Triatominae Subfamily Research Articles

Trypanosoma cruzi reprograms mitochondrial metabolism within the anterior midgut of its vector Rhodnius prolixus during the early stages of infection

BackgroundTrypanosoma cruzi is transmitted to humans by hematophagous bugs belonging to the Triatominae subfamily. Its intra-vectorial cycle is complex and occurs exclusively in the insect's midgut. Dissecting the elements involved in the cross-talk between the parasite and its vector within the digestive tract should provide novel targets for interrupting the parasitic life cycle and affecting vectorial competence. These interactions are shaped by the strategies that parasites use to infect and exploit their hosts, and the host's responses that are designed to detect and eliminate parasites. The objective of the current study is to characterize the impact of T. cruzi establishment within its vector on the dynamics of its midgut.MethodsIn this study, we evaluated the impact of T. cruzi infection on protein expression within the anterior midgut of the model insect Rhodnius prolixus at 6 and 24 h post-infection (hpi) using high-throughput quantitative proteomics.ResultsShortly after its ingestion, the parasite modulates the proteome of the digestive epithelium by upregulating 218 proteins and negatively affecting the expression of 11 proteins involved in a wide array of cellular functions, many of which are pivotal due to their instrumental roles in cellular metabolism and homeostasis. This swift response underscores the intricate manipulation of the vector's cellular machinery by the parasite. Moreover, a more in-depth analysis of proteins immediately induced by the parasite reveals a pronounced predominance of mitochondrial proteins, thereby altering the sub-proteomic landscape of this organelle. This includes various complexes of the respiratory chain involved in ATP generation. In addition to mitochondrial metabolic dysregulation, a significant number of detoxifying proteins, such as antioxidant enzymes and P450 cytochromes, were immediately induced by the parasite, highlighting a stress response.ConclusionsThis study is the first to illustrate the response of the digestive epithelium upon contact with T. cruzi, as well as the alteration of mitochondrial sub-proteome by the parasite. This manipulation of the vector's physiology is attributable to the cascade activation of a signaling pathway by the parasite. Understanding the elements of this response, as well as its triggers, could be the foundation for innovative strategies to control the transmission of American trypanosomiasis, such as the development of targeted interventions aimed at disrupting parasite proliferation and transmission within the triatomine vector.Graphical

Multilocus genetic analysis of Trypanosoma cruzi supports non-domestic intrusion into domestic transmission in an endemic region of Colombia

Trypanosoma cruzi, the causative agent of Chagas disease, is primarily transmitted to humans by hematophagous bugs of the Triatominae subfamily. In the Colombian Caribbean region, particularly on Margarita Island, T. cruzi transmission is highly endemic and associated with vectors such as Triatoma maculata and Rhodnius pallescens. Additionally, T. cruzi-infected Didelphis marsupialis are commonly found in close proximity to human dwellings. Given the complex transmission dynamics involving various domestic and non-domestic hosts, this study aimed to analyze 145 T. cruzi clones from twelve strains isolated from T. maculata, R. pallescens, and D. marsupialis using spliced leader intergenic region (SL-IR) sequences and nine polymorphic microsatellite loci. The results indicate the presence of a single polymorphic T. cruzi population, suggesting sustained local transmission dynamics between triatomines adapted to A. butyracea forests and peridomestic areas inhabited by synanthropic mammal reservoir such as D. marsupialis. Notably, this population appears to lack substructure, highlighting the importance of adopting an alternative eco-health approach to complement traditional chemical vector control methods for more effective and sustainable interruption of transmission.

Chapter 65: Triatominae (Subfamily): Kissing Bugs [Concepts in Animal Parasitology

Chapter 65: Triatominae (Subfamily): Kissing Bugs [Concepts in Animal Parasitology

Differential Spreading of Microsatellites in Holocentric Chromosomes of Chagas Disease Vectors: Genomic and Evolutionary Implications.

