Lipid metabolism dynamic in Triatomine Rhodnius prolixus during acute Trypanosoma rangeli infection.

During its life cycle, Trypanosoma rangeli invades the hemolymph of its invertebrate host and colonizes hemocytes and salivary glands. The parasite cannot synthesize some lipid classes, and during its cycle, it depends on the uptake of these molecules from its vertebrate and invertebrate hosts to meet growth and differentiation requirements. However, until now, knowledge on how the parasite affects the lipid physiology of individual insect organs has been largely unknown. Herein, the biochemical and molecular dynamics of triatomine R. prolixus lipid metabolism in response to acute T. rangeli infection were investigated. Biochemical and microscopic assays revealed the lipid droplet profile and the levels of the different identified lipid classes. In addition, a qRT‒PCR approach was used to determine the expression profile of 6 protein-coding genes involved in the R. prolixus lipid physiology. We observed that triacylglycerol (TAG), monoacylglycerol (MAG), phosphatidylethanolamine (PE) and phosphatidylcholine (PC) levels in the fat body decreased in infected insects. On the other hand, high levels of free fatty acids were observed in the hemolymph during infection. Analysis by confocal microscopy revealed a decrease in lipid droplets size from infected fat bodies, and investigations by scanning electron microscopy revealed a significant number of parasites adhered to the surface of the organ. T. rangeli infection upregulated the transcript levels of the protein-coding gene for the acetyl-CoA carboxylase, the first enzyme in the de novo fatty acid synthesis pathway, responsible for the production of malonyl-CoA. On the other hand, downregulation of lipophorin receptor was observed. In conclusion, this study reveals a new set of molecular events that occur within the vector in response to the challenge imposed by the parasite.

Alterations in energy metabolism of Rhodnius prolixus induced by Trypanosoma rangeli infection.

Trypanosoma rangeli is a protozoan parasite that infects triatomines and mammals in the Americas, producing mixed infections with Trypanosoma cruzi, the etiological agent of Chagas disease. The former parasite is not pathogenic to humans, but has different levels of pathogenicity, as well as causing physiological and behavioral alterations, to its invertebrate hosts. In this study, we measured locomotory activity, and the glyceride accumulation profile in the hemolymph and fat body, as well as the expression of key genes related to triglyceride metabolism, of Rhodnius prolixus nymphs infected with T. rangeli. We found that the locomotory activity of the insects was correlated with the amount of triglycerides in the fat body. Infected nymphs had increased activity when starved, and also had an accumulation of glycerides in the fat body and hemolymph. These alterations were also associated with a higher expression of the diacylglycerol acyltransferase, lipophorin and lipophorin receptor genes in the fat body. We infer that T. rangeli is able to alter the energetic processes of its invertebrate host, in order to increase the availability of lipids to the parasite, which, in turn modifies the activity levels of the insect. These alterations are discussed with regard to their potential to increase the transmission rate of the parasite.

Modelling the dynamics of Trypanosoma rangeli and triatomine bug with logistic growth of vector and systemic transmission.

In this paper, an insect-parasite-host model with logistic growth of triatomine bugs is formulated to study the transmission between hosts and vectors of the Chagas disease by using dynamical system approach. We derive the basic reproduction numbers for triatomine bugs and Trypanosoma rangeli as two thresholds. The local and global stability of the vector-free equilibrium, parasite-free equilibrium and parasite-positive equilibrium is investigated through the derived two thresholds. Forward bifurcation, saddle-node bifurcation and Hopf bifurcation are proved analytically and illustrated numerically. We show that the model can lose the stability of the vector-free equilibrium and exhibit a supercritical Hopf bifurcation, indicating the occurrence of a stable limit cycle. We also find it unlikely to have backward bifurcation and Bogdanov-Takens bifurcation of the parasite-positive equilibrium. However, the sustained oscillations of infected vector population suggest that Trypanosoma rangeli will persist in all the populations, posing a significant challenge for the prevention and control of Chagas disease.

Trypanosoma rangeli infection increases the exposure and predation endured by Rhodnius prolixus.

