Memorias Do Instituto Oswaldo Cruz[JOURNAL]
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200 papers
A comparison of the cost-effectiveness of the current standard of care and of the haematology analyser XN31-microscopy combination for diagnosing malaria in a nonendemic country.
Picot S, Bienvenu AL
Mem Inst Oswaldo Cruz · 2026 · PMID 41538520 · Full text
BACKGROUND: The biological diagnosis of imported malaria cases is a challenge that requires efficient methods, trained staff and high-quality proficiency. Microscopy, rapid diagnosis tests and molecular tests are widely...
BACKGROUND: The biological diagnosis of imported malaria cases is a challenge that requires efficient methods, trained staff and high-quality proficiency. Microscopy, rapid diagnosis tests and molecular tests are widely available and provide excellent results. New methods such using haematology analysers have been recently developed. OBJECTIVES: In the context of limited resources, a complete cost-effectiveness analysis of the different scenarios should aid in the decision-making process for the most appropriate methods. METHODS: The full cost-effectiveness of each malaria diagnosis scenario relative to the clinical benefits of the outcome was measured. The study population was a cohort of patients who were receiving health care at Lyon University Hospital for suspected malaria during 2023. Four scenarios were tested: microscopy, rapid diagnosis test + microscopy combination, loop-mediated isothermal amplification (LAMP) + microscopy combination, all identified as the control tests, and haematology analyser XN-31 + microscopy combination, identified as the intervention. The direct costs were calculated based on prices paid in France for material and consumables needed to perform malaria diagnosis for one sample among 1000 tests per year. The indirect cost of technical training, supervision and quality proficiency was calculated based on the hourly salary of the laboratory technician, junior and senior doctors according to the time needed for each scenario. FINDINGS: This approach provides a global approach for determining the cost-effectiveness of the most frequent scenarios for diagnosing malaria. The diagnosis accuracy and the short time-to-result of the haematology analyser combined with microscopy were the key points of the cost-effectiveness result. MAIN CONCLUSION: The generalisability of our findings is restricted by the specificity of the costs observed in France and the limited panel of methods tested. However, this may promote similar studies from other countries to document the cost-effectiveness of the different scenarios used for malaria diagnosis.
The 50th Anniversary Conference - Caxambu 2024.
Tonelli RR, Lahr DJG, Saraiva EM … +1 more , Lopes AHCS
Mem Inst Oswaldo Cruz · 2025 · PMID 41538519 · Full text
Chagas disease (CD), caused by Trypanosoma (Schizotrypanum) cruzi, remains a major global health concern, particularly in Latin America, where millions are at risk. To mark five decades of Chagas research, the Brazilian...
Chagas disease (CD), caused by Trypanosoma (Schizotrypanum) cruzi, remains a major global health concern, particularly in Latin America, where millions are at risk. To mark five decades of Chagas research, the Brazilian Society of Protozoology (SBPz) hosted a four-day conference held in Caxambu, Minas Gerais, Brazil, from November 3 to 7, 2024. The meeting brought together world-renowned experts from diverse disciplines whose work has significantly advanced the boundaries of CD studies. Key discussions focused on the parasite's genetic and metabolic adaptability, with special emphasis on genomic compartmentalisation, RNA processing, and metabolic flexibility essential for survival and pathogenesis. New insights into host-parasite interactions highlighted inflammatory and vascular remodelling processes that drive parasite dissemination and disease progression, especially in cardiac tissue. In the area of drug development, researchers noted treatment limitations, the urgency for novel therapeutic candidates, and ongoing clinical trials assessing alternative regimens of benznidazole (BZN) and nifurtimox (NFX). Progress in biomarker discovery and vaccine development was also discussed as pivotal to improving disease diagnosis, prognosis, and prevention. Beyond laboratory research, the meeting highlighted the importance of science communication and public health engagement. Outreach initiatives and educational exhibitions were showcased as tools to raise awareness and enhance access to disease diagnosis and treatment. Altogether the integration of multidisciplinary approaches from molecular biology to public policy underscores the enduring commitment to combating CD through research, collaboration, and innovation.
In vitro and in vivo studies on the activity and selectivity of butoconazole in experimental infection by Trypanosoma cruzi.
Leite GR, Batista DDGJ, Batista MM … +9 more , da Costa KN, Loughlin TM, Barrionuevo EM, Talevi A, Aberca LN, Moreira OC, Faier-Pereira A, Ferreira BIDS, Soeiro MNC
Mem Inst Oswaldo Cruz · 2025 · PMID 41538518 · Full text
BACKGROUND: The protozoan Trypanosoma cruzi causes Chagas disease (CD). There are two drugs available for the treatment with limited efficacy, especially in the later stage. Focusing on drug repurposing by virtual screen...
