Acta tropica最新文献

{"title":"WITHDRAWN: In vitro efficacy of azithromycin against the larvae of Echinococcus multilocularis.","authors":"Xia Liao, Jinlong Zhao, Ziyi Fang, Yun Du, Abulaiti Maierhaba, Tengfei Qiu, Yutong Jia, Nazhaketi Simayili, Jun Zhao, Renyong Lin, Guodong Lü","doi":"10.1016/j.actatropica.2026.108232","DOIUrl":"10.1016/j.actatropica.2026.108232","url":null,"abstract":"<p><p>Alveolar echinococcosis (AE) is a serious zoonotic parasitic disease caused by the larvae of Echinococcus multilocularis. Given the limitations of current medications, there is an urgent necessity for the development of novel pharmacological treatments for AE. Azithromycin, a macrolide antibiotic, exhibits both antibacterial and antiparasitic effects. This study aimed to investigate its effects on the viability of E. multilocularis larvae and to elucidate the underlying mechanisms. Ultrastructural changes were examined using scanning and transmission electron microscopy. Glucose assays, ROS assays, mitochondrial membrane potential assays, and Western blot were used to evaluate the in vitro effects of azithromycin on protoscoleces. Our results demonstrated that azithromycin treatment significantly decreased the viability of E. multilocularis protoscoleces and caused pronounced ultrastructural damage. Mechanistically, it significantly downregulated glucose transporter 1 (GLUT1) and protein kinase B (AKT) signaling, elevated ROS levels (P < 0.001), and decreased mitochondrial membrane potential. Furthermore, it downregulated the DNA damage marker γ-H2AX expression (P < 0.001) and induced ferroptosis, as evidenced by concurrent elevations in lipid peroxidation and Fe²⁺ (P < 0.001), along with reduced GSH content and diminished GPX4 and DHODH expression (P < 0.001). Collectively, azithromycin exerts multiple effects on protoscoleces, encompassing metabolic disruption, oxidative stress, and ferroptosis, thereby providing a mechanistic foundation for AE treatment.</p>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":" ","pages":"108232"},"PeriodicalIF":2.6,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148417870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterization of midgut Peritrophin-44 and Peritrophin-48 and their role in Plasmodium development.","authors":"Alok Dubey, Vinod Kumar Chauhan, Krishna Chaitanya Rapalli","doi":"10.1016/j.actatropica.2026.108176","DOIUrl":"10.1016/j.actatropica.2026.108176","url":null,"abstract":"<p><p>The peritrophic matrix (PM) is a semi-permeable, chitin-peritrophin layer lining the insect midgut. It facilitates digestive compartmentalization, maintains midgut homeostasis, mitigates the oxidative cytotoxicity of free heme, and acts as a mechanical barrier impeding the midgut invasion of pathogens like Plasmodium. The specific roles of individual peritrophins during parasite transmission are not well characterized. This study provides the first functional characterization of two peritrophins, Peritrophin-44 (Per-44) and Peritrophin-48 (Per-48), in Anopheles stephensi. Sequence analysis confirmed that both proteins contain peritrophin A-domain (PAD) with conserved six-cysteine motifs, identifying them as Class III chitin-binding proteins. Both Per-44 and Per-48 genes were predominantly expressed in the midgut. These transcripts are expressed throughout the lifecycle (i.e. larvae, pupae, and adults), with peak expression in fourth-instar larvae and adults. Following an infectious blood meal, both are significantly upregulated during ookinete invasion. RNA interference (RNAi)-mediated silencing of Per-44 and Per-48 impaired mosquito fitness, increasing mortality and reducing fecundity in infected vectors. Notably, Per-48 knockdown induced the most severe phenotype, causing a significant reduction in oocyst burden and demonstrating its essential role in Plasmodium transmission. These results demonstrate that Per-44 and Per-48 are essential PM components that may modulate midgut integrity and vector competence, highlighting them as viable targets for transmission-blocking strategies against malaria.