Memorias do Instituto Oswaldo Cruz最新文献

{"title":"Effects of exposure to Rickettsia bellii on reservoir competence of guinea pigs for Rickettsia rickettsii","authors":"Lina de Campos Binder, Carlos Eduardo Camargo Fanchini, Herbert Sousa Soares, Talita Beck Strabelli Dos Santos, Sueli Akemi Taniwaki, Marcelly Bastos Nassar, Andrea Cristina Fogaça, Maria Carolina de Azevedo Serpa, Matheus Pasini Martins, Marcelo Bahia Labruna","doi":"10.1590/0074-02760250195","DOIUrl":"10.1590/0074-02760250195","url":null,"abstract":"<p><strong>Background: </strong>Amblyomma sculptum is the main vector implicated in the transmission of Rickettsia rickettsii in southeastern Brazil, where capybaras are known to be the main amplifying hosts of this pathogen. Interestingly, many areas inhabited by large populations of capybaras and A. sculptum remain free of R. rickettsii, suggesting that other drivers may be involved in the pathogen perpetuation. A. sculptum frequently occurs in sympatry with Amblyomma dubitatum ticks, sharing the same hosts with them. Considering that A. dubitatum ticks are frequently infected with Rickettsia bellii, a possible interference of R. bellii in the reservoir competence of capybaras for R. rickettsii could explain the heterogeneous distribution of R. rickettsii in A. sculptum populations in southeastern Brazil.</p><p><strong>Objectives: </strong>The present study aimed to evaluate the effect of primary exposure to R. bellii-infected A. dubitatum on the reservoir competence for R. rickettsii using guinea pigs as experimental models.</p><p><strong>Methods: </strong>Three guinea pigs were infested with R. bellii-infected A. dubitatum (Group GB), four guinea pigs with uninfected A. dubitatum (Group GD), and three guinea pigs were not exposed to A. dubitatum (Group GC). After infestation with A. dubitatum, all guinea pigs were exposed to one single R. rickettsii-infected A. sculptum female and then were infested with uninfected A. sculptum larvae. After ecdysis, nymphs were tested for detection of spotted fever group rickettsiae.</p><p><strong>Findings: </strong>Five out of six guinea pigs from GD and GC groups died, while one out of three guinea pigs in the GB group had a fatal outcome. R. rickettsii infection rate among ticks fed on animals from GB group was 21% (17/80), significantly lower than the rate of 54% (60/111) recorded in ticks fed on animals from GD and GC groups.</p><p><strong>Main conclusions: </strong>Prior exposure of guinea pigs to R. bellii-infected A. dubitatum ticks reduced their reservoir competence for R. rickettsii.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250195"},"PeriodicalIF":2.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13008364/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immune dysregulation, apoptosis impairment, and enhanced seroreactivity to Anisakis simplex in Crohn's disease: interplay of IL-7/IL-7R signalling and CD132 deficiency","authors":"Carmen Cuéllar, Carolina Hurtado-Marcos, Elizabeth Valdivieso, Lucianna Vaccaro, Juan González-Fernández, Ana Isabel Jiménez, Jaume Pérez-Griera, Salvador Benlloch, Cirilo Amorós, Rafael Gil-Borrás, Rosa Sorando-Serra, María José Cano-Cano, Juan Carlos Andreu-Ballester","doi":"10.1590/0074-02760250129","DOIUrl":"10.1590/0074-02760250129","url":null,"abstract":"<p><strong>Background: </strong>In previous studies, we identified a deficiency of γδ T cells and an increased prevalence of anti-Anisakis simplex antibodies in patients with Crohn's disease (CD). Additionally, decreased gene expression of the interleukin 2 (IL-2) receptor γ subunit (CD132) was observed in tissues from CD patients.</p><p><strong>Objective: </strong>To analyse the gene expression of IL-7 and its receptors in tissues from CD patients and to explore its relationship with anti-A. simplex antibodies.</p><p><strong>Methods: </strong>52 patients diagnosed with CD were compared with a control group of 52 healthy individuals. Peripheral blood samples were analysed to assess levels of anti-A. simplex antibodies and IL-7. In addition, intestinal tissue samples from 20 subjects in each group were examined to evaluate IL-7 gene expression, IL-7 protein levels, the IL-2 receptor γ subunit (CD132), the IL-7 receptor α subunit (CD127), and caspase-3 expression.