Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.102
Filtrar
1.
Arch Virol ; 166(10): 2841-2846, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34357464

RESUMO

Native Australian soldier flies, Inopus spp. (Diptera: Stratiomyidae), are agricultural pests of economic importance to the sugarcane industry. A screen of the salivary gland transcriptome of Inopus flavus (James) revealed the presence of viral RNA belonging to a potentially novel member of the family Dicistroviridae. The complete genome sequence consists of 9793 nucleotides with two open reading frames. The genome includes two potential internal ribosomal entry sites (IRESs): one within the 5' UTR and the other in the intergenic region (IGR). Virus particles purified from infected larvae and visualised by electron microscopy were found to be icosahedral, non-enveloped, and 30 nm in diameter.


Assuntos
Dicistroviridae/classificação , Dípteros/virologia , Saccharum/parasitologia , Sequência de Aminoácidos , Animais , Austrália , Dicistroviridae/genética , Variação Genética , Genoma Viral/genética , Sítios Internos de Entrada Ribossomal/genética , Larva/virologia , Fases de Leitura Aberta/genética , Filogenia , RNA Viral/genética , Glândulas Salivares/virologia , Vírion/ultraestrutura
2.
Biotechnol Bioeng ; 118(10): 4129-4137, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34264519

RESUMO

Serology testing for COVID-19 is important in evaluating active immune response against SARS-CoV-2, studying the antibody kinetics, and monitoring reinfections with genetic variants and new virus strains, in particular, the duration of antibodies in virus-exposed individuals and vaccine-mediated immunity. In this study, recombinant S protein of SARS-CoV-2 was expressed in Rachiplusia nu, an important agronomic plague. One gram of insect larvae produces an amount of S protein sufficient for 150 determinations in the ELISA method herein developed. We established a rapid production process for SARS-CoV-2 S protein that showed immunoreactivity for anti-SARS-CoV-2 antibodies and was used as a single antigen for developing the ELISA method with high sensitivity (96.2%) and specificity (98.8%). Our findings provide an efficient and cost-effective platform for large-scale S protein production, and the scale-up is linear, thus avoiding the use of complex equipment like bioreactors.


Assuntos
Teste Sorológico para COVID-19 , COVID-19/diagnóstico , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/biossíntese , Animais , Larva/metabolismo , Larva/virologia , Nucleopoliedrovírus , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , SARS-CoV-2/metabolismo , Células Sf9 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Spodoptera
3.
Science ; 373(6554): 535-541, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34326235

RESUMO

Interkingdom competition occurs between hymenopteran parasitoids and insect viruses sharing the same insect hosts. It has been assumed that parasitoid larvae die with the death of the infected host or as result of competition for host resources. Here we describe a gene family, parasitoid killing factor (pkf), that encodes proteins toxic to parasitoids of the Microgastrinae group and determines parasitism success. Pkfs are found in several entomopathogenic DNA virus families and in some lepidopteran genomes. We provide evidence of equivalent and specific toxicity against endoparasites for PKFs found in entomopoxvirus, ascovirus, baculovirus, and Lepidoptera through a mechanism that elicits apoptosis in the cells of susceptible parasitoids. This highlights the evolutionary arms race between parasitoids, viruses, and their insect hosts.


Assuntos
Entomopoxvirinae/fisiologia , Proteínas de Insetos/toxicidade , Lepidópteros/parasitologia , Lepidópteros/virologia , Proteínas Virais/toxicidade , Vespas/fisiologia , Animais , Apoptose , Evolução Biológica , Transferência Genética Horizontal , Genoma de Inseto , Interações Hospedeiro-Parasita , Proteínas de Insetos/química , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Vírus de Insetos/fisiologia , Larva/genética , Larva/parasitologia , Larva/virologia , Lepidópteros/genética , Lepidópteros/metabolismo , Nucleopoliedrovírus/fisiologia , Spodoptera/genética , Spodoptera/metabolismo , Spodoptera/parasitologia , Spodoptera/virologia , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo , Vespas/crescimento & desenvolvimento
4.
Neotrop Entomol ; 50(4): 615-621, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34129209