Trypanosoma rangeli is a protozoan that infects triatomines and mammals in Latin America, sharing hosts with Trypanosoma cruzi, the etiological agent of Chagas disease. Trypanosoma rangeli does not cause disease to humans but is strongly pathogenic to its invertebrate hosts, increasing mortality rates and affecting bug development and reproductive success. We have previously shown that this parasite is also capable of inducing a general increase in the locomotory activity of its vector Rhodnius prolixus in the absence of host cues. In this work, we have evaluated whether infection impacts the insect­vertebrate host interaction. For this, T. rangeli-infected and uninfected R. prolixus nymphs were released in glass arenas offering single shelters. After a 3-day acclimatization, a caged mouse was introduced in each arena and shelter use and predation rates were evaluated. Trypanosoma rangeli infection affected all parameters analysed. A larger number of infected bugs was found outside shelters, both in the absence and presence of a host. Infected bugs also endured greater predation rates, probably because of an increased number of individuals that attempted to feed. Interestingly, mice that predated on infected bugs did not develop T. rangeli infection, suggesting that the oral route is not effective for these parasites, at least in our system. Finally, a smaller number of infected bugs succeeded in feeding in this context. We suggest that, although T. rangeli is not transmitted orally, an increase in the proportion of foraging individuals would promote greater parasite transmission rates through an increased frequency of very effective infected-bug bites.

Differential expression and activity of arginine kinase between the American trypanosomatids Trypanosoma rangeli and Trypanosoma cruzi.

Trypanosoma rangeli is a non-virulent hemoflagellate parasite infecting humans, wild and domestic mammals in Central and Latin America. The share of genotypic, phenotypic, and biological similarities with the virulent, human-infective T. cruzi and T. brucei, allows comparative studies on mechanisms of pathogenesis. In this study, investigation of the T. rangeli Arginine Kinase (TrAK) revealed two highly similar copies of the AK gene in this taxon, and a distinct expression profile and activity between replicative and infective forms. Although TrAK expression seems stable during epimastigotes growth, the enzymatic activity increases during the exponential growth phase and decreases from the stationary phase onwards. No differences were observed in activity or expression levels of TrAK during in vitro differentiation from epimastigotes to infective forms, and no detectable AK expression was observed for blood trypomastigotes. Overexpression of TrAK by T. rangeli showed no effects on the in vitro growth pattern, differentiation to infective forms, or infectivity to mice and triatomines. Although differences in TrAK expression and activity were observed among T. rangeli strains from distinct genetic lineages, our results indicate an up-regulation during parasite replication and putative post-translational myristoylation of this enzyme. We conclude that up-regulation of TrAK activity in epimastigotes appears to improve proliferation fitness, while reduced TrAK expression in blood trypomastigotes may be related to short-term and subpatent parasitemia in mammalian hosts.

The innate immune response of triatomines against Trypanosoma cruzi and Trypanosoma rangeli with an unresolved question: Do triatomines have immune memory?

The present work aimed to review the immune response from different triatomines against Trypanosoma cruzi and Trypanosoma rangeli and propose the study of immune memory in such insects. Trypanosoma use triatomines as vectors to reach and infect mammals. A key question to be answered about vector-parasite interaction is why the immune defense and resistance of the insect against the parasites vary. Up to date data shows that the defense of triatomines against parasites includes cellular (phagocytosis, nodulation and encapsulation) and humoral (antimicrobial peptides, phenoloxidase and reactive oxygen and nitrogen species) responses. The immune response varies depending on the triatomine species, the trypanosome strain and species, and the insect intestinal microbiota. Despite significant advances to understand parasite-insect interaction, it is still unknown if triatomines have immune memory against parasites and if this memory may derive from tolerance to parasites attack. Therefore, a closer study of such interaction could contribute and establish new proposals to control the parasite at the vector level to reduce parasite transmission to mammals, including men. For instance, if immune memory exists in the triatomines, it would be interesting to induce weak infections in insects to find out if subsequent infections are less intense and if the insects succeed in eliminating the parasites.

Enzymatic production of 3'-sialyllactose in milk.

