Search Results (111)

Congenital Chagas disease (CCD) is caused when Trypanosoma cruzi crosses the placental barrier during pregnancy and reaches the fetus, which can lead to serious consequences in the developing fetus. Current treatment is carried out with nifurtimox or benznidazole, but their effectiveness is limited, and they cause side effects, requiring the search for new therapeutic strategies. In this sense, many studies have demonstrated the potential of different compounds of the Copaifera genus in the control of parasitic diseases. Here, we aimed to evaluate the effect of oleoresin (OR) and leaf hydroalcoholic extract (LHE) of Copaifera multijuga on Trypanosoma cruzi infection in human villous trophoblast cells (BeWo line) and human placenta explants. Treatment with both compounds reduced invasion, proliferation, and release of trypomastigotes. Furthermore, OR and LHE affected the trypomastigotes and amastigote morphology, compromising their ability to invade and proliferate in BeWo cells, respectively. Also, treatment with OR decreased ROS production in infected BeWo cells, while LHE induced an increase. In addition, both compounds induced pro-inflammatory and anti-inflammatory cytokine production. In human placental explants, both compounds also decreased T. cruzi infection, in addition to inducing the production of pro-inflammatory cytokines. Thus, both OR and LHE of C. multijuga control T. cruzi infection at the human maternal–fetal interface, highlighting the possible therapeutic potential of these compounds for the treatment of CCD. Full article

Chagas disease (ChD) caused by Trypanosoma cruzi remains a major public health concern, affecting approximately 8 million people worldwide. However, the number of undiagnosed cases is likely much higher. Existing treatments rely on benznidazole and nifurtimox which, despite their efficacy during the acute phase of infection, are often associated with severe side effects that can be life-threatening. As a promising alternative, actinomycetes—which are renowned for producing pharmacologically and industrially relevant metabolites—have demonstrated potent antimicrobial properties; however, their antiparasitic potential remains largely unexplored. This study evaluated the anti-trypanocidal activities of extracellular metabolites produced by Streptomyces thermocarboxydus strain Chi-43 (ST-C43) and Streptomyces sp. strain Chi-104 (S-C104) against epimastigote, trypomastigote, and amastigote forms of T. cruzi. The strains were cultured in ISP2 broth, and their extracellular metabolites were assessed via antiparasitic diffusion assays in microplates. The 50% lethal concentration (LC₅₀) values ranged from 102 to 116 μg/mL against epimastigotes and trypomastigotes. The antiparasitic activity was confirmed through 3-(4,5-dimetiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based spectrophotometric assays and optical microscopy. Toxicity assays revealed that the extracellular metabolites were non-toxic to Artemia salina, non-cytotoxic to Huvecs, and non-hemolytic to human erythrocytes. Dose–response regression analysis showed statistically significant differences (p ≤ 0.05). LC-MS/MS analysis identified amphomycin and K-252c aglycone staurosporine as the active antiparasitic compounds. These findings highlight the potential of Streptomyces-derived extracellular metabolites as novel, selective, and safe anti-T. cruzi agents. Nevertheless, further studies in murine or preclinical models are needed to validate their efficacy and support future clinical applications for the treatment of ChD. Full article

Trypanosoma cruzi, the causative agent of Chagas disease, undergoes epimastigogenesis—a critical differentiation step in which trypomastigotes transform into epimastigotes. While this process is essential for the parasite’s survival in its insect vector, the molecular mechanisms regulating it remain poorly understood. Here, we present the first evidence implicating extracellular vesicles (EVs) as enhancing mediators of epimastigogenesis. Using in vitro models with T. cruzi strains CL Brener and Dm28c, we demonstrate that EVs, membrane-bound vesicles, were shown to enhance differentiation in a strain-specific and temperature-dependent manner. We observed strain-specific EV release patterns: Dm28c produced more EVs at 24 h, whereas CL Brener peaked at 72 h. Additionally, we confirm that epimastigogenesis occurs exclusively at 28 °C after 72 h. These findings establish EVs as novel regulators of T. cruzi differentiation and suggest new insight into parasite development, highlighting potential targets for therapeutic intervention. The observed enhancement of differentiation in the presence of EVs indicates a potential role for these vesicles in this developmental process, although the underlying mechanisms remain undefined. Full article