BACKGROUND: The protozoan Trypanosoma cruzi causes Chagas disease (CD). There are two drugs available for the treatment with limited efficacy, especially in the later stage. Focusing on drug repurposing by virtual screening of chemical databases, butoconazole (BTZ) was identified as promising hit. OBJECTIVES: Our aim was to explore the trypanosomicidal effect of BTZ alone or in combination with benznidazole (BZ) against T. cruzi. METHODS AND FINDINGS: Our in vitro assays validated the low cytotoxicity of BTZ and high potency on amastigotes (EC50 = 0.07 μM), being 24-fold more potent than BZ. Washout assays demonstrated the sterilisation capacity of BTZ, whereas its combination with BZ gave an additive interaction (xƩFICI = 0.66). In a mouse model of acute T. cruzi infection, BTZ was unable to suppress parasitaemia but ensured the animal survival. BTZ plus BZ reduced parasitaemia and provided higher survival rates than monotherapies. However, quantitative polymerase chain reaction (qPCR) revealed that BTZ + BZ protocol gave 100% of lack of parasitological cure, as parasite satDNA was amplified in the heart of all surviving animals. MAIN CONCLUSIONS: Our dataset reinforces the relevance of drug repurposing and combination strategies to advance into the development of novel therapeutic approaches for CD.
The Deanes' malarias and the antimalarial drugs in 1939 and the 1940s.
Paumgartten FJR, de Oliveira ACAX, Daniel-Ribeiro CT
Mem Inst Oswaldo Cruz · 2025 · PMID 41417553 · Full text
Malaria was one of the main research themes of Leônidas de Mello Deane (1914-1993) and Maria José von Paumgartten Deane (1916-1995), a couple of parasitologists - known among their peers as "the Deanes" - who in the late...
Malaria was one of the main research themes of Leônidas de Mello Deane (1914-1993) and Maria José von Paumgartten Deane (1916-1995), a couple of parasitologists - known among their peers as "the Deanes" - who in the late 1930s and 1940s ventured into areas of the Amazon, where the disease was endemic, and of the northeastern Brazil, where an important epidemic outbreak ecloded. Despite their knowledge of the disease and the adoption of preventive measures, both contracted malaria, he the malignant tertian fever (Plasmodium falciparum) and she the benign form of the disease (Plasmodium vivax). This article describes the circumstances in which they became infected and the evolution and outcome of their malaria. The years subsequent to the period in which they became ill witnessed extraordinary progress in the pharmacological treatment of malaria. The Deanes' two episodes of malaria are contextualised in relation to the treatment alternatives available at the time and the couple's suspicions regarding the development of resistance to existing antimalarial drugs in view of the persistence of recurrences of the disease despite treatment.
Sex influences murine T cell responses to vaccination with BCG or BCG∆BCG1419 grown as biofilms.
Flores-Valdez MA, Segura-Cerda CA, Pedroza-Roldán C … +3 more , Gómez-Haro J, Mata-Espinosa D, Jorge-Espinoza MG
Mem Inst Oswaldo Cruz · 2025 · PMID 41417552 · Full text
BACKGROUND: It is known that host sex can influence the immune response to administration of Mycobacterium bovis Bacillus Calmette-Guérin (BCG). However, the effect of BCG or BCG-derived vaccines cultured as biofilms on...
BACKGROUND: It is known that host sex can influence the immune response to administration of Mycobacterium bovis Bacillus Calmette-Guérin (BCG). However, the effect of BCG or BCG-derived vaccines cultured as biofilms on development of T cell responses in both sexes remains unclear. OBJECTIVES: To compare the influence of sex and vaccine strain (BCG Pasteur vs. BCGΔBCG1419c) on ex vivo T cell responses against mycobacterial purified protein derivative (PPD) stimulation in lung and spleen cells of mice vaccinated with bacteria grown as biofilms. METHODS: Male and female BALB/c mice were subcutaneously vaccinated with disaggregated, biofilm-derived BCG Pasteur or BCGΔBCG1419c. Sixty days later, lung and spleen cells were collected and stimulated ex vivo with PPD. Flow cytometry was used to quantify frequencies of mono- and bi-functional CD4⁺ and CD8a⁺ T cells expressing interferon gamma (IFN-γ) and tumour necrosis factor alpha (TNF-α) or interleukin-2 (IL-2), as well as frequencies of tissue-resident memory CD4⁺ T cells. FINDINGS: Sex influenced T cell responses in both organs. Lungs of female mice vaccinated with BCGΔBCG1419c showed reduced frequencies of CD8a⁺ IFN-γ⁺, and reduced frequency of CD4⁺ IFN-γ⁺ in spleen, compared with males. On the other hand, female mice vaccinated with BCG produced higher IL-2+ and IL-2+TNF-α+ T cells in spleen than paired males. Vaccine strain alone had limited effects, but sex-strain interactions shaped distinct immune profiles. MAIN CONCLUSIONS: Sex modulates the immunogenicity of BCG-based vaccines grown as biofilms. Our results underscore the importance of considering host sex and vaccine preparation in tuberculosis preclinical research.