This study focused on analyzing the distribution of microsatellites in holocentric chromosomes of the Triatominae subfamily, insect vectors of Chagas disease. We employed a non-denaturing FISH technique to determine the chromosomal distribution of sixteen microsatellites across twenty-five triatomine species, involving five genera from the two principal tribes: Triatomini and Rhodniini. Three main hybridization patterns were identified: strong signals in specific chromosomal regions, dispersed signals dependent on microsatellite abundance and the absence of signals in certain chromosomal regions or entire chromosomes. Significant variations in hybridization patterns were observed between Rhodniini and Triatomini species. Rhodniini species displayed weak and scattered hybridization signals, indicating a low abundance of microsatellites in their genomes. In contrast, Triatomini species exhibited diverse and abundant hybridization patterns, suggesting that microsatellites are a significant repetitive component in their genomes. One particularly interesting finding was the high abundance of GATA repeats, and to a lesser extent AG repeats, in the Y chromosome of all analyzed Triatomini species. In contrast, the Y chromosome of Rhodniini species did not show enrichment in GATA and AG repeats. This suggests that the richness of GATA repeats on the Y chromosome likely represents an ancestral trait specific to the Triatomini tribe. Furthermore, this information can be used to elucidate the evolutionary relationships between Triatomini and other groups of reduviids, contributing to the understanding of the subfamily's origin. Overall, this study provides a comprehensive understanding of the composition and distribution of microsatellites within Triatominae genomes, shedding light on their significance in the evolutionary processes of these species.

Trypanosoma cruzi Parasite Burdens of Several Triatomine Species in Colombia.

Trypanosoma cruzi, the causal agent of Chagas disease, is mainly transmitted by insects of the Triatominae subfamily. In Colombia, there are 26 triatomine species, and 16 of them are naturally infected with the parasite. The parasite loads of naturally infected vectors can be significant in targeting specific species that can affect the epidemiology of the disease. Studying their ecology and behavior is vital to understand their role in T. cruzi transmission dynamics. We evaluated the parasite loads of 182 field-collected triatomines corresponding to 10 species in 13 departments across Colombia. We standardized a methodology to quantify T. cruzi DNA in these insects. We obtained a LOD (limit of detection) of 3.05 p-eq/mL. The 82% of triatomines we evaluated were positive for T. cruzi infection, with loads ranging from hundreds to millions of equivalent parasites per milliliter. Panstrongylus geniculatus, Rhodnius prolixus, and Triatoma dimidiata were the species with the highest loads of T. cruzi; however, other species whose role as vectors is still unknown were also found with high loads of parasites. Our results suggest the relevance of secondary species for T. cruzi transmission in Colombia. We hope our data can help improve entomological surveillance and vector control programs in the country and the region.

Altitudinal distribution and species richness of triatomines (Hemiptera:Reduviidae) in Colombia

BackgroundChagas disease is considered to be endemic in up to 40% of the territory of Colombia, and to date 27 triatomine species have been reported the country. The purpose of this study was to update the geographical distribution of triatomine species in Colombia and assess the species richness patterns and their altitudinal distribution.MethodsOccurrence data were compiled between 2007 and 2020, including from reports of entomological surveillance from the Instituto Nacional de Salud (INS), the Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT) at Universidad de Los Andes and a review of the literature. Geographic Information Systems (GIS) were used to describe general species richness patterns of the Triatominae subfamily. To establish the altitudinal distribution of the triatomine species, ranges were obtained from reports with unique elevation values. A generalized linear model was fitted, based on a Poisson distribution, to test the relation between triatomine species richness and Chagas disease cases (2012–2019).ResultsAn updated geographical and altitudinal distribution for triatomine species in Colombia was established, with 507 municipalities added to the previously known distributions. The greatest triatomine richness in Colombia was found to be concentrated in the northeastern region of the country, extending towards the center to the departments of Arauca, Casanare and Meta. Regarding the altitudinal distribution, the study revealed that the species Rhodnius prolixus and Triatoma dimidiata have the greatest altitudinal ranges. The data also suggest a positive relation between species richness and number of Chagas disease cases reported per department.ConclusionsAltitudinal ranges for 17 triatomine species found in Colombia are presented. Species richness and species composition patterns are also described, and areas with a higher risk of transmission based on the relation found with Chagas disease cases are highlighted. This updated distribution reveals that Panstrongylus geniculatus is the triatomine with the largest presence by municipalities in Colombia, being reported in 284 municipalities, followed by Rhodnius prolixus in 277 municipalities.Graphical

