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Mougabure-Cueto G, Hernández ML, Gilardoni JJ, Nattero J. Morphometric study of the legs of the main Chagas vector, Triatoma infestans (Hemiptera: Reduviidae). Acta Trop 2024; 255:107219. [PMID: 38649106 DOI: 10.1016/j.actatropica.2024.107219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/25/2024]
Abstract
In triatomines, vectors of Chagas disease, active dispersal takes place by walking and flying. Flight has received more attention than walking although the last is the dispersal modality used by nymphs due to their lack of wings and also used by adults, which would facilitate the colonization and reinfestation of houses after vector control actions. The present work studied the morphometrical variation of Triatoma infestans legs, the main vector of Chagas disease the Southern Cone of South America. We described morphometric traits and the natural variation of each leg segment. Different linear, size and shape variables of each component of the three right legs of fifth instar nymphs of T. infestans were analyzed using morphometric tools. We analyzed differentiation, variation and correlation for each segment across the fore-, mid and hind legs using different statistical approaches such as general linear model, canonical variates analysis, test of equality of coefficient of variation and partial least square analysis. We also analyzed variation and correlation between segments within each leg with partial least square and morphometric disparity analyses. Our results showed that the segments differed between legs, as general trends, the dimensions (length, width and/or size) were greater in the hind legs, smaller in the forelegs and intermediate in the mid ones. The femur and tibia (length and/or width) showed differences in morphometric variation between legs and the femur and tibia showed the highest levels of correlation between legs. On the other hand, in the fore- and mid legs, the femur (length or width) showed similar variation with tibia and tarsus lengths, but in the hind legs, the femur showed similar variation with all segments and not with the tibia length, and there were strong correlations between linear measurement within each leg. Our results suggest that the femur and tibia could play a determining role in the coordination between the legs that determines the walking pattern. Considering that these segments would also be linked to the specific function that each leg has, this study suggests a preponderant role of the femur and tibia in the walking locomotion of T. infestans.
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Affiliation(s)
- Gastón Mougabure-Cueto
- Laboratorio de Fisiología de Insectos, Departamento Biodiversidad y Biología Experimental (DBBE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA, UBA-CONICET). Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - María Laura Hernández
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Unidad Operativa de Vectores y Ambiente (UnOVE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán, Centro Nacional de Diagnostico e Investigación en Endemo-Epidemias (CeNDIE), Cordoba, Argentina
| | - Juan José Gilardoni
- Laboratorio de Fisiología de Insectos, Departamento Biodiversidad y Biología Experimental (DBBE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA, UBA-CONICET). Buenos Aires, Argentina
| | - Julieta Nattero
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología. Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA). Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina.
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Verly T, Pita S, Carbajal-de-la-Fuente AL, Burgueño-Rodríguez G, Piccinali RV, Fiad FG, Ríos N, Panzera F, Lobbia P, Sánchez-Casaccia P, Rojas de Arias A, Cavallo MJ, Gigena GV, Rodríguez CS, Nattero J. Relationship between genetic diversity and morpho-functional characteristics of flight-related traits in Triatoma garciabesi (Hemiptera: Reduviidae). Parasit Vectors 2024; 17:145. [PMID: 38500121 PMCID: PMC10949591 DOI: 10.1186/s13071-024-06211-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/22/2024] [Indexed: 03/20/2024] Open
Abstract
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.
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Affiliation(s)
- Thaiane Verly
- Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán" (ANLIS), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Sebastián Pita
- Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
| | - Ana Laura Carbajal-de-la-Fuente
- Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán" (ANLIS), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | | | - Romina V Piccinali
- Departamento de Ecología Genética y Evolución, Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución (IEGEBA), CONICET/Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Federico G Fiad
- Cátedras de Introducción a la Biología y Morfología Animal, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT), Facultad de Ciencias Exactas Físicas y Naturales, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Néstor Ríos
- Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Francisco Panzera
- Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Patricia Lobbia
- Unidad Operativa de Vectores y Ambiente (UnOVE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán", Centro Nacional de Diagnostico e Investigación en Endemo-Epidemias (CeNDIE), Córdoba, Argentina
| | - Paz Sánchez-Casaccia
- Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán" (ANLIS), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Asunción, Paraguay
| | | | - María José Cavallo
- Centro Regional de Energía y Ambiente Para el Desarrollo Sustentable (CREAS-CONICET), Universidad Nacional de Catamarca (UNCA), San Fernando del Valle de Catamarca, Catamarca, Argentina
| | - Gisel V Gigena
- Cátedras de Introducción a la Biología y Morfología Animal, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT), Facultad de Ciencias Exactas Físicas y Naturales, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Claudia S Rodríguez
- Cátedras de Introducción a la Biología y Morfología Animal, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT), Facultad de Ciencias Exactas Físicas y Naturales, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Julieta Nattero
- Departamento de Ecología Genética y Evolución, Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Instituto de Ecología, Genética y Evolución (IEGEBA), CONICET/Universidad de Buenos Aires, Buenos Aires, Argentina.
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Piccinali RV, Gaspe MS, Nattero J, Gürtler RE. Population structure and migration in Triatoma infestans (Hemiptera: Reduviidae) from the Argentine Chaco: An integration of genetic and morphometric data. Acta Trop 2023; 247:107010. [PMID: 37666351 DOI: 10.1016/j.actatropica.2023.107010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/06/2023]
Abstract
Genetic and morphological structure of vector populations are useful to identify panmictic groups, reinfestation sources and minimal units for control interventions. Currently, no studies have integrated genetic and morphometric data in Triatoma infestans (Hemiptera: Reduviidae), one of the main vectors of Trypanosoma cruzi. We characterized the genetic and phenotypic structure of T. infestans at a small spatial scale (2-8 km), identified potential migrants and compared flight-related traits among genetic groups and between migrant and non-migrant insects in a well-defined area without insecticide spraying in the previous 12 years. We obtained microsatellite genotypes (N = 303), wing shape and size (N = 164) and body weight-to-length ratios (N = 188) in T. infestans from 11 houses in Pampa del Indio, Argentine Chaco. The uppermost level of genetic structuring partially agreed with the morphological groups, showing high degrees of substructuring. The genetic structure showed a clear spatial pattern around Route 3 and one genetic group overlapped with an area of persistent infestation and insecticide resistance. Females harboured more microsatellite alleles than males, which showed signs of isolation-by-distance. Wing shape discriminant analyses of genetic groups revealed low reclassification scores whereas wing size differed among genetic groups for both sexes. Potential migrants (8%) did not differ from non-migrants in sex, ecotope, wing shape and size. However, male migrants had lower W/L than non-migrants suggesting poorer nutritional state. Our findings may contribute to the understanding of population characteristics, dispersal dynamics and ongoing elimination efforts of T. infestans.