Mosquito-disseminated diflubenzuron and spinosad as alternatives to mosquito-disseminated pyriproxyfen: a proof-of-concept, blind, controlled comparison in experimental cages.
de Abreu GBA, Gouveia AS, Ferreira FADS … +4 more , Carvajal-Cortés JJ, Codeço CT, Abad-Franch F, Luz SLB
Mem Inst Oswaldo Cruz · 2025 · PMID 41417357 · Full text
BACKGROUND: Mosquito-disseminated pyriproxyfen (MD-PPF) is a promising novel tool for urban-mosquito control, yet resistance to PPF (a juvenile-hormone analogue) may arise in exposed mosquito populations. Alternative lar...
BACKGROUND: Mosquito-disseminated pyriproxyfen (MD-PPF) is a promising novel tool for urban-mosquito control, yet resistance to PPF (a juvenile-hormone analogue) may arise in exposed mosquito populations. Alternative larvicide/pupicide molecules suitable for mosquito-driven dissemination, but with distinct modes of action, are therefore needed. OBJECTIVES: To provide a proof-of-concept evaluation of mosquito-disseminated diflubenzuron (MD-DFB, a chitin-synthesis inhibitor) and spinosad (MD-SPN, a biological neurotoxin composite) as potential alternatives to MD-PPF. METHODS: We studied Aedes aegypti-driven dissemination in 20 blind, controlled experiments run in 110 × 90 × 30-cm cages. Of primary interest was whether and how (a) mosquito-driven dissemination affected adult-mosquito emergence (1705 larvae in 40 open and 20 closed cups set inside cages; generalised linear mixed models) and (b) exposure to larvicide/pupicide-treated dissemination stations affected adult-female lifespan (400 females released inside cages; proportional-hazards mixed models). FINDINGS: Adult-mosquito emergence was similar across treatments in closed cups. In open cups, average emergence fell from ~90% [95% confidence interval (CI), 84-95%] in control cages to ~30% (20-43%), ~56% (42-69%), and ~75% (63-85%) in, respectively, MD-PPF, MD-DFB, and MD-SPN cages. Exposure to SPN, but not to DFB or PPF, clearly reduced adult-female lifespan (SPN death-hazard ratio 2.4; 1.2-5.0). CONCLUSION: Mosquito-disseminated diflubenzuron holds promise as a potential alternative to MD-PPF; further testing in field settings seems warranted.
Influence of a hyperglycaemic diet on Trypanosoma cruzi infection in mice model.
das Mercês AC, Marques FS, Martins BT … +6 more , Moreira GJL, Roatt BM, Carneiro CM, Paula-Gomes S, do Amaral JF, Vieira PMA
Mem Inst Oswaldo Cruz · 2025 · PMID 41417356 · Full text
BACKGROUND: Parasitic diseases may increase the risk of metabolic abnormalities through persistent inflammation. However, the effects of a hyperglycaemic diet during Trypanosoma cruzi infection remain poorly understood....
BACKGROUND: Parasitic diseases may increase the risk of metabolic abnormalities through persistent inflammation. However, the effects of a hyperglycaemic diet during Trypanosoma cruzi infection remain poorly understood. OBJECTIVES: This study aimed to investigate the metabolic, parasitological, immunological, and histological effects of a hyperglycaemic diet during acute T. cruzi infection in mice. METHODS: C57BL/6 mice were divided into four groups: non-infected with standard diet (NISD), infected with a standard diet (ISD), non-infected with hyperglycaemic diet (NIHD), and infected with hyperglycaemic diet (IHD). Animals were fed their respective diets for eight weeks prior to infection and monitored up to 30 days post-infection (DPI) for blood glucose, body mass, biochemical markers, parasitaemia, tissue alterations, and immune cell profiles. FINDINGS: At the time of infection, hyperglycaemic diet groups showed higher blood glucose and body mass. By 30 DPI, these animals exhibited lower glucose, increased parasitaemia, adipose tissue hypertrophy, and reduced cholesterol levels compared with controls. Infected groups showed an increased CD4+ IFN-γ+ T cells at 10 DPI, whereas macrophage expansion was observed only in ISD mice. Cardiac parasitism was higher at 30 DPI than at 10 DPI. MAIN CONCLUSIONS: These results show that T. cruzi infection affects metabolic parameters and that a hyperglycaemic diet worsens parasitological outcomes during the acute phase of infection and appears to downregulate the immune response.
Evidence of ascariasis in a Celtic newborn from northern Italy.
López-Gijón R, Teegen WR, Laffranchi Z … +3 more , Vitali D, Zink A, Milella M
Mem Inst Oswaldo Cruz · 2025 · PMID 41417355 · Full text
BACKGROUND: Infections with Ascaris lumbricoides can be traced back to the late Pleistocene by palaeoparasitological analysis. Even today, Ascaris infections are still very common worldwide. OBJECTIVES: In a pilot study,...