RESUMO

The baculovirus Chrysodeixis includens nucleopolyhedrovirus (ChinNPV) is pathogenic to Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) larvae, known as soybean looper, which is an important pest of soybean and bean. In this study, some parameters were tested to overcome the difficulties in the in vivo production of ChinNPV aiming to increase its use as a biopesticide. First, different combinations of larval instars (3rd and 4th instars), larval incubation temperatures (23 °C and 26 °C), and rearing densities (individually and 10 larvae/cup) were compared for larval weight and the production of occlusion bodies (OBs). A positive correlation (p< 0.001) was observed for OB production and larval weight. Fourth instar larvae produced more OBs than third instar larvae (p<0.05); however, no significant differences in OBs/larva (p>0.05) were observed for larvae kept in groups or individually. Therefore, a second assay was performed using fourth instar larvae incubated at 26 °C and two larval densities (10 larvae/cup and 40 larvae/cup). The losses of insects and OB production were evaluated as well as the influence of storage temperatures post-mortem (-20 °C, 4 °C, and 15 °C) in the OB yield. As expected, insect losses due to cannibalism or microbial contamination were greater (p<0.05) with the increase in larval density, although no difference was observed in OBs/larva (p>0.05). In addition, the storage temperature post-mortem did not influence the OB yield (p>0.05). The average production of ChinNPV OBs was 3×1010 OBs/40 larvae cup. The results demonstrate the viability of rearing C. includens in groups to enhance the mass production and reduce virus production costs.


Assuntos
Agentes de Controle Biológico , Mariposas , Nucleopoliedrovírus , Animais , Larva/virologia , Mariposas/virologia , Controle Biológico de Vetores , Cultura de Vírus
5.
Front Immunol ; 12: 645359, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995363

RESUMO

A wide range of hemocyte types exist in insects but a full definition of the different subclasses is not yet established. The current knowledge of the classification of silkworm hemocytes mainly comes from morphology rather than specific markers, so our understanding of the detailed classification, hemocyte lineage and functions of silkworm hemocytes is very incomplete. Bombyx mori nucleopolyhedrovirus (BmNPV) is a representative member of the baculoviruses and a major pathogen that specifically infects silkworms (Bombyx mori) and causes serious losses in sericulture industry. Here, we performed single-cell RNA sequencing (scRNA-seq) of hemocytes in BmNPV and mock-infected larvae to comprehensively identify silkworm hemocyte subsets and determined specific molecular and cellular characteristics in each hemocyte subset before and after viral infectmadion. A total of 20 cell clusters and their potential marker genes were identified in silkworm hemocytes. All of the hemocyte clusters were infected by BmNPV at 3 days after inoculation. Interestingly, BmNPV infection can cause great changes in the distribution of hemocyte types. The cells appearing in the infection group mainly belong to prohemocytes (PR), while plasmatocytes (PL) and granulocytes (GR) are very much reduced. Furthermore, we found that BmNPV infection suppresses the RNA interference (RNAi) and immune response in the major hemocyte types. In summary, our results revealed the diversity of silkworm hemocytes and provided a rich resource of gene expression profiles for a systems-level understanding of their functions in the uninfected condition and as a response to BmNPV.


Assuntos
Bombyx , Hemócitos , Nucleopoliedrovírus/imunologia , RNA-Seq , Análise de Célula Única , Animais , Bombyx/imunologia , Bombyx/virologia , Hemócitos/imunologia , Hemócitos/virologia , Larva/imunologia , Larva/virologia
6.
Acta Trop ; 220: 105959, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34000262

RESUMO

We conducted an island-wide survey of the Caribbean islands Puerto Rico and Vieques, U.S.A. during late 2018 and early 2019 to document the current richness of mosquitoes (Diptera: Culicidae). We used a combination of larval surveys and adult trapping using baited CDC light traps and BG-Sentinel traps across 41 of the 78 municipalities. We collected 9 genera, 12 subgenera, and 31 species, which when combined with past studies yields 44 species on the islands. We also note species occurrences across habitat types and elevations from around the islands. One new record, Aedes (Ochlerotatus) obturbator Dyar and Knab, is noted. However we found no evidence of the presence of Aedes albopictus (Skuse), an invasive found throughout the Caribbean, or Aedes (Fredwardsius) vittatus (Bigot), an exotic species recently reported in the Dominican Republic and Cuba. Habitat associations and information regarding the medical importance of species are also included. Given that the islands often experience outbreaks of several arboviruses, obtaining a complete picture of the species present is of high importance.