</p><p><strong>Findings: </strong>Anti-A. simplex antibody levels were elevated in patients with CD. Caspase-3 expression was significantly reduced in the tissues of CD patients with anti-A. simplex IgA, and this reduction extended to IgG and IgE in healthy individuals. A negative correlation was observed between caspase-3 levels and serum anti-A. simplex IgA, as well as IL-7 levels in the tissues of CD patients. In healthy subjects, tissue IL-7 levels were lower in those positive for anti-A. simplex IgA, while serum IL-7 levels were higher in individuals positive for anti-A. simplex IgG.</p><p><strong>Main conclusions: </strong>This study revealed the interplay between IL-7 signalling, γδ T cell deficiency, and immune responses to A. simplex in CD. Our findings underscored a cause-effect relationship between CD132 deficiency, γδ T cell depletion, and defective mucosal immunity, which may drive both CD inflammation and susceptibility to parasitic infections like A. simplex.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250129"},"PeriodicalIF":2.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078791/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterisation of Trypanosoma cruzi in Triatoma dimidiata from a highland locality in western Panamá","authors":"Vanessa Jenny Pineda, Kadir González, José Eduardo Calzada, Azael Saldaña","doi":"10.1590/0074-02760250172","DOIUrl":"10.1590/0074-02760250172","url":null,"abstract":"<p><strong>Background: </strong>Triatoma dimidiata is a widely distributed vector of Trypanosoma cruzi in Mesoamerica, but its epidemiological role in most regions of Panamá remains poorly understood.</p><p><strong>Objectives: </strong>To investigate the presence, infection status, and feeding behaviour of T. dimidiata populations in peridomestic areas of Palmira Arriba, western Panamá.</p><p><strong>Methods: </strong>Entomological surveys were conducted in five peridomestic sites of a rural highland community. Thirty-seven triatomines (13 adults and 24 nymphs) were collected from wooden piles and construction materials in contact with the ground. DNA from 30 specimens was analysed by polymerase chain reaction (PCR) for T. cruzi detection, genotyping [discrete typing unit (DTU) and haplotype identification], and blood meal source determination through cytochrome b amplification.</p><p><strong>Findings: </strong>Twenty-one insects (70.0%) were positive for T. cruzi. Sixteen infections (76.2%) belonged to DTU I (TcI), including 13 TcIDOM and 14 TcIa genotypes, both linked to domestic and sylvatic cycles. Blood meal analysis revealed one mammalian and two avian feedings, indicating opportunistic behaviour.</p><p><strong>Main conclusions: </strong>This study provides the first molecular confirmation of T. cruzi infection in T. dimidiata from Palmira Arriba. The combination of high infection prevalence, multiple developmental stages, and recent feeding suggests active local transmission favoured by humid and cool ecological conditions. Expanded surveillance and integrative One Health approaches are needed to elucidate transmission dynamics in highland rural Panamá.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250172"},"PeriodicalIF":2.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reframing vector control: land use and climate shape malaria risk in Amazonian communities","authors":"André Luis Acosta, Eduardo Sterlino Bergo, Elder Augusto G Figueira, Jan E Conn, Maria Anice Mureb Sallum","doi":"10.1590/0074-02760250171","DOIUrl":"10.1590/0074-02760250171","url":null,"abstract":"<p><strong>Background: </strong>Malaria remains a major public health challenge in the Brazilian Amazon, where ecological heterogeneity and socio-economic vulnerability hinder the effectiveness of vector elimination. The primary vector, Nyssorhynchus darlingi, shows substantial spatiotemporal variation influenced by land-use changes and local microclimates.</p><p><strong>Objectives: </strong>Investigate how land cover and microclimatic factors affect Ny. darlingi human biting rate (HBR) across different Amazonian ecoregions.</p><p><strong>Methods: </strong>HBR was measured through human landing catches at 70 sites in four ecoregions, with simultaneous temperature and humidity recordings. Landscape composition was quantified within 100-, 250-, and 500-m buffers. Data were analyzed using linear regressions, mixed-effects models, and principal component analysis.