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Affiliation(s)
- Romina V Piccinali
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina.
| | - M Sol Gaspe
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina
| | - Julieta Nattero
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina
| | - Ricardo E Gürtler
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EGA, Argentina
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Hernández ML, Dujardin JP, Villacís AG, Yumiseva CA, Remón C, Mougabure-Cueto G. Resistance to deltamethrin in Triatoma infestans (Hemiptera: Reduviidae): does it influence the phenotype of antennae, wings, and heads? Acta Trop 2023:106976. [PMID: 37352997 DOI: 10.1016/j.actatropica.2023.106976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023]
Abstract
In vector control terms, insecticide resistance is the development of the capacity, of an insect population, to tolerate doses of an insecticide that are lethal to most individuals in a typical population of the same species. The genetic changes that determine resistance may have adaptive costs in the resistant phenotype or, conversely, may result in an adaptive advantage when compared to susceptible insects in the environment without insecticides. Triatoma infestans is one of the main vectors of Trypanosoma cruzi in the southern cone of South America. High insecticide resistance in T. infestans was detected in Argentina in Salta and Chaco provinces. The objective of this study was to determine the possible morphometric changes in wings, heads, and the antennal phenotype of deltamethrin-resistant T. infestans (RR) males and females compared to susceptible insects (SS), evaluating its implication in adaptive processes such as olfactory capacity, dispersion, and probability of colonizing new habitats, among others. Nine type I landmarks were marked on wings, 5 type II landmarks on heads, and 10 antennal sensilla were counted on 106 adults of both sexes (resistant and susceptible from first and second laboratory generations). Morphological divergence was observed between the two groups (RR and SS). The RR insects showed smaller sizes of wings and heads and shape compatible with lower dispersal potential and different active dispersal behaviors. Antennae also revealed sensory simplification in RR and divergence between RR and SS, although more marked in females. This study characterizes for the first time T. infestans RR and SS through wings, heads, and antennae. The results suggest a lower dispersive potential in resistant insects and the differences described lay the foundations for the identification of a resistance biomarker in triatomines.
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Affiliation(s)
- M L Hernández
- Unidad Operativa de Vectores y Ambiente (UnOVE). Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias. Administración Nacional de Laboratorios e Institutos de Salud Dr. Carlos Malbrán (CeNDIE- ANLIS Malbrán). Santa María de Punilla, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
| | - J P Dujardin
- Institut de Recherche pour le Développement (IRD), UMR INTERTRYP IRD-CIRAD, University of Montpellier, F-34398 Montpellier, France
| | - A G Villacís
- Centro de Investigación para la Salud en América Latina (CISeAL), Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica de Ecuador, Quito, Ecuador
| | - C A Yumiseva
- Centro de Investigación para la Salud en América Latina (CISeAL), Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica de Ecuador, Quito, Ecuador
| | - C Remón
- Unidad Operativa de Vectores y Ambiente (UnOVE). Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias. Administración Nacional de Laboratorios e Institutos de Salud Dr. Carlos Malbrán (CeNDIE- ANLIS Malbrán). Santa María de Punilla, Córdoba, Argentina
| | - G Mougabure-Cueto
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Laboratorio de Fisiología de Insectos, Instituto De Biodiversidad y Biología Experimental y Aplicada, IBBEA (UBA-CONICET). Buenos Aires, Argentina
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Nattero J, Mougabure-Cueto G, Gürtler RE. Sublethal effects of a pyrethroid insecticide on cuticle thickness, wing size and shape in the main vector Triatoma infestans. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:397-407. [PMID: 35946595 DOI: 10.1111/mve.12600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
Exposure to sublethal doses of insecticide may affect biological traits in triatomines. We investigated the effects of toxicological phenotype (pyrethroid resistance status) and exposure to sublethal doses of deltamethrin on two traits of Triatoma infestans Klug (Heteroptera: Reduviidae) using a phenotypic plasticity experimental design. First-instar nymphs from 14 and 10 full-sib families from pyrethroid-susceptible and pyrethroid-resistant populations, respectively, were used. For the susceptible population, we treated first instars topically with acetone (control) or deltamethrin (treatment) once. For the resistant population, instars were treated once, twice and three times as first, third or fifth-instar nymphs, respectively. We measured cuticle thickness, wing size and wing shape of 484 emerging adults, and tested for treatment effects using mixed ANOVA and MANOVA models. Toxicological phenotype, exposure to deltamethrin and full-sib family exerted significant effects on cuticle thickness, wing size and wing shape. Adult triatomines previously treated with deltamethrin developed significantly thicker cuticles than control triatomines only in the resistant population and significantly bigger wings in both populations. Mean cuticle thickness and wing size increased with increasing exposures to deltamethrin. Exposure to sublethal doses of deltamethrin generated morphological modifications that may affect insect survival and flight dispersal, and hence may have evolutionary and epidemiological consequences.
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Affiliation(s)
- Julieta Nattero
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología, Ciudad Autónoma de Buenos Aires, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), Int. Güiraldez 2160, Piso 2, Pabellón 2, Ciudad Universitaria, CABA, C1428EGA, Argentina
| | - Gastón Mougabure-Cueto
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Ministerio de Salud de la Nación, Santa María de Punilla, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CABA, Argentina
| | - Ricardo E Gürtler
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología, Ciudad Autónoma de Buenos Aires, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), Int. Güiraldez 2160, Piso 2, Pabellón 2, Ciudad Universitaria, CABA, C1428EGA, Argentina
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Montes de Oca-Aguilar AC, González-Martínez A, Chan-González R, Ibarra-López P, Smith-Ávila S, Córdoba-Aguilar A, Ibarra-Cerdeña CN. Signs of Urban Evolution? Morpho-Functional Traits Co-variation Along a Nature-Urban Gradient in a Chagas Disease Vector. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.805040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Environmental change (i.e., urbanization) impacts species in contrasting ways, with some species experiencing benefits given their way of life (i.e., blood-sucking insects). How these species respond to such change is not well understood and for species involved in human diseases, this “how” question is particularly important. Most Triatominae bug species inhabit tropical and subtropical forests where their vertebrate hosts’ temporal abundance depends on climate seasonality. However, in human encroached landscapes, triatomines can benefit from resource stability which may lead to adaptive phenotypic change to track novel hosts. We tested for an association between different landscapes and morpho-functional traits linked to sensory, motion, and feeding functions in Triatoma dimidiata and compared fecundity (i.e., number of eggs) in each landscape as a proxy of fitness. Using geometric and traditional morphometric tools, we predicted a morphological simplification in bugs inhabiting urbanized areas. While wing morphology or proboscis were not influenced by landscape class, the opposite occurred for thorax morphology and number of sensilla. Wing and thorax morphology did not covary under modified landscape scenarios, yet we detected a morpho-functional convergence for thorax size and antennal phenotype in both sexes, with a simplification trend, from nature to urban settings. Given no fecundity differences across landscapes, there is no potential reproductive costs. Moreover, the convergence of thorax size and antennal phenotype suggests differences in flight/locomotion performance and host/environment perception, as a possible adaptive response to relaxed selective pressures of the bug’s native habitat. These results imply that T. dimidiata could be adapting to urbanized areas.
