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1.
Biologicals ; 86: 101769, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38759304

RESUMO

This study focuses on the development and initial assessment of an indirect IgG enzyme-linked immunosorbent assay (ELISA) specifically designed to detect of anti-SARS-CoV-2 antibodies. The unique aspect of this ELISA method lies in its utilization of a recombinant nucleocapsid (N) antigen, produced through baculovirus expression in insect cells. Our analysis involved 292 RT-qPCR confirmed positive serum samples and 54 pre-pandemic healthy controls. The process encompassed cloning, expression, and purification of the SARS-CoV-2 N gene in insect cells, with the resulted purified protein employed in our ELISA tests. Statistical analysis yielded an Area Under the Curve of 0.979, and the optimized cut-off exhibited 92 % sensitivity and 94 % specificity. These results highlight the ELISA's potential for robust and reliable serological detection of SARS-CoV-2 antibodies. Further assessments, including a larger panel size, reproducibility tests, and application in diverse populations, could enhance its utility as a valuable biotechnological solution for diseases surveillance.


Assuntos
Anticorpos Antivirais , Baculoviridae , COVID-19 , Ensaio de Imunoadsorção Enzimática , Proteínas Recombinantes , SARS-CoV-2 , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Baculoviridae/genética , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , COVID-19/diagnóstico , COVID-19/sangue , COVID-19/imunologia , Animais , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/genética , Teste Sorológico para COVID-19/métodos , Células Sf9 , Antígenos Virais/imunologia , Antígenos Virais/genética , Proteínas do Nucleocapsídeo/imunologia , Proteínas do Nucleocapsídeo/genética , Sensibilidade e Especificidade , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Fosfoproteínas/imunologia , Fosfoproteínas/genética
2.
Arch Microbiol ; 205(4): 143, 2023 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-36967401

RESUMO

Bacillus thuringiensis (Bt) is a biological alternative to the indiscriminate use of chemical insecticides in agriculture. Due to resistance development on insect pests to Bt crops, isolating novel Bt strains is a strategy for screening new pesticidal proteins or strains containing toxin profile variety that can delay resistance. Besides, the combined genomic and proteomic approaches allow identifying pesticidal proteins and virulence factors accurately. Here, the genome of a novel Bt strain (Bt TOL651) was sequenced, and the proteins from the spore-crystal mixture were identified by proteomic analysis. Toxicity bioassays with the spore-crystal mixture against larvae of Diatraea saccharalis and Anticarsia gemmatalis, key pests of sugarcane and soybean, respectively, were performed. The toxicity of Bt TOL651 varies with the insect; A. gemmatalis (LC50 = 1.45 ng cm-2) is more susceptible than D. saccharalis (LC50 = 73.77 ng cm-2). Phylogenetic analysis of the gyrB gene indicates that TOL651 is related to Bt kenyae strains. The genomic analysis revealed the presence of cry1Aa18, cry1Ac5, cry1Ia44, and cry2Aa9 pesticidal genes. Virulence factor genes such as phospholipases (plcA, piplc), metalloproteases (inhA), hemolysins (cytK, hlyIII, hblA, hblC, hblD), and enterotoxins (nheA, nheB, nheC) were also identified. The combined use of the genomic and proteomic data indicated the expression of Cry1Aa18, Cry1Ac5, and Cry2Aa9 proteins, with Cry1Ac5 being the most abundant. InhA1 also was expressed and may contribute to Bt TOL651 pathogenicity. These results provide Bt TOL651 as a new tool for the biocontrol of lepidopteran pests.


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/química , Fatores de Virulência/genética , Proteômica , Filogenia , Endotoxinas/genética , Endotoxinas/toxicidade , Larva , Insetos , Genômica , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/toxicidade , Proteínas de Bactérias/genética , Proteínas de Bactérias/toxicidade , Controle Biológico de Vetores/métodos
3.
Arch Virol ; 168(1): 29, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36598610

