-
The CRISPR Journal Apr 2024is currently the model vector of choice for studying Chagas disease transmission, a debilitating disease caused by parasites. However, transgenesis and gene editing...
is currently the model vector of choice for studying Chagas disease transmission, a debilitating disease caused by parasites. However, transgenesis and gene editing protocols to advance the field are still lacking. Here, we tested protocols for the maternal delivery of CRISPR-Cas9 (clustered regularly spaced palindromic repeats/Cas-9 associated) elements to developing oocytes and strategies for the identification of insertions and deletions (indels) in target loci of resulting gene-edited generation zero (G0) nymphs. We demonstrate successful gene editing of the eye color markers and , and the cuticle color marker with highest effectiveness obtained using Receptor-Mediated Ovary Transduction of Cargo (ReMOT Control) with the ovary-targeting BtKV ligand. These results provide proof of concepts for generating somatic mutations in and potentially for generating germ line-edited lines in triatomines, laying the foundation for gene editing protocols that could lead to the development of novel control strategies for vectors of Chagas disease.
Topics: Animals; Female; Gene Editing; Rhodnius; CRISPR-Cas Systems; Insect Vectors; Chagas Disease
PubMed: 38564197
DOI: 10.1089/crispr.2023.0076 -
Revista Da Sociedade Brasileira de... 2024Chagas disease, a zoonosis transmitted mainly by hematophagous insects of the subfamily Triatominae, is caused by Trypanosoma cruzi, classified into six discrete typing...
BACKGROUND
Chagas disease, a zoonosis transmitted mainly by hematophagous insects of the subfamily Triatominae, is caused by Trypanosoma cruzi, classified into six discrete typing units (DTUs: TcI-TcVI and Tcbat).
METHODS
Insect vectors were collected from 84 human dwellings in the municipality of Santo Domingo Tehuantepec, Oaxaca, Mexico; 4.76% were infested. DTUs were determined using conventional and nested PCR.
RESULTS
The infection rate was 43.6%. All insects were infected with TcI while one specimen showed mixed infection with TcII.
CONCLUSIONS
This is the first report of T. cruzi mixed infection in Triatoma phyllosoma, its main vector in the study region.
Topics: Animals; Humans; Triatoma; Trypanosoma cruzi; Mexico; Coinfection; Chagas Disease; Genotype
PubMed: 38537000
DOI: 10.1590/0037-8682-0449-2023 -
Insects Feb 2024Due to the variability of body coloration and morphological similarity among closely related species, unresolved issues and debates still persist in the taxonomic study...
Due to the variability of body coloration and morphological similarity among closely related species, unresolved issues and debates still persist in the taxonomic study of the genus from China. In this study, we conducted phylogenetic analyses and species delimitation for in China based on a COI DNA barcoding dataset comprising 81 samples. The results revealed that all the samples could be classified into 12 species by integrating molecular analyses with morphological comparison. This paper provides a comprehensive systematic review of the species found in China, including descriptions of three new species: Zhao & Cai sp. nov., Li & Cai sp. nov., and Wang & Cai sp. nov. Furthermore, it is proposed that Dohrn, 1859, Walker, 1873, and Stål, 1863, are three synonyms of (Fabricius, 1787); Hsiao, 1979, is a synonym of Dohrn, 1859; and Maldonado-Capriles, 1990, is a synonym of Putshkov, 1987. Additionally, brief biological information is provided for two species, Stål, 1863, and Hsiao, 1979.
PubMed: 38535361
DOI: 10.3390/insects15030165 -
The American Journal of Tropical... May 2024In July and October 2023, two live triatomine bugs were found inside a home in New Castle County, Delaware. The bugs were identified as Triatoma sanguisuga, the most...
In July and October 2023, two live triatomine bugs were found inside a home in New Castle County, Delaware. The bugs were identified as Triatoma sanguisuga, the most widespread triatomine bug species in the United States. Triatoma sanguisuga is a competent vector of Trypanosoma cruzi, the causative agent of Chagas disease. The two specimens were tested via real-time PCR (qPCR) for infection with T. cruzi, and one of the specimens was positive. Despite T. sanguisuga being endemic to the area, attainment of accurate species identification and T. cruzi testing of the bugs required multiple calls to federal, state, private, and academic institutions over several months. This constitutes the first report of T. sanguisuga infected with T. cruzi in Delaware. In addition, this is the first published report of T. sanguisuga in New Castle County, the northernmost and most densely populated county in Delaware. New Castle County still conforms to the described geographic range of T. sanguisuga, which spans from Texas to the East Coast of the United States. The T. cruzi infection prevalence of the species has not been studied in the northeastern United States, but collections in southern states have found prevalences as high as 60%. The Delaware homeowner's lengthy pursuit of accurate information about the vector highlights the need for more research on this important disease vector in Delaware.