BACKGROUND: Infections with Ascaris lumbricoides can be traced back to the late Pleistocene by palaeoparasitological analysis. Even today, Ascaris infections are still very common worldwide. OBJECTIVES: In a pilot study, soil samples from the pelvic area of ten individuals from the Celtic necropolis of Povegliano Veronese (northern Italy) were examined using palaeoparasitological methods. The burials date from the 3rd to 1st century Before the Common Era (BCE). METHODS: The palaeoparasitological methods already proven in earlier studies were applied. FINDINGS: Positive evidence of Ascaris eggs was obtained in three individuals, including a newborn. This neonate is the focus of the article. The causes of a possible Ascaris infection in a newborn are discussed. MAIN CONCLUSIONS: It may represent the oldest documented instance of ascariasis in a neonatal individual.
Reconstructing Sordida subcomplex (Hemiptera, Reduviidae, Triatominae) phylogeny across species distribution range.
Burgueño-Rodríguez G, Nattero J, Ríos N … +13 more , Piccinali RV, Carbajal-de-la-Fuente AL, Panzera F, Lopes CM, Lobbia PA, Rojas de Arias A, Sansoni-Ruidíaz BA, Cavallo MJ, Rodríguez CS, Lorite P, Vega-Gómez MC, Rolon M, Pita S
Mem Inst Oswaldo Cruz · 2025 · PMID 41417354 · Full text
BACKGROUND: The conformation of the Sordida subcomplex has been a topic of prolonged debate, with diverse methodological approaches employed to discern its constituent species. Up to now, Triatoma sordida, T. garciabesi...
BACKGROUND: The conformation of the Sordida subcomplex has been a topic of prolonged debate, with diverse methodological approaches employed to discern its constituent species. Up to now, Triatoma sordida, T. garciabesi and T. rosai comprise part of this subcomplex. Distinguishing and identifying these three species pose significant challenges due to their pronounced morphological similarity, overlapping distributions, and presence of natural hybrids. OBJECTIVES: This study aims to uncover the genetic diversity and geographic spread of these three species. METHODS: We analysed a mitochondrial cytochrome b gene fragment and complemented it with chromosomal studies across natural populations from an extensive geographical range, including Argentina, Bolivia, Brazil, and Paraguay. FINDINGS: Phylogenetic analyses revealed genetic distances that suggest the presence of at least six putative species, rather than the three currently recognised. MAIN CONCLUSIONS: The present findings underscore the potency and significance of molecular analyses from natural populations for species identification and highlight the limitations of morphology in classifying Triatominae species.
Breaking the ice - simplified freeze-fracture of parasitic protists: a cost-effective approach without highly specialised equipment.
Attias M, Pacheco LODS, Ortiz SFDN … +5 more , Verdan R, Miranda K, Gadelha AP, de Souza W, Benchimol M
Mem Inst Oswaldo Cruz · 2025 · PMID 41417353 · Full text
BACKGROUND: We present a simplified freeze-fracture method to reveal the internal structure of protozoan parasites and their host cells, without the need for costly transmission electron microscopy (TEM) equipment. In a...
BACKGROUND: We present a simplified freeze-fracture method to reveal the internal structure of protozoan parasites and their host cells, without the need for costly transmission electron microscopy (TEM) equipment. In a traditional procedure, the four key steps in making a freeze-fracture replica are (1) freezing, (2) fracturing, (3) replication, and (4) replica cleaning. In conventional protocols, visualisation is performed using a TEM. OBJECTIVES: This study aimed to adapt the traditional freeze-fracture protocol to a more accessible method, eliminating the need for vacuum equipment and TEM, while preserving the capacity to visualise cellular structures. METHODS: In our adapted method, vacuum equipment was not required for sample fracturing, shadowing, or replica preparation. Cells were fixed with glutaraldehyde, embedded in a gelatin-chitosan matrix, cryoprotected with dimethyl sulfoxide (DMSO), and subsequently frozen in Freon, followed by immersion in liquid nitrogen. We manually break the cells with a previously frozen razor blade and macerate them with osmium tetroxide (OsO4). The samples are visualised using scanning electron microscopy (SEM). FINDINGS: We present various structures of Toxoplasma gondii, Trypanosoma cruzi, Trichomonas vaginalis, Giardia intestinalis, and cultured cells observed using our adapted freeze-fracture method. MAIN CONCLUSIONS: This is a rapid and low-cost technique that reveals cell structures comparable to those observed using traditional freeze-fracture methods, although with reduced resolution.
The activity of miltefosine combined with oral probiotics in a mouse model of cutaneous leishmaniasis.
