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Tritrichomonas foetus is a flagellated and anaerobic parasite able to infect cattle and felines. Despite its prevalence, there is no effective standardized or legal treatment for T. foetus- infected cattle; the vaccination still has limited success in mitigating infections and reducing abortion risk; and nowadays, the diagnosis of T. foetus presents important limitations in terms of sensitivity and specificity in bovines. Here, we characterize the plasma membrane proteome of T. foetus and identify proteins that are represented in different isolates of this protozoan. Additionally, we performed a bioinformatic analysis that revealed the antigenicity potential of some of those proteins. This analysis is the first study to identify common proteins at the plasma membrane of different T. foetus isolates that could be targets for alternative diagnostic or vaccine techniques in the future.

Trichomonas vaginalis and Tritrichomonas foetus are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types, and extra-axonemal structures (EASs) have been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic, and sensory platforms in many organisms. It has been assumed that T. vaginalis and T. foetus do not have EASs. However, here, we used complementary electron microscopy techniques to reveal the ultrastructure of EASs in both parasites. Such EASs are thin filaments (3–5 nm diameter) running longitudinally along the axonemes and surrounded by the flagellar membrane, forming prominent flagellar swellings. We observed that the formation of EAS increases after parasite adhesion on the host cells, fibronectin, and precationized surfaces. A high number of rosettes, clusters of intramembrane particles that have been proposed as sensorial structures, and microvesicles protruding from the membrane were observed in the EASs. Our observations demonstrate that T. vaginalis and T. foetus can connect to themselves by EASs present in flagella. The protein VPS32, a member of the ESCRT-III complex crucial for diverse membrane remodeling events, the pinching off and release of microvesicles, was found in the surface as well as in microvesicles protruding from EASs. Moreover, we demonstrated that the formation of EAS also increases in parasites overexpressing VPS32 and that T. vaginalis -VPS32 parasites showed greater motility in semisolid agar. These results provide valuable data about the role of the flagellar EASs in the cell-to-cell communication and pathogenesis of these extracellular parasites.

Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogenital tract, where it remains extracellular and adheres to epithelial cells. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Despite the serious consequences associated with trichomoniasis disease, little is known about parasite or host factors involved in attachment of the parasite-to-host epithelial cells. Here, we report the identification of microvesicle-like structures (MVs) released by T. vaginalis . MVs are considered universal transport vehicles for intercellular communication as they can incorporate peptides, proteins, lipids, miRNA, and mRNA, all of which can be transferred to target cells through receptor–ligand interactions, fusion with the cell membrane, and delivery of a functional cargo to the cytoplasm of the target cell. In the present study, we demonstrated that T. vaginalis release MVs from the plasma and the flagellar membranes of the parasite. We performed proteomic profiling of these structures demonstrating that they possess physical characteristics similar to mammalian extracellular vesicles and might be selectively charged with specific protein content. In addition, we demonstrated that viable T. vaginalis parasites release large vesicles (LVs), membrane structures larger than 1 µm that are able to interact with other parasites and with the host cell. Finally, we show that both populations of vesicles present on the surface of T vaginalis are induced in the presence of host cells, consistent with a role in modulating cell interactions.

Trichomonas vaginalis is a common sexually transmitted extracellular parasite that adheres to epithelial cells in the human urogenital tract. Extracellular vesicles (EVs) have been described as important players in the pathogenesis of this parasite as they deliver proteins and RNA into host cells and modulate parasite adherence. EVs are heterogeneous membrane vesicles released from virtually all cell types that collectively represent a new dimension of intercellular communication. The Endosomal Sorting Complex Required for Transport (ESCRT) machinery contributes to several key mechanisms in which it reshapes membranes. Based on this, some components of the ESCRT have been implicated in EVs biogenesis in other cells. Here, we demonstrated that VPS32, a member of ESCRTIII complex, contribute to the biogenesis and cargo sorting of extracellular vesicles in the parasite T. vaginalis. Moreover, we observe that parasites overexpressing VPS32 have a striking increase in adherence to host cells compared to control parasites; demonstrating a key role for this protein in mediating host: parasite interactions. These results provide valuable information on the molecular mechanisms involved in extracellular vesicles biogenesis, cargo-sorting, and parasite pathogenesis.