Simultaneous external and internal marking of Triatoma sordida nymphs: trace element efficacy and microgeographic dispersal in a peridomestic Brazilian Cerrado rural household

BackgroundChagas disease (American trypanosomiasis) is an important neglected tropical illness, which has the flagellate protozoan Trypanosoma cruzi as etiological agent and blood-feeding insects of the Triatominae subfamily as vectors. Despite its importance for disease epidemiology, field studies targeting microgeographic dispersal of triatomines in endemic areas are rare. The ability wingless nymphs have to move (crawl) within peridomestic settings is a key component regarding the design and development of rational control strategies.MethodsWe double-marked Triatoma sordida fourth-instar nymphs (N4) with a reliable fluorescent dye and a trace element. This new methodology allowed us to simultaneously evaluate (i) nymph dispersal and (ii) the effectiveness of copper (Cu), chromium (Cr), and cadmium (Cd) trace elements as potential new markers. In the mark-release-recapture (MRR) experiment, 390 T. sordida N4 were released in the peridomicile of a single rural household, 130 individuals at each of three release points, at distances of 2, 5, and 10 m from the chicken coop (CC) and 27, 32, and 35 m away from the horse corral (HC). All specimens were double marked (Cu/blue, Cr/orange, Cd/green). Recaptures occurred in two intervals: 1–3 days and 15–17 days after release.ResultsSpecimens were successfully recaptured at all distances up to 10 m. A total of 19, 23, and 10 specimens were able to disperse 2, 5, and 10 m, respectively, to reach the CC. No insects were recaptured at the HC. Of the three analyte/paint combinations tested, Cr/orange gave the most promising results; Cu/blue marker and Cd/green marker performed very poorly with only 4/19 and 0/10 analyte/paint ratios, respectively.ConclusionsTriatoma sordida N4 could cover a distance of 10 m in 17 days. This indicates that nymphs seem to have a reduced dispersal capability compared to adults. Ninety-one percent of the 22 recaptured orange-marked nymphs were still Cr positive after the 17-day period evaluated. This makes this analyte a good candidate for future investigations that will apply this marking method in MRR studies.Graphical

Variation in the Mitochondrial Genome of the Chagas Disease Vector Triatoma infestans (Hemiptera: Reduviidae).

Chagas' disease is transmitted mainly by members of the subfamily Triatominae (Hemiptera: Reduviidae). Among them, Triatoma infestans (Klug) is the main vector of the disease in Southern Cone of Latin America. In order to contribute to knowledge of the genetic variation between triatomine vectors, in the present study, we analyzed the intraspecific and interspecific variations of the seven mitogenomes available from Triatominae. In addition, in order to examine their evolutionary relationships with others species of Reduviidae and to estimate the divergence time of the main lineages, we constructed phylogenetic trees including mitogenome sequences of 30 species from Reduviidae. Comparative analysis between mitochondrial DNA sequences from two specimens of T. infestans revealed a total of 54 variable sites. Triatoma infestans, Triatoma dimidiata (Latreille), Triatoma rubrofasciata (De Geer), Triatoma migrans (Breddin), Rhodnius pictipes (Stål), and Panstrongylus rufotuberculatus (Champion) present similar mitogenome organization and the length differences observed among these species are primarily caused by variations in control region (CR) and intergenic spacers (IGS). The relative synonymous codon usage values (RSCU) were similar in the six species of Triatominae, and in agreement with the observed in other insects, a biased use of A and C nucleotides in the majority strand was detected. The monophyly of five subfamilies was strongly supported (Phymatinae, Peiratinae, Triatominae, Stenopodainae, and Harpactorinae), while the sampled species of Reduviinae were grouped with one specie from the Salyavatinae subfamily. The oldest subfamily is Phymatinae at 100.3 Mya (99.6-102.2 Mya) and the youngest is Triatominae and Stenopodainae at 52.6 Mya (42.5-63.7 Mya). The estimated diversification time for the Triatominae subfamily agrees with the Andean uplift geological event. An analysis with more mitogenomes from more Triatominae species would be necessary to provide sufficient evidence to support this finding.