Background: The availability of laboratory tests to screen and diagnose migrants and travellers for neglected and tropical parasitic diseases significantly impacts individual and public health. Italian scientific societies for parasitology, tropical diseases, and global health developed a survey to assess number and geographical localisation of laboratories able to carry out adequate diagnostics. Methods: An open-ended and multiple-choice questionnaire was constructed and sent to 752 members working in Italian microbiology laboratories via scientific societies’ mailing lists. Data concerning malaria, cystic echinococcosis, leishmaniasis, schistosomiasis, strongyloidiasis, and Chagas disease were included. Results: Members from 96 laboratories replied. At least one laboratory responded from 18 out of 20 Italian regions. Serological tests for Schistosoma spp., Strongyloides stercoralis, Trypanosoma cruzi, Echinococcus spp., and Leishmania spp. are performed in <50% of responding laboratories. Only 56.6% of labs provide all three recommended tests for malaria diagnosis in the emergency room. Direct identification methods availability varies for Schistosoma eggs (75–95.8%), S. stercoralis larvae (53.1%), trypomastigotes (59.4%), and Leishmania amastigotes (53.1%). Geographical differences (mainly northern versus southern regions) were evident. Conclusions: The survey underlines the need to improve diagnosis for neglected and tropical diseases, to define a network of reference laboratories for testing less prevalent diseases, and to share information, education, and training for both clinicians and microbiologists/parasitologists. Full article

Metacyclogenesis is a critical process in the Trypanosoma cruzi life cycle. This transition naturally occurs in an insect vector’s gut. Although Triatomine Artificial Urine (TAU) medium is the widely adopted approach to metacyclogenesis in vitro, its efficiency decreases with prolonged epimastigote culture, limiting the availability of metacyclic trypomastigotes for study. We aimed to establish a practical and efficient method for generating high concentrations and purities of metacyclic trypomastigotes in vitro. Epimastigotes of the Dm28c strain were exposed to pH shifts in nutrient-rich (MT-LIT) and nutrient-poor (M16) media, under static or agitated conditions. Both media promoted higher metacyclogenesis rates than TAU, with epimastigotes’ adherence to the substrate being a crucial factor. Metacyclogenesis efficiency varies depending on the strains and culture conditions. Notably, both LIT and M16 at pH 6 produced metacyclic trypomastigotes with infective capacity on Vero cells. Under these conditions, a variety of intermediate forms were observed compared to those induced by TAU metacyclogenesis. Our findings further emphasize the strain-dependent nature of optimal in vitro metacyclogenesis conditions and offer new opportunities for studying the intermediate forms involved in this essential process. Full article

Background/Objectives: α-carbonic anhydrase (α-TcCA) has emerged as a promising drug target in T. cruzi, the causative agent of Chagas disease in the Americas. Sulfonamides, known inhibitors of CAs, bind to the zinc ion on the enzyme’s active site. This study proposes the repositioning of sulfonamide-based drugs to identify new trypanocidal agents. Method: Ligand-based virtual screening and molecular docking analysis were performed on FDA-approved drugs targeting α-TcCA. These compounds were evaluated in vitro and ex vivo against the A1 and NINOA strains, followed by enzymatic assays. Results: Four sulfonylureas were selected: glimepiride (Glim), acetohexamide (Ace), gliclazide (Glic), and tolbutamide (Tol). Ace and Tol had half-maximal inhibitory concentration (IC₅₀) values similar or better than reference drugs against the NINOA strain in the epimastigote and trypomastigote stages, while Glic and Glim had the highest activity against the A1 strain (epimastigotes and amastigotes). Notably, Ace had the highest trypanocidal activity against all stages in NINOA, with IC₅₀ values of 6.5, 46.5, and 46 μM for epimastigotes, trypomastigotes, and amastigotes, respectively. Additionally, Ace inhibited α-TcCA with K_I = 5.6 μM, suggesting that its trypanocidal effect is associated to the enzyme inhibition. Conclusions: This study supports the repositioning of FDA-approved sulfonamide-based hypoglycaemic agents as trypanocidal compounds. Future studies should focus on structural modifications to improve selectivity. Integrating docking, parasitological, and enzymatic data is crucial for optimizing drug candidates for Chagas disease. Full article