RESUMO

The cotton boll weevil (CBW; Anthonomus grandis; Coleoptera: Curculionidae) is considered the major insect pest of cotton, causing considerable losses in yield and fiber quality. An increase in the boll weevil population due to increasingly inefficient chemical control measures is of great concernamong cotton producers. The absence of conventional or transgenic cultivars with minimal resistance to CBW has stimulated the search for new molecular and biological tools for efficient control of this insect pest. In this study, we used a metagenomic approach based on RNA deep sequencing to investigate the presence of viruses and coding viral RNA in apparently healthy native adult CBW insects collected from cotton crops in Mato Grosso state, Brazil. Using an Illumina HiSeq 2000 paired-end platform, 138,798 virus-related reads were obtained, and a consensus sequence of a putative new virus, 10,632 nucleotides in length, was assembled. The sequences of the 5' and 3' untranslated regions (UTRs) were determined by rapid amplification of cDNA ends (RACE), followed by Nanopore sequencing. The complete genome sequence included a 5'-UTR (1,158 nucleotides), a 3'-UTR (561 nucleotides), and a single ORF of 8,913 nucleotides encoding a large polyprotein. Sequence analysis of the putative polyprotein showed several regions with high sequence similarity to structural and non-structural proteins of viruses of the family Iflaviridae. Pairwise alignments of polyprotein amino acid sequences showed the highest sequence identity (32.13%) to a partial polyprotein sequence of a putative iflavirus (QKN89051.1) found in samples from wild zoo birds in China. Phylogenetic analysis based on full polyprotein sequences of different iflaviruses indicated that this new picorna-like virus is most closely related to iflaviruses found in lepidopteran insects, and it was therefore tentatively named "Anthonomus grandis iflavirus 1" (AgIV-1). This is, to our knowledge, the first complete viral genome sequence found in CBW, and it could provide a basis for further studies about the infectivity and transmission of this virus and its possible association with symptoms or acute disease. AgIV-1 could potentially be used to develop biological or molecular tools, such as a viral vector to carry interfering RNA molecules for CBW control.


Assuntos
Besouros , Vírus , Gorgulhos , Animais , Filogenia , Vírus/genética , Nucleotídeos , RNA , Gossypium
4.
Arch Virol ; 168(9): 222, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37548749

RESUMO

Bacterial spot is a highly damaging tomato disease caused by members of several species of the genus Xanthomonas. Bacteriophages have been studied for their potential use in the biological control of bacterial diseases. In the current study, bacteriophages were obtained from soil and tomato leaves in commercial fields in Brazil with the aim of obtaining biological control agents against bacterial spot. Phage isolation was carried out by co-cultivation with isolates of Xanthomonas euvesicatoria pv. perforans, which was prevalent in the collection areas. In a host range evaluation, none of the phage isolates was able to induce a lytic cycle in all of the bacterial isolates tested. In in vivo tests, treatment of susceptible bacterial isolates with the corresponding phage prior to application to tomato plants led to a reduction in the severity of the resulting disease. The level of disease control provided by phage application was equal to or greater than that achieved using copper hydroxide. Electron microscopy analysis showed that all of the phages had similar morphology, with head and tail structures similar to those of viruses belonging to the class Caudoviricetes. The presence of short, non-contractile tubular tails strongly suggested that these phages belong to the family Autographiviridae. This was confirmed by phylogenetic analysis, which further revealed that they all belong to the genus Pradovirus. The phages described here are closely related to each other and potentially belong to a new species within the genus. These phages will be evaluated in future studies against other tomato xanthomonad strains to assess their potential as biological control agents.


Assuntos
Bacteriófagos , Caudovirales , Solanum lycopersicum , Bacteriófagos/genética , Filogenia , Brasil , Agentes de Controle Biológico , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia
5.
Virol J ; 19(1): 93, 2022 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-35619142

RESUMO

BACKGROUND: Phylogenetic studies indicate bats as original hosts of SARS-CoV-2. However, it remains unclear whether other animals, including pets, are crucial in the spread and maintenance of COVID-19 worldwide. METHODS: In this study, we analyzed the first fatal case of a SARS-CoV-2 and FeLV co-infection in an eight-year-old male cat. We carried out a clinical evaluation and several laboratory analyses. RESULTS: As main results, we observed an animal presenting severe acute respiratory syndrome and lesions in several organs, which led to the animal's death. RT-qPCR analysis showed a SARS-CoV-2 as the causative agent. The virus was detected in several organs, indicating a multisystemic infection. The virus was found in a high load in the trachea, suggesting that the animal may have contribute to the transmission of the virus. The whole-genome sequencing revealed an infection by SARS-CoV-2 Gamma VOC (P.1), and any mutations indicating host adaptation were observed. CONCLUSION: Our data show that FeLV-positive cats are susceptible to SARS-CoV-2 infection and raise questions about the potential of immunocompromised FeLV-positive cats to act as a reservoir for SARS-CoV-2 new variants.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Humanos , Vírus da Leucemia Felina , Masculino , Filogenia , SARS-CoV-2/genética
6.
Mem Inst Oswaldo Cruz ; 117: e220127, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36478156

