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Salcedo-Porras N, Umaña-Diaz C, de Oliveira Barbosa Bitencourt R, Lowenberger C. The Role of Bacterial Symbionts in Triatomines: An Evolutionary Perspective. Microorganisms 2020; 8:E1438. [PMID: 32961808 PMCID: PMC7565714 DOI: 10.3390/microorganisms8091438] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/10/2020] [Accepted: 09/17/2020] [Indexed: 12/16/2022] Open
Abstract
Insects have established mutualistic symbiotic interactions with microorganisms that are beneficial to both host and symbiont. Many insects have exploited these symbioses to diversify and expand their ecological ranges. In the Hemiptera (i.e., aphids, cicadas, and true bugs), symbioses have established and evolved with obligatory essential microorganisms (primary symbionts) and with facultative beneficial symbionts (secondary symbionts). Primary symbionts are usually intracellular microorganisms found in insects with specialized diets such as obligate hematophagy or phytophagy. Most Heteroptera (true bugs), however, have gastrointestinal (GI) tract extracellular symbionts with functions analogous to primary endosymbionts. The triatomines, are vectors of the human parasite, Trypanosoma cruzi. A description of their small GI tract microbiota richness was based on a few culturable microorganisms first described almost a century ago. A growing literature describes more complex interactions between triatomines and bacteria with properties characteristic of both primary and secondary symbionts. In this review, we provide an evolutionary perspective of beneficial symbioses in the Hemiptera, illustrating the context that may drive the evolution of symbioses in triatomines. We highlight the diversity of the triatomine microbiota, bacterial taxa with potential to be beneficial symbionts, the unique characteristics of triatomine-bacteria symbioses, and the interactions among trypanosomes, microbiota, and triatomines.
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Affiliation(s)
- Nicolas Salcedo-Porras
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; (C.U.-D.); (R.d.O.B.B.); (C.L.)
| | - Claudia Umaña-Diaz
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; (C.U.-D.); (R.d.O.B.B.); (C.L.)
| | - Ricardo de Oliveira Barbosa Bitencourt
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; (C.U.-D.); (R.d.O.B.B.); (C.L.)
- Programa de Pós-graduação em Ciências Veterinárias, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, 23890-000 Seropédica, Brasil
| | - Carl Lowenberger
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; (C.U.-D.); (R.d.O.B.B.); (C.L.)
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Padilla N A, Moncayo AL, Keil CB, Grijalva MJ, Villacís AG. Life Cycle, Feeding, and Defecation Patterns of Triatoma carrioni (Hemiptera: Reduviidae), Under Laboratory Conditions. J Med Entomol 2019; 56:617-624. [PMID: 30768666 PMCID: PMC6467638 DOI: 10.1093/jme/tjz004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Indexed: 05/12/2023]
Abstract
Chagas disease is caused by Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae). It is transmitted to humans primarily through contaminated feces of blood-sucking vectors of the subfamily Triatominae, known in Ecuador as 'chinchorros'. Some Triatominae species can adapt to domiciliary and peridomiciliary environments where T. cruzi can be transmitted to humans. Triatoma carrioni (Larrousse 1926) colonizes domestic and peridomestic habitats up to 2,242 m above sea level (masl) in southern Ecuador (Loja Province) and northern Peru. This study describes the life cycle, feeding, and defecation patterns of T. carrioni under controlled laboratory conditions using mice as hosts. Specimens were collected in Loja Province, Ecuador, and maintained in the laboratory. The life cycle was approximately 385.7 ± 110.6 d. There was a high mortality rate, 40.9% for first instars and 38.9% for fifth instars (NV). Feeding and defecation patterns for each life stage were examined by recording: insertion time of the proboscis into the host, total feeding time, time to first defecation, and weight of the bloodmeal. Total feeding time varied between 20.6 ± 11.4 min for first instars (NI) and 48.9 ± 19.0 min for adult females. The time to first defecation was variable but ranged from 9.8 ± 10.6 min for NI to 39.4 ± 24.7 min for NV during feeding. This suggests that T. carrioni has an annual life cycle and is a potential vector of T. cruzi in Loja Province. Improved knowledge of populations of T. carrioni in domestic and peridomestic environments of Ecuador can have a significant impact on the prevention and control of Chagas disease.