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Nattero J, Mougabure-Cueto G, Debat V, Gürtler RE. Phenotypic plasticity, canalisation and developmental stability of Triatoma infestans wings: effects of a sublethal application of a pyrethroid insecticide. Parasit Vectors 2021; 14:355. [PMID: 34229739 PMCID: PMC8259426 DOI: 10.1186/s13071-021-04857-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/21/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Triatomine control campaigns have traditionally consisted of spraying the inside of houses with pyrethroid insecticides. However, exposure to sublethal insecticide doses after the initial application is a common occurrence and may have phenotypic consequences for survivors. Here, using Triatoma infestans (the main vector of Chagas disease in the Southern Cone of South America) as a model species, we quantified the effects of exposure to a sublethal dose of pyrethroid insecticide on wing morphology. We tested if the treatment (i) induced a plastic effect (change in the character mean); (ii) altered environmental canalisation (higher individual variation within genotypes); (iii) altered genetic canalisation (higher variation among genotypes); and (iv) altered developmental stability (higher fluctuating asymmetry [FA]). METHODS Each of 25 full-sib families known to be susceptible to pyrethroid insecticides were split in two groups: one to be treated with a sublethal dose of deltamethrin (insecticide-treated group) and the other to be treated with pure acetone (control group). Wings of the emerging adults were used in a landmark-based geometric morphometry analysis to extract size and shape measurements. Average differences among treatments were measured. Levels of variation among families, among individuals within families and among sides within individuals were computed and compared among treatments. RESULTS Wing size and shape were affected by a sublethal dose of deltamethrin. The treated insects had larger wings and a more variable wing size and shape than control insects. For both wing size and shape, genetic variation was higher in treated individuals. Individual variations and variations in FA were also greater in deltamethrin-treated insects than in control ones for all full-sib families; however, the patterns of shape variation associated with genetic variation, individual variation and FA were different. CONCLUSIONS Insects exposed to a sublethal dose of deltamethrin presented larger, less symmetrical and less canalised wings. The insecticide treatment jointly impaired developmental stability and genetic and environmental canalisation. The divergent patterns of shape variation suggest that the related developmental buffering processes differed at least partially. The morphological modifications induced by a single sublethal exposure to pyrethroids early in life may impinge on subsequent flight performance and consequently affect the dynamics of house invasion and reinfestation, and the effectiveness of triatomine control operations.
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Affiliation(s)
- Julieta Nattero
- Departamento de Ecología, Genética y Evolución/Laboratorio de Eco-Epidemiología, Ciudad Autónoma de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), CONICET–Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gastón Mougabure-Cueto
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Ministerio de Salud de La Nación, Santa María de Punilla, Córdoba, Argentina
- Consejo Nacional de Investigación Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Vincent Debat
- Institut de Systématique, Evolution, Biodiversité (ISYEB) (UMR7205), CNMuséum National d’Histoire Naturelle, Sorbonne Université, Ecole Pratique des Hautes Etudes (EPHE) and Université des Antilles, Paris, France
| | - Ricardo E. Gürtler
- Departamento de Ecología, Genética y Evolución/Laboratorio de Eco-Epidemiología, Ciudad Autónoma de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), CONICET–Universidad de Buenos Aires, Buenos Aires, Argentina
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Beriotto AC, Garzón MJ, Schweigmann N. Is There a Minimum Number of Landmarks That Optimizes the Geometric Morphometric Analysis of Mosquito (Diptera, Culicidae) Wings? JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:576-587. [PMID: 33017459 DOI: 10.1093/jme/tjaa187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Indexed: 06/11/2023]
Abstract
Culicids are the most significant arthropods affecting human health. Thus, their correct identification is critical. The use of Geometric Morphometrics (GM) has been recently incorporated into mosquito taxonomy and has begun to complement classic diagnostic techniques. Since sampling size depends on the number of Landmarks (LMs) used, this study aimed to establish the minimum number of wing LMs needed to optimize GM analysis of mosquito species and/or genera from urban and peri-urban areas of Argentina. Female left wings were used for the optimization phase, in which 17 LMs were reduced to four by iterative LM exclusion. To verify its efficiency, Principal Component Analysis (PCA), Discriminant Analysis (DA), and Canonical Variate Analysis (CVA) were performed. Additionally, a phenogram was constructed to visualize the results. We observed that five LMs for the PCA, CVA, and phenogram and nine for the DA enabled discrimination and/or clustering of almost all species and genera. Therefore, we tested the LM selection by using nine LMs and adding new species. The resulting PCA showed little overlap between species and almost all species clustered as expected, which was also reflected in the phenogram. Significant differences were found between wing shape among all species, together with a low total error rate in the DA. In conclusion, the number of LMs can be reduced and still be used to effectively differentiate and cluster culicids. This is helpful for better exploitation of available material and optimization of data processing time when classic taxonomy methods are inadequate or the material is scarce.
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Affiliation(s)
- Agustina C Beriotto
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Intendente, Güiraldes (C1428), Departamento de Ecología, Genética y Evolución, Grupo de Estudio de Mosquitos, Buenos Aires, Argentina
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
| | - Maximiliano J Garzón
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Intendente, Güiraldes (C1428), Departamento de Ecología, Genética y Evolución, Grupo de Estudio de Mosquitos, Buenos Aires, Argentina
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
| | - Nicolás Schweigmann
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Intendente, Güiraldes (C1428), Departamento de Ecología, Genética y Evolución, Grupo de Estudio de Mosquitos, Buenos Aires, Argentina
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
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9
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Vilaseca C, Méndez MA, Pinto CF, Lemic D, Benítez HA. Unraveling the Morphological Variation of Triatoma infestans in the Peridomestic Habitats of Chuquisaca Bolivia: A Geometric Morphometric Approach. INSECTS 2021; 12:insects12020185. [PMID: 33671621 PMCID: PMC7926573 DOI: 10.3390/insects12020185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/27/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022]
Abstract
Morphometrics has been used on Triatomines, a well-known phenotypically variable insect, to understand the process of morphological plasticity and infer the changes of this phenomenon. The following research was carried out in two regions of the inter-Andean valleys and two Chaco regions of Chuquisaca-Bolivia. Triatoma infestans adults were collected from the peridomestic (pens and chicken coops) along a geographic gradient in order to evaluate the morphological differentiation between groups and their pattern of sexual shape dimorphism. Geometric morphometric methods were applied on the wings and heads of T. infestans. The main findings include that we proved sexual dimorphism in heads and wings, determined the impact of environmental factors on size and shape and validated the impact of nutrition on head shape variation. These results show that geometric morphometric procedures can be used to provide key insight into the biological adaptation of T. infestans on different biotic (nutrition) and abiotic (environment) conditions, which could serve in understanding and evaluating infestation processes and further vector control programs.
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Affiliation(s)
- Carolina Vilaseca
- Laboratorio de Ecología Química, Universidad Mayor Real y Pontificia San Francisco Xavier de Chuquisaca, Sucre, Bolivia; (C.V.); (C.F.P.)
| | - Marco A. Méndez
- Laboratorio de Genética y Evolución, Facultad de Ciencias, Instituto de Ecología y Biodiversidad, Universidad de Chile, Santiago 6640022, Chile;
| | - Carlos F. Pinto
- Laboratorio de Ecología Química, Universidad Mayor Real y Pontificia San Francisco Xavier de Chuquisaca, Sucre, Bolivia; (C.V.); (C.F.P.)
| | - Darija Lemic
- Department of Agricultural Zoology, Faculty of Agriculture, University of Zagreb, Svetošimunska 25, 10000 Zagreb, Croatia;
| | - Hugo A. Benítez
- Laboratorio de Ecología y Morfometría Evolutiva, Centro de Investigación de Estudios Avanzados del Maule, Universidad Católica del Maule, Talca 3466706, Chile
- Correspondence:
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Assessment of Shape Variation Patterns in Triatoma infestans (Klug 1834) (Hemiptera: Reduviidae: Triatominae): A First Report in Populations from Bolivia. INSECTS 2020; 11:insects11050274. [PMID: 32365855 PMCID: PMC7290822 DOI: 10.3390/insects11050274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 11/18/2022]
Abstract
The morphological variations of four populations of geographically isolated Triatoma infestans located in the area of inter-Andean valleys and Chaco of Chuquisaca, Bolivia, were evaluated. Fifty-three females and sixty-one males were collected in the peri-domicile and analyzed with geometric morphometrics tools to study the patterns of the head and wing shape variation. The principal component analysis and canonical variate analysis revealed morphological variations between the populations studied, which were then confirmed by the permutation test of the differences between populations using Mahalanobis and Procustes distances. The multivariate regression analysis shows that the centroid size influences the shape of the heads and wings. T. infestans of the inter-Andean valleys are longer in the head and wings compared to the population of the Chaco. We propose that the geometric shape variation may be explained by geographical changes in climatic conditions, peri-domiciliar habitats, food source quality, and the use of insecticides.