Assuntos
Culicidae/classificação , Animais , Arbovírus/fisiologia , Culicidae/virologia , Larva/virologia , Porto Rico
7.
Fish Shellfish Immunol ; 114: 282-292, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33971258

RESUMO

The gilthead sea bream (Sparus aurata) is a marine fish of great importance for Mediterranean aquaculture. This species has long been considered resistant to Nervous Necrosis Virus (NNV), an RNA virus that causes massive mortalities in several farmed fish animals. However, the recent appearance of RGNNV/SJNNV reassortant strains started to pose a serious threat to sea bream hatcheries, as it is able to infect larvae and juveniles of this species. While host response to NNV has been extensively studied in adult fish, little attention has been devoted to early life history stages, which are generally the most sensitive ones. Here we report for the first time a time-course RNA-seq analysis on 21-day old fish gilthead sea bream larvae experimentally infected with a RGNNV/SJNNV strain. NNV-infected and mock-infected samples were collected at four time points (6 h, 12 h, 24 h, and 48 h post infection). Four biological replicates, each consisting of five pooled larvae, were analysed for each time point and group. A large set of genes were found to be significantly regulated, especially at early time points (6 h and 12 h), with several heat shock protein encoding transcripts being up-regulated (e.g. hspa5, dnaj4, hspa9, hsc70), while many immune genes were down-regulated (e.g. myd88 and irf5 at T06, pik3r1, stat3, jak1, il12b and il6st at T12). A gene set enrichment analysis (GSEA) identified several altered pathways/processes. For instance, the formation of peroxisomes, which are important anti-viral components as well as essential for nervous system homeostasis, and the autophagy pathway were down-regulated at 6 h and 24 h post infection (hpi). Finally, two custom "reactomes" (i.e. significant gene sets observed in other studies) were defined and used. The first reactome integrated the transcriptomic response to NNV in different fish species, while the second one included all genes found to be stimulated either by interferon (IFN) or by IFN and Chikungunya virus in zebrafish. Genes in both reactomes showed predominant up-regulation at 6hpi and 12hpi and a general down-regulation at 24hpi. Such evidence suggest a certain degree of similarity between the response of sea bream and that of other fish species to NNV, while the observed down-regulation of IFN- and viral-stimulated pathways argues for a possible interference of NNV against the host response.


Assuntos
Doenças dos Peixes/virologia , Nodaviridae , Infecções por Vírus de RNA/veterinária , Dourada/virologia , Animais , Doenças dos Peixes/imunologia , Doenças dos Peixes/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Larva/imunologia , Larva/virologia , Infecções por Vírus de RNA/imunologia , Infecções por Vírus de RNA/virologia , Vírus Reordenados , Replicação Viral
8.
Acta Trop ; 220: 105952, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33979644

RESUMO

Sindbis virus (SINV) and Chikungunya virus (CHIKV) are among the most widely spread mosquito-borne viruses worldwide. Due to the key role of mosquitoes in the transmission cycle of vector-borne diseases, models such as Maximum Entropy (MaxEnt) have been used in recent years to predict the environmental suitability and ecological niches of mosquito vectors. Infection of three mosquito species (Anopheles maculipennis s.l., Culex tritaeniorhynchus, and Culiseta longiareolata) with CHIKV has recently been reported in Iran. However, given the importance of vector-borne diseases in the country, there is a need for extensive studies on the infection of mosquitoes with CHIKV and SINV in different areas of the country. Accordingly, the current research was conducted to investigate the infection of mosquitoes with the two aforementioned viruses in the northwestern part of Iran and also to model the ecological niches of the vectors of these mosquito-borne viruses in the country. In the current study, 4639 mosquito specimens, consisting of 2515 adults and 2124 larvae, were collected from the wetlands of West Azerbaijan Province and identified. Ten species belonging to four genera were identified in this study. The specimens were allocated to 149 pools for the determination of infection with CHIKV and SINV. The amplification pattern of five pools comprising two mosquito species (Culex pipiens complex and Cx. Theileri) corresponded to the reference strain of SINV, and the isolates were sequenced to confirm the presence of SINV genome. No cases of CHIKV infection were found among the 149 examined mosquito pools. Data on the distribution of Cx. Pipiens complex and Cx. Theileri were mapped using ArcMap 10.5. Prediction maps of the presence probability for these species revealed that they are most likely to be found in and spread to the north, northwest, south, and southeastern areas of the country and in areas with abundant water resources. For the first time in Iran, our study investigated the presence probability of SINV vectors using ecological niche modeling. Ecological niche profiling showed that the most suitable habitats for Cx. pipiens are mainly concentrated in the north and northwestern parts of the country, whereas Cx. theileri is mostly located in the northwest and western regions. However, there were some other areas of low suitability for these two species in the country. Further studies in a broader geographical area with more species of mosquitos and the determination of infection with other mosquito-borne viruses can provide a clear understanding of the potential spread of mosquito-borne diseases in various regions of Iran.