Human milk oligosaccharides (HMOs) are lactose-based glycan molecules present in human breast milk. HMOs are essentially not present in cow's milk and hence not naturally available in infant formulas. HMOs possess several health and developmentally beneficial properties, and the sialylated HMOs are thought to play a particularly important role for infant brain development. Enzymatic transsialylation directly in cow's milk, involving enzyme catalyzed transfer of sialic acid from a sialic acid donor to an acceptor, is a novel route for producing sialylated HMOs for e.g. infant formulas. The transsialidase (EC 2.4.1.-) of Trypanosoma cruzi is linked to trypanosomatid pathogenicity, but certain hydrolytic sialidases (neuraminidases), EC 3.2.1.18, from non-pathogenic organisms, can actually catalyze transsialylation. Here, we report enzymatic production of the HMO compound 3'-sialyllactose directly in cow's milk using engineeredsialidases, Tr15 and Tr16, originating from the nonpathogenic Trypanosoma rangeli. Both Tr15 and Tr16 readily catalyzed transsialylation in milk at 5 °C-40 °C using κ(kappa)-casein glycomacropeptide (cGMP) as sialyl donor substrate. Tr15 was the most efficient as this enzyme produced 1160 mg/L (1.8 mM) 3'-sialyllactose in whole milk during 10 min of reaction at 5 °C. The activation energy values, Ea, of the enzymatic transsialylation reactions were similar in milk and in buffer solutions containing cGMP and lactose. The Ea of the Tr15 catalyzed transialylation reaction in milk was 16.5 kJ/mol, which was three times lower than the Ea of Tr16 (66 kJ/mol) and of T. cruzi transsialidase (50 kJ/mol), corroborating that Tr15 was the fastest of the three enzymes and a promising candidate for potential industrial production of 3'-sialyllactose in milk. 3'sialyllactose was stable during pasteurization (30 min. at 62.5 °C) and freeze-drying.

Rhodnius spp. infestation in palm trees and natural infection by Trypanosoma cruzi and Trypanosoma rangeli in periurban and rural areas of state of the Rondônia, in the Brazilian Amazon.

The state of Rondônia in the Brazilian Amazon is prone to diseases transmitted by insect vectors because of the environmental and population changes resulting from large hydroelectric projects and the expansion of agricultural and livestock industries. The first case of Chagas disease by vectorial transmission was recorded in 2019 in a rural area in Rondônia, reinforcing the need for entomological surveillance. Hence, our goal was to estimate the abundance of Rhodnius spp. in palm trees located in rural and periurban areas and in Brazil-Bolivia border regions, perform domiciliary searches, and check for possible associations between triatomines and the presence/absence of palm-inhabiting fauna and outdoor farming, domestic animals, and buildings. The sampling took place in five municipalities of Rondônia in 2014 (June to August) and 2015 (April to June). Triatomines were collected by active searches during the selective pruning of palm tree crowns. Domiciliary inspections lasted from 30 to 60 min. A set of captured triatomines was analyzed for Trypanosoma cruzi and T. rangeli infection by PCR. Overall, 496 insects were captured during sampling of 150 palms in rural areas and 150 in periurban areas. No triatomine was found during active searches of 59 dwelling either indoors or outdoors. The majority of triatomines caught in the palm trees were identified as Rhodnius robustus (98.6%), and seven specimens were R. pictipes. Triatomine infestation was observed in only 20% of the sampled palms (61/300) in the vicinity of 26/59 households. Nearly half of the infested palm trees had only one or two triatomines, and few palms presented more than 15 triatomines. The municipality of Buritis had the highest triatomine abundance and percentage of infested palms; however, the highest triatomine density per infested palm was observed in Alvorada D'Oeste, where a quarter of the palms were infested. Ants, arachnids, termites, reptiles, and rodents were frequently found in palm trees. Dogs were the predominant domestic animals in households, whereas hens and cattle were the main farming animals. Model estimates showed that the number of triatomines was affected by the presence of henhouses and varied strongly between localities. No relationships were detected between the average number of triatomines and palm fauna and/or palm height. Overall, approximately half of the triatomines were infected with T. cruzi (51.4%) and/or T. rangeli (47.2%), reinforcing the need for continuous entomological surveillance and implementation of community-based approaches because the Brazilian state of Rondônia borders areas experiencing reinfestation by domiciled species and potential colonization of animal shelters by triatomines.

Azadirachtin interferes with basal immunity and microbial homeostasis in the Rhodnius prolixus midgut.