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11
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Nattero J, Carbajal de la Fuente AL, Piccinali RV, Cardozo M, Rodríguez CS, Crocco LB. Characterization of melanic and non-melanic forms in domestic and peridomestic populations of Triatoma infestans (Hemiptera: Reduviidae). Parasit Vectors 2020; 13:47. [PMID: 32014037 PMCID: PMC6998255 DOI: 10.1186/s13071-020-3912-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/21/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Melanic (dark) morphs have been barely reported in peridomestic and sylvatic conditions for Triatoma infestans, the most important vector of Chagas disease in the Southern Cone of South America. Adults with dark and small yellow markings on the connexivum were collected after manual searches conducted by technical personnel in 62 domiciliary units in Cruz del Eje, Córdoba Province, Argentina. The last community-wide insecticide spraying campaign before the study had been conducted three years earlier. We investigated if there was a measurable color morph variation (melanic and non-melanic) in wings and connexivum; we determined infestation, distribution of melanic and non-melanic forms, and correspondence of colorimetric variation with variations in morphology (wing size and shape and body length), development (wing fluctuating asymmetry), physiology (nutritional status) or behaviour (flight initiation). RESULTS Forty-nine females, 54 males and 217 nymphs were collected in 24 domiciliary units. House infestation and colonization were 53% and 47%, respectively. Most of the T. infestans individuals (83.2%) were collected in chicken coops; intradomicile infestation was recorded in only one case. The chromatic cluster analysis showed two well-defined groups: melanic and non-melanic. The melanic group included 17 (35%) females and 25 (46%) males. Peridomestic infestation was lower for melanic than for non-melanic adults. Melanic morphs were collected in houses from several localities. Sexual dimorphisms were confirmed by morphometric measurements. Body length was large in melanic adults (P < 0.01 only for males). Differences between groups were significant for wing size and shape, but not for weight or weight/body length ratio. Melanic females and males showed significantly higher fluctuating asymmetry (FA) indices than their non-melanic counterparts. CONCLUSIONS This is the second report of melanic forms of T. infestans in domestic and peridomestic habitats in the Dry Chaco region of Argentina. Although non-melanic adults exhibited a higher infestation rate, melanic adults were widespread in the area and were collected in the infested domicile and in most types of peridomestic annexes. Differences in morphometric variables between groups might be due to different ecological adaptations. The higher FA levels observed in melanic individuals suggest a higher developmental instability and a selective advantage of non-melanic individuals in domestic and peridomestic habitats.
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Affiliation(s)
- Julieta Nattero
- Departamento de Ecología, Genética y Evolución/Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - Ana Laura Carbajal de la Fuente
- Departamento de Ecología, Genética y Evolución/Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Romina Valeria Piccinali
- Departamento de Ecología, Genética y Evolución/Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Miriam Cardozo
- Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT-CONICET), Avda. Vélez Sarsfield 299, piso 5, X5000JJC, Córdoba, Argentina
| | - Claudia Susana Rodríguez
- Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT-CONICET), Avda. Vélez Sarsfield 299, piso 5, X5000JJC, Córdoba, Argentina
| | - Liliana Beatriz Crocco
- Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT-CONICET), Avda. Vélez Sarsfield 299, piso 5, X5000JJC, Córdoba, Argentina
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12
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Nattero J, Piccinali RV, Gaspe MS, Gürtler RE. Fluctuating asymmetry and exposure to pyrethroid insecticides in Triatoma infestans populations in northeastern Argentina. INFECTION GENETICS AND EVOLUTION 2019; 74:103925. [PMID: 31220610 DOI: 10.1016/j.meegid.2019.103925] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/25/2019] [Accepted: 06/15/2019] [Indexed: 11/19/2022]
Abstract
Fluctuating asymmetry (FA), a phenotypic marker used as indicator of developmental stress or instability, is sometimes associated with insecticide application and resistance. Here we investigated the occurrence and amount of wing size and wing shape FA in Triatoma infestans females and males collected before and 4 months after a community-wide pyrethroid spraying campaign in a well-defined rural area of Pampa del Indio, Argentina. Moderate levels of pyrethroid resistance were previously confirmed for this area, and postspraying house infestation was mainly attributed to this condition. In the absence of insecticide-based selective pressures over the previous 12 years, we hypothesized that 1- if postspraying triatomines were mostly survivors to insecticide spraying (pyrethroid resistant), they would have higher levels of FA than prespraying triatomines. 2- if postspraying triatomines have a selective advantage, they would have lower FA levels than their prespraying counterparts, whereas if postspraying infestation was positively associated with immigrants not exposed to the insecticide, prespraying and postspraying triatomines would display similar FA levels. For 243 adult T. infestans collected at identified sites before insecticide spraying and 112 collected 4 months postspraying, wing size and wing shape asymmetry was estimated from landmark configurations of left and right sides of each individual. At population level, wing size and shape FA significantly decreased in both females and males after spraying. Males displayed greater wing size and shape FA than females. However, at a single peridomestic site that was persistently infested after spraying, FA declined similarly in females whereas the reverse pattern occurred in males. Our results suggest differential survival of adults with more symmetric wings. This pattern may be related to a selective advantage of survivors to insecticide spraying, which may be mediated or not by their pyrethroid-resistant status or to lower triatomine densities after insecticide spraying and the concomitant increase in feeding success.
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Affiliation(s)
- Julieta Nattero
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, C1428EGA Ciudad Autónoma de Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución (IEGEBA), Ciudad Autónoma de Buenos Aires, Argentina.
| | - Romina Valeria Piccinali
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, C1428EGA Ciudad Autónoma de Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución (IEGEBA), Ciudad Autónoma de Buenos Aires, Argentina.
| | - María Sol Gaspe
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, C1428EGA Ciudad Autónoma de Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución (IEGEBA), Ciudad Autónoma de Buenos Aires, Argentina.
| | - Ricardo Esteban Gürtler
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, C1428EGA Ciudad Autónoma de Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución (IEGEBA), Ciudad Autónoma de Buenos Aires, Argentina.