Assuntos
Infecções por Arbovirus/veterinária , Culicidae/virologia , Modelos Estatísticos , Vírus Sindbis/fisiologia , Áreas Alagadas , Animais , Irã (Geográfico) , Larva/virologia , Probabilidade
9.
Viruses ; 13(3)2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799811

RESUMO

Human noroviruses (hNoVs) cause heavy disease burden worldwide and there is no clinically approved vaccination or antiviral hitherto. In this study, with the use of a zebrafish larva in vivo platform, we investigated the anti-hNoV potentials of fucoidan (from brown algae Fucus vesiculosus) and 2'-Fucosyllactose (2'-FL). As a result, although both fucoidan and 2'-FL were able to block hNoV GII.4 virus-like particle (VLPs) from binding to type A saliva as expected, only fucoidan, but not 2'-FL, was able to inhibit the replication of hNoV GII.P16-GII.4 in zebrafish larvae, indicating the possible needs of higher molecular weights for fucosylated carbohydrates to exert anti-hNoV effect.


Assuntos
Antivirais/farmacologia , Norovirus/crescimento & desenvolvimento , Polissacarídeos/farmacologia , Trissacarídeos/farmacologia , Peixe-Zebra/virologia , Animais , Humanos , Larva/virologia , Norovirus/efeitos dos fármacos , Saliva/virologia , Ligação Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Peixe-Zebra/embriologia
10.
Int J Mol Sci ; 22(7)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808210

RESUMO

Autographa californica Multiple Nucleopolyhedrovirus (AcMNPV) is a baculovirus that causes systemic infections in many arthropod pests. The specific molecular processes underlying the biocidal activity of AcMNPV on its insect hosts are largely unknown. We describe the transcriptional responses in two major pests, Spodoptera frugiperda (fall armyworm) and Trichoplusia ni (cabbage looper), to determine the host-pathogen responses during systemic infection, concurrently with the viral response to the host. We assembled species-specific transcriptomes of the hemolymph to identify host transcriptional responses during systemic infection and assessed the viral transcript abundance in infected hemolymph from both species. We found transcriptional suppression of chitin metabolism and tracheal development in infected hosts. Synergistic transcriptional support was observed to suggest suppression of immune responses and induction of oxidative stress indicating disease progression in the host. The entire AcMNPV core genome was expressed in the infected host hemolymph with a proportional high abundance detected for viral transcripts associated with replication, structure, and movement. Interestingly, several of the host genes that were targeted by AcMNPV as revealed by our study are also targets of chemical insecticides currently used commercially to control arthropod pests. Our results reveal an extensive overlap between biological processes represented by transcriptional responses in both hosts, as well as convergence on highly abundant viral genes expressed in the two hosts, providing an overview of the host-pathogen transcriptomic landscape during systemic infection.


Assuntos
Interações Hospedeiro-Patógeno/genética , Proteínas de Insetos/genética , Mariposas/genética , Mariposas/virologia , Nucleopoliedrovírus/fisiologia , Agricultura , Animais , Quitina/genética , Quitina/metabolismo , Perfilação da Expressão Gênica , Genoma Viral , Hemócitos/imunologia , Hemócitos/virologia , Hemolinfa/fisiologia , Hemolinfa/virologia , Larva/virologia , Metabolismo dos Lipídeos/genética , Nucleopoliedrovírus/genética , Nucleopoliedrovírus/patogenicidade , Estresse Oxidativo/genética , Spodoptera/genética , Spodoptera/virologia , Replicação Viral
11.
PLoS One ; 16(3): e0247500, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33657150

RESUMO

Thrips and thrips-transmitted tospoviruses cause significant losses in crop yields worldwide. The melon thrips (Thrips palmi) is not only a pest of cucurbit crops, but also a vector that transmits tospoviruses, such as the watermelon silver mottle virus (WSMoV). Vector transmission of tospoviruses has been well studied in the tomato spotted wilt virus (TSWV)-Frankliniella occidentalis model system; however, until now the transmission mode of WSMoV by T. palmi has not been sufficiently examined. The results of the transmission assays suggest that T. palmi transmits WSMoV in a persistent manner, and that the virus is mainly transmitted by adults, having been ingested at the first-instar larval stage. Complementary RNAs corresponding to the NSm and NSs genes of WSMoV were detected in viruliferous thrips by reverse transcription-polymerase chain reaction; NSs protein was also detected in viruliferous thrips by western blotting, verifying the replication of WSMoV in T. palmi. Furthermore, we demonstrated that in thrips infected with WSMoV at the first-instar larval stage, the virus eventually infected various tissues of the adult thrips, including the primary salivary glands. Taken together, these results suggest that T. palmi transmits WSMoV in a persistent-propagative mode. The results of this study make a significant contribution to the understanding of the transmission biology of tospoviruses in general.