Rhodnius prolixus is an insect vector of two flagellate parasites, Trypanosoma rangeli and Trypanosoma cruzi, the latter being the causative agent of Chagas disease in Latin America. The R. prolixus neuroendocrine system regulates the synthesis of the steroid hormone ecdysone, which is essential for not only development and molting but also insect immunity. Knowledge for how this modulates R. prolixus midgut immune responses is essential for understanding interactions between the vector, its parasites and symbiotic microbes. In the present work, we evaluated the effects of ecdysone inhibition on R. prolixus humoral immunity and homeostasis with its microbiota, using the triterpenoid natural product, azadirachtin. Our results demonstrated that azadirachtin promoted a fast and lasting inhibitory effect on expression of both RpRelish, a nuclear factor kappa B transcription factor (NF-kB) component of the IMD pathway, and several antimicrobial peptide (AMP) genes. On the other hand, RpDorsal, encoding the equivalent NF-kB transcription factor in the Toll pathway, and the defC AMP gene were upregulated later in azadirachtin treated insects. The treatment also impacted on proliferation of Serratia marcescens, an abundant commensal bacterium. The simultaneous administration of ecdysone and azadirachtin in R. prolixus blood meals counteracted the azadirachtin effects on insect molting and also on expression of RpRelish and AMPs genes. These results support the direct involvement of ecdysone in regulation of the IMD pathway in the Rhodnius prolixus gut.

New features on the survival of human-infective Trypanosoma rangeli in a murine model: Parasite accumulation is observed in lymphoid organs.

Trypanosoma rangeli is a non-pathogenic protozoan parasite that infects mammals, including humans, in Chagas disease-endemic areas of South and Central America. The parasite is transmitted to a mammalian host when an infected triatomine injects metacyclic trypomastigotes into the host's skin during a bloodmeal. Infected mammals behave as parasite reservoirs for several months and despite intensive research, some major aspects of T. rangeli-vertebrate interactions are still poorly understood. In particular, many questions still remain unanswered, e.g. parasite survival and development inside vertebrates, as no parasite multiplication sites have yet been identified. The present study used an insect bite transmission strategy to investigate whether the vector inoculation spot in the skin behave as a parasite-replication site. Histological data from the skin identified extracellular parasites in the dermis and hypodermis of infected mice in the first 24 hours post-infection, as well as the presence of inflammatory infiltrates in a period of up to 7 days. However, qPCR analyses demonstrated that T. rangeli is eliminated from the skin after 7 days of infection despite being still consistently found on circulating blood and secondary lymphoid tissues for up to 30 days post-infection. Interestingly, significant numbers of parasites were found in the spleen and mesenteric lymph nodes of infected mice during different periods of infection and steady basal numbers of flagellates are maintained in the host's bloodstream, which might behave as a transmission source to insect vectors. The presence of parasites in the spleen was confirmed by fluorescent photomicrography of free and cell-associated T. rangeli forms. Altogether our results suggest that this organ could possibly behave as a T. rangeli maintenance hotspot in vertebrates.

Comparative Analysis of the Secretome and Interactome of Trypanosoma cruzi and Trypanosoma rangeli Reveals Species Specific Immune Response Modulating Proteins.

Chagas disease, a zoonosis caused by the flagellate protozoan Trypanosoma cruzi, is a chronic and systemic parasitic infection that affects ~5-7 million people worldwide, mainly in Latin America. Chagas disease is an emerging public health problem due to the lack of vaccines and effective treatments. According to recent studies, several T. cruzi secreted proteins interact with the human host during cell invasion. Moreover, some comparative studies with T. rangeli, which is non-pathogenic in humans, have been performed to identify proteins directly involved in the pathogenesis of the disease. In this study, we present an integrated analysis of canonical putative secreted proteins (PSPs) from both species. Additionally, we propose an interactome with human host and gene family clusters, and a phylogenetic inference of a selected protein. In total, we identified 322 exclusively PSPs in T. cruzi and 202 in T. rangeli. Among the PSPs identified in T. cruzi, we found several trans-sialidases, mucins, MASPs, proteins with phospholipase 2 domains (PLA2-like), and proteins with Hsp70 domains (Hsp70-like) which have been previously characterized and demonstrated to be related to T. cruzi virulence. PSPs found in T. rangeli were related to protozoan metabolism, specifically carboxylases and phosphatases. Furthermore, we also identified PSPs that may interact with the human immune system, including heat shock and MASP proteins, but in a lower number compared to T. cruzi. Interestingly, we describe a hypothetical hybrid interactome of PSPs which reveals that T. cruzi secreted molecules may be down-regulating IL-17 whilst T. rangeli may enhance the production of IL-15. These results will pave the way for a better understanding of the pathophysiology of Chagas disease and may ultimately lead to the identification of molecular targets, such as key PSPs, that could be used to minimize the health outcomes of Chagas disease by modulating the immune response triggered by T. cruzi infection.

