RESUMO
Picobirnaviruses (PBVs) are emerging and opportunistic viruses with possible zoonotic potential. In this study, we present the detection, molecular characterization, and genotypic differentiation of PBVs from genogroup I in bovine stool samples from different Brazilian regions. A high proportion of PCR-positive samples (23.4%) was detected in a total of 77 analyzed. Nucleotide identity, alignment, and phylogenetic analyses revealed high diversity among the studied sequences. The results obtained indicate, for the first time, the circulation of bovine PBVs belonging to genogroup I in different Brazilian states, with heterogeneous phylogenetic-clustering profiles.
Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , Variação Genética , Picobirnavirus/classificação , Picobirnavirus/genética , Infecções por Vírus de RNA/veterinária , Animais , Brasil/epidemiologia , Bovinos , Genes Virais , Epidemiologia Molecular , Filogenia , RNA ViralRESUMO
It is suggested that Bovine kobuvirus (BKV) is involved in the etiology of gastroenteric diseases especially among calves; however, this association remains unknown. This study evaluated 216 fecal samples from cattle with and without diarrhea symptoms obtained from different regions of Brazil. A 216 bp fragment of the BKV 3D gene was amplified by RT-PCR in 14.4 % (31/216) of the studied samples, and 17 samples were subjected to nucleotide sequencing. All positive samples were obtained from animals aged less than 5 months, and most of animals presented diarrhea (p < 0.05). Phylogenetic analyses showed that the obtained sequences were grouped within the genogroup 2 of BKV forming subclades specific for each Brazilian municipality sampled. In addition, the alignment of the sequences revealed differences of nucleotides between sequences from different locations. Our results indicate for the first time that there is a regional genotypic differentiation of BKV in Brazil.
Assuntos
Variação Genética , Kobuvirus/classificação , Kobuvirus/genética , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , Genes Virais , Genoma Viral , Genótipo , Filogenia , Infecções por Picornaviridae/veterinária , Análise de Sequência de DNARESUMO
Bovine astrovirus (BoAstV) is associated with gastroenterical disorders such as diarrhea, particularly in neonates and immunocompromised animals. Its prevalence is >60 % in the first five weeks of the animal's life. The aim of this study was to detect and perform a phylogenetic analysis of BoAstV in Brazilian cattle. A prevalence of 14.3 % of BoAstV in fecal samples from 272 head of cattle from different Brazilian states was detected, and 11 samples were analyzed by nucleotide sequencing. The majority of positive samples were obtained from diarrheic animals (p < 0.01). Phylogenetic analysis revealed that Brazilian samples were grouped in clades along with other BoAstV isolates. There was 74.3 %-96.5 % amino acid sequence similarity between the samples in this study and >74.8 % when compared with reference samples for enteric BoAstV. Our results indicate, for the first time, the occurrence of BoAstV circulation in cattle from different regions of Brazil, prevalently in diarrheic calves.
Assuntos
Infecções por Astroviridae/veterinária , Astroviridae/genética , Doenças dos Bovinos/virologia , Animais , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/virologia , Brasil/epidemiologia , Bovinos/virologia , Doenças dos Bovinos/epidemiologia , Feminino , Masculino , FilogeniaRESUMO
Dengue is a major worldwide public health problem, especially in the tropical and subtropical regions of the world. Primary infection with a single Dengue virus (DENV) serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients experiencing a secondary infection with a different serotype progress to the severe form of the disease, called dengue hemorrhagic fever. In this study, the vaccine potential of three tetravalent and conserved synthetic peptides derived from DENV envelope domain I (named Pep01) and II (named Pep02 and Pep03) was evaluated. Human dengue IgM/IgG positive serum (n=16) showed reactivity against Pep01, Pep02 and Pep03 in different degrees. Mice immunization experiments showed that these peptides were able to induce a humoral response characterized by antibodies with low neutralizing activity. The spleen cells derived from mice immunized with the peptides showed a significant cytotoxic activity (only for Pep02 and Pep03), a high expression of IL-10 (P<0.01) and a reduced expression of TNF-α and IFN-gamma (P<0.001) compared to DENV-1 infected splenocytes. Thus these peptides, and specially the Pep03, can induce a humoral response characterized by antibodies with low neutralizing activities and probably a T cell response that could be beneficial to induce an effective immune response against all DENV serotypes and do not contributed to the immunopathogenesis. However, further studies in peptide sequence will be required to induce the production of neutralizing antibodies against all four DENV serotypes and also to improve immunogenicity of these peptides.
