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Rengifo‐Correa L, Abad‐Franch F, Martínez‐Hernández F, Salazar‐Schettino PM, Téllez‐Rendón JL, Villalobos G, Morrone JJ. A biogeographic–ecological approach to disentangle reticulate evolution in the
Triatoma phyllosoma
species group (Heteroptera: Triatominae), vectors of Chagas disease. J ZOOL SYST EVOL RES 2020. [DOI: 10.1111/jzs.12409] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Laura Rengifo‐Correa
- Departamento de Biología Evolutiva Facultad de Ciencias Museo de Zoología ‘Alfonso L. Herrera’Universidad Nacional Autónoma de México Mexico City Mexico
| | - Fernando Abad‐Franch
- Programa de Pós‐graduação em Medicina Tropical Núcleo de Medicina Tropical Facultade Medicina Universidade de Brasília Brasília Brazil
| | | | - Paz M. Salazar‐Schettino
- Laboratorio de Biología de Parásitos Departamento de Microbiología y Parasitología Facultad de Medicina Universidad Nacional Autónoma de México Mexico City Mexico
| | | | - Guiehdani Villalobos
- Departamento de Ecología de Agentes Patógenos Hospital General Dr. Manuel Gea González Mexico City Mexico
| | - Juan J. Morrone
- Departamento de Biología Evolutiva Facultad de Ciencias Museo de Zoología ‘Alfonso L. Herrera’Universidad Nacional Autónoma de México Mexico City Mexico
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Peterson JK, Hashimoto K, Yoshioka K, Dorn PL, Gottdenker NL, Caranci A, Stevens L, Zuniga C, Saldaña A, Rodriguez S, Monroy C. Chagas Disease in Central America: Recent Findings and Current Challenges in Vector Ecology and Control. Curr Trop Med Rep 2019; 6:76-91. [DOI: 10.1007/s40475-019-00175-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Pech-May A, Mazariegos-Hidalgo CJ, Izeta-Alberdi A, López-Cancino SA, Tun-Ku E, De la Cruz-Félix K, Ibarra-Cerdeña CN, González Ittig RE, Ramsey JM. Genetic variation and phylogeography of the Triatoma dimidiata complex evidence a potential center of origin and recent divergence of haplogroups having differential Trypanosoma cruzi and DTU infections. PLoS Negl Trop Dis 2019; 13:e0007044. [PMID: 30689662 DOI: 10.1371/journal.pntd.0007044] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 02/07/2019] [Accepted: 12/02/2018] [Indexed: 11/19/2022] Open
Abstract
The population genetics of Triatoma dimidiata haplogroups was analyzed at landscape and sub-regional scales in Chiapas and regional level across the Mexican Neotropics, and phylogeography of the complex was re-analyzed across its complete geographic range. Two contiguous fragments of the ND4 gene were analyzed due to bias from differential haplogroup specificity using a previously designed sequence. At both landscape (anthropic modification gradient) and regional (demographic, fragmentation, biogeographic, climate) scales, lowest T. dimidiata genetic diversity occurs where there is greatest historical anthropic modification, and where T. cruzi infection prevalence is significantly highest. Trypanosoma cruzi prevalence was significantly higher than expected in haplogroups 1 and 3, while lower than expected in haplogroup 2. There was also a significant difference of DTUI and DTUVI infection frequencies in both haplogroups 1 and 3, while no difference of either in haplogroup 2. All haplogroups from the Mexican Neotropics had moderate to high haplotype diversity, while greatest genetic differentiation was between haplogroups 1 and 3 (above FST = 0.868, p < 0.0001). Divergence of the complex from the MRCA was estimated between 0.97 MYA (95% HPD interval = 0.55–1.53 MYA) and 0.85 MYA (95% HPD interval = 0.42–1.5 MYA) for ND4A and both concatenated fragments, respectively, with primary divergence from the MRCA of haplogroups 2 and 3. Effective population size for Mexican haplogroups 1 and 2 increased between 0.02 and 0.03 MYA. This study supports previous ecological niche evidence for the complex´s origin surrounding the Tehuantepec Isthmus, and provides evidence for recent divergence of three primary dimidiata haplogroups, with differential T. cruzi infection frequency and DTU specificity, important components of vector capacity. Triatoma dimidiata is one of the broadest distributed triatomine species´ complexes transmitting Trypanosoma cruzi. In Mexico, three haplogroups of the T. dimidiata complex have been reported and all are primary vectors of Chagas disease south of the Tehuantepec Isthmus. Given their epidemiological importance, the question arises whether haplogroups have similar genetic diversity in domestic/modified landscapes, as well as infection characteristics and parasite DTU associations, key components of vector capacity. The aim of the present study was to analyze Triatoma dimidiata population genetics across landscapes, sub-regional, regional, and global Neotropical realm scales, using two contiguous fragments of the ND4 gene. Our results support previous evidence for the complex´s origin surrounding the Tehuantepec Isthmus, and provides evidence for recent divergence of three principal dimidiata haplogroups and significant secondary divergence within each. Differential T. cruzi prevalence and Discrete Typing Unit (DTU) specificity for individual haplogroups provide evidence for potential differential vector capacity within the complex in Mexico.