Tritrichomonas foetus is a flagellated parasite able to infect cattle, cats, and pigs. Despite its prevalence, feline tritrichomonosis has received markedly less attention than venereal infection, and little information about the molecular mechanisms that participate in feline host infection is available. Through a bioinformatics approach, we integrated public transcriptomic data for three T. foetus isolates and explored the differences at transcript level with a focus on pathogenesis and adaptation processes, particularly for the feline isolate. Our analysis revealed higher abundance levels of predicted virulence factors, such as proteases and surface antigens. Additionally, by a comparative and expression analysis of T. foetus genes, we proposed putative virulence factors that could be involved in feline infection. Finally, we identified a great proportion of predicted transcription factors of the MYB protein family and, by a promoter analysis, we revealed that MYB-related proteins could participate in the regulation of gene transcription in T. foetus . In conclusion, this integrated approach is a valuable resource for future studies of host–pathogen interactions and identifying new gene targets for improved feline tritrichomonosis diagnosis and treatment.

Background Toxoplasmosis is a worldwide infection caused by the protozoan parasite Toxoplasma gondii , which causes chorioretinitis and neurological defects in congenitally infected newborns or immunodeficient patients. The efficacy of the current treatment is limited, primarily by serious host toxicity. In recent years, research has focused on the development of new drugs against T. gondii . β-Carbolines (βCs), such as harmane, norharmane and harmine, are a group of naturally occurring alkaloids that show microbicidal activity. In this work, harmane, norharmane and harmine were tested against T. gondii . Findings The treatment of extracellular tachyzoites with harmane, norharmane and harmine showed a 2.5 to 3.5-fold decrease in the invasion rates at doses of 40 μM (harmane and harmine) and 2.5 μM (norharmane) compared with the untreated parasites. Furthermore, an effect on the replication rate could also be observed with a decrease of 1 (harmane) and 2 (norharmane and harmine) division rounds at doses of 5 to 12.5 μM. In addition, the treated parasites presented either delayed or no monolayer lysis compared with the untreated parasites. Conclusions The three βC alkaloids studied (norharmane, harmane and harmine) exhibit anti- T. gondii effects as evidenced by the partial inhibition of parasite invasion and replication. A dose–response effect was observed at a relatively low drug concentration (< 40 μM), at which no cytotoxic effect was observed on the host cell line (Vero).

Toxoplasmosis is a worldwide infection caused by the protozoan parasite Toxoplasma gondii, which causes chorioretinitis and neurological defects in congenitally infected newborns or immunodeficient patients. The efficacy of the current treatment is limited, primarily by serious host toxicity. In recent years, research has focused on the development of new drugs against T. gondii. [beta]-Carbolines ([beta]Cs), such as harmane, norharmane and harmine, are a group of naturally occurring alkaloids that show microbicidal activity. In this work, harmane, norharmane and harmine were tested against T. gondii. The treatment of extracellular tachyzoites with harmane, norharmane and harmine showed a 2.5 to 3.5-fold decrease in the invasion rates at doses of 40 [mu]M (harmane and harmine) and 2.5 [mu]M (norharmane) compared with the untreated parasites. Furthermore, an effect on the replication rate could also be observed with a decrease of 1 (harmane) and 2 (norharmane and harmine) division rounds at doses of 5 to 12.5 [mu]M. In addition, the treated parasites presented either delayed or no monolayer lysis compared with the untreated parasites. The three [beta]C alkaloids studied (norharmane, harmane and harmine) exhibit anti-T. gondii effects as evidenced by the partial inhibition of parasite invasion and replication. A dose-response effect was observed at a relatively low drug concentration (< 40 [mu]M), at which no cytotoxic effect was observed on the host cell line (Vero).

Trichomonas vaginalis and Tritrichomonas foetus are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types; and extra-axonemal structures (EASs) has been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic and sensory platforms in many organisms. Here, we identified the presence of EASs forming prominent flagellar swellings in T. vaginalis and T. foetus and we observed that their formation was associated with the parasites adhesion on the host cells, fibronectin, and precationized surfaces; and parasite:parasite interaction. A high number of rosettes, clusters of intramembrane particles that has been proposed as sensorial structures, and microvesicles protruding from the membrane were observed in the EASs. The protein VPS32, a member of the ESCRT-III complex crucial for diverse membrane remodeling events, the pinching off and release of microvesicles, was found in the surface as well as in microvesicles protruding from EASs. Moreover, we demonstrated that overexpression of VPS32 protein induce EAS formation and increase parasite motility in semi-solid medium. These results provide valuable data about the role of the flagellar EASs in the cell-to-cell communication and pathogenesis of these extracellular parasites.