Topics: Animals; Triatoma; Chagas Disease; Delaware; Trypanosoma cruzi; Insect Vectors; Humans
PubMed: 38531096
DOI: 10.4269/ajtmh.23-0915 -
Parasites & Vectors Mar 2024Triatoma garciabesi, a potential vector of the parasitic protozoan Trypanosoma cruzi, which is the causative agent of Chagas disease, is common in peridomestic and wild...
BACKGROUND
Triatoma garciabesi, a potential vector of the parasitic protozoan Trypanosoma cruzi, which is the causative agent of Chagas disease, is common in peridomestic and wild environments and found throughout northwestern and central Argentina, western Paraguay and the Bolivian Chaco. Genetic differentiation of a species across its range can help to understand dispersal patterns and connectivity between habitats. Dispersal by flight is considered to be the main active dispersal strategy used by triatomines. In particular, the morphological structure of the hemelytra is associated with their function. The aim of this study was to understand how genetic diversity is structured, how morphological variation of dispersal-related traits varies with genetic diversity and how the morphological characteristics of dispersal-related traits may explain the current distribution of genetic lineages in this species.
METHODS
Males from 24 populations of T. garciabesi across its distribution range were examined. The cytochrome c oxidase I gene (coI) was used for genetic diversity analyses. A geometric morphometric method based on landmarks was used for morpho-functional analysis of the hemelytra. Centroid size (CS) and shape of the forewing, and contour of both parts of the forewing, the head and the pronotum were characterised. Length and area of the forewing were measured to estimate the aspect ratio.
RESULTS
The morphometric and phylogenetic analysis identified two distinct lineages, namely the Eastern and Western lineages, which coincide with different ecological regions. The Eastern lineage is found exclusively in the eastern region of Argentina (Chaco and Formosa provinces), whereas the Western lineage is prevalent in the rest of the geographical range of the species. CS, shape and aspect ratio of the hemelytra differed between lineages. The stiff portion of the forewing was more developed in the Eastern lineage. The shape of both portions of the hemelytra were significantly different between lineages, and the shape of the head and pronotum differed between lineages.
CONCLUSIONS
The results provide preliminary insights into the evolution and diversification of T. garciabesi. Variation in the forewing, pronotum and head is congruent with genetic divergence. Consistent with genetic divergence, morphometry variation was clustered according to lineages, with congruent variation in the size and shape of the forewing, pronotum and head.
Topics: Male; Animals; Triatoma; Phylogeny; Insect Vectors; Chagas Disease; Genetic Variation
PubMed: 38500121
DOI: 10.1186/s13071-024-06211-x -
Zootaxa Mar 2024
Topics: Animals; Reduviidae; Heteroptera; Hemiptera; Animal Distribution; Names
PubMed: 38480347
DOI: 10.11646/zootaxa.5418.4.8 -
Zootaxa Mar 2024The study of the Heteroptera (Hemiptera) fauna of the El Impenetrable National Park, resulted in an inventory composed of: Alydidae (2 spp.), Aradidae (1 sp.),...
The study of the Heteroptera (Hemiptera) fauna of the El Impenetrable National Park, resulted in an inventory composed of: Alydidae (2 spp.), Aradidae (1 sp.), Belostomatidae (5 spp.), Berytidae (1 sp.), Blissidae (1 sp.), Coreidae (11 spp.), Corixidae (2 spp.), Geocoridae (1 sp.), Gerridae (1 sp.), Hebridae (1 sp.), Largidae (4 spp.), Lygaeidae (5 spp.), Miridae (17 spp.), Nabidae (1 sp.), Notonectidae (1 sp.), Oxycarenidae (1 sp.), Pachygronthidae (1 sp.), Pachynomidae (2 spp.), Pentatomidae (16 spp.), Pleidae (1 sp.), Pyrrhocoridae (1 sp.), Reduviidae (30 spp.), Rhopalidae (5 spp.), Rhyparochromidae (12 spp.), Saldidae (1 sp.), Scutelleridae (2 spp.), Tingidae (1 sp.), and Veliidae (1 sp.). These findings include six new records for the Argentinean fauna: Prytanes foedus (Stl), Saldula pallipes (Fabricius), Camirus brevilinea (Walker), Atopozelus opsimus Elkins, Doldina bicarinata Stl, Rocconota sextuberculata St and 39 new records for Chaco Province.
Topics: Animals; Argentina; Hemiptera; Heteroptera; Parks, Recreational; Reduviidae
PubMed: 38480302
DOI: 10.11646/zootaxa.5424.1.1 -
Frontiers in Insect Science 2023The fall armyworm (FAW), , an invasive pest originating from the Americas is a serious pest threatening cereal production and food security in Zambia. We studied the...