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13
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Wilk-da-Silva R, de Souza Leal Diniz MMC, Marrelli MT, Wilke ABB. Wing morphometric variability in Aedes aegypti (Diptera: Culicidae) from different urban built environments. Parasit Vectors 2018; 11:561. [PMID: 30367678 PMCID: PMC6203966 DOI: 10.1186/s13071-018-3154-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/16/2018] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Aedes aegypti is the main vector of the dengue, Zika and several other arboviruses. It is highly adapted to urbanized environments and can be found worldwide. Mosquito population control is considered the best strategy for fighting mosquito-borne diseases, making an understanding of their population dynamics vital for the development of more effective vector control programs. This study therefore sought to investigate how different levels of urbanization affect Aedes aegypti populations and modulate population structure in this species with the aid of wing geometric morphometrics. METHODS Specimens were collected from eleven locations in three areas with distinct levels of urbanization in the city of São Paulo, Brazil: conserved, intermediate and urbanized. The right wings of female mosquitoes collected were removed, and photographed and digitized. Canonical variate analysis and Mahalanobis distance were used to investigate the degree of wing-shape dissimilarity among populations. Thin-plate splines were calculated by regression analysis of Canonical Variation Analysis scores against wing-shape variation, and a cross-validated reclassification was performed for each individual; a neighbor-joining tree was then constructed. RESULTS Metapopulation and individual population analysis showed a clear segregation pattern in the Canonical Variation Analysis. Pairwise cross-validated reclassification yielded relatively high scores considering the microgeographical scale of the study and the fact that the study populations belong to the same species. The neighbor-joining tree showed that mosquitoes in the intermediate urban area segregated in the metapopulation and individual population analyses. Our findings show significant population structuring in Aedes aegypti mosquitoes in the areas studied. This is related to the different degrees of urbanization in the areas where the specimens were collected along with their geographical location. CONCLUSIONS Urbanization processes in the study areas appear to play an important role in microevolutionary processes triggered by man-made modifications in the environment, resulting in a previously unknown population structuring pattern of major epidemiological importance.
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Affiliation(s)
- Ramon Wilk-da-Silva
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil
| | | | - Mauro Toledo Marrelli
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil
| | - André Barretto Bruno Wilke
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil
- Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL USA
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Gaspe MS, Provecho YM, Fernández MP, Vassena CV, Santo Orihuela PL, Gürtler RE. Beating the odds: Sustained Chagas disease vector control in remote indigenous communities of the Argentine Chaco over a seven-year period. PLoS Negl Trop Dis 2018; 12:e0006804. [PMID: 30278044 PMCID: PMC6168123 DOI: 10.1371/journal.pntd.0006804] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/29/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Rapid reinfestation of insecticide-treated dwellings hamper the sustained elimination of Triatoma infestans, the main vector of Chagas disease in the Gran Chaco region. We conducted a seven-year longitudinal study including community-wide spraying with pyrethroid insecticides combined with periodic vector surveillance to investigate the house reinfestation process in connection with baseline pyrethroid resistance, housing quality and household mobility in a rural section of Pampa del Indio mainly inhabited by deprived indigenous people (Qom). METHODOLOGY/PRINCIPAL FINDINGS Despite evidence of moderate pyrethroid resistance in local T. infestans populations, house infestation dropped from 31.9% at baseline to 0.7% at 10 months post-spraying (MPS), with no triatomine found at 59 and 78 MPS. Household-based surveillance corroborated the rare occurrence of T. infestans and the house invasion of other four triatomine species. The annual rates of loss of initially occupied houses and of household mobility were high (4.6-8.0%). Housing improvements did not translate into a significant reduction of mud-walled houses and refuges for triatomines because most households kept the former dwelling or built new ones with mud walls. CONCLUSIONS/SIGNIFICANCE Our results refute the assumption that vector control actions performed in marginalized communities of the Gran Chaco are doomed to fail. The larger-than-expected impacts of the intervention program were likely associated with the combined effects of high-coverage, professional insecticide spraying followed by systematic vector surveillance-and-response, broad geographic coverage creating a buffer zone, frequent housing replacement and residential mobility. The dynamical interactions among housing quality, mobility and insecticide-based control largely affect the chances of vector elimination.
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Affiliation(s)
- M. Sol Gaspe
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
| | - Yael M. Provecho
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
- Coordinación de Vectores, Dirección Nacional de Epidemiología y Análisis de la Situación de Salud, Ministerio de Salud de la Nación, Buenos Aires, Argentina
| | - María P. Fernández
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
- Earth Institute, Columbia University, New York, New York, United States of America
| | - Claudia V. Vassena
- Centro de Investigaciones de Plagas e Insecticidas (UNIDEF, CITEDEF, CONICET, CIPEIN), Buenos Aires, Argentina
- Cátedra de Química Analítica Instrumental, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pablo L. Santo Orihuela
- Centro de Investigaciones de Plagas e Insecticidas (UNIDEF, CITEDEF, CONICET, CIPEIN), Buenos Aires, Argentina
- Departamento de Investigación e Ingeniería Ambiental (3iA), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Ricardo E. Gürtler
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
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15
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Piccinali RV, Gaunt MW, Gürtler RE. A Microsatellite-Based Analysis of House Infestation With Triatoma Infestans (Hemiptera: Reduviidae) After Insecticide Spraying in the Argentine Chaco. JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:609-619. [PMID: 29385501 DOI: 10.1093/jme/tjx256] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Indexed: 06/07/2023]
Abstract
Prevention of vector-borne transmission of Chagas disease mainly relies on residual insecticide spraying. Despite significant success at a regional scale, house infestation with Triatoma infestans (Klug) (Hemiptera: Reduviidae) still persists in the Gran Chaco ecoregion. One key aspect is the identification of the sources of reinfestant triatomines. After detecting fine-scale genetic structure in two rural villages of Pampa del Indio, Argentine Chaco, we tested hypotheses on the putative origins of the triatomines collected at 4, 8, and 12 mo after insecticide house spraying. We genotyped 10 microsatellite loci in 262 baseline and 83 postspraying triatomines from different houses. Genetic variability was similar between baseline and postspraying populations, but 13 low-frequency alleles were not detected at postspraying. FSTs were not significant between insects collected before and after insecticide spraying at the same house in all but one case, and they clustered together in a neighbor-joining tree. A clustering algorithm detected seven genetic groups, four of them mainly composed of baseline and postspraying insects from the same house. Assignment tests suggested multiple putative sources (including the house of collection) for most postspraying insects but excluded a house located more than 9 km from the study area. The origin of three triatomines was attributed to immigration from other unaccounted sources. Our study is compatible with the hypothesis that house reinfestations in the Argentine Chaco are mostly related to residual foci (i.e., survival of insects within the same community), in agreement with field observations, spatial analysis, and morphometric studies previously published.
