.9 (n=2), GII.12 (n=1), GII.14 (n=1), GI.1 (n=1) and GI.4 (n=2). Due to low quality of sequences obtained, eight samples could not be genotyped for GI and three for GII. Of 96 samples with concentration of thermotolerant coliforms above the recommended, 34 (35.4%) were also NoV positive. Increase on conductivity and total dissolved solids was observed in materials from Ver-o-Peso and Tucunduba, as well as the turbidity was notably higher in these places and the Acai’s Port. In the less rainy period (July to November) there was a trend in positivity increasing for NoV, and in the highest rainfall (December to June) a decrease in the incidence of this agent was noted. The results obtained in the present study indicate the circulation of NoV GI and GII in aquatic environments in Belem, revealing the degradation that these water bodies have suffered, as a result of poverty or lack of sanitation in our city, allowing the permanence of pathogens in these ecosystems, along with its effluents.