The fall armyworm (FAW), , an invasive pest originating from the Americas is a serious pest threatening cereal production and food security in Zambia. We studied the prevalence and abundance of natural enemies of FAW in three Agroecological regions (AERs I, II, and III) to identify those that could potentially serve as bio-control agents. Sampling of FAW parasitoids and predators was done along trunk roads at intervals of 10 km. Molecular sequence analysis and morphological characterization were used to identify natural enemies. Over 11 species of FAW natural enemies, including egg, egg-larval, and larval parasitoids, and predators, were identified in Zambia. The mean number of natural enemies and species richness was higher in AER I and IIa. Consequently, egg parasitism was highest in those two regions, at 24.5% and 12.2%, respectively. Larvae parasitism was highest in AER I (4.8%) and AER III (1.9), although no significant differences were observed. The most abundant and widely distributed parasitoid was sp. (Diptera: Tachinidae), while (Germar) (Hemiptera: Reduviidae) and sp. (Hymenoptera: Vespidae) were the most prevalent predators. Our study reveals the presence of two natural enemies belonging to the genus and , uncommon to FAW. Significant differences in the number of parasitoids were observed in polycropping, with the highest recovery of 12 ± 10% from maize + cowpeas + pumpkin and watermelon mixed cropping. The higher the rainfall, the lower the number of natural enemies recorded. Variations in rainfall patterns which affect FAW availability, cropping systems and the three AERs may explain natural enemies' species diversity in Zambia. The information provided in this study can aid the development of a national biological control programme for sustainable management of fall armyworm.
PubMed: 38469517
DOI: 10.3389/finsc.2023.1091084 -
Journal of Medical Entomology Mar 2024The transmission and incidence of vector-borne diseases rely on vector distribution and life history traits such as survival, fecundity, and feeding. Since arthropod...
The transmission and incidence of vector-borne diseases rely on vector distribution and life history traits such as survival, fecundity, and feeding. Since arthropod disease vectors are ectotherms, these vital rates are strongly influenced by temperature. Chagas disease is a neglected tropical disease caused by the protozoan parasite, Trypanosoma cruzi. This parasite is transmitted when the feces of the infected triatomine enter the bloodstream of the host. One of the most important vector-species of this disease in the Southern Cone region of South America is Triatoma infestans. In this study, we evaluated the role of constant and variable environmental temperature on the feeding behavior of T. infestans. Fifth-instar nymphs were acclimatized to 4 thermal treatments comprising 2 temperatures (27 °C and 18 °C) with and without diurnal thermal variability (27 ± 5 °C and 18 ± 5 °C). Individuals were fed weekly for 7 wk to quantify their feeding. Our results showed lower feeding frequency in nymphs acclimatized to cold temperature compared to those from warmer temperature treatments. However, treatments with thermal variability presented a nonlinear effect on feeding, with an increased feeding rate in the cold, variable treatment and a decreased feeding rate in the warm, variable treatment. Individuals maintained under cold treatments, the variable temperature exhibited a higher feeding rate and the lowest amount of ingested blood among all treatments. Thus, natural diurnal temperature variation cannot be ignored if we are to make more accurate T. cruzi transmission risk predictions now and in the future.
PubMed: 38461045
DOI: 10.1093/jme/tjae034 -
Acta Tropica May 2024Triatoma dimidiata is a vector of the hemoparasite Trypanosoma cruzi, the causal agent of Chagas disease. It settles reproductive colonies in the peridomicile of the...
Triatoma dimidiata is a vector of the hemoparasite Trypanosoma cruzi, the causal agent of Chagas disease. It settles reproductive colonies in the peridomicile of the premises. The peridomicile is comprised of a random set of artificial and natural features that overlap and assemble a network of microenvironmental suitable sites (patches) that interact with each other and favor the structure and proliferation of T. dimidiata colonies. The heterogeneity of patch characteristics hinders the understanding and identification of sites susceptible to colonization. In this study, a classification system using a random forest algorithm was used to identify peridomiciles susceptible to colonization to describe the spatial distribution of these sites and their relationship with the colonies of T. dimidiata in ten localities of Yucatan. From 1,000 peridomiciles reviewed, the classification showed that 13.9 % (139) of the patches were highly susceptible (HSP), and 86.1 % (861) were less susceptible (LSP). All localities had at least one HSP. The occupancy by patch type showed that the percentage of total occupancy and by colonies was higher in the HSP, while the occupancy by adult T. dimidiata without evidence of nymphs or exuviae (propagules) was higher in the LSP. A generalized additive model (GAM) revealed that the percentage of occupied patches increases as the abundance of individuals in the localities increases however, the percentage of occupied patches in LSP is lower than occupied in HSP. Distance analyses revealed that colonies and propagules were located significantly closer (approximately 200 m) to a colony in a HSP than any colony in a LSP. The distribution of T. dimidiata in the localities was defined by the distribution of patch type; as the occupancy in these patches increased, a network of peridomestic populations was configured, which may be promoted by a greater abundance of insects inside the localities. These results reveal that the spatial distribution of T. dimidiata individuals and colonies in the peridomicile at the locality scale corresponds to a metapopulation pattern within the localities through a system of patches mediated by distance and level of the vectors' occupancy.
Topics: Humans; Animals; Triatoma; Insect Vectors; Chagas Disease; Trypanosoma cruzi; Nymph
PubMed: 38432403
DOI: 10.1016/j.actatropica.2024.107169