Cranshoff Y, Azevedo R, Batista MM … +9 more , Demarque KC, Girão RD, Faier-Pereira A, Ferreira BIDS, Moreira O, Cascabulho CM, Fiuza LF, Caljon G, Soeiro MNC
Mem Inst Oswaldo Cruz · 2025 · PMID 41259559 · Full text
BACKGROUND: Leishmaniasis, caused by the protozoan Leishmania, is a neglected tropical disease (NTD) with diverse clinical forms, the most common being cutaneous leishmaniasis (CL). Antileishmanial treatments rely on a s...
BACKGROUND: Leishmaniasis, caused by the protozoan Leishmania, is a neglected tropical disease (NTD) with diverse clinical forms, the most common being cutaneous leishmaniasis (CL). Antileishmanial treatments rely on a small arsenal of chemoherapeutic agents, which are outdated, toxic, and increasingly ineffective due to drug resistance. New antileishmanial treatments and/or adjunctive therapies are warranted. OBJECTIVES: Given the role of microbiota in modulating host immunity, we explored whether probiotics (PB8-multistrain probiotic blend, or Lactobacillus rhamnosus GG, LGG-single strain) alone or in combination with the reference drug miltefosine (ML) could improve clinical outcomes against Leishmania amazonensis infection in a BALB/c mouse model for CL. METHODS: Mice were administered probiotics [gavage, 109 colony-forming units (CFU)] for a 7-day pre-treatment before infection, followed by another 14-day probiotic treatment with ML co-administration. Paw lesions were measured using a digital calliper, and parasite loads were determined through lesion imprinting and quantitative polymerase chain reaction (qPCR). The potential immunoregulatory effects of probiotic administration on the mouse serum cytokine profiles were investigated via flow cytometry. FINDINGS AND MAIN CONCLUSIONS: Probiotics alone reduced lesion size slightly, with PB8 achieving a 32% and LGG a 10% reduction at the endpoint (47-50 days post-infection, dpi). The combination of PB8 with a suboptimal ML dose (4 mg/kg/day) reduced the lesion size by 74% compared to the vehicle-treated mice, while ML alone achieved 53%. These findings were corroborated by amastigote quantification via imprinting (light microscopy) and qPCR: PB8 plus ML reduced parasite load by 76% and 87%, respectively. Multiplex cytokine analysis [interferon (IFN)-γ, interleukin (IL)-6, IL-10, IL-12p70, tumour necrosis factor (TNF) and chemokine CCL2] showed reduced serum CCL2 in PB8-cotreated groups. This suggests that PB8 could modulate serum cytokine levels to mitigate the risk of excessive inflammation, as elevated CCL2 is linked to disease exacerbation through monocyte recruitment. Our findings demonstrate the potential effect of probiotic administration to enhance antileishmanial efficacy of antiparasitic drugs.
Foodborne acute gastroenteritis outbreak associated with a rare norovirus recombinant GII.10[P16] genotype, Brazil, 2023.
Burlandy FM, Malta FC, Mello MS … +5 more , Fialho AM, Baduy GA, Guarnier RV, Moreira KCS, Fumian TM
Mem Inst Oswaldo Cruz · 2025 · PMID 41259429 · Full text
BACKGROUND: Norovirus is a major cause of acute gastroenteritis (AGE) outbreaks worldwide. On 1 August 2023, the health surveillance agency of Espírito Santo received a notification of a set cases of AGE from patients wh...
BACKGROUND: Norovirus is a major cause of acute gastroenteritis (AGE) outbreaks worldwide. On 1 August 2023, the health surveillance agency of Espírito Santo received a notification of a set cases of AGE from patients who attended an event organised by the Municipal Health Department. A local catering company provided lunch on 30 July (30 lunch boxes). The menu provided included macaroni, rice, tropeiro beans and cooked potatoes. The ingredients used in the preparation of tropeiro beans were beans, banana, cabbage, sausage and cassava flour. Diarrhoea, nausea, vomiting, abdominal pain, headache and weakness were the main reported symptoms peaking between 30 and 31 July. OBJECTIVES: In the present study, we aimed to establish the agent responsible for a gastroenteritis outbreak during a lunch event in Espírito Santo State, Brazil. METHODS: Stool samples (n = 5) of AGE patients were analysed by real-time quantitative polymerase chain reaction (RT-qPCR) to detect rotavirus A (RVA) and norovirus GI/GII. For norovirus molecular characterisation an open reading frame (ORF)1-2 junction region was used. FINDINGS: All samples tested positive for norovirus GII, showing high viral loads. Rotavirus and norovirus GI were not detected in any of the samples. Norovirus sequencing identified a rare recombinant genotype GII.10[P16] as the cause of the outbreak. Norovirus sequences from specimens from five individuals shared 100% of nucleotide (nt) identity and had the highest nt similarity with a South Africa GII.10 strain detected in 2020. MAIN CONCLUSION: This is the first report of a rare GII.10[P16] recombinant norovirus strain in Brazil.