RESUMO

BACKGROUND: In Brazil, the yellow fever virus (YFV) is maintained in a sylvatic cycle involving wild mosquitoes and non-human primates (NHPs). The virus is endemic to the Amazon region; however, waves of epidemic expansion reaching other Brazilian states sporadically occur, eventually causing spillovers to humans. OBJECTIVES: To report a surveillance effort that led to the first confirmation of YFV in NHPs in the state of Minas Gerais (MG), Southeast region, in 2021. METHODS: A surveillance network was created, encompassing the technology of smartphone applications and coordinated actions of several research institutions and health services to monitor and investigate NHP epizootics. FINDINGS: When alerts were spread through the network, samples from NHPs were collected and YFV infection confirmed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and genome sequencing at an interval of only 10 days. Near-complete genomes were generated using the Nanopore MinION sequencer. Phylogenetic analysis indicated that viral genomes were related to the South American genotype I, clustering with a genome detected in the Amazon region (state of Pará) in 2017, named YFVPA/MG sub-lineage. Fast YFV confirmation potentialised vaccination campaigns. MAIN CONCLUSIONS: A new YFV introduction was detected in MG 6 years after the beginning of the major outbreak reported in the state (2015-2018). The YFV strain was not related to the sub-lineages previously reported in MG. No human cases have been reported, suggesting the importance of coordinated surveillance of NHPs using available technologies and supporting laboratories to ensure a quick response and implementation of contingency measures to avoid YFV spillover to humans.


Assuntos
Vírus da Febre Amarela , Vírus da Febre Amarela/genética , Filogenia , Brasil/epidemiologia
7.
Arch Virol ; 166(6): 1763-1767, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33755801

RESUMO

Rice (Oryza sativa L.) is an important food crop for humanity, being cultivated in tropical and temperate regions of the world. This study reports the nearly complete genome sequences of four Brazilian rice stripe necrosis virus (RSNV) isolates. The nucleotide sequences of the RNA1 and RNA2 genome segments of these Brazilian isolates were 96.5 to 99.9% identical, indicating their close phylogenetic relationship to each other. Phylogeny and recombination analysis indicated that the genome of one of the isolates consisted of RNA segments of different origins, suggesting that a reassortment event had occurred.


Assuntos
Oryza/virologia , Vírus de Plantas/genética , Brasil , Filogenia
8.
Genomics ; 112(6): 3903-3914, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32629098

RESUMO

The Southern armyworm Spodoptera eridania (Lepidoptera: Noctuidae) is native to the American tropics and a polyphagous pest of several crops. Here we characterized a novel alphabaculovirus isolated from S. eridania, isolate Spodoptera eridania nucleopolyhedrivurus CNPSo-165 (SperNPV-CNPSo-165). SperNPV-CNPSo-165 occlusion bodies were found to be polyhedral and to contain virions with multiple nucleocapsids. The virus was lethal to S. eridania and S. albula but not to S. frugiperda. The SperNPV-CNPSo-165 genome was 137.373 bp in size with a G + C content of 42.8%. We annotated 151 ORFs with 16 ORFs unique among baculoviruses. Phylogenetic inference indicated that this virus was closely related to the most recent common ancestor of other Spodoptera-isolated viruses.


Assuntos
Condroitinases e Condroitina Liases/genética , Evolução Molecular , Nucleopoliedrovírus/isolamento & purificação , Spodoptera/virologia , Animais , Genoma Viral , Nucleopoliedrovírus/genética
9.
Mol Biol Rep ; 47(10): 7333-7340, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32997310