Assuntos
Citrullus/virologia , Doenças das Plantas/virologia , Tisanópteros/virologia , Tospovirus/genética , Animais , Feminino , Larva/virologia , Masculino , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glândulas Salivares/virologia , Replicação Viral
12.
PLoS Pathog ; 17(3): e1009365, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33647060

RESUMO

Parasites alter host energy homeostasis for their own development, but the mechanisms underlying this phenomenon remain largely unknown. Here, we show that Cotesia vestalis, an endoparasitic wasp of Plutella xylostella larvae, stimulates a reduction of host lipid levels. This process requires excess secretion of P. xylostella tachykinin (PxTK) peptides from enteroendocrine cells (EEs) in the midgut of the parasitized host larvae. We found that parasitization upregulates PxTK signaling to suppress lipogenesis in midgut enterocytes (ECs) in a non-cell-autonomous manner, and the reduced host lipid level benefits the development of wasp offspring and their subsequent parasitic ability. We further found that a C. vestalis bracovirus (CvBV) gene, CvBV 9-2, is responsible for PxTK induction, which in turn reduces the systemic lipid level of the host. Taken together, these findings illustrate a novel mechanism for parasite manipulation of host energy homeostasis by a symbiotic bracovirus gene to promote the development and increase the parasitic efficiency of an agriculturally important wasp species.


Assuntos
Interações Hospedeiro-Parasita/imunologia , Metabolismo dos Lipídeos/fisiologia , Parasitos/virologia , Polydnaviridae/genética , Animais , Sistema Digestório/metabolismo , Interações Hospedeiro-Parasita/genética , Larva/metabolismo , Larva/virologia , Metabolismo dos Lipídeos/imunologia , Parasitos/patogenicidade , Polydnaviridae/patogenicidade , Transdução de Sinais/imunologia , Transdução de Sinais/fisiologia , Vespas/fisiologia , Vespas/virologia
13.
Rev. iberoam. micol ; 38(1): 9-11, ene.-mar. 2021. graf
Artigo em Inglês | IBECS | ID: ibc-202388

RESUMO

BACKGROUND: The virulence of isolates among different Candida species causing candidemia may play a role in the prognosis of the patients. Furthermore, the potential relationship between genotype and virulence is still unclear and need to be further studied. AIMS: We aim to assess the relationship between genotype and virulence in Candida species using a Galleria mellonella larvae infection model. METHODS: One hundred and ninety-four isolates from 68 clusters (Candida albicans, 114/41; Candida parapsilosis, 74/24; Candida tropicalis, 6/3) were compared against the same number of each species singleton genotypes in terms of survival of G. mellonella larvae. RESULTS: The median of survival and the IQR ranges of clusters and singleton were as follows: C. albicans (2 days, IQR 1.5-2 vs. 2 days, IQR 1-2.25), C. parapsilosis (2 days, IQR 1.5-2.6 vs. 2 days, IQR 2-3.3), and C. tropicalis (1 day, IQR 1-3.5 vs. 2 days, IQR 2-3.5; p < 0.05). High intra-cluster variability in terms of median of survival was found regardless the species. CONCLUSIONS: No relationship between genotype and virulence in Candida was observed with the G. mellonella model


ANTECEDENTES: La virulencia de cepas de diferentes especies de Candida causantes de candidemia puede jugar un papel en el pronóstico de los pacientes, y su estudio en el modelo de infección en Galleria mellonella puede ser útil para entender su contribución general a la infección. Además, la potencial relación entre genotipo y virulencia requiere de más estudios. OBJETIVOS: Se evaluó la relación entre genotipo y virulencia en especies de Candida mediante el modelo de infección de larvas de G. mellonella. MÉTODOS: Se estudió la supervivencia de las larvas infectadas con 194 aislados incluidos en 68 clusters (Candida albicans, 114/41; Candida parapsilosis, 74/24; Candida tropicalis, 6/3) y con el mismo número de aislados con genotipos únicos por especie. RESULTADOS: La mediana de supervivencia y los rangos intercuartílicos (IQR) de clusters y genotipos únicos se muestra a continuación: C. albicans (2 días, IQR: 1,5-2 vs. 2 días, IQR: 1-2,25), C. parapsilosis (2 días, IQR: 1,5-2,6 vs. 2 días, IQR: 2-3,3), y C. tropicalis (un día, IQR: 1-3,5 vs. 2 días, IQR: 2-3,5; p < 0,05). Encontramos una importante variabilidad en la mediana de supervivencia entre cepas del mismo cluster, independientemente de la especie analizada. CONCLUSIONES: No se encontró relación entre el genotipo y la virulencia entre los aislados de Candida evaluados mediante el modelo de infección de G. mellonella