A systematic review of the diagnostic aspects and use of Trypanosoma rangeli as an immunogen for Trypanosoma cruzi infection.

INTRODUCTION: Trypanosoma rangeli is a protozoan that infects several domestic and wild mammals and shows significant distribution in Latin American countries. T. rangeli infection is similar to Chagas disease, both in diagnostic and prophylactic terms. Thus, the objective of this work was to review the diagnostic aspects and use of T. rangeli as an immunogen for Trypanosoma cruzi infection. METHODS: For this elaboration, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adopted with descriptors derived from the Medical Subject Headings (MeSH) platform in the PubMed/MEDLINE and SciELO databases. The inclusion criteria were defined as original articles on "Trypanosoma rangeli" and diagnostic aspects of T. rangeli infection in humans and/or research on the possible vaccines developed using T. rangeli strains for T. cruzi infection. RESULTS: After applying the inclusion and exclusion criteria, 18 articles were procured, of which 4 addressed research on the possible vaccines developed using T. rangeli for T. cruzi infection in vertebrates and the remaining 14 predominantly dealt with the diagnostic aspects of T. rangeli infection in humans. CONCLUSIONS: In this study, we formulated a compilation of the essential literature on this subject, emphasizing the need for more accurate and accessible techniques for the differential diagnosis of infections caused by both protozoa, and underscored several prospects in the search for a vaccine for Chagas disease.

Remarkable genetic diversity of Trypanosoma cruzi and Trypanosoma rangeli in two localities of southern Ecuador identified via deep sequencing of mini-exon gene amplicons.

BACKGROUND: Trypanosoma cruzi, the causative agent of Chagas disease, and T. rangeli are kinetoplastid parasites endemic to Latin America. Although closely related to T. cruzi and capable of infecting humans, T. rangeli is non-pathogenic. Both parasite species are transmitted by triatomine bugs, and the presence of T. rangeli constitutes a confounding factor in the study of Chagas disease prevalence and transmission dynamics. Trypanosoma cruzi possesses high molecular heterogeneity: seven discrete typing units (DTUs) are currently recognized. In Ecuador, T. cruzi TcI and T. rangeli KP1(-) predominate, while other genetic lineages are seldom reported. METHODS: Infection by T. cruzi and/or T. rangeli in different developmental stages of triatomine bugs from two communities of southern Ecuador was evaluated via polymerase chain reaction product size polymorphism of kinetoplast minicircle sequences and the non-transcribed spacer region of the mini-exon gene (n = 48). Forty-three mini-exon amplicons were also deep sequenced to analyze single-nucleotide polymorphisms within single and mixed infections. Mini-exon products from ten monoclonal reference strains were included as controls. RESULTS: Trypanosoma cruzi genetic richness and diversity was not significantly greater in adult vectors than in nymphal stages III and V. In contrast, instar V individuals showed significantly higher T. rangeli richness when compared with other developmental stages. Among infected triatomines, deep sequencing revealed one T. rangeli infection (3%), 8 T. cruzi infections (23.5%) and 25 T. cruzi + T. rangeli co-infections (73.5%), suggesting that T. rangeli prevalence has been largely underestimated in the region. Furthermore, deep sequencing detected TcIV sequences in nine samples; this DTU had not previously been reported in Loja Province. CONCLUSIONS: Our data indicate that deep sequencing allows for better parasite identification/typing than amplicon size analysis alone for mixed infections containing both T. cruzi and T. rangeli, or when multiple T. cruzi DTUs are present. Additionally, our analysis showed extensive overlap among the parasite populations present in the two studied localities (c.28 km apart), suggesting active parasite dispersal over the study area. Our results highlight the value of amplicon sequencing methodologies to clarify the population dynamics of kinetoplastid parasites in endemic regions and inform control campaigns in southern Ecuador.

Infecting Triatomines with Trypanosomes.

The infection of triatomines with trypanosomes can be performed with different forms of the parasite, and the procedure is important not only for vector-parasite interaction studies but also for maintaining the infectivity of parasite strains, which guarantees more realistic biological and molecular investigations. Here, I describe how to infect the vector Rhodnius prolixus, a model species, with two different species of Trypanosoma.