RESUMO

Dengue virus and Zika virus are arthropod-borne flaviviruses that cause millions of infections worldwide. The co-circulation of both viruses makes serological diagnosis difficult as they share high amino acid similarities in viral proteins. Antigens are one of the key reagents in the differential diagnosis of these viruses through the detection of IgG antibodies in serological assays during the convalescent-phase of infections. Here, we report the expression of Dengue virus (DENV) and Zika virus (ZIKV) antigens containing non-conserved and immunodominant amino acid sequences using the baculovirus expression vector system in insect cells. We designed DENV and ZIKV antigens based on the domain III of the E protein (EDIII) after analyzing previously reported epitopes and by multiple alignment of the most important flaviviruses. The ZIKV and DENV multi-epitope genes were designed as tandem repeats or impaired repeats separated by tetra- or hexa-glycine linkers. The biochemical analyses revealed adequate expression of the antigens. Then, the obtained multi-epitope antigens were semi-purified in a sucrose gradient and tested using patients' sera collected during the convalescent-phase that were previously diagnosed positive for anti-DENV and -ZIKV IgG antibodies. The optimal serum dilution was 1:200, and the mean absorbance values in the preliminary tests show that multi-epitope antigens have been recognized by human sera. The production of both antigens using the multi-epitope strategy in the eukaryotic system and based on the EDIII regions provide a proof of concept for the use of antigens in the differentiation between DENV and ZIKV.


Assuntos
Antígenos Virais , Vírus da Dengue/genética , Epitopos , Expressão Gênica , Proteínas Recombinantes de Fusão , Proteínas do Envelope Viral , Zika virus/genética , Animais , Antígenos Virais/biossíntese , Antígenos Virais/genética , Baculoviridae/genética , Baculoviridae/metabolismo , Linhagem Celular , Epitopos/biossíntese , Epitopos/genética , Mariposas , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas do Envelope Viral/biossíntese , Proteínas do Envelope Viral/genética
10.
Arch Virol ; 164(7): 1753-1760, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31025116

RESUMO

The expression of several structural proteins from a wide variety of viruses in heterologous cell culture systems results in the formation of virus-like particles (VLPs). These VLPs structurally resemble the wild-type virus particles and have been used to study viral assembly process and as antigens for diagnosis and/or vaccine development. Tomato blistering mosaic virus (ToBMV) is a tymovirus that has a 6.3-kb positive-sense ssRNA genome. We have employed the baculovirus expression vector system (BEVS) for the production of tymovirus-like particles (tVLPs) in insect cells. Two recombinant baculoviruses containing the ToBMV wild-type coat protein (CP) gene or a modified short amino-terminal deletion (Δ2-24CP) variant were constructed and used to infect insect cells. Both recombinant viruses were able to express ToBMV CP and Δ2-24CP from infected insect cells that self-assembled into tVLPs. Therefore, the N-terminal residues (2-24) of the native ToBMV CP were shown not to be essential for self-assembly of tVLPs. We also constructed a third recombinant baculovirus containing a small sequence coding for the major epitope of the chikungunya virus (CHIKV) envelope protein 2 (E2) replacing the native CP N-terminal 2-24 amino acids. This recombinant virus also produced tVLPs. In summary, ToBMV VLPs can be produced in a baculovirus/insect cell heterologous expression system, and the N-terminal residues 2-24 of the CP are not essential for this assembly, allowing its potential use as a protein carrier that facilitates antigen purification and might be used for diagnosis.


Assuntos
Baculoviridae/genética , Proteínas do Capsídeo/biossíntese , Tymovirus/crescimento & desenvolvimento , Tymovirus/genética , Proteínas do Envelope Viral/biossíntese , Montagem de Vírus/genética , Animais , Proteínas do Capsídeo/genética , Linhagem Celular , Vírus Chikungunya/genética , Expressão Gênica/genética , Solanum lycopersicum/virologia , Mariposas/citologia , Proteínas do Envelope Viral/genética
12.
Arch Virol ; 160(11): 2873-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26323262

RESUMO

In this work, we showed that cell death induced by a recombinant (vAcNSs) Autographa californica multiple nucleopolyhedrovirus (AcMNPV) expressing the silencing suppressor (NSs) protein of Tomato spotted wilt virus (TSWV) was enhanced on permissive and semipermissive cell lines. The expression of a heterologous gene (firefly luciferase) during co-infection of insect cells with vAcNSs and a second recombinant baculovirus (vAgppolhfluc) was shown to increase when compared to single vAgppolhfluc infections. Furthermore, the vAcNSs mean time-to-death values were significantly lower than those for wild-type AcMNPV on larvae of Spodoptera frugiperda and Anticarsia gemmatalis. These results showed that the TSWV-NSs protein could efficiently increase heterologous protein expression in insect cells as well as baculovirus pathogenicity and virulence, probably by suppressing the gene-silencing machinery in insects.