</p><p><strong>Findings: </strong>We recorded 14,689 mosquito bites across 384 events. HBR was highest in areas with intermediate forest degradation and was positively associated with temperature and negatively with humidity. Floodable vegetation was the strongest land cover predictor, especially at the 500-m scale. Intrazonal variation exceeded interzonal differences.</p><p><strong>Main conclusions: </strong>Local environmental conditions, particularly floodable vegetation near human settlements, strongly influence Ny. darlingi activity. Vector elimination in the Amazon should adopt climate-sensitive, spatially targeted strategies informed by land cover and microclimate data.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250171"},"PeriodicalIF":2.5,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Giardia duodenalis assemblage A: new genotype in non-human primates from the Brazilian Amazon region revealed by high-resolution MLST","authors":"Lisiane Lappe Dos Reis, Lirna Salvioni Silva de Souza, Maria Gabriela Rodrigues Antunes, Alessandra Ferreira Dales Nava, Ana Carolina Paulo Vicente","doi":"10.1590/0074-02760250234","DOIUrl":"10.1590/0074-02760250234","url":null,"abstract":"<p><strong>Background: </strong>Giardia duodenalis is an intestinal protozoan parasite that infects a wide range of vertebrate hosts, including humans, and is the etiological agent of giardiasis. Within this species, assemblage A is further subdivided into three sub-assemblages: AI, AII, and AIII.</p><p><strong>Objectives: </strong>To apply the high-resolution multilocus sequence typing (MLST) to perform molecular epidemiology of G. duodenalis assemblage A in humans and animals in the State of Amazonas, Brazil.</p><p><strong>Methods: </strong>We performed parasitological analyses of faecal samples from animals and collected Giardia-positive samples from humans in the State of Amazonas, Brazil. Giardia genotyping was carried out using an MLST scheme based on six genes (CID1, NEK15411, DIS3, HCMP22547, HCMP6372, RHP26), as well as the three conventional loci (tpi, bg and gdh), followed by phylogenetic analysis.</p><p><strong>Findings: </strong>Using an extended MLST scheme for assemblage A, we identified a new genotype infecting two non-human primate (NHP) species from the Amazon region. Additionally, Giardia from sub-assemblage AII infecting humans in this region shows a close phylogenetic relationship with isolates from other countries. Furthermore, a sub-assemblage AI isolate from an anteater (Tamandua tetradactyla) belongs to a lineage infecting diverse animals and humans, highlighting its zoonotic and cosmopolitan nature.</p><p><strong>Main conclusions: </strong>These findings reveal a new, genetically distinct lineage within G. duodenalis assemblage A, likely representing a new sub-assemblage (AIV) associated with NHPs in the Amazon region, and reinforce the usefulness of high-resolution MLST for detecting fine-scale genetic diversity and potential zoonotic transmission pathways.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250234"},"PeriodicalIF":2.5,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of neurotropic arboviruses in wild and domestic animals in Amazon region, 2023-2024.","authors":"Daniel Jun Hayashi, Bruno Tardelli Diniz Nunes, Sandro Patroca da Silva, Tânia Cristina Alves da Silveira da Cunha, Francisco Amilton Dos Santos Paiva, Ivy Tsuya Essashika Prazeres, Alessandra da Conceição Miranda Santos, Landeson Junior Leopoldino Barros, Ana Cláudia da Silva Ribeiro, Felipe Baraldi Sobral, Luiz Mário Fernandes, Taciana Fernandes Souza Barbosa Coelho, Valéria Lima Carvalho, Ana Cecilia Ribeiro Cruz, Daniele Barbosa de Almeida Medeiros, Livia Medeiros Neves Casseb","doi":"10.1590/0074-02760250013","DOIUrl":"10.1590/0074-02760250013","url":null,"abstract":"<p><strong>Background: </strong>Arboviruses represent a potential threat to global public health due to their ability to infect various vertebrate hosts and vectors, as well as their adaptability to diverse ecosystems, allowing them to expand geographically across continents.