Assuntos
Humanos , Candida/isolamento & purificação , Candidemia/diagnóstico , Candida/genética , Candidemia/etiologia , Larva/genética , Candida parapsilosis/genética , Candidemia/microbiologia , Larva/virologia , Candida/virologia , Candidemia/virologia , Candida parapsilosis/virologia , Candida tropicalis/virologia , Técnicas de Genotipagem/métodos , Virulência , Fatores de Virulência
14.
J Microbiol Biotechnol ; 31(4): 529-539, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33526755

RESUMO

NPVThe beet armyworm, Spodoptera exigua, is a serious insect pest infesting various vegetable crops. Two infectious insect viruses, baculovirus and iflavirus, are known to induce epizootics in S. exigua populations. Indeed, some laboratory colonies have appeared to be covertly infected by these viruses. Diagnostic PCR tests detected two different viruses: Spodoptera exigua multiple nucleopolyhedrosis virus (SeMNPV) and iflaviruses (SeIfV1 and SeIfV2). Viral extract from dead larvae of S. exigua could infect Sf9 cells and produce occlusion bodies (OBs). Feeding OBs to asymptomatic larvae of S. exigua caused significant viral disease. Interestingly, both SeIfV1 and SeIfV2 increased their titers at late larval stages. Sterilization of laid eggs with 1% sodium hypochloride significantly reduced SeMNPV titers and increased larval survival rate. Doublestranded RNA (dsRNA) specific to SeIfV1 or SeIfV2 significantly reduced viral titers and increased larval survival rate. To continuously feed dsRNA, a recombinant Escherichia coli HT115 expressing SeIfV1-dsRNA was constructed with an L4440 expression vector. Adding this recombinant E. coli to the artificial diet significantly reduced the SeIfV1 titer and increased larval survival. These results indicate that laboratory colony collapse of S. exigua is induced by multiple viral infections. In addition, either suppression of SeMNPV or SeIfV infection significantly increased larval survival, suggesting a cooperative pathogenicity between baculovirus and iflavirus against S. exigua.


Assuntos
Antivirais/farmacologia , Baculoviridae/efeitos dos fármacos , Vírus de RNA/efeitos dos fármacos , Spodoptera/virologia , Animais , Baculoviridae/patogenicidade , Larva/virologia , Reação em Cadeia da Polimerase , Interferência de RNA , Vírus de RNA/patogenicidade , Células Sf9
15.
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33591247

RESUMO

Bracoviruses (BVs) are endogenized nudiviruses that braconid parasitoid wasps have coopted for functions in parasitizing hosts. Microplitis demolitor is a braconid wasp that produces Microplitis demolitor bracovirus (MdBV) and parasitizes the larval stage of the moth Chrysodeixis includens. Some BV core genes are homologs of genes also present in baculoviruses while others are only known from nudiviruses or other BVs. In this study, we had two main goals. The first was to separate MdBV virions into envelope and nucleocapsid fractions before proteomic analysis to identify core gene products that were preferentially associated with one fraction or the other. Results indicated that nearly all MdBV baculovirus-like gene products that were detected by our proteomic analysis had similar distributions to homologs in the occlusion-derived form of baculoviruses. Several core gene products unknown from baculoviruses were also identified as envelope or nucleocapsid components. Our second goal was to functionally characterize a core gene unknown from baculoviruses that was originally named HzNVorf64-like. Immunoblotting assays supported our proteomic data that identified HzNVorf64-like as an envelope protein. We thus renamed HzNVorf64-like as MdBVe46, which we further hypothesized was important for infection of C. includens. Knockdown of MdBVe46 by RNA interference (RNAi) greatly reduced transcript and protein abundance. Knockdown of MdBVe46 also altered virion morphogenesis, near-fully inhibited infection of C. includens, and significantly reduced the proportion of hosts that were successfully parasitized by M. demolitor.


Assuntos
Mariposas/virologia , Polydnaviridae/fisiologia , Vírion/ultraestrutura , Animais , DNA Viral/química , DNA Viral/genética , Larva/virologia , Polydnaviridae/genética , Proteômica/métodos , Interferência de RNA , Proteínas Virais
16.
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33625353