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Affiliation(s)
- Romina V Piccinali
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET-Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Michael W Gaunt
- Infectious and Tropical Diseases Department, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Ricardo E Gürtler
- Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Laboratorio de Eco-Epidemiología Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET-Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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Gürtler RE, Fernández MDP, Cecere MC, Cohen JE. Body size and hosts of Triatoma infestans populations affect the size of bloodmeal contents and female fecundity in rural northwestern Argentina. PLoS Negl Trop Dis 2017; 11:e0006097. [PMID: 29211791 PMCID: PMC5734792 DOI: 10.1371/journal.pntd.0006097] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 12/18/2017] [Accepted: 11/04/2017] [Indexed: 11/26/2022] Open
Abstract
Human sleeping quarters (domiciles) and chicken coops are key source habitats of Triatoma infestans—the principal vector of the infection that causes Chagas disease—in rural communities in northern Argentina. Here we investigated the links among individual bug bloodmeal contents (BMC, mg), female fecundity, body length (L, mm), host blood sources and habitats. We tested whether L, habitat and host blood conferred relative fitness advantages using generalized linear mixed-effects models and a multimodel inference approach with model averaging. The data analyzed include 769 late-stage triatomines collected in 120 sites from six habitats in 87 houses in Figueroa, Santiago del Estero, during austral spring. L correlated positively with other body-size surrogates and was modified by habitat type, bug stage and recent feeding. Bugs from chicken coops were significantly larger than pig-corral and kitchen bugs. The best-fitting model of log BMC included habitat, a recent feeding, bug stage, log Lc (mean-centered log L) and all two-way interactions including log Lc. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts whereas goat-fed bugs ranked last, in consistency with average blood-feeding rates. Fecundity was maximal in chicken-fed bugs from chicken coops, submaximal in human- and pig-fed bugs, and minimal in goat-fed bugs. This study is the first to reveal the allometric effects of body-size surrogates on BMC and female fecundity in a large set of triatomine populations occupying multiple habitats, and discloses the links between body size, microsite temperatures and various fitness components that affect the risks of transmission of Trypanosoma cruzi. The few bug species of Triatominae that have become domesticated are the most important vectors of human Trypanosoma cruzi infection, which causes Chagas disease. Evolutionary theory predicts that the fitness of hematophagous species closely adapted to human habitations should increase with feeding on human hosts and insect body length (L). Testing these hypotheses is important for a better understanding of triatomine population dynamics, identifying key productive habitats, modeling parasite transmission and designing innovative vector control strategies. This study is the first to describe the distributions of L and total individual bloodmeal contents (BMC) of triatomines over bug stages and habitats in rural villages where Chagas disease is endemic, and provides a direct link between individual BMC and female fecundity, host-feeding choices and L. L positively and significantly correlated with other body-size surrogates and was modified by habitat and host associations. Feeding on humans was associated with larger BMC and maximal female fecundity in domestic triatomine populations. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts. Goat-fed bugs ranked last over all habitats, in agreement with other evidence. This study demonstrates that identifiable habitat-host associations provide nearly optimal resources and conditions for T. infestans.
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Affiliation(s)
- Ricardo E. Gürtler
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- * E-mail:
| | - María del Pilar Fernández
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Carla Cecere
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Joel E. Cohen
- Laboratory of Populations, Rockefeller and Columbia Universities, New York, New York, United States of America
- Earth Institute and Department of Statistics, Columbia University, New York, New York, United States of America
- Department of Statistics, University of Chicago, Chicago, Illinois, United States of America
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Temporal variations of fluctuating asymmetry in wing size and shape of Triatoma infestans populations from northwest Argentina. INFECTION GENETICS AND EVOLUTION 2017; 56:133-142. [DOI: 10.1016/j.meegid.2017.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/23/2017] [Accepted: 11/11/2017] [Indexed: 11/17/2022]
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18
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Head shape variation in response to diet in Triatoma williami (Hemiptera, Reduviidae: Triatominae), a possible Chagas disease vector of legal Amazônia. ZOOL ANZ 2017. [DOI: 10.1016/j.jcz.2017.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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19
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Yssouf A, Almeras L, Raoult D, Parola P. Emerging tools for identification of arthropod vectors. Future Microbiol 2016; 11:549-66. [PMID: 27070074 DOI: 10.2217/fmb.16.5] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The rapid and reliable identification of arthropod vector species is an essential component of the fight against vector-borne diseases. However, owing to the lack of entomological expertise required for the morphological identification method, development of alternative and complementary tools is needed. This review describes the main methods used for arthropod identification, focusing on the emergence of protein profiling using MALDI-TOF MS technology. Sample preparation, analysis of reproducibility, database creation and blind tests for controlling accuracy of this tool for arthropod identification are described. The advantages and limitations of the MALDI-TOF MS method are illustrated by emphasizing different hematophagous arthropods, including mosquitoes and ticks, the top two main vectors of infectious diseases.
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Affiliation(s)
- Amina Yssouf
- Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198 (Dakar, Sénégal), Inserm 1095, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France
| | - Lionel Almeras
- Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198 (Dakar, Sénégal), Inserm 1095, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France
| | - Didier Raoult
- Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198 (Dakar, Sénégal), Inserm 1095, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France
| | - Philippe Parola
- Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198 (Dakar, Sénégal), Inserm 1095, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France
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20
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Insecticide resistance in vector Chagas disease: evolution, mechanisms and management. Acta Trop 2015; 149:70-85. [PMID: 26003952 DOI: 10.1016/j.actatropica.2015.05.014] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 05/14/2015] [Accepted: 05/16/2015] [Indexed: 11/22/2022]
Abstract
Chagas disease is a chronic parasitic infection restricted to America. The disease is caused by the protozoa Trypanosoma cruzi, which is transmitted to human through the feces of infected triatomine insects. Because no treatment is available for the chronic forms of the disease, vector chemical control represents the best way to reduce the incidence of the disease. Chemical control has been based principally on spraying dwellings with insecticide formulations and led to the reduction of triatomine distribution and consequent interruption of disease transmission in several areas from endemic region. However, in the last decade it has been repeatedly reported the presence triatomnes, mainly Triatoma infestans, after spraying with pyrethroid insecticides, which was associated to evolution to insecticide resistance. In this paper the evolution of insecticide resistance in triatomines is reviewed. The insecticide resistance was detected in 1970s in Rhodnius prolixus and 1990s in R. prolixus and T. infestans, but not until the 2000s resistance to pyrthroids in T. infestans associated to control failures was described in Argentina and Bolivia. The main resistance mechanisms (i.e. enhanced metabolism, altered site of action and reduced penetration) were described in the T. infestans resistant to pyrethrods. Different resistant profiles were demonstrated suggesting independent origin of the different resistant foci of Argentina and Bolivia. The deltamethrin resistance in T. infestans was showed to be controlled by semi-dominant, autosomally inherited factors. Reproductive and developmental costs were also demonstrated for the resistant T. infestans. A discussion about resistance and tolerance concepts and the persistence of T. infestans in Gran Chaco region are presented. In addition, theoretical concepts related to toxicological, evolutionary and ecological aspects of insecticide resistance are discussed in order to understand the particular scenario of pyrethroid resistance in triatomines.
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21
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Piccinali RV, Gürtler RE. Fine-scale genetic structure of Triatoma infestans in the Argentine Chaco. INFECTION GENETICS AND EVOLUTION 2015; 34:143-52. [DOI: 10.1016/j.meegid.2015.05.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 10/23/2022]
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Gaspe MS, Provecho YM, Piccinali RV, Gürtler RE. Where do these bugs come from? Phenotypic structure of Triatoma infestans populations after control interventions in the Argentine Chaco. Mem Inst Oswaldo Cruz 2015; 110:310-8. [PMID: 25946158 PMCID: PMC4489468 DOI: 10.1590/0074-02760140376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 03/18/2015] [Indexed: 11/22/2022] Open
Abstract
House re-invasion by native triatomines after insecticide-based control campaigns
represents a major threat for Chagas disease vector control. We conducted a
longitudinal intervention study in a rural section (Area III, 407 houses) of Pampa
del Indio, northeastern Argentina, and used wing geometric morphometry to compare
pre-spray and post-spray (re-infestant bugs) Triatoma infestans
populations. The community-wide spraying with pyrethroids reduced the prevalence of
house infestation by T. infestans from 31.9% to < 1% during a
four-year follow-up, unlike our previous studies in the neighbouring Area I. Two
groups of bug collection sites differing in wing shape variables before interventions
(including 221 adults from 11 domiciles) were used as a reference for assigning 44
post-spray adults. Wing shape variables from post-spray, high-density bug colonies
and pre-spray groups were significantly different, suggesting that re-infestant
insects had an external origin. Insects from one house differed strongly in wing
shape variables from all other specimens. A further comparison between insects from
both areas supported the existence of independent re-infestation processes within the
same district. These results point to local heterogeneities in house re-infestation
dynamics and emphasise the need to expand the geographic coverage of vector
surveillance and control operations to the affected region.