Immature instars of three species of Rhodnius St\xe5l, 1859 (Hemiptera, Reduviidae, Triatominae): morphology, morphometry, and taxonomic implications

BackgroundAmong the 18 genera of the Triatominae subfamily, three stand out for their diversity and epidemiological importance: Triatoma, Panstrongylus, and Rhodnius. Rhodnius includes 21 species that can transmit Trypanosoma cruzi (the etiological agent of Chagas disease, also known as American trypanosomiasis) and Trypanosoma rangeli. The Rhodnius prolixus complex comprises seven species, including Rhodnius marabaensis, Rhodnius prolixus, and Rhodnius robustus, which occur in the northern region of Brazil. Since both adults and immatures can carry T. cruzi, in this study the five nymphal instars of the three species mentioned were dorsally characterized.MethodsUsing microscopy, morphometrics, and geometric morphometrics, the present work measures and describes the morphological characters of the five nymphal instars of R. marabaensis, R. prolixus, and R. robustus.ResultsThe study enabled the characterization of all five nymphal instars, as well as the distinction between the three species in each of their instars.ConclusionsThe morphological, morphometrics of the head, thorax, and abdomen and geometric morphometrics studies of the head enabled the specific distinction of these three species in all five instars.Graphical

New in morphometry: Geometric morphometry of the external female genitalia of Triatominae (Hemiptera: Reduviidae)

The study of geometric morphometry has an impact on Triatominae studies. Currently, several taxonomic and systematic studies use this approach. The Triatominae subfamily comprises three fossil species and 154 extant species potentially capable of transmitting Trypanosoma cruzi, the causative agent of Chagas disease. This study aims to evaluate the external female genitalia of adult triatomines using multivariate geometric morphometric approaches, not only for validation but also for systematic inferences. Specimens belonging to the genera Panstrongylus, Psammolestes, Rhodnius, and Triatoma were evaluated, in addition to two species previously included in Triatoma: T. longipennis and T. phyllosoma. The results show that the external female genitalia have operational morphology and allow characterization of the species and the genera of the Triatominae. In addition, the multivariate technique enabled delimitation of the phylogenetic relationships of the subfamily, presenting results consistent with systematic studies. It can be concluded that the external female genitalia evaluated by geometric morphometry is a useful character for the taxonomy and systematics of Triatominae.

The Neglected Virome of Triatomine Insects

The Triatominae subfamily (Reduviidae) harbors some hematophagous insect species that have been firmly connected to the transmission of Trypanosoma cruzi, the causative agent of Chagas disease. Triatomines not only host and transmit trypanosomatids, but also coexist with a variety of symbiotic microorganisms that generally reside in the insect’s intestinal flora. The microbiome has profound effects on the physiology, immunity, fitness and survival of animals and plants. The interaction between triatomines and bacteria has been investigated to some extent and has revealed important bacteria symbionts. In contrast, the range of viral species that can infect triatomine insects is almost completely unknown. In some cases, genomic and metatranscriptomic approaches have uncovered sequences related to possible viral genomes, but, to date, only eight positive single-strand RNA viruses, namely Triatoma virus and Rhodnius prolixus viruses 1 - 7 have been investigated in more detail. Here, we review the literature available on triatomine viruses and the viruses-insect host relationship. The lack of broader metagenomic and metatranscriptomic studies in these medically relevant insects underscores the importance of expanding our knowledge of the triatomine virome both for surveillance purposes as well as to possibly harness their potential for insect vector population control strategies.