Infection of endothelial cells by Streptococcus agalactiae reveals potential role of PI-2b pilus on endothelial barrier dysfunction.
de Oliveira JSS, Pimentel BADS, Ferreira LN … +3 more , Negreiro E Silva ME, Santos GDS, Nagao PE
Mem Inst Oswaldo Cruz · 2025 · PMID 41259428 · Full text
BACKGROUND: Streptococcus agalactiae is responsible for sepsis and meningitis, and the major cause of neonatal morbidity and mortality. However, how S. agalactiae disrupts endothelial barriers is poorly understood. OBJEC...
BACKGROUND: Streptococcus agalactiae is responsible for sepsis and meningitis, and the major cause of neonatal morbidity and mortality. However, how S. agalactiae disrupts endothelial barriers is poorly understood. OBJECTIVES: Analyse the influence of endothelial cell (HUVECs) growth under static and shear stress conditions during infection with S. agalactiae, and the role of pilus PI-2b during endothelial barrier disruption and increased endothelial permeability. METHODS: HUVECs under static and shear conditions were infected by S. agalactiae (GBS90356 and GBS90356Δpilus2b) strains in the presence and absence of fibrinogen. VE-cadherin was evaluated by immunofluorescence and RT-PCR assays, and the endothelial permeability by transwell assay. FINDS: Shear stress induced the alignment of HUVECs and increased the adherence of S. agalactiae strains (GBS90356 and GBS90356Δpilus2b), mainly in the presence of fibrinogen, in addition to greater peripheral localisation of VE-cadherin. Rupture points and damage to endothelial integrity was visualised after infection with the GBS90356WT strain, mainly in the presence of fibrinogen. RT-PCR analyses identified increase in VE-cadherin expression in HUVECs under shear stress and a decrease in VE-cadherin after infection, with increased levels of endothelial permeability. MAIN CONCLUSION: Data demonstrate for the first time the dysfunction of the adhesive barrier induced by the S. agalactiae ST-17 strain, mainly in HUVECs under shear stress, where PI-2b expression was essential to optimise the damage to endothelial integrity.
First isolation of Mycobacterium brisbanense from humans in the Americas.
Campos CED, Vasconcelos RDSS, da Silva WMV … +4 more , de Carvalho LD, Eccard MAB, Dos Santos IPN, Ramos JP
Mem Inst Oswaldo Cruz · 2025 · PMID 41172512 · Full text
BACKGROUND: Mycobacterium brisbanense is a rare nontuberculous mycobacteria and was for the first time detected in the Americas in humans. However, this, like several other species of mycobacteria, may be underreported w...
BACKGROUND: Mycobacterium brisbanense is a rare nontuberculous mycobacteria and was for the first time detected in the Americas in humans. However, this, like several other species of mycobacteria, may be underreported worldwide. Therefore, their study is increasingly important. OBJECTIVES: The aim of this article is to report and analyse the first seven human isolates of M. brisbanense in the Americas, derived from six Brazilian patients. METHODS: We sequenced the genes hsp65, rpoB and 16s rRNA, of seven mycobacterial clinical isolates, constructed a phylogenetic tree, and determined their drug susceptibility profile. FINDINGS: The regions sequenced were highly similar between the M. brisbanense type strain and the Brazilian strains. Similarly, their susceptibility profiles were similar to that of M. brisbanense type strain, except for two antibiotics tested, cefoxitin and doxycycline. MAIN CONCLUSIONS: All studied strains were identified at the species level by a concatenated tree as M. brisbanense.
IgY antibodies/Cysteamine: simple and effective methodology for electrochemical detection of SARS-CoV-2 S-protein.
Gandarilla A, Romaguera-Barcelay Y, Glória JC … +6 more , Freire L, Farias T, Feitosa J, Anzola C, Mariuba LAM, Brito WR
Mem Inst Oswaldo Cruz · 2025 · PMID 41124408 · Full text
BACKGROUND: The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections was a serious disease that spread rapidly around the world and led to a state of global health emergency. During the pan...
BACKGROUND: The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections was a serious disease that spread rapidly around the world and led to a state of global health emergency. During the pandemic, millions of deaths were notified as result of the progression of the disease to a serious condition. Research into the development of diagnostic tests was very important for the identification and control of new cases. OBJECTIVES: In this work a label-free electrochemical platform was developed for sensing of SARS-CoV-2 S-protein. METHODS: The S- antibodies (IgY type) from egg yolk were immobilised though stable bonding onto screen-printed gold electrodes surface, which was previously modified with self-assembled monolayers of cysteamine (Cys). The analytical performance of the devices was followed by differential pulse voltammetry after incubation in various concentrations of S-protein. FINDINGS: The electrical response exhibited a linear behaviour from 10 to 1000 ng mL-1 [with limit of detection (LOD) of 6.2 ng mL-1]. Also, we confirmed that our method is more sensitive than an enzyme-linked immuno-sorbent assay (ELISA), which was conducted with the same molecules (antibody and antigen) (500-4000 ng mL-1, with LOD = 235 ng mL-1). The immunosensor was selective for S-protein detection, and no significative changes were registered by differential pulse voltammetry in presence of SARS-CoV-2 N-protein. Tests on saliva samples recorded similar results to S protein standards. MAIN CONCLUSIONS: The developed immunosensor showed good performance and selectivity, therefore, it can be an alternative method for coronavirus disease 2019 (Covid-19) detecting in saliva samples.