</p><p><strong>Objective: </strong>The present study aimed to describe the molecular epidemiology of encephalitic arboviruses, including Venezuelan equine encephalitis virus (VEEV), Eastern equine encephalitis virus (EEEV), Western equine encephalitis virus (WEEV), West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Toscana virus (TOSV), and Rift Valley fever virus (RVFV) in nervous tissue samples from domestic and wild animals from the Northern region of Brazil, between February 2023 and June 2024.</p><p><strong>Methods: </strong>Samples negative for rabies virus were analysed by reverse transcription real-time polymerase chain reaction (RT-qPCR) targeting Alphavirus, Orthoflavivirus and Phlebovirus species.Positive samples were subjected to viral isolation in cell culture and whole-genome sequencing using next-generation sequencing.Phylogenetic and molecular clock analyses were performed to characterise viral lineages and evolutionary relationships.</p><p><strong>Findings: </strong>Two samples tested positive for arboviruses by RT-qPCR: one SLEV sample from the state of Amazonas, which showed a low viral load, preventing virus isolation and sequencing, and one Madariaga virus (MADV) sample from the state of Pará, which could be isolated and sequenced.The isolated agent belongs to lineage III of EEEV, showing most similarity to strains from Guyana and Argentina.</p><p><strong>Main conclusions: </strong>The present study detected two arboviruses in animals, suggesting its circulation in the study area.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250013"},"PeriodicalIF":2.5,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12991413/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147481068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome mining and characterisation of biosynthetic clusters in Aspergillus japonicus isolated from the Amazon rainforest.","authors":"Josy Caldas Rodrigues, Maria Eduarda Grisolia, Alice da Silva Queiroz, Ana Luísa Rodrigues Lima, Clarice Virginia Santos Goiabeira, Leila de Mendonça Lima, Ormezinda Celeste Cristo Fernandes","doi":"10.1590/0074-02760250075","DOIUrl":"10.1590/0074-02760250075","url":null,"abstract":"<p><strong>Background: </strong>In light of the biotechnological potential demonstrated by Aspergillus species and, considering the great need for further research into the search for new sources of active molecules and the biodiversity of these microorganisms occurring in the Amazon region.</p><p><strong>Objectives: </strong>This research aimed to investigate the biotechnological potential of the fungus Aspergillus japonicus Amazon Fungi Collection (CFAM) 0234, a fungal strain isolated from Amazonian soil and stored in the CFAM.</p><p><strong>Methods: </strong>For this purpose, the Aspergillus species was investigated through comparative genomic analysis and antimicrobial activity assays.</p><p><strong>Findings: </strong>Genome sequencing revealed a fragmented assembly (72.67 Mbp, N50 = 152 kbp) containing 106 biosynthetic clusters (BGCs), surpassing the reference strain CBS 114.51 (57 BGCs). Among the clusters identified, NRPS, PKS type I and hybrid NRPS-PKS systems stood out, including clusters exclusive to betalactones and isocyanides, potentially involved in the synthesis of β-lactam antibiotics and innovative metabolites. BiG-SCAPE analysis identified 63 BGC families unique to CFAM 0234, suggesting evolutionary adaptations to the competitive environment of the Amazon. Biological assays demonstrated selective antimicrobial activity of the ethyl acetate extract against Escherichia coli, Shigella sonnei and Sthapylococcus aureus (MRSA), with inhibition halos ranging from 8 mm to 6 mm in diameter, pathogens classified as priorities for research into new antibiotics. The correlation between predicted BGCs and antimicrobial activity reinforces the strain's biotechnological potential. Despite the fragmentation of the genome, the high completeness assessed by BUSCO (98.5%) confirms the quality of the assembly, while the detection of single nucleotide polymorphisms (SNPs) in regulatory regions and rearrangements close to BGCs suggests evolutionary pressure for metabolic diversification. The lack of correspondence with the minimum information about a biosynthetic gene cluster (MIBiG) bank and the limitations of crude extracts highlight the need for complementary techniques, such as long-read sequencing (Oxford Nanopore) and metabolomic analysis [liquid chromatography-mass espectrometry (LC-MS)], to link clusters to active metabolites.