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Affiliation(s)
- María Sol Gaspe
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Yael Mariana Provecho
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Romina Valeria Piccinali
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ricardo Esteban Gürtler
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
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23
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García-Alzate R, Lozano-Arias D, Reyes-Lugo RM, Morocoima A, Herrera L, Mendoza-León A. Triatoma maculata, the Vector of Trypanosoma cruzi, in Venezuela. Phenotypic and Genotypic Variability as Potential Indicator of Vector Displacement into the Domestic Habitat. Front Public Health 2014; 2:170. [PMID: 25325053 PMCID: PMC4179684 DOI: 10.3389/fpubh.2014.00170] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 09/17/2014] [Indexed: 11/13/2022] Open
Abstract
Triatoma maculata is a wild vector of Trypanosoma cruzi, the causative agent of Chagas disease; its incursion in the domestic habitat is scant. In order to establish the possible domestic habitat of T. maculata, we evaluated wing variability and polymorphism of genotypic markers in subpopulations of T. maculata that live in different habitats in Venezuela. As markers, we used the mtCyt b gene, previously apply to evaluate population genetic structure in triatomine species, and the β-tubulin gene region, a marker employed to study genetic variability in Leishmania subgenera. Adults of T. maculata were captured in the period 2012-2013 at domestic, peridomestic (PD), and wild areas of towns in the Venezuelan states of Anzoátegui, Bolívar, Portuguesa, Monagas, Nueva Esparta, and Sucre. The phenotypic analysis was conducted through the determination of the isometric size and conformation of the left wing of each insect (492 individuals), using the MorphoJ program. Results reveal that insects of the domestic habitat showed significant reductions in wing size and variations in anatomical characteristics associated with flying, in relation to the PD and wild habitats. The largest variability was found in Anzoátegui and Monagas. The genotypic variability was assessed by in silico sequence comparison of the molecular markers and PCR-RFLP assays, demonstrating a marked polymorphism for the markers in insects of the domestic habitat in comparison with the other habitats. The highest polymorphism was found for the β-tubulin marker with enzymes BamHI and KpnI. Additionally, the infection rate by T. cruzi was higher in Monagas and Sucre (26.8 and 37.0%, respectively), while in domestic habitats the infestation rate was highest in Anzoátegui (22.3%). Results suggest domestic habitat colonization by T. maculata that in epidemiological terms, coupled with the presence in this habitat of nymphs of the vector, represents a high risk of transmission of Chagas disease.
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Affiliation(s)
- Roberto García-Alzate
- Facultad de Ciencias, Instituto de Biología Experimental (IBE), Universidad Central de Venezuela , Caracas , Venezuela ; Facultad de Ciencias, Instituto de Zoología & Ecología Tropical (IZET), Universidad Central de Venezuela , Caracas , Venezuela
| | - Daisy Lozano-Arias
- Facultad de Ciencias, Instituto de Biología Experimental (IBE), Universidad Central de Venezuela , Caracas , Venezuela ; Facultad de Ciencias, Instituto de Zoología & Ecología Tropical (IZET), Universidad Central de Venezuela , Caracas , Venezuela
| | - Rafael Matías Reyes-Lugo
- Facultad de Medicina, Instituto de Medicina Tropical (IMT), Universidad Central de Venezuela , Caracas , Venezuela
| | - Antonio Morocoima
- Instituto de Medicina Tropical (IMT), Universidad de Oriente , Cumana , Venezuela
| | - Leidi Herrera
- Facultad de Ciencias, Instituto de Zoología & Ecología Tropical (IZET), Universidad Central de Venezuela , Caracas , Venezuela
| | - Alexis Mendoza-León
- Facultad de Ciencias, Instituto de Biología Experimental (IBE), Universidad Central de Venezuela , Caracas , Venezuela
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24
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Raymond L, Vialatte A, Plantegenest M. Combination of morphometric and isotopic tools for studying spring migration dynamics inEpisyrphus balteatus. Ecosphere 2014. [DOI: 10.1890/es14-00075.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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25
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Gonçalves TCM, Teves-Neves SC, Santos-Mallet JRD, Carbajal-de-la-Fuente AL, Lopes CM. Triatoma jatai sp. nov. in the state of Tocantins, Brazil (Hemiptera: Reduviidae: Triatominae). Mem Inst Oswaldo Cruz 2014; 108:429-37. [PMID: 23828010 DOI: 10.1590/s0074-0276108042013006] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 11/30/2012] [Indexed: 11/22/2022] Open
Abstract
Triatoma jatai sp. nov. is the first new species of triatomine to be described in the state of Tocantins, in the northern region of Brazil. It was caught on rock outcrops in the wild environment and, more recently, invading homes. While T. jatai sp. nov. is morphologically similar to Triatoma costalimai, it is distinguished by its general colouring, differences in the blotches on the connexivum, wing size in females and external structures of the male genitalia. The type series has been deposited in the Entomological Collection and Herman Lent Collection, Oswaldo Cruz Institute-Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
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Affiliation(s)
- Teresa Cristina Monte Gonçalves
- Laboratório de Transmissores de Leishmanioses, Setor de Entomologia Médica e Forense, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
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26
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Germano MD, Picollo MI, Mougabure-Cueto GA. Microgeographical study of insecticide resistance in Triatoma infestans from Argentina. Acta Trop 2013; 128:561-5. [PMID: 23962389 DOI: 10.1016/j.actatropica.2013.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 08/02/2013] [Accepted: 08/11/2013] [Indexed: 11/16/2022]
Abstract
Chagas disease is a chronic parasitic infection restricted to America where it is currently estimated that 90 million people are at risk of acquiring the infection. Chemical control with pyrethroid insecticides has been effective to reduce disease transmission in several areas of the Southern Cone, although insecticide resistance has evolved and diminished the campaigns' results. Considering previous reports on the different levels of resistance between Triatoma infestans from different geographical areas, the objective of this work was to determine if T. infestans populations are toxicologically structured within localities. Response to the insecticide was measured and compared between houses of two Argentine localities. Different toxicity of deltamethrin was detected between dwellings of Chaco province, accounting for both susceptible and resistant houses within the same locality. However no difference was found among houses of Salta province. The results obtained in this work suggest that geographical structure is present not only at the between localities level, but also at the microgeograhical level.
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Affiliation(s)
- Mónica D Germano
- Centro de Investigaciones de Plagas e Insecticidas, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF-CONICET), Juan Bautista de la Salle 4397, B1603ALO Buenos Aires, Argentina.