</p>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":" ","pages":"108176"},"PeriodicalIF":2.6,"publicationDate":"2026-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148196979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Repurposing of FDA-approved drugs to identify potential NS2B/NS3 protease inhibitors against dengue virus: In silico and in vitro evaluation” [Acta Tropica volume 274 (2026) 107987]","authors":"Adiba ,&nbsp;Alia Uzma ,&nbsp;Mustafeez Mujtaba Babar ,&nbsp;Muhammad Armaghan Khalid ,&nbsp;Muhammad Tariq Navid ,&nbsp;Liaqat Ali ,&nbsp;Deeba Amraiz","doi":"10.1016/j.actatropica.2026.108019","DOIUrl":"10.1016/j.actatropica.2026.108019","url":null,"abstract":"","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 108019"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146218196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine Learning forecasting of dengue in São Paulo using virtual data augmentation and urban incident predictors: Addressing the exceptional surge of cases in 2024","authors":"Mohamad Al Bannoud ,&nbsp;Jorge Luiz Mendes ,&nbsp;Rodrigo Seiti Sacay ,&nbsp;Tiago Dias Martins ,&nbsp;Iara Rocha Antunes Pereira Bresolin ,&nbsp;Joana Bratz Lourenço","doi":"10.1016/j.actatropica.2026.107992","DOIUrl":"10.1016/j.actatropica.2026.107992","url":null,"abstract":"<div><div>Dengue remains one of the most critical vector-borne diseases globally, with Brazil consistently reporting the highest incidence in the Americas. The 2024 epidemic was the largest in the country’s history, with São Paulo as its epicenter. This study developed and evaluated a machine learning (ML) framework to forecast dengue under extreme epidemic conditions, focusing on enhancing model robustness when testing data exceed the range of historical observations. A novel virtual data augmentation strategy was introduced to expose models to synthetic large-scale outbreaks and to assess the predictive value of urban incident variables such as flooding and flooded streets. Epidemiological, climatic, and urban incident data from 2014 to 2022 were used for model training, and 2023–mid-2025 for testing. Fourteen ML algorithms were systematically evaluated under multiple preprocessing configurations, including feature scaling, lagged predictors, feature combinations, data augmentation, and feature reduction. Forecasts targeted probable, confirmed, severe, and fatal dengue cases at a one-week horizon. The algorithms AdaBoost and CatBoost achieved the highest predictive accuracy. Virtual data augmentation substantially improved robustness when test values exceeded training maxima, reducing RMSE by up to 80% for probable and confirmed cases, 42% for severe cases, and 53% for deaths compared with models trained on unaugmented data. Flooding-related indicators, especially flooded-street case counts, were among the most influential predictors. The proposed ML framework accurately forecasted dengue incidence and severity during the unprecedented 2024 outbreak. The virtual augmentation method effectively managed distributional shifts and extreme epidemic magnitudes, providing a transferable foundation for early-warning systems and public-health preparedness in urban settings.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 107992"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new species of Myxidium (Myxozoa) infecting the gallbladder of siluriform fish Pimelodus pantaneiro from the Brazilian Pantanal wetland","authors":"Tatiane Carolina Ponzetto ,&nbsp;Edson A Adriano ,&nbsp;Antonio Augusto Mendes Maia","doi":"10.1016/j.actatropica.2026.107996","DOIUrl":"10.1016/j.actatropica.2026.107996","url":null,"abstract":"<div><div>This study describes a new species of myxozoan, <em>Myxidium pantanalense</em> n. sp., parasitizing the gallbladder of the freshwater fish <em>Pimelodus pantaneiro</em> Souza-Filho and Shibatta, 2007, collected in the Brazilian Pantanal wetland, Mato Grosso do Sul State. The identification was based on morphological and molecular analyses. Myxospores exhibited a fusiform shape, 7–8 striations on the valvular surface, measuring 16.5 μm in length and 4.4 μm in width, with equally sized pyriform nematocysts measuring 5.5 μm in length and 2.8 μm in width, each containing a tubule making 4 to 5 turns. Phylogenetic analysis, based on small subunit ribosomal DNA sequences, positioned <em>M. pantanalense</em> n. sp. as the sister species to <em>Myxidium amazonense</em>. Morphological, genetic, and phylogenetic data support the designation of <em>M. pantanalense</em> n. sp. as a new taxon and expand the known diversity and geographic distribution of the genus <em>Myxidium</em> in South America.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 107996"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146083762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut microbiome diversity and functional profiles of Culicoides across Sanya, Ruili, and Linyi, China","authors":"Juan Teng ,&nbsp;Wen Li ,&nbsp;Yuda Wei ,&nbsp;Chongcai Wang ,&nbsp;Xiaoyun Yun ,&nbsp;Yunlan Lu ,&nbsp;Jian Chen ,&nbsp;Xuzhi Ma ,&nbsp;Yae Zhao","doi":"10.1016/j.actatropica.2026.108013","DOIUrl":"10.1016/j.actatropica.2026.108013","url":null,"abstract":"<div><h3>Background</h3><div>Biting midges (<em>Culicoides</em> spp.) are vectors of diverse microbes such as viruses, bacteria, protozoa, and nematodes that cause diseases in both wild and domestic animals. Despite their ecological significance and role in disease transmission, the composition and underlying mechanisms shaping the gut microbiota of <em>Culicoides</em> remain poorly characterized.