This review summarizes the interactions between Trypanosoma cruzi, the etiologic agent of Chagas disease, and its vectors, the triatomines, and highlights open questions. Four important facts should be emphasized at the outset: (1) The development of T. cruzi strains and their interactions with the mammalian host and the insect vector vary greatly. (2) Only about 10 of over 150 triatomine species have been studied for their interactions with the protozoan parasite. (3) The use of laboratory strains of triatomines makes generalizations difficult, as maintenance conditions influence the interactions. (4) The intestinal microbiota is involved in the interactions, but the mutualistic symbionts, Actinomycetales, have so far only been identified in four species of triatomines. The effects of the vector on T. cruzi are reflected in a different colonization ability of T. cruzi in different triatomine species. In addition, the conditions in the intestine lead to strong multiplication in the posterior midgut and rectum, with infectious metacyclic trypomastigotes developing almost exclusively in the latter. Starvation and feeding of the vector induce the development of certain stages of T. cruzi. The negative effects of T. cruzi on the triatomines depend on the T. cruzi strain and are particularly evident when the triatomines are stressed. The intestinal immunity of the triatomines responds to ingested blood-stage trypomastigotes of some T. cruzi strains and affects many intestinal bacteria, but not all and not the mutualistic symbionts. The specific interaction between T. cruzi and the bacteria is evident after the knockdown of antimicrobial peptides: the number of non-symbiotic bacteria increases and the number of T. cruzi decreases. In long-term infections, the suppression of intestinal immunity is indicated by the growth of specific microbiota. Full article

Chagas disease, caused by Trypanosoma cruzi, is a neglected tropical disease with few options for treatment and no available vaccine. Deletion mutants for live attenuated vaccines, particularly deletions of proteins related to the cytoskeleton, have been widely tested in related parasites but candidates have not been tested in T. cruzi. Kharon is one such protein, identified as being associated with the cytoskeleton in Leishmania and essential for amastigote replication. Here we investigated the T. cruzi Kharon ortholog (TcKharon) to test if it has orthologous function and thus potential in generating a live attenuated vaccine. In silico analysis predicted TcKharon to be an intrinsically disordered protein, consistent with its ortholog feature, and GFP fusion protein revealed that TcKharon is associated with the cytoskeleton of epimastigotes. CRISPR-Cas9-mediated gene disruption impaired epimastigote proliferation and cytokinesis, resulting in altered nucleus-to-kinetoplast ratios and pronounced morphological defects, particularly in the posterior cell region. Despite these abnormalities, TcKharon^−/− mutants retained the ability to differentiate into metacyclic trypomastigotes and exhibited in vitro infection rates comparable to wild-type parasites. Our data show that TcKharon is crucial for cell morphology. However, in contrast to close related parasites, TcKharon is not essential for in vitro infectivity. Full article

(1) Background: Surra is a debilitating disease of wild and domestic animals caused by Trypanosoma evansi (T. evansi), resulting in significant mortality and production losses in the affected animals. This study is the first to assess the genetic relationships of T. evansi in naturally affected buffaloes from Multan district, Pakistan, using ITS-1 primers and evaluating the effects of parasitemia and oxidative stress on DNA damage and hematobiochemical changes in infected buffaloes. (2) Methods: Blood samples were collected from 167 buffaloes using a multi-stage cluster sampling strategy, and trypomastigote identification was performed through microscopy and PCR targeting RoTat 1.2 and ITS-1 primers. Molecular characterization involved ITS-1 via neighbor-joining analysis. The impact of parasitemia loads was correlated with oxidative stress markers, genotoxicity, and hematobiochemical parameters using Pearson correlation and multivariable regression models. (3) Results: Field-stained thin blood film microscopy and molecular identification revealed 8.98% and 10.18% infection rates, respectively. Phylogenetic analysis based on ITS-1 region sequences of the identified isolates showed close genetic associations with Indian isolates. The mean trypomastigote count observed in the infected buffaloes was 5.15 × 10⁶ (±5.3 × 10²)/µL of blood. The parasitemia loads were significantly correlated with the alterations in oxidative stress markers, DNA damage, and changes in hematobiochemical parameters. Infected animals exhibited significant (p < 0.05) alterations in oxidative stress biomarkers, including catalase, nitric oxide, and malondialdehyde concentrations. Noteworthily, a comet assay revealed a significantly (p < 0.0001) higher mean genetic damage index in the infected buffaloes (0.7 ± 0.04) compared with the healthy ones (0.196 ± 0.004). Alongside significant (p < 0.05) reductions in red cell indices, a marked elevation in leukocyte counts and serum hepatic enzyme levels was recorded in the affected buffaloes. (4) Conclusion: T. evansi isolates of buffaloes from Multan, Pakistan, have genetic similarities to Indian isolates. This study also revealed that higher parasitemia loads induce genotoxicity in the infected animals through oxidative stress and cause hematobiochemical alterations under natural field conditions. Full article

