RESUMO
BACKGROUND: Vesicular stomatitis virus (VSV), a vector-borne pathogen of livestock, emerges periodically in the western US. In New Mexico (NM), US, most cases occur close to the Rio Grande River, implicating black flies (Simulium spp.) as a possible vector. In 2020, VS cases were reported in NM from April to May, although total black fly abundance remained high until September. We investigated the hypothesis that transience of local VSV transmission results from transient abundance of key, competent black fly species. Additionally, we investigated whether irrigation canals in southern NM support a different community of black flies than the main river. Lastly, to gain insight into the source of local black flies, in 2023 we collected black fly larvae prior to the release of water into the Rio Grande River channel. METHODS: We randomly sub-sampled adult black flies collected along the Rio Grande during and after the 2020 VSV outbreak. We also collected black fly adults along the river in 2021 and 2022 and at southern NM farms and irrigation canals in 2022. Black fly larvae were collected from dams in the area in 2023. All collections were counted, and individual specimens were subjected to molecular barcoding for species identification. RESULTS: DNA barcoding of adult black flies detected four species in 2020: Simulium meridionale (N = 158), S. mediovittatum (N = 83), S. robynae (N = 26) and S. griseum/notatum (N = 1). Simulium robynae was only detected during the VSV outbreak period, S. meridionale showed higher relative abundance, but lower absolute abundance, during the outbreak than post-outbreak period, and S. mediovittatum was rare during the outbreak period but predominated later in the summer. In 2022, relative abundance of black fly species did not differ significantly between the Rio Grande sites and farm and irrigation canals. Intriguingly, 63 larval black flies comprised 56% Simulium vittatum, 43% S. argus and 1% S. encisoi species that were either extremely rare or not detected in previous adult collections. CONCLUSIONS: Our results suggest that S. robynae and S. meridionale could be shaping patterns of VSV transmission in southern NM. Thus, field studies of the source of these species as well as vector competence studies are warranted.
Assuntos
Simuliidae , Estomatite Vesicular , Animais , Estomatite Vesicular/epidemiologia , New Mexico/epidemiologia , Insetos Vetores , Vesiculovirus , Larva , Surtos de DoençasRESUMO
Vesicular stomatitis caused by Alagoas vesiculovirus (VSAV) has generated disease outbreaks in Brazil, mainly in the northeast region. Phylogenetic studies divide the isolates into three distinct genotypes (A, B, and C). However, there is no description of how this genetic divergence reflects on the phenotype of VSAV isolates such as in vitro replication fitness. Therefore, the objective of this work was to evaluate the ability of three distinct genotypes of Brazilian isolates of VSAV to grow in different cell-culture lines (BHK-21, Vero, and NCI-H1299). Quantification of viral RNA was performed using RT-PCR digital droplet from supernatant of cell culture collected every 4 h for a period of 24 h of viral growth in three different cell lines (BHK-21, Vero, and NCI-H1299). It was observed that the genotype C isolate has the lowest replication efficiency among the three analyzed viruses, without major changes in the copies of viral RNA over the entire time of the study.
Assuntos
Estomatite Vesicular , Vesiculovirus , Animais , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Filogenia , Vesiculovirus/genética , RNA Viral/genéticaRESUMO
The vesicular stomatitis virus belongs to the Rhabdoviridae family, genus Vesiculovirus. Four species (New Jersey, Indiana, Cocal, and Alagoas) are responsible for disease outbreaks in Western Hemisphere countries. In Brazil, the Alagoas virus is responsible for the main outbreaks of the disease, mainly in the states of the Northeast, Midwest, and Southeast regions of the country. The present study aimed to perform the genetic characterization of 41 vesicular stomatitis virus samples. RNA was extracted using Trizol and used to amplify part of gene P. Amplicons were sequenced using the Sanger method. The phylogenetic trees generated showed that Alagoas vesiculoviruses were positioned into three groups: group A formed by the first virus isolate; group B by isolates from states in the Northeast region; and group C by isolates from the states of Bahia, Goiás, and Tocantins. Their divergence to date has generated the formation of two genotypes evolving independently in regions that until the present study had little geographic overlap.
Assuntos
Estomatite Vesicular , Animais , Brasil/epidemiologia , Filogenia , Vírus da Estomatite Vesicular Indiana/genética , Vesiculovirus/genéticaRESUMO
This article describes the recurrence of outbreaks of Vesicular Stomatitis in the State of Maranhão, Brazil. The procedures for treating the outbreak of vesicular disease, sample collection, laboratory tests performed, and the results obtained were described. The clinical signs and observed injuries have been described. The sera showed antibodies that cross-react between the Vesiculovirus Indiana, Cocal, and Alagoas. The serological profile shows the presence of high antibody titers for Alagoas vesiculovirus in cattle, swine, and horses. Higher antibody titers indicate the viral serotype present in the outbreak. The genetic sequencing of the isolates confirmed the presence of Alagoas vesiculovirus, which grouped with the virus isolated in 2013 from cattle from the State of Maranhão.