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Lima-Cordón RA, Stevens L, Solórzano Ortíz E, Rodas GA, Castellanos S, Rodas A, Abrego V, Zúniga Valeriano C, Monroy MC. Implementation science: Epidemiology and feeding profiles of the Chagas vector Triatoma dimidiata prior to Ecohealth intervention for three locations in Central America. PLoS Negl Trop Dis 2018; 12:e0006952. [PMID: 30485265 PMCID: PMC6287883 DOI: 10.1371/journal.pntd.0006952] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/10/2018] [Accepted: 10/29/2018] [Indexed: 11/19/2022] Open
Abstract
The Ecohealth strategy is a multidisciplinary data-driven approach used to improve the quality of people's lives in Chagas disease endemic areas, such as regions of Central America. Chagas is a vector-borne disease caused by the parasite Trypanosoma cruzi. In Central America, the main vector is Triatoma dimidiata. Because successful implementation of the Ecohealth approach reduced home infestation in Jutiapa department, Guatemala, it was scaled-up to three localities, one in each of three Central American countries (Texistepeque, El Salvador; San Marcos de la Sierra, Honduras and Olopa, Guatemala). As a basis for the house improvement phase of the Ecohealth program, we determined if the localities differ in the role of sylvatic, synanthropic and domestic animals in the Chagas transmission cycle by measuring entomological indices, blood meal sources and parasite infection from vectors collected in and around houses. The Polymerase Chain Reaction (PCR) with taxa specific primers to detect both, blood sources and parasite infection, was used to assess 71 T. dimidiata from Texistepeque, 84 from San Marcos de la Sierra and 568 from Olopa. Our results show that infestation (12.98%) and colonization (8.95%) indices were highest in Olopa; whereas T. cruzi prevalence was higher in Texistepeque and San Marcos de la Sierra (>40%) than Olopa (8%). The blood meal source profiles showed that in Olopa, opossum might be important in linking the sylvatic and domestic Chagas transmission cycle, whereas in San Marcos de la Sierra dogs play a major role in maintaining domestic transmission. For Texistepeque, bird was the major blood meal source followed by human. When examining the different life stages, we found that in Olopa, the proportion bugs infected with T. cruzi is higher in adults than nymphs. These findings highlight the importance of location-based recommendations for decreasing human-vector contact in the control of Chagas disease.