Modelling triatomine bug population and Trypanosoma rangeli transmission dynamics: Co-feeding, pathogenic effect and linkage with chagas disease.

Trypanosoma rangeli (T. rangeli), a parasite, is not pathogenic to human but pathogenic to some vector species to induce the behavior changes of infected vectors and subsequently impact the transmission dynamics of other diseases such as Chagas disease which shares the same vector species. Here we develop a mathematical model and conduct qualitative analysis for the transmission dynamics of T. rangeli. We incorporate both systemic and co-feeding transmission routes, and account for the pathogenic effect using infection-induced fecundity and fertility change of the triatomine bugs. We derive two thresholds Rv (the triatomine bug basic reproduction number) and R0 (the T. rangeli basic reproduction number) to delineate the dynamical behaviors of the ecological and epidemiological systems. We show that when Rv>1 and R0>1, a unique parasite positive equilibrium E* appears. We find that E* can be unstable and periodic oscillations can be observed where the pathogenic effect plays a significant role. Implications of the qualitative analysis and numerical simulations suggest the need of an integrative vector-borne disease prevention and control strategy when multiple vector-borne diseases are transmitted by the same set of vector species.

Modulation of IMD, Toll, and Jak/STAT Immune Pathways Genes in the Fat Body of Rhodnius prolixus During Trypanosoma rangeli Infection.

Trypanosoma rangeli is the second most common American trypanosome that infects man. It is vectored by triatomines from the genus Rhodnius, in which it invades the hemolymph and infects the salivary glands, avoiding the bug immune responses. In insects, these responses are initiated by well conserved pathways, mainly the IMD, Toll, and Jak/STAT. We hypothesize that long-term infection with T. rangeli in the gut or hemolymph of Rhodnius prolixus triggers different systemic immune responses, which influence the number of parasites that survive inside the vector. Thus, we investigated groups of insects with infections in the gut and/or hemolymph, and evaluated the parasite load and the expression in the fat body of transcription factors (Rp-Relish, Rp-Dorsal, and Rp-STAT) and inhibitors (Rp-Cactus and Rp-Caspar) of the IMD, Toll, and Jak/STAT pathways. We detected lower parasite counts in the gut of insects without hemolymph infection, compared to hemolymph-infected groups. Besides, we measured higher parasite numbers in the gut of bugs that were first inoculated with T. rangeli and then fed on infected mice, compared with control insects, indicating that hemolymph infection increases parasite numbers in the gut. Interestingly, we observed that genes from the three immune pathways where differentially modulated, depending on the region parasites were present, as we found (1) Rp-Relish downregulated in gut-and/or-hemolymph-infected insects, compared with controls; (2) Rp-Cactus upregulated in gut-infected insect, compared with controls and gut-and-hemolymph-infected groups; and (3) Rp-STAT downregulated in all groups of hemolymph-infected insects. Finally, we uncovered negative correlations between parasite loads in the gut and Rp-Relish and Rp-Cactus expression, and between parasite counts in the hemolymph and Rp-Relish levels, suggesting an association between parasite numbers and the IMD and Toll pathways. Overall, our findings reveal new players in R. prolixus-T. rangeli interactions that could be key for the capacity of the bug to transmit the pathogen.

Trypanosoma rangeli 28Sß Ribosomal Gene Allows Intra and Interspecific Molecular Differentiation.

Trypanosoma rangeli is an avirulent flagellate protozoan that could mislead correct diagnosis of Trypanosoma cruzi infection, the causative agent of Chagas' disease, given their high similarity. Besides, T. rangeli presents two genetic groups, whose differentiation is achieved mainly by molecular approaches. In this context, ribosomal DNA (rDNA) is a useful target for intra and interspecific molecular differentiation. Analyzing the rDNA of T. rangeli and comparison with other trypanosomatid species, two highly divergent regions (Trß1 and Trß2) within the 28Sß gene were found. Those regions were amplified and sequenced in KP1(+) and KP1(-) strains of T. rangeli, revealing group-specific polymorphisms useful for intraspecific distinction through restriction fragment length polymorphism technique. Also, amplification of Trß1 allowed differentiation between T. rangeli and T. cruzi. Trß2 predicted restriction length profile, allowed differentiation between T. rangeli, T. cruzi, Trypanosoma brucei, and Leishmania braziliensis, increasing the use of Trß1 and Trß2 beyond a molecular approach for T. rangeli genotyping, but also as a useful target for trypanosomatid classification.