Assuntos
Estomatite Vesicular , Vesiculovirus , Animais , Brasil/epidemiologia , Bovinos , Surtos de Doenças/veterinária , Cavalos , Sorogrupo , Suínos , Estomatite Vesicular/epidemiologia , Vesiculovirus/genéticaRESUMO
BACKGROUND: More than 3 years since the last Zika virus (ZIKV) outbreak in Brazil, researchers are still deciphering the molecular mechanisms of neurovirulence and vertical transmission, as well as the best way to control spread of ZIKV, a flavivirus. The use of pesticides was the main strategy of mosquito control during the last ZIKV outbreak. METHODS: We used vesicular stomatitis virus (VSV) tagged with green fluorescent protein (GFP) as our prototypical virus to study the impact of insecticide pyriproxyfen (PPF). VZV-GFP infected and uninfected Jurkat, HeLa and trophoblast cells were treated with PPF and compared to untreated cells (control). Cell viability was determined by the MTT assay. Cell morphology, presence of extracellular vesicles (EVs), virus infection/GFP expression as well as active mitochondrial levels/localization were examined by confocal microscopy. RESULTS: PPF, which was used to control mosquito populations in Brazil prior to the ZIKV outbreak, enhances VSV replication and has cell membrane-altering properties in the presence of virus. PPF causes enhanced viral replication and formation of large EVs, loaded with virus as well as mitochondria. Treatment of trophoblasts or HeLa cells with increasing concentrations of PPF does not alter cell viability, however, it proportionately increases Jurkat cell viability. Increasing concentrations of PPF followed by VSV infection does not interfere with HeLa cell viability. Both Jurkats and trophoblasts show proportionately increased cell death with increased concentrations of PPF in the presence of virus. CONCLUSIONS: We hypothesize that PPF disrupts the lipid microenvironment of mammalian cells, thereby interfering with pathways of viral replication. PPF lowers viability of trophoblasts and Jurkats in the presence of VSV, implying that the combination renders immune system impairment in infected individuals as well as enhanced vulnerability of fetuses towards viral vertical transmission. We hypothesize that similar viruses such as ZIKV may be vertically transmitted via EV-to-cell contact when exposed to PPF, thereby bypassing immune detection. The impact of pesticides on viral replication must be fully investigated before large scale use in future outbreaks of mosquito borne viruses.
Assuntos
Infecções por Flavivirus/transmissão , Inseticidas/farmacologia , Piridinas/farmacologia , Vesiculovirus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Aedes/virologia , Animais , Brasil , Sobrevivência Celular/efeitos dos fármacos , Vírus da Dengue/efeitos dos fármacos , Vesículas Extracelulares/efeitos dos fármacos , Vesículas Extracelulares/virologia , Proteínas de Fluorescência Verde/genética , Células HeLa , Humanos , Células Jurkat , Trofoblastos/efeitos dos fármacos , Trofoblastos/virologia , Virulência , Zika virus/efeitos dos fármacosRESUMO
Cocal virus (COCV) is one of the causative agents of vesicular stomatitis, presenting clinical signs indistinguishable from those caused by foot-and-mouth disease virus (FMDV). Therefore, the differentiation of these two viruses via laboratory diagnosis is essential. The objective of this study was to develop and validate a real-time quantitative PCR (RT-qPCR) protocol for the diagnosis of COCV directly from epithelial samples. The method developed had 97% accuracy at 3950 pfu and a repeatability error of 1.29%. RT-qPCR was able to distinguish COCV from other viruses that cause vesicular diseases, an important factor because seroneutralization may produce cross-reactivity between COCV and vesicular stomatitis Alagoas virus (VSAV). No epithelial sample originating from vesicular disease outbreaks between 2014 and 2018 in Brazil was positive for COCV.
Assuntos
Estomatite Vesicular/diagnóstico , Estomatite Vesicular/virologia , Vesiculovirus/genética , Animais , Brasil , Vírus de DNA/genética , Febre Aftosa/diagnóstico , Febre Aftosa/virologia , Vírus da Febre Aftosa/genética , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/métodosRESUMO
Maraba virus is a member of the genus Vesiculovirus of the Rhabdoviridae family that was isolated in 1983 from sandflies captured in the municipality of Maraba, state of Pará, Amazônia, Brazil. Despite 30 years having passed since its isolation, little is known about the neuropathology induced by the Maraba virus. Accordingly, in this study the histopathological features, inflammatory glial changes, cytokine concentrations, and nitric oxide activity in the encephalon of adult mice subjected to Maraba virus nostril infection were evaluated. The results showed that 6 days after intranasal inoculation, severe neuropathological-associated disease signs appeared, including edema, necrosis and pyknosis of neurons, generalized congestion of encephalic vessels, and intra- and perivascular meningeal lymphocytic infiltrates in several brain regions. Immunolabeling of viral antigens was observed in almost all central nervous system (CNS) areas and this was associated with intense microglial activation and astrogliosis. Compared to control animals, infected mice showed significant increases in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (INF)-γ, MCP-1, nitric oxide, and encephalic cytokine levels. We suggest that an exacerbated inflammatory response in several regions of the CNS of adult BALB/c mice might be responsible for their deaths.