RESUMO

The baculovirus Cydia pomonella granulovirus (CpGV) is a biocontrol agent used worldwide against the codling moth (CM), Cydia pomonella L., a severe pest in organic and integrated pome fruit production. Its successful application is increasingly challenged by the occurrence of CM populations resistant to commercial CpGV products. Whereas three types (I-III) of CpGV resistance have been identified, type I resistance compromising the efficacy of CpGV-M, the so-called Mexican isolate of CpGV, is assumed to be the most widely distributed resistance type in Central Europe. Despite the wide use of CpGV products as biocontrol agents, little information is available on gene-expression levels in CM larvae. In this study, the in vivo transcriptome of CpGV-M infecting susceptible (CpS) and resistant (CpRR1) CM larvae was analysed at 24, 48, 72, 96 and 120 hours post infection in the midgut and fat body tissue by using a newly developed microarray covering all ORFs of the CpGV genome. According to their transcript abundance, the CpGV genes were grouped into four temporal clusters to which groups of known and unknown function could be assigned. In addition, sets of genes differentially expressed in the midgut and fat body were found in infected susceptible CpS larvae. For the resistant CpRR1 larvae treated with CpGV-M, viral entry in midgut cells could be confirmed from onset but a significantly reduced gene expression, indicating that type I resistance is associated with a block of viral gene transcription and replication.


Assuntos
Granulovirus/genética , Granulovirus/isolamento & purificação , Mariposas/virologia , Transcriptoma , Animais , Europa (Continente) , Granulovirus/classificação , Granulovirus/fisiologia , Larva/imunologia , Larva/virologia , Mariposas/crescimento & desenvolvimento , Mariposas/imunologia , Doenças das Plantas/parasitologia
17.
Arch Insect Biochem Physiol ; 106(2): e21762, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33415772

RESUMO

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of primary silkworm pathogens and causes a serious damage of cocoon losses every year. Recent years, many works have been done to clarify the silkworm anti-BmNPV mechanism, and a significant progress has been made in screening and studying of genes and proteins related to BmNPV infection, but several of them lacked the proofs in vivo. In this study, to further validate the function of seven newly reported genes in vivo, including BmAtlatin-n, Bmferritin-heavy chain (BmFerHCH), Bmthymosin (BmTHY), Bmseroin1, Bmseroin2, Bmnuclear hormone receptors 96 (BmNHR96), and BmE3 ubiquitin-protein ligase SINA-like 10 (BmSINAL10), the response of them in the midgut, fat body, and hemolymph of differentially resistant strains (resistant strain YeA and susceptible strain YeB) at 48 h following BmNPV infection were analyzed. The results showed that the relative stable or upregulated expression level of BmAtlatin-n, BmTHY, Bmseroin1, and Bmseroin2 in YeA resistant strain following BmNPV infection further indicated their antiviral role in vivo, compared with susceptible YeB strain. Moreover, the significant downregulation of BmFerHCH, BmNHR96, and BmSINAL10 in both strains following BmNPV infection revealed their role in benefiting virus infection, as well as the upregulation of BmFerHCH in YeB midgut and BmSINAL10 in YeB hemolymph. These data could be used to complementary the proofs of the function of these genes in response to BmNPV infection.


Assuntos
Bombyx/genética , Bombyx/virologia , Genes de Insetos , Interações Hospedeiro-Patógeno , Nucleopoliedrovírus/fisiologia , Animais , Bombyx/crescimento & desenvolvimento , Bombyx/metabolismo , Corpo Adiposo/metabolismo , Trato Gastrointestinal/metabolismo , Hemolinfa/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/virologia
18.
Acta Trop ; 215: 105819, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33406443

RESUMO

The outbreaks caused by the Aedes aegypti-transmitted dengue virus (DENV), zakat virus (ZIKV), and chikungunya virus (CHIKV) result in a significant impact to the health systems of tropical countries. Furthermore, the occurrence of patients coinfected by at least two of these arboviruses is an aggravating factor in that scenario. On this basis, surveillance tools such as the Rapid Index Survey for Aedes aegypti (LIRAa) are used to estimate vector infestation in order to improve the prediction of human outbreaks. Ae. aegypti eggs were collected in the city of Vitória da Conquista, in Bahia State, Brazil, and subsequently hatched into larvae, which were analyzed in pools or individually for the presence of DENV, ZIKV, and CHIKV by molecular biology methods. The detection data for arboviruses were crossed with the LIRAa obtained in each region of the study city. Thirty larvae pools were analyzed, and fourteen (46.6%) of them were detected positive for DENV, ZIKV, and/or CHIKV. Among the individually analyzed larvae (n = 30), nine (30%) were positive for any of these arboviruses, and four (13.3%) were simultaneously coinfected by DENV and ZIKV. Furthermore, there was a positive correlation between the detection of circulating arboviruses and LIRAa. The simultaneous Ae. aegypti larvae infection by two different arboviruses is an unprecedented finding. This result suggests the occurrence of a vertical arboviruses co-transmission from the female mosquito to its offspring in nature. The occurrence of concomitant circulation of DENV, ZIKV, and CHIKV in Ae. aegypti from a single study region is another finding of this article. Finally, LIRAa seems to not only estimate vector infestation but also to predict circulation of arboviruses.