Assuntos
Mariposas/virologia , Nucleopoliedrovírus/patogenicidade , Spodoptera/virologia , Tospovirus/genética , Proteínas Virais/genética , Proteínas Virais/metabolismo , Animais , Linhagem Celular , Expressão Gênica , Inativação Gênica , Mariposas/genética , Nucleopoliedrovírus/genética , Nucleopoliedrovírus/metabolismo , Spodoptera/genética , Virulência
13.
Mem Inst Oswaldo Cruz ; 110(6): 822-3, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26517667

RESUMO

Bacillus thuringiensis is a ubiquitous Gram-positive and sporulating bacterium. Its crystals and secreted toxins are useful tools against larvae of diverse insect orders and, as a consequence, an alternative to recalcitrant chemical insecticides. We report here the draft genome sequence of B. thuringiensis147, a strain isolated from Brazil and with high insecticidal activity. The assembled genome contained 6,167,994 bp and was distributed in seven replicons (a chromosome and 6 plasmids). We identified 12 coding regions, located in two plasmids, which encode insecticidal proteins.


Assuntos
Bacillus thuringiensis/genética , DNA Bacteriano/análise , Inseticidas , Bacillus thuringiensis/classificação , Brasil , Plasmídeos/genética , Replicon/genética , Análise de Sequência de DNA
14.
BMC Genomics ; 15: 856, 2014 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-25280947

RESUMO

BACKGROUND: Cassava (Manihot esculenta) is the basic source for dietary energy of 500 million people in the world. In Brazil, Erinnyis ello ello (Lepidoptera: Sphingidae) is a major pest of cassava crops and a bottleneck for its production. In the 1980s, a naturally occurring baculovirus was isolated from E. ello larva and successfully applied as a bio-pesticide in the field. Here, we described the structure, the complete genome sequence, and the phylogenetic relationships of the first sphingid-infecting betabaculovirus. RESULTS: The baculovirus isolated from the cassava hornworm cadavers is a betabaculovirus designated Erinnyis ello granulovirus (ErelGV). The 102,759 bp long genome has a G + C content of 38.7%. We found 130 putative ORFs coding for polypeptides of at least 50 amino acid residues. Only eight genes were found to be unique. ErelGV is closely related to ChocGV and PiraGV isolates. We did not find typical homologous regions and cathepsin and chitinase homologous genes are lacked. The presence of he65 and p43 homologous genes suggests horizontal gene transfer from Alphabaculovirus. Moreover, we found a nucleotide metabolism-related gene and two genes that could be acquired probably from Densovirus. CONCLUSIONS: The ErelGV represents a new virus species from the genus Betabaculovirus and is the closest relative of ChocGV. It contains a dUTPase-like, a he65-like, p43-like genes, which are also found in several other alpha- and betabaculovirus genomes, and two Densovirus-related genes. Importantly, recombination events between insect viruses from unrelated families and genera might drive baculovirus genomic evolution.


Assuntos
Genoma Viral , Granulovirus/genética , Lepidópteros/virologia , Animais , Bases de Dados Genéticas , Granulovirus/classificação , Granulovirus/isolamento & purificação , Larva/virologia , Lepidópteros/crescimento & desenvolvimento , Manihot/parasitologia , Fases de Leitura Aberta/genética , Filogenia , Pirofosfatases/genética , Análise de Sequência de DNA , Proteínas Virais/classificação , Proteínas Virais/genética
15.
J Gen Virol ; 95(Pt 4): 980-989, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24443474

RESUMO

Baculoviruses infect insects, producing two distinct phenotypes during the viral life cycle: the budded virus (BV) and the occlusion-derived virus (ODV) for intra- and inter-host spread, respectively. Since the 1980s, several countries have been using Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) as a biological control agent against the velvet bean caterpillar, A. gemmatalis. The genome of AgMNPV isolate 2D (AgMNPV-2D) carries at least 152 potential genes, with 24 that possibly code for structural proteins. Proteomic studies have been carried out on a few baculoviruses, with six ODV and two BV proteomes completed so far. Moreover, there are limited data on virion proteins carried by AgMNPV-2D. Therefore, structural proteins of AgMNPV-2D were analysed by MALDI- quadrupole-TOF and liquid chromatography MS/MS. A total of 44 proteins were associated with the ODV and 33 with the BV of AgMNPV-2D. Although 38 structural proteins were already known, we found six new proteins in the ODV and seven new proteins carried by the AgMNPV-2D BV. Eleven cellular proteins that were found on several other enveloped viruses were also identified, which are possibly carried with the virion. These findings may provide novel insights into baculovirus biology and their host interaction. Moreover, our data may be helpful in subsequent applied studies aiming to improve AgMNPV use as a biopesticide and a biotechnology tool for gene expression or delivery.