Assuntos
Meningoencefalite/complicações , Estomatite Vesicular/complicações , Animais , Astrócitos/metabolismo , Brasil , Citocinas/análise , Modelos Animais de Doenças , Citometria de Fluxo , Masculino , Meningoencefalite/patologia , Camundongos , Camundongos Endogâmicos BALB C , Microglia/metabolismo , Óxido Nítrico/análise , Estomatite Vesicular/patologia , VesiculovirusRESUMO
We previously demonstrated, using the Piry virus model, that environmental enrichment promotes higher T-cell infiltration, fewer microglial changes, and faster central nervous system (CNS) virus clearance in adult mice. However, little is known about disease progression, behavioral changes, CNS cytokine concentration, and neuropathology in limbic encephalitis in experimental models. Using Cocal virus, we infected C57Bl6 adult mice and studied the neuroanatomical distribution of viral antigens in correlation with the microglial morphological response, measured the CNS cytokine concentration, and assessed behavioral changes. C57Bl6 adult mice were maintained in an impoverished environment (IE) or enriched environment (EE) for four months and then subjected to the open field test. Afterwards, an equal volume of normal or virus-infected brain homogenate was nasally instilled. The brains were processed to detect viral antigens and microglial morphological changes using selective immunolabeling. We demonstrated earlier significant weight loss and higher mortality in IE mice. Additionally, behavioral analysis revealed a significant influence of the environment on locomotor and exploratory activity that was associated with less neuroinvasion and a reduced microglial response. Thus, environmental enrichment was associated with a more effective immune response in a mouse model of limbic encephalitis, allowing faster viral clearance/decreased viral dissemination, reduced disease progression, and less CNS damage.
Assuntos
Encéfalo/patologia , Encéfalo/virologia , Encefalite Límbica/patologia , Encefalite Límbica/virologia , Vesiculovirus/fisiologia , Animais , Antígenos Virais/imunologia , Comportamento Animal , Biomarcadores , Encéfalo/fisiopatologia , Encéfalo/ultraestrutura , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Camundongos , Microglia/patologia , Microglia/virologia , Mortalidade , Neuropatologia , Avaliação de Sintomas , Carga ViralRESUMO
Maraba virus is a member of the genus Vesiculovirus of the Rhabdoviridae family that was isolated in 1983 from sandflies captured in the municipality of Maraba, state of Pará, Amazônia, Brazil. Despite 30 years having passed since its isolation, little is known about the neuropathology induced by the Maraba virus. Accordingly, in this study the histopathological features, inflammatory glial changes, cytokine concentrations, and nitric oxide activity in the encephalon of adult mice subjected to Maraba virus nostril infection were evaluated. The results showed that 6 days after intranasal inoculation, severe neuropathological-associated disease signs appeared, including edema, necrosis and pyknosis of neurons, generalized congestion of encephalic vessels, and intra- and perivascular meningeal lymphocytic infiltrates in several brain regions. Immunolabeling of viral antigens was observed in almost all central nervous system (CNS) areas and this was associated with intense microglial activation and astrogliosis. Compared to control animals, infected mice showed significant increases in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (INF)-γ, MCP-1, nitric oxide, and encephalic cytokine levels. We suggest that an exacerbated inflammatory response in several regions of the CNS of adult BALB/c mice might be responsible for their deaths.
Assuntos
Animais , Masculino , Coelhos , Estomatite Vesicular/complicações , Meningoencefalite/complicações , Brasil , Astrócitos/metabolismo , Citocinas/análise , Vesiculovirus , Microglia/metabolismo , Modelos Animais de Doenças , Estomatite Vesicular/patologia , Citometria de Fluxo , Meningoencefalite/patologia , Camundongos Endogâmicos BALB C , Óxido Nítrico/análiseRESUMO
OBJECTIVES: ß-Escin, one of the constituents of Aesculus hippocastanum L. (Hippocastanaceae) seed extract (AH), inhibits NF-κB activation, which plays an important role in HSV-1 replication. The aim was to examine the antiherpetic activity of ß-escin and AH, as well as their effect on the activation of NF-κB and AP-1 and cytokine secretion in epithelial cells and macrophages. METHODS: Cell viability was evaluated using MTT assay, and antiviral and virucidal activity was determined by plaque assay. The effect on NF-κB and AP-1 signalling pathways activation was determined by a luciferase reporter assay, and cytokine production was measured by ELISA. KEY FINDINGS: ß-Escin and AH had virucidal and anti-HSV-1 activities, and the antiviral activity was discovered for other enveloped viruses (VSV and Dengue). Moreover, ß-escin and AH significantly reduced NF-κB and AP-1 activation and cytokine production in macrophages stimulated with HSV-1 and TLRs ligands. However, an enhanced activation of these pathways and an increase in the levels of pro-inflammatory cytokines in ß-escin and AH-treated HSV-1-infected epithelial cells were found. CONCLUSIONS: This study demonstrates virucidal and broad-spectrum antiviral activities for ß escin and AH. Besides, ß-escin and AH modulate cytokine production depending on the stimuli (viral or non-viral) and the cell type under study.