Assuntos
Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Testes Imunológicos de Citotoxicidade , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/genética , Vírus da Dengue/genética , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Camundongos , Testes de Neutralização , Linfócitos T Citotóxicos/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/genéticaRESUMO
OBJECTIVE: Hantaviruses are rodent-borne RNA viruses that have caused hantavirus cardiopulmonary syndrome in several Brazilian regions. In the present study, geographical distribution, seroprevalence, natural host range, and phylogenetic relations of rodent-associated hantaviruses collected from seven counties of Southeastern Brazil were evaluated. METHODS: ELISA, RT-PCR and phylogenetic analysis were used in this study. RESULTS: Antibodies to hantavirus were detected in Bolomys lasiurus, Akodon sp. and Oligoryzomys sp., performing an overall seroprevalence of 5.17%. All seropositive rodents were associated with grasslands or woods surrounded by sugar cane fields. Phylogenetic analysis of partial S- and M-segment sequences showed that viral sequences isolated from B. lasiurus specimens clustered with Araraquara virus. However, a sequence from Akodon sp. shared 100% similarity with Argentinian/Chilean viruses based on the partial S-segment amino acid sequence. CONCLUSION: These results indicate that there are associations between rodent reservoirs and hantaviruses in some regions of Southeastern Brazil, and suggest the existence of additional hantavirus genetic diversity and host ecology in these areas.
Assuntos
Variação Genética , Orthohantavírus/classificação , Orthohantavírus/isolamento & purificação , RNA Viral/genética , Sigmodontinae/virologia , Animais , Anticorpos Antivirais/sangue , Brasil , Análise por Conglomerados , Ensaio de Imunoadsorção Enzimática , Orthohantavírus/genética , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência , Estudos SoroepidemiológicosRESUMO
The hantavirus pulmonary syndrome (HPS) is an emerging syndrome in the Americas. The disease results from intense immune activation and changes in vascular permeability. The aim of this study was to determine the profile of serum cytokines in HPS patients looking for correlation with the clinical parameters, severity and outcome of illness. Studying 21 HPS patients, we found that IL-6 may have an important role in the pathogenesis of HPS, being associated with fatal outcome. Our results also support a mixed Th1/Th2 immune response during the course of HPS and that the magnitude of Th1 response effector cytokines is correlated to HPS severity. The decreased levels of TGF-beta observed in HPS patients suggest that immunoregulatory activity could be damaged in these patients.
Assuntos
Citocinas/sangue , Síndrome Pulmonar por Hantavirus/diagnóstico , Síndrome Pulmonar por Hantavirus/imunologia , Células Th1/imunologia , Células Th2/imunologia , Pressão Sanguínea , Progressão da Doença , Orthohantavírus/patogenicidade , Síndrome Pulmonar por Hantavirus/patologia , Humanos , Interleucinas/sangue , Linfotoxina-alfa/sangue , Óxido Nítrico/sangue , PrognósticoRESUMO
Paracoccidioidomycosis, the major systemic mycosis in Latin America, is caused by the thermally dimorphic fungus Paracoccidioides brasiliensis. To investigate the role of interleukin (IL)-12 in this disease, IL-12p40-/- deficient mice (IL-12p40-/-) and wild type mice (WT) were infected intravenously with viable yeast cells of P. brasiliensis 18 isolate. We found that, unlike WT mice, IL-12p40-/- mice did not control fungal proliferation and dissemination and succumbed to infection by day 21 after inoculation. Additionally, IL-12p40-/- mice presented a higher number of granulomas/mm2 in lung tissue than WT mice, and showed unorganized granulomas containing high numbers of yeast cells. Moreover, IL-12p40-/- mice did not release detectable levels of IFN-gamma, but they produced high levels of IL-10, as well as IgG1 antibody. Additionally, splenocytes from both infected IL-12p40-/- and WT mice exhibited a suppressed Con-A-induced T cell proliferative response. Our findings suggest that the IL-12p40 subunit mediates resistance in paracoccidioidomycosis by inducting IFN-gamma production and a Th1 immune response.