An Integrative Sialomic Analysis Reveals Molecules From Triatoma sordida (Hemiptera: Reduviidae).

Triatomines have evolved salivary glands that produce versatile molecules with various biological functions, including those leading their interactions with vertebrate hosts’ hemostatic and immunological systems. Here, using high-throughput transcriptomics and proteomics, we report the first sialome study on the synanthropic triatomine Triatoma sordida. As a result, 57,645,372 reads were assembled into 26,670 coding sequences (CDS). From these, a total of 16,683 were successfully annotated. The sialotranscriptomic profile shows Lipocalin as the most abundant protein family within putative secreted transcripts. Trialysins and Kazal-type protease inhibitors have high transcript levels followed by ubiquitous protein families and enzyme classes. Interestingly, abundant trialysin and Kazal-type members are highlighted in this triatomine sialotranscriptome. Furthermore, we identified 132 proteins in T. sordida salivary gland soluble extract through LC-MS/MS spectrometry. Lipocalins, Hemiptera specific families, CRISP/Antigen-5 and Kazal-type protein inhibitors proteins were identified. Our study provides a comprehensive description of the transcript and protein compositions of the salivary glands of T. sordida. It significantly enhances the information in the Triatominae sialome databanks reported so far, improving the understanding of the vector’s biology, the hematophagous behaviour, and the Triatominae subfamily’s evolution.

Orientation of Belminus triatomines to cockroaches and cockroaches’ fecal volatiles: an ethological approach

Most triatomine bugs (Hemiptera: Reduviidae: Triatominae) are hematophagous, though Belminus species can live off of cockroach hemolymph to complete their life cycle. In this work, we described the fixed action pattern (FAP) employed by B. ferroae to identify, approach, and suck on a living cockroach. The FAP described here is composed of the following stereotyped behaviors: (1) visual and/or olfactory detection of the cockroach, (2) reaching, (3) cautious approach, (4) antennal exploration, (5) extension of the proboscis, (6) piercing to sedate, (7) walking away and waiting (postsedation behavior), (8) second cautious approach, (9) extension of the proboscis, (10) piercing to suck hemolymph. The FAP sequence observed suggests that Belminus bugs are not predators like the rest of reduviids (assassin bugs)—but are kleptophagous ectoparasites, since they do not attack and kill a prey but rather steal hemolymph from its invertebrate host. Based on these ethological observations, we propose kleptophagy as a trait that naturally groups the Belminus species into the Triatominae subfamily. In order to identify chemicals cues that could elicit such FAP, we examined the behavior of B. corredori, B. ferroae, and B. herreri in response to the cockroaches’ odor, fresh cockroach feces and fresh rodent wastes. The last two sources were tested based on the assumption that abundant chemicals near host refuges could serve as cues for host orientation. We found that the cockroach odor emanating from a box significantly attracted B. corredori and B. herreri in a still air olfactometer. The three Belminus species approached the captive cockroach after 1 h, but avoided to climb the box. Odors emanating from the cockroach feces attracted B. corredori and B. ferroae in a Y-olfactometer. Triatomines and their hosts have intimately shared the same refuge for millions of years; certain molecules occur across invertebrate and vertebrate refuges and are recurrent in human abodes, thus plausibly explaining how these bugs can readily switch to the domestic habitat, while keeping with their kleptophagous nature.

Chagas Disease Vectors of Espírito Santo, Brazil: First Report of Triatoma infestans (Klug, 1834) (Hemiptera, Triatominae) in the Brazilian State and Development of an Identification Key Based on Cytogenetic Data.