A systematic review of the diagnostic aspects and use of Trypanosoma rangeli as an immunogen for Trypanosoma cruzi infection

Abstract INTRODUCTION: Trypanosoma rangeli is a protozoan that infects several domestic and wild mammals and shows significant distribution in Latin American countries. T. rangeli infection is similar to Chagas disease, both in diagnostic and prophylactic terms. Thus, the objective of this work was to review the diagnostic aspects and use of T. rangeli as an immunogen for Trypanosoma cruzi infection. METHODS: For this elaboration, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adopted with descriptors derived from the Medical Subject Headings (MeSH) platform in the PubMed/MEDLINE and SciELO databases. The inclusion criteria were defined as original articles on "Trypanosoma rangeli" and diagnostic aspects of T. rangeli infection in humans and/or research on the possible vaccines developed using T. rangeli strains for T. cruzi infection. RESULTS: After applying the inclusion and exclusion criteria, 18 articles were procured, of which 4 addressed research on the possible vaccines developed using T. rangeli for T. cruzi infection in vertebrates and the remaining 14 predominantly dealt with the diagnostic aspects of T. rangeli infection in humans. CONCLUSIONS: In this study, we formulated a compilation of the essential literature on this subject, emphasizing the need for more accurate and accessible techniques for the differential diagnosis of infections caused by both protozoa, and underscored several prospects in the search for a vaccine for Chagas disease.

Messenger RNA levels of the Polo-like kinase gene (PLK) correlate with cytokinesis in the Trypanosoma rangeli cell cycle.

BACKGROUND: Trypanosoma rangeli is a protozoan parasite that is non-virulent to the mammalian host and is morphologically and genomically related to Trypanosoma cruzi, whose proliferation within the mammalian host is controversially discussed. OBJECTIVES: We aimed to investigate the T. rangeli cell cycle in vitro and in vivo by characterizing the timespan of the parasite life cycle and by proposing a molecular marker to assess cytokinesis. METHODOLOGY: The morphological events and their timing during the cell cycle of T. rangeli epimastigotes were assessed using DNA staining, flagellum labelling and bromodeoxyuridine incorporation. Messenger RNA levels of four genes previously associated with the cell cycle of trypanosomatids (AUK1, PLK, MOB1 and TRACK) were evaluated in the different T. rangeli forms. FINDINGS: T. rangeli epimastigotes completed the cell cycle in vitro in 20.8 h. PLK emerged as a potential molecular marker for cell division, as its mRNA levels were significantly increased in exponentially growing epimastigotes compared with growth-arrested parasites or in vitro-differentiated trypomastigotes. PLK expression in T. rangeli can be detected near the flagellum protrusion site, reinforcing its role in the cell cycle. Interestingly, T. rangeli bloodstream trypomastigotes exhibited very low mRNA levels of PLK and were almost entirely composed of parasites in G1 phase. MAIN CONCLUSIONS: Our work is the first to describe the T. rangeli cell cycle in vitro and proposes that PLK mRNA levels could be a useful tool to investigate the T. rangeli ability to proliferate within the mammalian host bloodstream.

The correct subgeneric name of Trypanosoma rangeli Tejera, 1920 (Euglenozoa: Trypanosomatidae), a human-infective endoparasite of neotropical mammals.

Trypanosoma rangeli Tejera, 1920 is peculiar in being transmitted to mammal hosts through the bite of triatomine bugs. For this reason, it has been placed in its own subgenus, Tejeraia Añez, 1982. This name is a junior homonym of Tejeraia Díaz-Ungría, 1963, used for the roundworm Tejeraia mediospiralis (Molin, 1860). The mandatory substitute name of Tejeraia Añez, 1982 is Aneza Özdikmen, 2009. T. (Aneza) rangeli Tejera, 1920 is often referred to as T. (Herpetosoma) rangeli Tejera, 1920. According to nomenclature rules, both name combinations are available. Which one to choose depends on evolutionary and taxonomic considerations. Phylogenetic knowledge indicates that T. (Aneza) rangeli should be used.