</div></div><div><h3>Objectives</h3><div>This study aimed to investigate the composition and functional profiles of the gut microbiota of adult <em>Culicoides</em> collected from three representative cities spanning tropical, subtropical, and temperate climate zones in China.</div></div><div><h3>Methods</h3><div>16S high-throughput sequencing was used to study the microbial composition and function of <em>Culicoides</em> in the three regions. This study further incorporated six environmental factors and seven genetic diversity indices to explore their relationships with the microbial community.</div></div><div><h3>Results</h3><div>The findings revealed significant variations in the gut microbial composition, dominant species, and diversity of <em>Culicoides</em> across different climate zones. Notable differences were observed in microbial functions related to insect growth, development, and oxidative stress, with <em>Culicoides</em> from the Sanya zone exhibiting a greater abundance of functions and participating in more signaling processes. Environmental factors and host genetic diversity across different habitats collectively shape the composition of the gut microbiota of <em>Culicoides</em>. Structural equation modeling (SEM) revealed that environmental factors exert predominantly direct selective effects on microbial community assembly, whereas host genetic diversity plays a critical indirect regulatory role. These environment-host-microbiota interactions exhibit significant spatial heterogeneity. In low-latitude regions (Sanya), environmental factors mainly manifest direct filtering effects, whereas in ecotone areas (Ruili), environmental pressures indirectly modulate microbial composition by altering host genetic adaptation.</div></div><div><h3>Conclusions</h3><div>Our findings revealed that <em>Culicoides</em> gut microbiomes exhibit distinct biogeographical divergence, characterized by environment-driven variations in microbial community structure and functional potential. Host genetic adaptation serves as a key mediator and synergistic modulator of these patterns. This tripartite environment-host-microbiome interaction demonstrates clear dependence on geographic gradient.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 108013"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146140737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Immunomodulatory and Anti-fibrotic Effects of Toxocara canis Infection in a Murine Model of Thioacetamide-Induced Chronic Hepatic Fibrosis” [Acta Tropica, Volume 272, December 2025, 107913]","authors":"Iman F. Abou-El-Naga ,&nbsp;Eman Dorry Elkerdany ,&nbsp;Rania G. Aly ,&nbsp;Enas Mohammed Mostafa Zaytoun","doi":"10.1016/j.actatropica.2026.108020","DOIUrl":"10.1016/j.actatropica.2026.108020","url":null,"abstract":"","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 108020"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146211902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acetazolamide as a novel therapeutic agent against acute experimental toxoplasmosis: Insights into carbonic anhydrase inhibition","authors":"Aceel Y. Hassan ,&nbsp;Hala Diab ,&nbsp;Sarah Ahmed Hassan ,&nbsp;Nahla El Skhawy","doi":"10.1016/j.actatropica.2026.108007","DOIUrl":"10.1016/j.actatropica.2026.108007","url":null,"abstract":"<div><div>Although the current therapeutic regimens for acute toxoplasmosis, most commonly a combination of pyrimethamine and sulfadiazine, are still considered the standard of care, they are associated with numerous drawbacks, such as bone marrow suppression, and hepatotoxicity. Given these challenges, there is an urgent need to explore and find safer and more effective therapeutic alternatives. Acetazolamide has been widely used in clinical practice for non-infectious illnesses. Lately, increasing attention has been directed toward its repurposing as an antiparasitic agent. Thirty-six mice were infected with <em>Toxoplasma gondii</em> (RH strain) tachyzoites, and divided into three groups: non-treated group, Acetazolamide-treated group and Septrin- treated group. In the present study, the anti - <em>Toxoplasma</em> efficacy of Acetazolamide was assessed in comparison to Septrin using parasitological, ultrastructural, biochemical, immunological, and histopathological studies. Treatment with Acetazolamide significantly prolonged the mice’s survival time and reduced tachyzoites count with percentages of reduction of 83.12% and 79.84 % in the peritoneal fluids and hepatic impression smears, respectively. Furthermore, Acetazolamide has dramatically altered the ultrastructure of the tachyzoites, decreased the liver and kidney malondialdehyde levels and suppressed serum cytokines (tumor necrosis factor alpha and interleukin-1β). Histopathological examination of hepatic and renal tissue sections showed amelioration of parenchymal inflammation and scanty parasite. In conclusion, Acetazolamide demonstrated a significant promise as a therapeutic agent for combating acute murine toxoplasmosis with anti-inflammatory and antioxidant effects.