Assuntos
Subunidade p40 da Interleucina-12/deficiência , Subunidade p40 da Interleucina-12/genética , Paracoccidioides/imunologia , Paracoccidioidomicose/genética , Paracoccidioidomicose/imunologia , Animais , Anticorpos Antifúngicos/sangue , Proliferação de Células , Contagem de Colônia Microbiana , Feminino , Granuloma de Corpo Estranho/microbiologia , Granuloma de Corpo Estranho/patologia , Imunoglobulina G/metabolismo , Interferon gama/metabolismo , Interleucina-10/metabolismo , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Paracoccidioidomicose/mortalidade , Paracoccidioidomicose/patologia , Baço/imunologia , Baço/microbiologia , Análise de Sobrevida , Linfócitos T/citologia , Linfócitos T/imunologiaRESUMO
Oropouche, Caraparu, Guama, Guaroa and Tacaiuma viruses (Orthobunyavirus genus) cause human febrile illnesses and/or encephalitis. To achieve a therapeutical agent to prevent and/or treat these diseases we evaluated the antiviral action of Interferon-alpha (IFN-alpha) on these orthobunyaviruses. In vitro results showed that all the studied orthobunyaviruses are susceptible to antiviral action of IFN-alpha, but this susceptibility is limited and dependent on both concentration of drug and treatment period. In vivo results demonstrated that IFN-alpha present antiviral action on Oropouche and Guaroa viruses when used as a prophylactic treatment. Moreover, a treatment initiated 3h after infection prevented the death of Guaroa virus infected-mice. Additionally, mortality of mice was related to the migration and replication of viruses in their brains. Our results suggest that IFN-alpha could be potentially useful in the prevention of diseases caused by Oropouche virus and in the prevention and/or treatment of diseases caused by Guaroa virus.
Assuntos
Infecções por Bunyaviridae/tratamento farmacológico , Interferon-alfa/uso terapêutico , Orthobunyavirus/efeitos dos fármacos , Animais , Animais Lactentes , Antivirais/farmacologia , Antivirais/uso terapêutico , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/virologia , Infecções por Bunyaviridae/mortalidade , Infecções por Bunyaviridae/prevenção & controle , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Interferon Tipo I/farmacologia , Interferon Tipo I/uso terapêutico , Interferon alfa-2 , Interferon-alfa/farmacologia , Camundongos , Orthobunyavirus/crescimento & desenvolvimento , Proteínas Recombinantes , Taxa de Sobrevida , Fatores de Tempo , Células Vero , Replicação Viral/efeitos dos fármacosRESUMO
OBJECTIVE: Oropouche, Caraparu, Guama, Guaroa and Tacaiuma are ssRNA viruses that belong to the genus Orthobunyavirus and have been associated with human febrile illnesses and/or encephalitis. In this study, we evaluated the antiviral action of mycophenolic acid (MPA) on theseorthobunyaviruses to achieve a therapeutic agent to treat the diseases caused by these viruses. METHODS: The in vitro antiviral evaluation to MPA was done by using plaque assay at different periods of treatment. RESULTS: Results showed that MPA at a concentration of 10 microg/ml has significant antiviral activity on Tacaiuma virus when treatment was initiated either 24 h before or 2 h after viral infection. Moreover, MPA has an inhibitory effect on Guama virus replication, but only when treatment was initiated before cell infection. Addition of guanosine in the culture reverted the inhibitory effect of MPA on Tacaiuma and Guama viruses, suggesting that the antiviral activity of this substance was via depletion of the intracellular guanosine pool. CONCLUSION: Our results suggest that MPA would not be a good therapeutic agent to treat the diseases caused by Oropouche, Caraparu, Guama, Guaroa, and Tacaiuma viruses.