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Affiliation(s)
- Raquel Asunción Lima-Cordón
- The Applied Entomology and Parasitology Laboratory at Biology School, Pharmacy Faculty, San Carlos University of Guatemala, Guatemala City, Guatemala
- Department of Biology, University of Vermont, Burlington, Vermont, United States of America
| | - Lori Stevens
- Department of Biology, University of Vermont, Burlington, Vermont, United States of America
| | - Elizabeth Solórzano Ortíz
- The Applied Entomology and Parasitology Laboratory at Biology School, Pharmacy Faculty, San Carlos University of Guatemala, Guatemala City, Guatemala
| | - Gabriela Anaité Rodas
- The Applied Entomology and Parasitology Laboratory at Biology School, Pharmacy Faculty, San Carlos University of Guatemala, Guatemala City, Guatemala
| | - Salvador Castellanos
- The Applied Entomology and Parasitology Laboratory at Biology School, Pharmacy Faculty, San Carlos University of Guatemala, Guatemala City, Guatemala
| | - Antonieta Rodas
- The Applied Entomology and Parasitology Laboratory at Biology School, Pharmacy Faculty, San Carlos University of Guatemala, Guatemala City, Guatemala
| | - Vianney Abrego
- Centro de Investigación y desarrollo en salud (CENSALUD-CID), Universidad de El Salvador, San Salvador, El Salvador
| | | | - María Carlota Monroy
- The Applied Entomology and Parasitology Laboratory at Biology School, Pharmacy Faculty, San Carlos University of Guatemala, Guatemala City, Guatemala
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May-Concha I, Guerenstein P, Malo E, Catalá S, Rojas J. Electroantennogram responses of the Triatoma dimidiata complex to volatiles produced by its exocrine glands. Acta Trop 2018; 185:336-343. [PMID: 29932928 DOI: 10.1016/j.actatropica.2018.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/11/2018] [Accepted: 06/18/2018] [Indexed: 12/15/2022]
Abstract
Members of the Triatoma dimidiata complex are vectors of the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. Morphological and genetic studies indicate that T. dimidiata complex has three principal haplogroups in Mexico. However, whether there are differences in the olfactory physiology among the haplogroups of this complex and a possible correlation with their antennal phenotype are not yet known. Antennal responses to 13 compounds released from the metasternal and Brindley´s glands, which are involved in the alarm and mating-related behaviours of T. dimidiata were investigated using electroantennography (EAG). Overall, of the 13 compounds tested, seven triggered EAG responses in both sexes of three Mexican haplogroups. The sensitivity of the EAG responses show some relationship with the total number of chemo-sensilla present on the antennae. Antennal sensitivity was different between sexes and haplogroups of the T. dimidiata complex. Discriminant analysis of EAG sensitivity was significant, separating the three haplogroups. Our finding is consistent with morphological and genetic evidence for haplogroups distinction within the complex.
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Justi SA, Cahan S, Stevens L, Monroy C, Lima-Cordón R, Dorn PL. Vectors of diversity: Genome wide diversity across the geographic range of the Chagas disease vector Triatoma dimidiata sensu lato (Hemiptera: Reduviidae). Mol Phylogenet Evol 2018; 120:144-150. [PMID: 29248626 PMCID: PMC5991476 DOI: 10.1016/j.ympev.2017.12.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 11/17/2017] [Accepted: 12/11/2017] [Indexed: 01/01/2023]
Abstract
To date, the phylogeny of Triatoma dimidiata sensu lato (s. l.) (Hemiptera: Reduviidae: Triatominae), the epidemiologically most important Chagas disease vector in Central America and a secondary vector in Mexico and northern South America, has only been investigated by one multi-copy nuclear gene (Internal Transcribed Spacer - 2) and a few mitochondrial genes. We examined 450 specimens sampled across most of its native range from Mexico to Ecuador using reduced representation next-generation sequencing encompassing over 16,000 single nucleotide polymorphisms (SNPs). Using a combined phylogenetic and species delimitation approach we uncovered two distinct species, as well as a well-defined third group that may contain multiple species. The findings are discussed with respect to possible drivers of diversification and the epidemiological importance of the distinct species and groups.
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Affiliation(s)
- Silvia A Justi
- Department of Biology, University of Vermont, Burlington, VT, United States.
| | - Sara Cahan
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Lori Stevens
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Carlota Monroy
- Biology School, University of San Carlos, Guatemala City, Guatemala
| | - Raquel Lima-Cordón
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Patricia L Dorn
- Department of Biological Sciences, Loyola University New Orleans, New Orleans, LA, United States
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Campos-Soto R, Panzera F, Pita S, Lages C, Solari A, Botto-Mahan C. Experimental crosses between Mepraia gajardoi and M. spinolai and hybrid chromosome analyses reveal the occurrence of several isolation mechanisms. Infect Genet Evol 2016; 45:205-212. [PMID: 27600593 DOI: 10.1016/j.meegid.2016.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/12/2016] [Accepted: 09/01/2016] [Indexed: 10/21/2022]
Abstract
Hematophagous insects of the subfamily Triatominae include several species with a large variety of shapes, behavior and distribution. They have great epidemiological importance since most of them transmit the flagellated protozoan Trypanosoma cruzi, the etiologic agent of Chagas disease. In this subfamily several cases of species hybridization have been reported under experimental and natural conditions. Mepraia is a genus of Triatominae endemic in Chile, responsible for transmitting T. cruzi in the sylvatic cycle. This genus includes three species, M. gajardoi, M. spinolai and M. parapatrica; however, the differentiation of M. parapatrica as a separate species remains controversial considering the possible occurrence of introgression/hybridization processes in some populations of this putative species. Mepraia species show conspicuous wing polymorphism, and it has been proposed that the genes related to wings are linked to the Y chromosome, thus wingless males could not engender winged progeny. In order to determine the degree of reproductive isolation and to assess the wing phenotype in the offspring, we performed experimental crosses between the two most divergent Mepraia species (M. gajardoi and M. spinolai) together with chromosome analyses of hybrid progenies. Although fertile F1 hybrids were obtained in only one direction of crossing, we verified the existence of different isolation mechanisms between parental species, including hybrid breakdown. The occurrence of winged males in the offspring of wingless parental males suggests that the wing character is not linked to the Y chromosome.