Trypanosoma cruzi, the etiological agent of Chagas disease, is a parasite known for its diverse genotypic variants, or Discrete Typing Units (DTUs), which have been associated with varying degrees of tissue involvement. However, aspects such as parasite attachment remain unclear. It has been suggested that the TcI genotype is associated with cardiac infection, the most common involved site in chronic human infection, while TcII is associated with digestive tract involvement. Traditional models for T. cruzi infection provide limited in vivo observation, making it challenging to observe the dynamics of parasite-host interactions. This study evaluates the cardiac attachment of trypomastigotes from TcI and TcII DTUs in zebrafish larvae. Labeled trypomastigotes were injected in the duct of Cuvier of zebrafish larvae and tracked by stereomicroscopy and light-sheet fluorescence microscopy (LSFM). Remarkably, it was possible to observe TcI parasites adhered to the atrium, atrioventricular valve, and circulatory system, while TcII trypomastigotes demonstrated adhesion to the atrium, atrioventricular valve, and yolk sac extension. When TcI and TcII were simultaneously injected, they both attached to the heart; however, more of the TcII trypomastigotes were observed attached to this organ. Although TcII DTU has previously been associated with digestive tissue infection, both parasite variants showed cardiac tissue attachment in this in vivo model. Full article

Infection with the protozoan parasite Trypanosoma cruzi causes human Chagas disease. Benznidazole (BNZ) and nifurtimox are the current drugs for the treatment; however, they induce severe adverse side effects in patients; therefore, there is a need to improve the treatment effectiveness and efficiency of these drugs for its safer use. Background/Objective: Glyburide, glipizide, and gliquidone, hypoglycemic drugs for diabetes treatment, were previously predicted to bind to dihydrofolate reductase-thymidylate synthase from T. cruzi by in silico docking analysis; they also showed antiproliferative effects against T. cruzi epimastigotes, the stage of the insect vector. In the present study, the potential parasiticidal effect of these antidiabetic drugs was tested in monotherapy and bi-therapy with BNZ in human cells in vitro and in animals. Methods: Evaluation was performed in (a) a model of in vitro infection of T. cruzi trypomastigotes using human fibroblasts as host cells and (b) in mice infected with T. cruzi. Results: The antidiabetic drugs in monotherapy showed antiparasitic effects in preventing infection progression (trypomastigotes release), with an IC₅₀ of 8.4–14.3 µM in comparison to that of BNZ (0.26 µM) in vitro. However, in bi-therapy, the presence of just 0.5 or 1 µM of the antidiabetics decreased the BNZ IC₅₀ by 5–10 times to 0.03–0.05 µM. Remarkably, the antidiabetic drugs in monotherapy decreased the infection in mice by 40–60% in a similar extent to BNZ (80%). In addition, the combination of BNZ plus antidiabetics perturbed the antioxidant metabolites in epimastigotes. Conclusions: These results identified antidiabetics as potential drugs in combination therapy with BNZ to treat T. cruzi infection. Full article