Assuntos
Aedes/virologia , Vírus Chikungunya/isolamento & purificação , Coinfecção/transmissão , Vírus da Dengue/isolamento & purificação , Transmissão Vertical de Doenças Infecciosas , Mosquitos Vetores/virologia , Zika virus/isolamento & purificação , Animais , Feminino , Humanos , Larva/virologia
19.
Parasitology ; 148(1): 105-109, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33054893

RESUMO

Many parasites manipulate host behaviour to enhance their transmission. Baculoviruses induce enhanced locomotory activity (ELA) combined with subsequent climbing behaviour in lepidopteran larvae, which facilitates viral dispersal. However, the mechanisms underlying host manipulation system are largely unknown. Previously, larval locomotion during ELA was summarized as the distance travelled for a few minutes at several time points, which are unlikely to characterize ELA precisely, as ELA typically persists for several hours. In this study, we modified a recently developed method using time-lapse recording to characterize locomotion of Bombyx mori larvae infected with B. mori nucleopolyhedrovirus (BmNPV) for 24 h at 3 s resolution. Our data showed that the locomotion of the mock-infected larvae was restricted to a small area, whereas the BmNPV-infected larvae exhibited a large locomotory area. These results indicate that BmNPV dysregulates the locomotory pattern of host larvae. Furthermore, both the mock- and BmNPV-infected larvae showed periodic cycles of movement and stationary behaviour with a similar frequency, suggesting the physiological mechanisms that induce locomotion are unaffected by BmNPV infection. In contrast, the BmNPV-infected larvae exhibited fast and long-lasting locomotion compared with mock-infected larvae, which indicates that locomotory speed and duration are manipulated by BmNPV.


Assuntos
Bombyx/virologia , Locomoção , Nucleopoliedrovírus/patogenicidade , Animais , Baculoviridae/patogenicidade , Comportamento , Bombyx/fisiologia , Interações entre Hospedeiro e Microrganismos , Larva/fisiologia , Larva/virologia , Imagem com Lapso de Tempo/métodos , Viroses
20.
Arch Virol ; 166(1): 125-138, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33111162

RESUMO

In a comparative analysis of genome sequences from isolates of the baculovirus Chrysodeixis includens nucleopolyhedrovirus (ChinNPV) from Brazil and Guatemala, we identified a subset of isolates possessing chimeric genomes. We identified six distinct phylogenetically incongruous regions (PIRs) dispersed in the genomes, of between 279 and 3345 bp in length. The individual PIRs possessed high sequence similarity among the affected ChinNPV isolates but varied in coverage in some instances. The donor for four of the PIRs implicated in horizontal gene transfer (HGT) was identified as Trichoplusia ni single nucleopolyhedrovirus (TnSNPV), an alphabaculovirus closely related to ChinNPV, or another unknown but closely related virus. BLAST searches of the other two PIRs returned only ChinNPV sequences, but HGT from an unknown donor baculovirus cannot be excluded. Although Chrysodeixis includens and Trichoplusia ni are frequently co-collected from soybean fields in Brazil, pathogenicity data suggest that natural coinfection of C. includens larvae with ChinNPV and TnSNPV is probably uncommon. Additionally, since the chimeric ChinNPV genomes with tracts of TnSNPV sequence were restricted to a single monophyletic lineage of closely related isolates, a model of progressive restoration of the native DNA sequence by recombination with ChinNPV possessing a fully or partially non-chimeric genome is reasonable. However, multiple independent HGT from TnSNPV to ChinNPV during the evolution of these isolates cannot be excluded. Mortality data suggest that the ChinNPV isolates with chimeric genomes are not significantly different in pathogenicity towards C. includens when compared to most other ChinNPV isolates. Exclusion of the PIRs prior to phylogenetic analysis had a large impact on the topology of part of the maximum-likelihood tree, revealing a homogenous clade of three isolates (IB, IC and ID) from Paraná state in Brazil collected in 2006, together with an isolate from Guatemala collected in 1972 (IA), comprising the lineage uniquely affected by HGT from TnSNPV. The other 10 Brazilian ChinNPV isolates from Paraná, Mato Grosso, and Minas Gerais states showed higher variability, where only three isolates from Paraná state formed a monophyletic group correlating with geographical origin.


Assuntos
Genoma Viral/genética , Nucleopoliedrovírus/genética , Virulência/genética , Animais , Baculoviridae/genética , Sequência de Bases , Brasil , Evolução Molecular , Larva/virologia , Mariposas/virologia , Controle Biológico de Vetores , Filogenia , Soja/virologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...