Chagas disease is a potentially life-threatening illness caused by the protozoan Trypanosoma cruzi and transmitted, mainly, by hematophagous insects of the Triatominae subfamily. In Brazil, there are currently about 66 triatomine species distributed throughout the country's 27 states. Triatoma infestans is considered as a species of great vectorial importance, mainly because of its biological characteristics, such as the high degree of anthropophilia, adaptation to the home environment, ability to withstand long periods of fasting, and present a wide geographical distribution. Taking into account the epidemiological importance of these species, we carried out the first report of T. infestans in the Espírito Santo, Brazil, and development of an identification key for all species notified in that state, based on cytogenetic data. This information is important because they contribute to the direction of epidemiological surveillance activities carried out by vector control programs of the Espírito Santo, Brazil.

Cytotaxonomy of Dipetalogaster maxima Uhler, 1894 (Hemiptera, Reduviidae, Triatominae).

The Triatomini tribe consists of ten genera and is regarded as one of the most important tribes from epidemiological point of view. The genus Dipetalogaster Usinger, 1939 is composed only by the species Dipetalogaster maxima Uhler, 1894. This triatomine is exclusive of the Mexico and is a potential vector for Chagas disease. Besides the epidemiological importance, the insects of the Triatominae subfamily are important biological models for cytogenetic studies. Therefore, in order to contribute to the knowledge on the reproductive biology and assist in citotaxonomy of D. maxima, this study aimed to describe spermatogenesis, as well as confirm the karyotype and heterochromatic patterns of this Mexican triatomine species. The seminiferous tubules were torn, fixed to a cover slip and underwent the cytogenetic technique of Lacto-acetic orcein and C-banding. Through the cytogenetics analysis of testicular material D. maxima it was possible to confirm the karyotype (2n = 22), describe the stages of spermatogenesis and characterize the heterochromatic pattern (restricted to sex chromosome Y) of the species. D. maxima showed the same arrangement of heterochromatin described for Triatoma lecticularia (Stål, 1859) (a species that occur in United States of American and Mexico and is phylogenetically related with D. maxima), highlighting the importance of this analysis as an optimization tool to explore phylogenetic correlations.

Taxonomy, Evolution, and Biogeography of the Rhodniini Tribe (Hemiptera: Reduviidae)

The Triatominae subfamily includes 151 extant and three fossil species. Several species can transmit the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, significantly impacting public health in Latin American countries. The Triatominae can be classified into five tribes, of which the Rhodniini is very important because of its large vector capacity and wide geographical distribution. The Rhodniini tribe comprises 23 (without R. taquarussuensis) species and although several studies have addressed their taxonomy using morphological, morphometric, cytogenetic, and molecular techniques, their evolutionary relationships remain unclear, resulting in inconsistencies at the classification level. Conflicting hypotheses have been proposed regarding the origin, diversification, and identification of these species in Latin America, muddying our understanding of their dispersion and current geographic distribution. Clarifying these factors can help for the design of vector control strategies. The aim of this review is to depict the different approaches used for taxonomy of the Rhodniini and to shed light on their evolution and biogeography.

Protein mass spectrometry detects multiple bloodmeals for enhanced Chagas disease vector ecology