Patients with Trichinella spiralis infection display unmodified antigen-specific immune response to SARS-CoV-2.
Mitic I, Glamoclija S, Radulovic N … +4 more , Sabljic L, Tomic S, Gruden-Movsesijan A, Sofronic-Milosavljevic L
Mem Inst Oswaldo Cruz · 2025 · PMID 41124407 · Full text
BACKGROUND: Through coevolution, helminths have developed immunomodulatory mechanisms that regulate exaggerated host immune responses and may influence immune responses to coinfections or vaccines. The coronavirus diseas...
BACKGROUND: Through coevolution, helminths have developed immunomodulatory mechanisms that regulate exaggerated host immune responses and may influence immune responses to coinfections or vaccines. The coronavirus disease 19 (COVID-19) pandemic has raised concerns about how such infections might affect vaccine-triggered immune responses. OBJECTIVES: The aim of the study was to investigate how ongoing Trichinella spiralis infection affects the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in individuals already vaccinated or virus-primed, during Trichinella outbreak in Serbia. METHODS: Among 21 individuals who tested positive for anti-Trichinella antibodies, 15 were included in the study, which allowed for the first time to examine the impact of Trichinella infection on the humoral and cellular immune response to the SARS-CoV-2 using flow cytometry. FINDINGS: The results showed that Trichinella infection did not impair antibody production or cellular responses to SARS-CoV-2. Specifically, anti-SARS-CoV-2 antibodies and memory B cells remain unaffected, and T cells (CD4+ and CD8+) responded to SARS-CoV-2 antigens by generating pro-inflammatory cytokines. MAIN CONCLUSIONS: Trichinella spiralis infection does not disrupt the host's humoral or cellular immune response to SARS-CoV-2, suggesting that the use of Trichinella antigens for the treatment of chronic inflammatory disorders, which is promising, will not affect the host's ability to respond to future viral challenges.
Concomitant immunity against superimposed homologous Echinostoma caproni infections in mice is mediated by interleuquin-25.
Cociancic P, Fiallos E, Esteban JG … +2 more , Muñoz-Antoli C, Toledo R
Mem Inst Oswaldo Cruz · 2025 · PMID 41124406 · Full text
BACKGROUND: The Institute of Cancer Research (ICR) mouse-Echinostoma caproni model is used to study mechanisms generating resistance against intestinal helminths due to the development chronic primary infections with Th1...
BACKGROUND: The Institute of Cancer Research (ICR) mouse-Echinostoma caproni model is used to study mechanisms generating resistance against intestinal helminths due to the development chronic primary infections with Th1 responses, and partial resistance to secondary infections. OBJECTIVES: This study aimed to evaluate the generation of concomitant immunity against superimposed homologous E. caproni infection. METHODS: Changes in cytokine expression and macrophages markers as a consequence of primary infection, superimposed infection and superimposed infection in anti (α)-interleuquin(IL)-25-treated mice were investigated by real-time polymerase chain reaction (PCR). Translocation and phosphorylation of STAT6 were studied by indirect immunofluorescence (IIF) on intestinal tissue sections. The IIF technique was also used to label M1 and M2 macrophages to confirm the activation pathways. FINDINGS: Primary E. caproni infections elicit partial resistance against homologous superimposed infections. The animal groups displayed distinct patterns in the expression of cytokines, macrophages markers and IL-13Rα2 as well as STAT6 phosphorylation in a process mediated by IL-25. Resistance appears to rely on the ability of to induce IL-13Rα2 upregulation. MAIN CONCLUSIONS: The concomitant immunity is based the production of IL-25, rather than in the development of Th2 responses. Regarding the IL-25-dependent mechanisms responsible for concomitant immunity, the ability of IL-25 to induce IL-13Rα2 upregulation which serves to limit the production of other regulatory proteins such as Ym1 affecting the maintenance of mucosal homeostasis appears to be critical.
The impact of probiotic administration on experimental in vitro and in vivo infection by Trypanosoma cruzi.
Batista DDGJ, Missagia LC, Demarque KC … +3 more , de Oliveira GM, Batista MM, Soeiro MNC
Mem Inst Oswaldo Cruz · 2025 · PMID 41124405 · Full text
BACKGROUND: Chagas disease (CD) caused by Trypanosoma cruzi has limited therapy. Probiotics sustain healthy microbiota, playing roles in biological events. OBJECTIVES: Our aim was to determine the impact of probiotics on...