</p><p><strong>Main conclusions: </strong>Aspergillus japonicus CFAM 0234 represents a promising microbial resource for bioprospecting in the Amazon, offering relevant genomic and chemical insights for the development of new antimicrobial agents. Future studies will focus on the purification of compounds and activation of silent BGCs, aiming at sustainable pharmaceutical applications.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250075"},"PeriodicalIF":2.5,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12987578/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147480978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential expression of miRNAs in Vero cells after Mayaro virus infection.","authors":"Juliana Santana de Curcio, Lívia do Carmo Silva, Evandro Novaes, Elisângela de Paula Silveira-Lacerda","doi":"10.1590/0074-02760250177","DOIUrl":"10.1590/0074-02760250177","url":null,"abstract":"<p><strong>Background: </strong>The Mayaro virus (MAYV) is an alphavirus endemic to Central and South America, primarily transmitted by mosquitoes of the Haemagogus genus. Human infection causes \"Mayaro fever,\" characterized by symptoms similar to dengue and chikungunya, including debilitating arthralgia. Despite its potential for urbanisation, many aspects of MAYV-host interactions, particularly the role of host microRNAs (miRNAs), remain poorly understood.</p><p><strong>Objectives: </strong>This study aimed to investigate the expression profile of miRNAs in Vero cells infected with MAYV and to predict their potential biological targets and associated pathways.</p><p><strong>Methods: </strong>Infection was performed using the MAYV strain (BeAr 20290), and small RNA libraries were prepared from infected and control cells. Initial experiments were conducted to evaluate viral replication, cell viability, and small RNA expression. Based on these parameters, the 24-h post-infection time point was selected for small RNA sequencing. Bioinformatic tools were used to identify differentially expressed miRNAs and predict their targets in Homo sapiens and the MAYV genome.</p><p><strong>Findings: </strong>Among the 348 miRNAs identified, 46 were differentially expressed at 24 h (42 upregulated and four downregulated). Principal component analysis (PCA) indicated a clear separation between infected and control groups. In silico predictions of the targets of these miRNAs suggest potential associations with biological processes that may be relevant to virus-host interactions, such as immune response, programmed cell death pathways, viral replication, and persistence. Additionally, one miRNA detected in Vero cells was predicted to target a viral non-structural protein.</p><p><strong>Main conclusions: </strong>Our findings indicate a potential dual role for host miRNAs during MAYV infection, involving both the modulation of host responses by the virus to enhance replication and a possible antiviral effect. While these interactions underscore the prospective relevance of miRNAs as biomarkers and therapeutic targets in arboviral infections, it is important to note that these conclusions are based solely on computational analyses. Therefore, they should be interpreted with caution until they are supported by further experimental validation.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250177"},"PeriodicalIF":2.5,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12987633/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147481058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptomics of Plasmodium vivax rosettingFIRST REVIEW ROUND - REVIEWERS COMMENTSREVIEWERS COMMENTS.","authors":"Catarina Bourgard, Julia Weber Ferraboli, Stefanie Costa Pinto Lopes, Marcus Vinicius Guimarães de Lacerda, Per Sunnerhagen, Letusa Albrecht, Fabio Trindade Maranhão Costa","doi":"10.1590/0074-02760250198","DOIUrl":"https://doi.org/10.1590/0074-02760250198","url":null,"abstract":"<p><strong>Background: </strong>Plasmodium vivax rosetting is a cytoadhesion phenomenon associated with parasite virulence and clinical manifestations of malaria. However, the molecular mechanisms underlying this process remain poorly understood. Comparative transcriptomic analysis between isolates with different rosetting capacities may provide insights into the molecular base and clinical outcome of parasite populations with distinct rosetting characteristics.