Chagas disease, a neglected tropical disease endemic in Latin America, is caused by the protozoan parasite Trypanosoma cruzi and is responsible for significant health impacts, especially in rural communities. The parasite is transmitted by insect vectors in the Triatominae subfamily and due to lack of vaccines and limited treatment options, vector control is the main way of controlling the disease. Knowing what vectors are feeding on directly enhances our understanding of the ecology and biology of the different vector species and can potentially aid in engaging communities in active disease control, a concept known as Ecohealth management. We evaluated bloodmeals in rural community, house-caught insect vectors previously evaluated for bloodmeals via DNA analysis as part of a larger collaborative project from three countries in Central America, including Guatemala. In addition to identifying bloodmeals in 100% of all samples using liquid chromatography tandem mass spectrometry (LC-MS/MS) (n = 50), strikingly for 53% of these samples there was no evidence of a recent bloodmeal by DNA-PCR. As individual vectors often feed on multiple sources, we developed an enhanced detection pipeline, and showed the ability to quantify a bloodmeal using stable-isotope-containing synthetic references peptides, a first step in further exploration of species-specific bloodmeal composition. Furthermore, we show that a lower resolution mass spectrometer is sufficient to correctly identify taxa from bloodmeals, an important and strong attribute of our LC-MS/MS-based method, opening the door to using proteomics in countries where Chagas disease is endemic.

Effects of atmospheric oscillations on infectious diseases: the case of Chagas disease in Chile.

BACKGROUND Currently, there is an increasing global interest for the study of how infectious diseases could be linked to climate and weather variability. The Chagas disease was described in 1909 by Carlos Chagas, and is caused by the flagellate protozoan Trypanosoma cruzi. The Chagas disease is considered one of the biggest concerns in public health in Latin America. In Chile, the main vectors involved in the transmission of T. cruzi are arthropods of the Triatominae subfamily. Moreover, another main transmission way is through of vectors by fecal-urine way, however, oral way also has been described among others transmission form.OBJECTIVES In order to get understand outbreaks of Chagas-disease, we search for possible relationships between the frequency of cases in the Chilean population and atmospheric oscillations.METHODS We explored the two most important atmospheric oscillations in the Southern Hemisphere: southern oscillation index (SOI) and Antarctic oscillation (AAO), during the available years with official data. Because the number of migrant people born outside from Chile increasing significantively between 2014 and 2018, we used for the analysis two different periods from data available official data: (i) 2001 to 2014, (ii) 2001 to 2017.FINDINGS For both periods we observed a significant and positive relation between AAO one year before. However, for the 2001 to 2014 period positive SOI one year before, which is related with La Niña phases, was the more important variable.MAIN CONCLUSIONS The Chagas disease frequency per year in Chile was found to depend mainly on SOI in previous year, whose values can be determined one year in advance. Therefore, it is possible to partially forecast annual frequency patterns. This could have important applications in public health strategies and for allocating resources for the management of the disease.

In silico Study of the Antichagasic Activity of Aromatic Compounds

Chagas disease is a parasitic tropical disease caused by Trypanosoma cruzi and transmissible to humans and other mammals by insects of the Triatominae subfamily. Due to the negligence of the pharmaceutical industry in relation to the development of new anti-drugs and the existing drugs have low efficacy and many side effects, the development of new research in the area is extremely relevant. Thus, the objective of this work was to relate the biological activity of glyceraldehyde 3-phosphate dehydrogenase enzyme inhibitors with molecular descriptors such as partition coefficient (LogP), water solubility (LogS), HOMO-LUMO frontier orbitals and potential of ionization. The descriptors were calculated machine learning techniques and semi-empirical calculations using the PM7 method. A molecular coupling simulation was also performed aiming at a better understanding of the interaction of the compounds with the active site of the enzymatic target. The compounds were found to have attractive interaction energy with the enzyme and to provide adequate solubility for good pharmacokinetics. It was also observed a relation of the pharmacological activity of some compounds with the energy of the LUMO orbital. DOI: http://dx.doi.org/10.17807/orbital.v10i5.1018

Karyotype Evolution of Chagas Disease Vectors (Hemiptera, Triatominae).

The Triatominae subfamily is composed of 153 hematophagous species that are potential vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Karyotypic studies in triatomines were initiated in 1909. There are 92 karyotypes described, all grouped into the tribes Rhodniini and Triatomini. Recently, a phylogenetic study of the triatomines that combines molecular data with geological changes was performed. We now discuss how the karyotype evolved with the diversification of the triatomines.