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Affiliation(s)
- Ricardo Campos-Soto
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile.
| | - Francisco Panzera
- Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Sebastian Pita
- Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Carol Lages
- Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Aldo Solari
- Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Carezza Botto-Mahan
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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Dorn PL, de la Rúa NM, Axen H, Smith N, Richards BR, Charabati J, Suarez J, Woods A, Pessoa R, Monroy C, Kilpatrick CW, Stevens L. Hypothesis testing clarifies the systematics of the main Central American Chagas disease vector, Triatoma dimidiata (Latreille, 1811), across its geographic range. Infect Genet Evol 2016; 44:431-43. [PMID: 27496718 DOI: 10.1016/j.meegid.2016.07.046] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 07/25/2016] [Accepted: 07/31/2016] [Indexed: 11/22/2022]
Abstract
The widespread and diverse Triatoma dimidiata is the kissing bug species most important for Chagas disease transmission in Central America and a secondary vector in Mexico and northern South America. Its diversity may contribute to different Chagas disease prevalence in different localities and has led to conflicting systematic hypotheses describing various populations as subspecies or cryptic species. To resolve these conflicting hypotheses, we sequenced a nuclear (internal transcribed spacer 2, ITS-2) and mitochondrial gene (cytochrome b) from an extensive sampling of T. dimidiata across its geographic range. We evaluated the congruence of ITS-2 and cyt b phylogenies and tested the support for the previously proposed subspecies (inferred from ITS-2) by: (1) overlaying the ITS-2 subspecies assignments on a cyt b tree and, (2) assessing the statistical support for a cyt b topology constrained by the subspecies hypothesis. Unconstrained phylogenies inferred from ITS-2 and cyt b are congruent and reveal three clades including two putative cryptic species in addition to T. dimidiata sensu stricto. Neither the cyt b phylogeny nor hypothesis testing support the proposed subspecies inferred from ITS-2. Additionally, the two cryptic species are supported by phylogenies inferred from mitochondrially-encoded genes cytochrome c oxidase I and NADH dehydrogenase 4. In summary, our results reveal two cryptic species. Phylogenetic relationships indicate T. dimidiata sensu stricto is not subdivided into monophyletic clades consistent with subspecies. Based on increased support by hypothesis testing, we propose an updated systematic hypothesis for T. dimidiata based on extensive taxon sampling and analysis of both mitochondrial and nuclear genes.
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Justi SA, Galvão C, Schrago CG. Geological Changes of the Americas and their Influence on the Diversification of the Neotropical Kissing Bugs (Hemiptera: Reduviidae: Triatominae). PLoS Negl Trop Dis 2016; 10:e0004527. [PMID: 27058599 PMCID: PMC4825970 DOI: 10.1371/journal.pntd.0004527] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/18/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The family Reduviidae (Hemiptera: Heteroptera), or assassin bugs, is among the most diverse families of the true bugs, with more than 6,000 species. The subfamily Triatominae (kissing bugs) is noteworthy not simply because it is the only subfamily of the Reduviidae whose members feed on vertebrate blood but particularly because all 147 known members of the subfamily are potential Chagas disease vectors. Due to the epidemiological relevance of these species and the lack of an efficient treatment and vaccine for Chagas disease, it is more common to find evolutionary studies focusing on the most relevant vectors than it is to find studies aiming to understand the evolution of the group as a whole. We present the first comprehensive phylogenetic study aiming to understand the events that led to the diversification of the Triatominae. METHODOLOGY/PRINCIPAL FINDINGS We gathered the most diverse samples of Reduviidae and Triatominae (a total of 229 Reduviidae samples, including 70 Triatominae species) and reconstructed a robust dated phylogeny with several fossil (Reduviidae and Triatominae) calibrations. Based on this information, the possible role of geological events in several of the major cladogenetic events within Triatominae was tested for the first time. We were able to not only correlate the geological changes in the Neotropics with Triatominae evolution but also add to an old discussion: Triatominae monophyly vs. paraphyly. CONCLUSIONS/SIGNIFICANCE We found that most of the diversification events observed within the Rhodniini and Triatomini tribes are closely linked to the climatic and geological changes caused by the Andean uplift in South America and that variations in sea levels in North America also played a role in the diversification of the species of Triatoma in that region.