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 108007"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146103537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Invasion and development of Plasmodium falciparum in erythroblasts of humans carrying G6PD viangchan","authors":"Kanyarat Boonpeng ,&nbsp;Attakorn Palasuwan ,&nbsp;Nutpakal Ketprasit ,&nbsp;Kasem Kulkeaw ,&nbsp;Duangdao Palasuwan","doi":"10.1016/j.actatropica.2026.108002","DOIUrl":"10.1016/j.actatropica.2026.108002","url":null,"abstract":"<div><div>Emerging evidence suggests the development of malaria parasites in the human bone marrow. Whether glucose-6-phosphate dehydrogenase (G6PD) deficiency affects parasite growth in erythroblast has yet to be determined. Here, we examine the invasion and development of <em>Plasmodium falciparum</em> in human erythroblasts of subjects carrying the most common variant of G6PD Viangchan (871G&gt;<em>A</em>) in Southeast Asia. Erythroblasts were generated by differentiation of erythroids of human CD34-positive hematopoietic stem and progenitor cells isolated from peripheral blood. The results showed that <em>P. falciparum</em> parasites invade polychromatic erythroblasts and develop into mature trophozoites. The percentages and stages of parasitized erythroblasts were not different between the subjects with G6PD normal, heterozygous, or hemizygous G6PD Viangchan. While the sample size (<em>n</em> = 6) limited statistical analysis, these preliminary findings suggest that protection against malaria is not observed in this i<em>n vitro</em> erythroblast model, supporting further validation in expanded cohorts.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 108002"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MiRNA and proteomic profiling of small extracellular vesicles secreted by Toxoplasma gondii cultured with two different human cervical epithelial feeder layers","authors":"Qing Yue ,&nbsp;Lin Mo ,&nbsp;Lijing Niu ,&nbsp;Dabin Chen ,&nbsp;Xiaoyan Zhu ,&nbsp;Jian Gao","doi":"10.1016/j.actatropica.2026.108000","DOIUrl":"10.1016/j.actatropica.2026.108000","url":null,"abstract":"<div><div><em>Toxoplasma gondii</em> has been reported to exert antitumor effects by inducing apoptosis and cell cycle arrest; however, the biological roles of small extracellular vesicles released by the parasite remain poorly understood. Small extracellular vesicles derived from parasite–host coculture systems may encapsulate molecular signals that reflect interactions between <em>T. gondii</em> and distinct epithelial microenvironments. In this study, tachyzoites of the <em>T. gondii</em> RH strain were cocultured with human cervical adenocarcinoma HeLa cells or normal cervical epithelial H8 cells, and small extracellular vesicles were isolated from coculture supernatants. High-throughput small RNA sequencing and liquid chromatography–tandem mass spectrometry were used to profile microRNA and protein cargo, followed by differential expression and functional enrichment analyses. Vesicles from both coculture systems contained components of both parasite and host origin, indicating bidirectional molecular exchange. Compared with vesicles derived from coculture with normal epithelial cells, those obtained from tumor cell coculture showed distinct enrichment of microRNAs and proteins associated with cell proliferation, DNA damage responses, and apoptotic regulation. Pathway analyses highlighted the involvement of cell cycle checkpoints, p53-related signaling, and programmed cell death. Overall, the molecular composition of parasite-derived vesicles varied according to the epithelial feeder layer, with tumor cell–associated vesicles exhibiting a stronger association with tumor-related regulatory pathways. These findings provide insight into parasite–host communication mediated by extracellular vesicles and suggest a potential role for <em>T. gondii</em>–derived vesicles in modulating tumor-associated biological processes.</div></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":"275 ","pages":"Article 108000"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}