Chagas disease is a prevalent health problem in Latin America which has received insufficient attention worldwide. Current treatments for this disease, benznidazole and nifurtimox, have limited efficacy and may cause side effects. A recent study proposed investigating a wide range of nitroindazole and indazolone derivatives as feasible treatments. Therefore, it is proposed that adding a nitro group at the 5-position of the indazole and indazolone structure could enhance trypanocidal activity by inducing oxidative stress through activation of the nitro group by NTRs (nitroreductases). The study results indicate that the nitro group advances free radical production, as confirmed by several analyses. Compound 5a (5-nitro-2-picolyl-indazolin-3-one) shows the most favorable trypanocidal activity (1.1 ± 0.3 µM in epimastigotes and 5.4 ± 1.0 µM in trypomastigotes), with a selectivity index superior to nifurtimox. Analysis of the mechanism of action indicated that the nitro group at the 5-position of the indazole ring induces the generation of reactive oxygen species (ROS), which causes apoptosis in the parasites. Computational docking studies reveal how the compounds interact with critical residues of the NTR and FMNH₂ (flavin mononucleotide reduced) in the binding site, which is also present in active ligands. The lipophilicity of the studied series was shown to influence their activity, and the nitro group was found to play a crucial role in generating free radicals. Further investigations are needed of derivatives with comparable lipophilic characteristics and the location of the nitro group in different positions of the base structure. Full article

The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, also called American trypanosomiasis. This neglected tropical disease affects millions of individuals across the Americas. To complete its life cycle, T. cruzi parasitizes both vertebrate hosts and its vector, commonly known as the ‘kissing bug’. The parasite’s survival and proliferation strategies are driven by the diverse environments it encounters. Despite being described by Carlos Chagas in 1909, significant knowledge gaps persist regarding the parasite’s various life forms and adaptive capabilities in response to environmental cues. In this study, we employed Ultrastructure Expansion Microscopy to explore the intricate journey of T. cruzi within the host cell. Upon entry into the host cell, trypomastigotes undergo folding, resulting in intermediate forms characterized by a rounded cell body, anterior positioning of basal bodies, and a shortened flagellum. The repositioning of basal bodies and the kinetoplast and the shortening of the flagella mark the culmination of intracellular amastigogenesis. Furthermore, we analyzed intracellular trypomastigogenesis, identifying discrete intermediate forms, including leaf-shaped stages and epimastigote-like forms, which suggests a complex differentiation process. Notably, we did not observe any dividing intracellular epimastigotes, indicating that these may be non-replicative forms within the host cell. Our detailed examination of amastigote cell division revealed semi-closed nuclear mitosis, with mitotic spindle formation independent of basal bodies. This study provides new insights into the morphological and cytoskeletal changes during the intracellular stages of T. cruzi, providing a model for understanding the dynamics of intracellular amastigogenesis and trypomastigogenesis. Full article

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease in humans. The current antichagasic drugs nifurtimox and benznidazole have inconveniences of toxicity; therefore, the search for alternative therapeutic strategies is necessary. The present study reports the synthesis, drug-likeness predictions, and in vitro anti-trypanosome activity of a series of 14 quinazoline 2,4,6-triamine derivatives. All compounds were tested against T. cruzi (epimastigotes and trypomastigotes) and in HFF1 human foreskin fibroblasts. The bioassays showed that compounds 2–4 containing nitrobenzoyl substituents at 6-position of the quinazoline 2,4,6-triamine nucleus were the most potent on its antiprotozoal activity. The effect was observed at 24 h and it was preserved for at least 5 days. Also, compounds 2–4 were not toxic to the human control cells, showing high selectivity index. The quinazoline nitro derivatives have potential use as antichagasic agents. Full article

Trypanosoma cruzi is the etiologic agent of Chagas disease, an infection that can lead to the development of cardiac fibrosis, which is characterized by the deposition of extracellular matrix (ECM) components in the interstitial region of the myocardium. The parasite itself can induce myofibroblast differentiation of cardiac fibroblast in vitro, leading to increased expression of ECM. Inorganic polyphosphate (polyP) is a linear polymer of orthophosphate that can also induce myofibroblast differentiation and deposition of ECM components and is highly abundant in T. cruzi. PolyP can modify proteins post-translationally by non-enzymatic polyphosphorylation of lysine residues of poly-acidic, serine-(S) and lysine (K)-rich (PASK) motifs. In this work, we used a bioinformatics screen and identified the presence of PASK domains in several surface proteins of T. cruzi. We also detected polyP in the external surface of its different life cycle stages and confirmed the stimulation of host cell fibrosis by trypomastigote infection. However, we were not able to detect significant secretion of the polymer or activation of transforming growth factor beta (TGF-β), an important factor for the generation of fibrosis by inorganic polyP- or trypomastigote-conditioned medium. Full article