</p><p><strong>Objectives: </strong>Our study aims to identify and describe the transcription profile of P. vivax isolates with high and low rosetting rates.</p><p><strong>Methods: </strong>We used RNA-seq to compare the transcriptomes of 10 field P. vivax isolates from the Brazilian Amazon.</p><p><strong>Findings: </strong>Among the 492 differentially expressed genes of P. vivax isolates with high rosetting (HR) versus low rosetting (LR) formation, 172 (34,96%) are annotated as genes conserved within Plasmodium and of unknown function. The expression profiles of the other 320 genes (65,04%) highlight the importance of integral membrane proteins and membrane-associated proteins with adhesive or adhesin-like properties, representing 10% of the transcribed genes (53 genes), such as Plasmodium Helical Interspersed Sub-telomeric (PHIST) proteins in rosetting phenotypes. Transcriptomic analyses revealed that approximately 4% (19 genes) of differentially expressed genes were kinases and 50% (248 genes) other proteins. Among cell surface proteins and integral/membrane-associated proteins, differentiated expression and positive regulation of representative 6-cysteine gene family were observed in HR formation group, which includes a tryptophan-rich protein (TRAG16), the 41K blood stage antigen precursor 41-3 protein, and merozoite surface protein 7-like (MSP7-like).</p><p><strong>Main conclusions: </strong>These results contribute to understanding the molecular basis of P. vivax rosetting.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250198"},"PeriodicalIF":2.5,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147433637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Entomo-virological investigation during the epizootic outbreak of sylvatic yellow fever in Rio Grande do Sul, Brazil, between 2021 and 2022","authors":"Nícolas Felipe Drumm Müller, Marcelo de Moura Lima, Edmilson Dos Santos, Aline Alves Scarpellini Campos, Thomas Rosa Menegazzi, Alanis Silva Melgarejo, Bruna Paredes-Galarza, Lina Violet-Lozano, Martha Trindade Oliveira, Cirilo Henrique Oliveira, Paulo Michel Roehe, Fabrício Souza Campos, Filipe Vieira Santos de Abreu, Jáder da Cruz Cardoso, Ana Cláudia Franco","doi":"10.1590/0074-02760250169","DOIUrl":"10.1590/0074-02760250169","url":null,"abstract":"<p><strong>Background: </strong>Yellow fever virus (YFV) re-emerged among non-human primates (NHPs) in Rio Grande do Sul in early 2021, more than a decade after its last detection in the state. The spread of the virus was accompanied by increased mortality among NHPs.</p><p><strong>Objectives: </strong>To conduct entomological surveillance and molecular detection of YFV and other Orthoflavivirus species in mosquito samples collected from affected and potentially receptive areas.</p><p><strong>Methods: </strong>Mosquitoes were collected during epizootics using human landing catches, BG-Pro traps, and ovitraps. Virus detection was performed using reverse transcription real-time polymerase chain reaction (RT-qPCR) assays targeting YFV and pan-Orthoflavivirus sequences.</p><p><strong>Findings: </strong>A total of 1,210 mosquitoes, representing 26 taxa, were collected across 17 municipalities. Psorophora ferox was the most abundant species, followed by Culex (Culex) spp., accounting for 27% and 12% of the specimens, respectively. Haemagogus leucocelaenus, the primary YFV vector in the region, was also among the most frequently captured species, representing 7%. In total, 203 mosquito pools were assembled by species, location, and date of collection. RT-qPCR analysis did not detect YFV or other Orthoflavivirus RNA in any of the samples.</p><p><strong>Main conclusions: </strong>Although mosquitoes were collected during a period of active YFV circulation, the absence of virus detection suggests that arboviral circulation in vector populations may occur at low frequencies, even during outbreaks.</p>","PeriodicalId":18469,"journal":{"name":"Memorias do Instituto Oswaldo Cruz","volume":"121 ","pages":"e250169"},"PeriodicalIF":2.5,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12971024/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147434137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}