BACKGROUND: Chagas disease (CD) caused by Trypanosoma cruzi has limited therapy. Probiotics sustain healthy microbiota, playing roles in biological events. OBJECTIVES: Our aim was to determine the impact of probiotics on T. cruzi infection in vitro and in mouse acute experimental models. METHODS: The multi strain - PB8 and the Lactobacillus rhamnosus (LR) were orally administered [106-109 colony-forming units (CFU)] for seven days prior to mice infection followed for 14 daily administrations. Peritoneal mouse macrophages (PMM) were obtained from mice treated with 109 probiotics one day before collection and infected in vitro with or not benznidazole (BZ). FINDINGS: LR and PB8 reduced by 44-87% and 23-16% the parasitaemia peak in male and female mice, respectively, but did not protect against mortality. Histopathology showed mild reduction in cardiac nests due to probiotics' administration. PB8 and LR suppressed the parasite infection of PMM by 24 and 26%, reaching 65 and 42% of declines, respectively when 3% thioglycolate was performed. PB8 increased BZ activity at 1 µM, reaching 40% of parasitism' declines compared to BZ alone (25%). No gender difference was noticed during probiotic in vivo administration. MAIN CONCLUSIONS: The results point to the potential of a combined therapeutic approach for CD, using probiotics and BZ.
Diagnosis of Trypanosoma cruzi infection in Mexican populations: current conventional serology lacks adequate sensitivity and specificity.
Ramsey JM, de la Cruz-Felix K, Tun-Ku E … +7 more , Schijman AG, Gutiérrez S, Virgen-Cuevas M, Reyes-Romero M, Escobedo-López K, Sánchez-González G, Pech-May A
Mem Inst Oswaldo Cruz · 2025 · PMID 41124404 · Full text
BACKGROUND: The performance of serological tests for Trypanosoma cruzi diagnosis in Mexico has not included discordant control sera nor has it evaluated the role of immune response specificities, patient infection histor...
BACKGROUND: The performance of serological tests for Trypanosoma cruzi diagnosis in Mexico has not included discordant control sera nor has it evaluated the role of immune response specificities, patient infection history or clinical status. OBJECTIVES: The performance of commercial serological and molecular diagnostic tests and diagnostic algorithms was analysed in Mixtecan and Zapotecan ethnic populations having recent and long-term infection history. METHODS: An amplified global gold standard for T. cruzi infection included serological (≥ 2 conventional tests positive) and molecular (sequence identity of any of five genes using end point polymerase chain reaction (epPCR) or any positive using quantitative polymerase chain reaction (qPCR) diagnostic test results. FINDINGS: Only 81% of previously diagnosed untreated infections were reconfirmed using serology, while an additional 14% only using PCR. Serological diagnosis sensitivity (≥ 2 tests positive) in the primary diagnosis cohort was 8%, while specificity was 16%. Diagnosis sensitivity was similar using epPCR and qPCR only in primary diagnoses and all identified using the satellite (SAT) gene. The 18S ribosomal DNA identified T. cruzi and T. dionisii co-infections from Pacific coast sites. MAIN CONCLUSIONS: The current study provides evidence for inadequate diagnostic performance of conventional serological tests and the need to develop appropriate antigenic tools and use molecular testing of seronegatives to ascertain absence of infection.
Role of the epitranscriptome in viral infections: beneficial or detrimental?
Abdullah MF, Yee KS, Zainal N … +2 more , AbuBakar S, Ling CK
Mem Inst Oswaldo Cruz · 2025 · PMID 41059804 · Full text
Epitranscriptomics, the study of post-transcriptional chemical base modifications of RNAs, has become a crucial area of research for understanding the complex interactions between viruses and their hosts. These RNA modif...
Epitranscriptomics, the study of post-transcriptional chemical base modifications of RNAs, has become a crucial area of research for understanding the complex interactions between viruses and their hosts. These RNA modifications significantly impact both viral and host RNA functions, influencing viral replication, transcription, translation, and immune evasion. The advancement of high-throughput technologies, such as mass spectrometry-based techniques and next-generation sequencing, has enabled researchers to investigate epitranscriptomic modifications and their roles in gene regulation in greater depth. Viral RNAs often carry various epitranscriptomic modifications that facilitate their stability and translation, enabling viruses to hijack the host environment, enhance replication, and evade immune defences. Conversely, host epitranscriptomic modifications can enhance antiviral responses by regulating gene expression and promoting the degradation of viral RNAs. This dual role underscores the complexity of virus-host dynamics, where epitranscriptomic modifications can be both beneficial and detrimental. This review aims to provide an overview of current knowledge on epitranscriptomic modifications in viral infections, focusing on their roles in viral replication and immune interactions, while considering their potential as targets for antiviral therapeutic intervention.
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