Assuntos
Nucleopoliedrovírus/química , Proteoma/análise , Proteínas Estruturais Virais/análise , Animais , Linhagem Celular , Cromatografia Líquida , Corpos de Inclusão Viral , Lepidópteros , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Liberação de Vírus
16.
Virus Genes ; 49(3): 477-84, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25212430

RESUMO

Brazil is one of the largest silk producers in the world. The domesticated silkworm (Bombyx mori) was formally introduced into the country in the twentieth century, and the state of Paraná is the main national producer. During larval stages, B. mori can be afflicted by many different infectious diseases, which lead to substantial losses in silk production. In this work, we describe the structure and complete genome sequence of the first non-Asian isolate of Bombyx mori nucleopolyhedrovirus (BmNPV), the most important silkworm pathogen. The BmNPV-Brazilian isolate is a nucleopolyhedrovirus with singly enveloped nucleocapsids within polyhedral occlusion bodies. Its genome has 126,861 bp with a G + C content of 40.4 %. Phylogenetic analysis clustered the virus with the Japanese strain (BmNPV-T3). As expected, we have detected intra-population variability in the virus sample. Variation along homologous regions (HRs) and bro genes was observed; there were seven HRs, deletion of bro-e, and division of bro-a into two ORFs. The study of baculoviruses allows for a better understanding of virus evolution providing insight for biological control of insect pests or protection against the pernicious disease caused by these viruses.


Assuntos
DNA Viral/química , DNA Viral/genética , Genoma Viral , Nucleopoliedrovírus/genética , Animais , Composição de Bases , Bombyx/virologia , Brasil , Análise por Conglomerados , Dados de Sequência Molecular , Nucleopoliedrovírus/isolamento & purificação , Filogenia , Análise de Sequência de DNA
17.
Braz J Microbiol ; 55(2): 1913-1921, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615311

RESUMO

Wasps are important parasitoids of stinkbugs and frequently exposed to various types of microorganisms through environmental contact and fecal-oral transmission route. Many parasitize stinkbug eggs and are commercially used in the field to control insect population. The parasitoid T. podisi is known for its high parasitism capacity and ability to target multiple species of stinkbugs. In this study we asked whether T. podisi exposed to eggs infected by a multispecies asymptomatic stinkbug virus, the Halyomorpha halys virus (HhV) would get infected. HhV is a geographically distributed multispecies iflavirus previously found to infect four stinkbug hosts, including three Brazilian species, Chinavia ubica, Euschistus heros and Diceraeus melacanthus, and T. posidi can parasitize all of them. As results, RT-PCR screening revealed positive samples for the HhV genome in two out of four tested pools of T. podisi, whereas the antigenome, indicative of replicative activity, was not detected. The wasps were raised in E. heros eggs that presented both the genome and the antigenome forms of the HhV genome. Subsequent RNA-deep sequencing of HhV positive T. podisi RNA pools yielded a complete genome of HhV with high coverage. Phylogenetic analysis positioned the isolate HhV-Tp (isolate Telenomus podisi) alongside with the stinkbug HhV. Analysis of transcriptomes from several hymenopteran species revealed HhV-Tp reads in four species. However, the transmission mechanism and the ecological significance of HhV remain elusive, warranting further studies to illuminate both the transmission process and its capacity for environmental propagation using T. podisi as a potential vector.