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27
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Carbajal-de-la-Fuente AL, Yadón ZE. A scientometric evaluation of the Chagas disease implementation research programme of the PAHO and TDR. PLoS Negl Trop Dis 2013; 7:e2445. [PMID: 24244761 PMCID: PMC3820726 DOI: 10.1371/journal.pntd.0002445] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The Special Programme for Research and Training in Tropical Diseases (TDR) is an independent global programme of scientific collaboration cosponsored by the United Nations Children's Fund, the United Nations Development Program, the World Bank, and the World Health Organization. TDR's strategy is based on stewardship for research on infectious diseases of poverty, empowerment of endemic countries, research on neglected priority needs, and the promotion of scientific collaboration influencing global efforts to combat major tropical diseases. In 2001, in view of the achievements obtained in the reduction of transmission of Chagas disease through the Southern Cone Initiative and the improvement in Chagas disease control activities in some countries of the Andean and the Central American Initiatives, TDR transferred the Chagas Disease Implementation Research Programme (CIRP) to the Communicable Diseases Unit of the Pan American Health Organization (CD/PAHO). This paper presents a scientometric evaluation of the 73 projects from 18 Latin American and European countries that were granted by CIRP/PAHO/TDR between 1997 and 2007. We analyzed all final reports of the funded projects and scientific publications, technical reports, and human resource training activities derived from them. Results about the number of projects funded, countries and institutions involved, gender analysis, number of published papers in indexed scientific journals, main topics funded, patents inscribed, and triatomine species studied are presented and discussed. The results indicate that CIRP/PAHO/TDR initiative has contributed significantly, over the 1997–2007 period, to Chagas disease knowledge as well as to the individual and institutional-building capacity.
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Affiliation(s)
- Ana Laura Carbajal-de-la-Fuente
- Leishmaniasis Transmitters Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, (IEGEBA-CONICET) University of Buenos Aires, Buenos Aires, Argentina
| | - Zaida E. Yadón
- Communicable Diseases Unit, Health Surveillance, Disease Prevention and Control, Pan American Health Organization, Washington, D.C., United States of America
- * E-mail:
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28
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Hernández ML, Dujardin JP, Gorla DE, Catalá SS. Potential sources of Triatoma infestans reinfesting peridomiciles identified by morphological characterization in Los Llanos, La Rioja, Argentina. Mem Inst Oswaldo Cruz 2013; 108:91-7. [PMID: 23440121 PMCID: PMC3974322 DOI: 10.1590/s0074-02762013000100015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 11/13/2012] [Indexed: 11/22/2022] Open
Abstract
The presence of Triatoma infestans in habitats treated with insecticides constitutes a frequent problem in endemic areas. Basing our study on the hypothesis that descendants of a residual population should be more similar to the pre-treatment population than to any other, we compared the indications of two quantitative morphological approaches. This study seeks to find the origin of 247 T. infestans from three populations found in two chicken coops and a goat corral after treatment with insecticides. The results obtained by quantitative morphology suggest that the T. infestans found between three-34 months after the application of insecticides formed mixed populations with insects derived from residual foci and neighbouring habitats. Our analyses also showed the presence of a phenotype which does not resemble neither the pre-treatment phenotype nor the one from neighbouring populations, suggesting the presence of a particular post-treatment phenotype. The heads size showed some variations in males from different populations and remained unchanged in females, which reinforces the hypothesis of an intraspecific competition for food with priority for females. This article presents, for the first time, the combined analysis of geometric morphometry of heads and antennal phenotypes to identify the composition of reinfesting populations.
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Affiliation(s)
- María Laura Hernández
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Consejo Nacional de Investigaciones Científicas y Técnicas, La Rioja, Argentina.
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29
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Gonçalves TCM, Teves-Neves SC, dos Santos-Mallet JR, Carbajal-de-la-Fuente AL, Lopes CM. Triatoma jatai sp. nov. in the state of Tocantins, Brazil (Hemiptera: Reduviidae: Triatominae). Mem Inst Oswaldo Cruz 2013; 108. [PMID: 23828010 PMCID: PMC3970630 DOI: 10.1590/0074-0276108042013006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Triatoma jatai sp. nov. is the first new species of triatomine to be described in the state of Tocantins, in the northern region of Brazil. It was caught on rock outcrops in the wild environment and, more recently, invading homes. While T. jatai sp. nov. is morphologically similar to Triatoma costalimai, it is distinguished by its general colouring, differences in the blotches on the connexivum, wing size in females and external structures of the male genitalia. The type series has been deposited in the Entomological Collection and Herman Lent Collection, Oswaldo Cruz Institute-Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
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Affiliation(s)
- Teresa Cristina Monte Gonçalves
- Laboratório de Transmissores de Leishmanioses, Setor de Entomologia
Médica e Forense, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
| | - Simone Caldas Teves-Neves
- Laboratório de Transmissores de Leishmanioses, Setor de Entomologia
Médica e Forense, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
| | - Jacenir Reis dos Santos-Mallet
- Laboratório de Transmissores de Leishmanioses, Setor de Entomologia
Médica e Forense, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
| | - Ana Laura Carbajal-de-la-Fuente
- Laboratório de Eco-epidemiologia, Departamento de Ecología, Genética
y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires,
Buenos Aires, Argentina
| | - Catarina Macedo Lopes
- Laboratório de Transmissores de Leishmanioses, Setor de Entomologia
Médica e Forense, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil, Corresponding author:
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30
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Gaspe MS, Gurevitz JM, Gürtler RE, Dujardin JP. Origins of house reinfestation with Triatoma infestans after insecticide spraying in the Argentine Chaco using wing geometric morphometry. INFECTION GENETICS AND EVOLUTION 2013; 17:93-100. [PMID: 23557838 DOI: 10.1016/j.meegid.2013.03.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/01/2013] [Accepted: 03/25/2013] [Indexed: 10/27/2022]
Abstract
Identifying the origins of insect vectors collected after community-wide residual insecticide applications is a relevant challenge in the Gran Chaco region where the main vector of Chagas disease Triatoma infestans usually reinfests human dwellings. Wing geometric morphometry was used to compare the right wings of 63 males and 54 females collected at 4 months post-spraying (MPS) with those from 165 males and 111 females collected before full-coverage spraying with pyrethroids in a well-defined rural area in Northeastern Argentina. Male and female wing centroid size resulted significantly larger at 4MPS than before interventions, but no significant changes in shape were detected. Metric disparity (variance of shape) varied significantly in males but not in females. Using shape variables, a relatively large fraction of post-spraying males (70%) and females (54%) could not be differentiated from those collected at the same source house or at the nearest infested house before interventions. Bugs collected at 4 and 8MPS in a persistently infested house were mainly assigned to the source house. These results support the hypothesis of persistent bug populations that survived the insecticide application at local spatial scales, and are consistent with the occurrence of vector control failures most likely related to moderate pyrethroid resistance. Wing geometric morphometry is a useful tool for identifying sources of reinfestation, but it is limited by the spatial structure found in the reference populations. Combined with field and genetic data, this approach may contribute to the understanding of the reinfestation process and improvement of vector control strategies.
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Affiliation(s)
- M Sol Gaspe
- Laboratorio de Eco-Epidemiología, Depto. de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires-IEGEBA, CONICET-UBA, Ciudad Universitaria, 1428EHA Buenos Aires, Argentina
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