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Affiliation(s)
- Silvia A. Justi
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Brazil
- Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Cleber Galvão
- Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Carlos G. Schrago
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Brazil
- * E-mail:
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May-Concha I, Guerenstein PG, Ramsey JM, Rojas JC, Catalá S. Antennal phenotype of Mexican haplogroups of the Triatoma dimidiata complex, vectors of Chagas disease. Infect Genet Evol 2016; 40:73-9. [PMID: 26921798 DOI: 10.1016/j.meegid.2016.02.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/24/2016] [Accepted: 02/22/2016] [Indexed: 11/21/2022]
Abstract
Triatoma dimidiata (Latreille) is a species complex that spans North, Central, and South America and which is a key vector of all known discrete typing units (DTU) of Trypanosoma cruzi, the etiologic agent of Chagas disease. Morphological and genetic studies indicate that T. dimidiata is a species complex with three principal haplogroups (hg) in Mexico. Different markers and traits are still inconclusive regarding if other morphological differentiation may indicate probable behavioral and vectorial divergences within this complex. In this paper we compared the antennae of three Mexican haplogroups (previously verified by molecular markers ND4 and ITS-2) and discussed possible relationships with their capacity to disperse and colonized new habitats. The abundance of each type of sensillum (bristles, basiconics, thick- and thin-walled trichoids) on the antennae of the three haplogroups, were measured under light microscopy and compared using Kruskal-Wallis non-parametric and multivariate non-parametric analyses. Discriminant analyses indicate significant differences among the antennal phenotype of haplogroups either for adults and some nymphal stages, indicating consistency of the character to analyze intraspecific variability within the complex. The present study shows that the adult antennal pedicel of the T. dimidiata complex have abundant chemosensory sensilla, according with good capacity for dispersal and invasion of different habitats also related to their high capacity to adapt to conserved as well as modified habitats. However, the numerical differences among the haplogroups are suggesting variations in that capacity. The results here presented support the evidence of T. dimidiata as a species complex but show females and males in a different way. Given the close link between the bug's sensory system and its habitat and host-seeking behavior, AP characterization could be useful to complement genetic, neurological and ethological studies of the closely related Dimidiata Complex haplogroups for a better knowledge of their vectorial capacity and a more robust species differentiation.
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Gómez-Palacio A, Arboleda S, Dumonteil E, Townsend Peterson A. Ecological niche and geographic distribution of the Chagas disease vector, Triatoma dimidiata (Reduviidae: Triatominae): Evidence for niche differentiation among cryptic species. Infect Genet Evol 2015; 36:15-22. [PMID: 26321302 DOI: 10.1016/j.meegid.2015.08.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 08/18/2015] [Accepted: 08/21/2015] [Indexed: 11/16/2022]
Abstract
The principal vector of Chagas disease in Central America, Triatoma dimidiata, shows considerable diversity of habitat, phenotype, and genotype across its geographic range (central Mexico to southern Ecuador), suggesting that it constitutes a complex of cryptic species. However, no consistent picture of the magnitude of ecological differentiation among populations of this complex has yet been developed. To assess ecological variation across the complex, we broadened the geographic coverage of phylogeographic data and analyses for the complex into Colombia and Mexico, with additional nuclear (ITS-2) and mitochondrial (ND4) DNA sequences. This information allowed us to describe distributions of previously documented clades in greater detail: Group I, from central Guatemala south to Ecuador; Group II, across Mexico south through the Yucatán Peninsula to Belize and northern Guatemala; and Group III, in northern Guatemala, Belize, and the Yucatán Peninsula. Using ecological niche modeling, we assessed ecological niche differentiation among the groups using four hypotheses of accessible areas (M) across the distribution of the complex. Results indicated clear niche divergence of Group I from Group II: the speciation process thus appears to have involved genetic and ecological changes, suggesting divergence in populations in response to environmental conditions.