Assuntos
Vespas , Animais , Vespas/virologia , Filogenia , Brasil , Heterópteros/virologia , Heterópteros/parasitologia , Óvulo/virologia , Himenópteros/virologia , Genoma Viral
18.
Sci Rep ; 14(1): 15421, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965297

RESUMO

Aedes aegypti and Aedes albopictus are the main vectors of arboviruses such as Dengue, Chikungunya and Zika, causing a major impact on global economic and public health. The main way to prevent these diseases is vector control, which is carried out through physical and biological methods, in addition to environmental management. Although chemical insecticides are the most effective strategy, they present some problems such as vector resistance and ecotoxicity. Recent research highlights the potential of the imidazolium salt "1-methyl-3-octadecylimidazolium chloride" (C18MImCl) as an innovative and environmentally friendly solution against Ae. aegypti. Despite its promising larvicidal activity, the mode of action of C18MImCl in mosquito cells and tissues remains unknown. This study aimed to investigate its impacts on Ae. aegypti larvae and three cell lines of Ae. aegypti and Ae. albopictus, comparing the cellular effects with those on human cells. Cell viability assays and histopathological analyses of treated larvae were conducted. Results revealed the imidazolium salt's high selectivity (> 254) for mosquito cells over human cells. After salt ingestion, the mechanism of larval death involves toxic effects on midgut cells. This research marks the first description of an imidazolium salt's action on mosquito cells and midgut tissues, showcasing its potential for the development of a selective and sustainable strategy for vector control.


Assuntos
Aedes , Imidazóis , Inseticidas , Larva , Aedes/efeitos dos fármacos , Animais , Larva/efeitos dos fármacos , Imidazóis/toxicidade , Imidazóis/farmacologia , Inseticidas/toxicidade , Inseticidas/farmacologia , Humanos , Mosquitos Vetores/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Controle de Mosquitos/métodos
19.
Heliyon ; 10(9): e29938, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38707409

RESUMO

Lateral flow immunoassays (LFIA) for antibody detection represent cost-effective and user-friendly tools for serology assessment. This study evaluated a new LFIA prototype developed with a recombinant chimeric antigen from the spike/S and nucleocapsid/N proteins to detect anti-SARS-CoV-2 IgG antibodies. The evaluation of LFIA sensitivity and specificity used 811 serum samples from 349 hospitalized, SARS-CoV-2 RT-qPCR positive COVID-19 patients, collected at different time points and 193 serum samples from healthy controls. The agreement between ELISA results with the S/N chimeric antigen and LFIA results was calculated. The LFIA prototype for SARS-CoV-2 using the chimeric S/N protein demonstrated 85 % sensitivity on the first week post symptoms onset, reaching 94 % in samples collected at the fourth week of disease. The agreement between LFIA and ELISA with the same antigen was 92.7 %, 0.827 kappa Cohen value (95 % CI [0.765-0.889]). Further improvements are needed to standardize the prototype for whole blood use. The inclusion of the novel chimeric S + N antigen in the COVID-19 IgG antibody LFIA demonstrated optimal agreement with results from a comparable ELISA, highlighting the prototype's potential for accurate large-scale serologic assessments in the field in a rapid and user-friendly format.

20.
Pathogens ; 13(6)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38921757

RESUMO

The Chikungunya virus (CHIKV) presents global health challenges, with Brazil experiencing outbreaks since its introduction in 2014. In 2023, following a CHIKV outbreak in Minas Gerais (MG), social media was used to optimize an entomological survey aimed at identifying vectors and viral lineages and assessing insecticide resistance. Following Instagram posts, residents with suspected CHIKV infection were able to schedule mosquito aspirations. In total, 421 mosquitoes (165 Aedes aegypti and 256 Culex quinquefasciatus) were captured from 40 households in Salinas city (MG) and tested for the Dengue, Zika, and Chikungunya viruses through RT-qPCR. Twelve of 57 pools (10 Ae. aegypti and two Cx. quinquefasciatus) tested positive for CHIKV RNA. Viral RNA was also detected in the heads of nine Ae. aegypti, indicating viral dissemination but not in Cx. quinquefasciatus. Genome sequencing yielded the first near-complete genome from the 2023 outbreak, unveiling that the CHIKV strain belonged to the East/Central/South African (ECSA) genotype. Additionally, genetic analyses revealed high frequencies of kdr alleles, including in CHIKV-infected mosquitoes, suggesting resistance to pyrethroid insecticides in this Ae. aegypti population. Social media was important for guiding mosquito-capture efforts in CHIKV transmission hotspots, thus optimizing the opportunity for viral detection. These findings emphasize the urgent need for innovative vector studies and control strategies, as well as interdisciplinary approaches in public health interventions.

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