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Affiliation(s)
- Andrés Gómez-Palacio
- Grupo Biología y Control de Enfermedades Infecciosas - BCEI, Universidad de Antioquia, Calle 70 No. 52-21, Medellin, Colombia.
| | - Sair Arboleda
- Grupo Biología y Control de Enfermedades Infecciosas - BCEI, Universidad de Antioquia, Calle 70 No. 52-21, Medellin, Colombia
| | - Eric Dumonteil
- Laboratorio de Parasitología, Instituto Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Mexico
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Stevens L, Monroy MC, Rodas AG, Dorn PL. Hunting, swimming, and worshiping: human cultural practices illuminate the blood meal sources of cave dwelling Chagas vectors (Triatoma dimidiata) in Guatemala and Belize. PLoS Negl Trop Dis 2014; 8:e3047. [PMID: 25211347 PMCID: PMC4161339 DOI: 10.1371/journal.pntd.0003047] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 06/16/2014] [Indexed: 11/18/2022] Open
Abstract
Background Triatoma dimidiata, currently the major Central American vector of Trypanosoma cruzi, the parasite that causes Chagas disease, inhabits caves throughout the region. This research investigates the possibility that cave dwelling T. dimidiata might transmit the parasite to humans and links the blood meal sources of cave vectors to cultural practices that differ among locations. Methodology/Principal Findings We determined the blood meal sources of twenty-four T. dimidiata collected from two locations in Guatemala and one in Belize where human interactions with the caves differ. Blood meal sources were determined by cloning and sequencing PCR products amplified from DNA extracted from the vector abdomen using primers specific for the vertebrate 12S mitochondrial gene. The blood meal sources were inferred by ≥99% identity with published sequences. We found 70% of cave-collected T. dimidiata positive for human DNA. The vectors had fed on 10 additional vertebrates with a variety of relationships to humans, including companion animal (dog), food animals (pig, sheep/goat), wild animals (duck, two bat, two opossum species) and commensal animals (mouse, rat). Vectors from all locations fed on humans and commensal animals. The blood meal sources differ among locations, as well as the likelihood of feeding on dog and food animals. Vectors from one location were tested for T. cruzi infection, and 30% (3/10) tested positive, including two positive for human blood meals. Conclusions/Significance Cave dwelling Chagas disease vectors feed on humans and commensal animals as well as dog, food animals and wild animals. Blood meal sources were related to human uses of the caves. We caution that just as T. dimidiata in caves may pose an epidemiological risk, there may be other situations where risk is thought to be minimal, but is not. Caves have enduring appeal to humans, and their lure in Central America includes tourism, religious ceremonies and shelter. The major Chagas disease vector in this region, Triatoma dimidiata, inhabits caves throughout its range. We challenge the assumption that cave-dwelling vectors are not important for human transmission by determining blood meal sources of vectors collected in caves from three locations that differ in the activities of humans at the caves, and link the results to cultural practices that differ among locations. Seventy percent of cave-collected vectors were positive for human DNA, and fed on 10 additional vertebrates with relationships to humans varying from companion animal (dog), food animals (pig, sheep/goat), wild animals (duck, bat, opossum) to commensal animals (mouse, rat). Feeding sources relate to human activities that vary among locations, for example, human and food animals were the main sources in Cahabón caves, located within deforested areas that are now agricultural fields and houses. We tested vectors from one location for infection with the Chagas disease parasite and found 30% (3 of 10) infected, including two of the three vectors from this location that had evidence of human blood. Humans should be aware of potential consequences of visiting and sleeping in caves.
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Affiliation(s)
- Lori Stevens
- Department of Biology, College of Arts and Sciences, University of Vermont, Burlington, Vermont, United States of America
- * E-mail:
| | - M. Carlota Monroy
- Escuela de Biologia, Universidad de San Carlos de Guatemala, Ciudad de Guatemala, Guatemala
| | | | - Patricia L. Dorn
- Department of Biological Sciences, Loyola University New Orleans, New Orleans, Louisiana, United States of America
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