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Affiliation(s)
| | - Ana L Moncayo
- Center for Research on Health in Latin America (CISeAL)
| | - Clifford B Keil
- Museum of Invertebrates, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Mario J Grijalva
- Center for Research on Health in Latin America (CISeAL)
- Infectious and Tropical Disease Institute, Biomedical Sciences Department, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH
| | - Anita G Villacís
- Center for Research on Health in Latin America (CISeAL)
- Corresponding author, e-mail:
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Flores-Ferrer A, Marcou O, Waleckx E, Dumonteil E, Gourbière S. Evolutionary ecology of Chagas disease; what do we know and what do we need? Evol Appl 2017; 11:470-487. [PMID: 29636800 PMCID: PMC5891055 DOI: 10.1111/eva.12582] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 11/19/2017] [Indexed: 01/02/2023] Open
Abstract
The aetiological agent of Chagas disease, Trypanosoma cruzi, is a key human pathogen afflicting most populations of Latin America. This vectorborne parasite is transmitted by haematophageous triatomines, whose control by large‐scale insecticide spraying has been the main strategy to limit the impact of the disease for over 25 years. While those international initiatives have been successful in highly endemic areas, this systematic approach is now challenged by the emergence of insecticide resistance and by its low efficacy in controlling species that are only partially adapted to human habitat. In this contribution, we review evidences that Chagas disease control shall now be entering a second stage that will rely on a better understanding of triatomines adaptive potential, which requires promoting microevolutionary studies and –omic approaches. Concomitantly, we show that our knowledge of the determinants of the evolution of T. cruzi high diversity and low virulence remains too limiting to design evolution‐proof strategies, while such attributes may be part of the future of Chagas disease control after the 2020 WHO's target of regional elimination of intradomiciliary transmission has been reached. We should then aim at developing a theory of T. cruzi virulence evolution that we anticipate to provide an interesting enrichment of the general theory according to the specificities of transmission of this very generalist stercorarian trypanosome. We stress that many ecological data required to better understand selective pressures acting on vector and parasite populations are already available as they have been meticulously accumulated in the last century of field research. Although more specific information will surely be needed, an effective research strategy would be to integrate data into the conceptual and theoretical framework of evolutionary ecology and life‐history evolution that provide the quantitative backgrounds necessary to understand and possibly anticipate adaptive responses to public health interventions.
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Affiliation(s)
- Alheli Flores-Ferrer
- UMR 228, ESPACE-DEV-IMAGES, 'Institut de Modélisation et d'Analyses en Géo-Environnement et Santé'Université de Perpignan Via Domitia Perpignan France.,UMR 5096 'Laboratoire Génome et Développement des Plantes' Université de Perpignan Via Domitia Perpignan France
| | - Olivier Marcou
- UMR 228, ESPACE-DEV-IMAGES, 'Institut de Modélisation et d'Analyses en Géo-Environnement et Santé'Université de Perpignan Via Domitia Perpignan France
| | - Etienne Waleckx
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi" Universidad Autónoma de Yucatán Mérida Mexico
| | - Eric Dumonteil
- Department of Tropical Medicine School of Public Health and Tropical Medicine Tulane University New Orleans LA USA
| | - Sébastien Gourbière
- UMR 228, ESPACE-DEV-IMAGES, 'Institut de Modélisation et d'Analyses en Géo-Environnement et Santé'Université de Perpignan Via Domitia Perpignan France.,UMR 5096 'Laboratoire Génome et Développement des Plantes' Université de Perpignan Via Domitia Perpignan France
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Durán P, Siñani E, Depickère S. On triatomines, cockroaches and haemolymphagy under laboratory conditions: new discoveries. Mem Inst Oswaldo Cruz 2016; 111:605-613. [PMID: 27706376 PMCID: PMC5066326 DOI: 10.1590/0074-02760160027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 07/19/2016] [Indexed: 11/22/2022] Open
Abstract
For a long time, haematophagy was considered an obligate condition for triatomines
(Hemiptera: Reduviidae) to complete their life cycle. Today, the ability to use
haemolymphagy is suggested to represent an important survival strategy for some
species, especially those in genus Belminus. As Eratyrus
mucronatus and Triatoma boliviana are found with
cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from
egg to adult under a “cockroach diet” was studied. The results suggested that having
only cockroach haemolymph as a food source compromised development cycle completion
in both species. Compared to a “mouse diet”, the cockroach diet increased: (i) the
mortality at each nymphal instar; (ii) the number of feedings needed to molt; (iii)
the volume of the maximum food intake; and (iv) the time needed to molt. In
conclusion, haemolymph could effectively support survival in the field in both
species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a
survival strategy in the first developmental stages of these species was not
supported, as their mortality was very high. Finally, when Triatoma
infestans, Rhodnius stali and Panstrongylus
rufotuberculatus species were reared on a cockroach diet under similar
conditions, all died rather than feeding on cockroaches. These results are discussed
in the context of the ecology of each species.
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Affiliation(s)
- Pamela Durán
- Universidad Mayor de San Andrés, Instituto de Investigación en Salud y Desarrollo, Cátedra de Parasitología, La Paz, Bolivia
| | - Edda Siñani
- Instituto Nacional de Laboratorios de Salud, Laboratorio de Entomología Médica, La Paz, Bolivia
| | - Stéphanie Depickère
- Instituto Nacional de Laboratorios de Salud, Laboratorio de Entomología Médica, La Paz, Bolivia.,Institut de Recherche pour le Développement, Embajada Francia, La Paz, Plurinational State of Bolivia
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Lunardi RR, Gomes LP, Peres Câmara T, Arrais-Silva WW. Life cycle and vectorial competence of Triatoma williami (Galvão, Souza e Lima, 1965) under the influence of different blood meal sources. Acta Trop 2015; 149:220-6. [PMID: 26056740 DOI: 10.1016/j.actatropica.2015.05.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 05/20/2015] [Accepted: 05/25/2015] [Indexed: 11/21/2022]
Abstract
Triatoma williami is naturally infected by Trypanosoma cruzi, the ethiological agent of Chagas disease, the most significant cause of morbidity and mortality in South and Central America.The possibility of domiciliation of T. williami increases the risk of human T. cruzi vetorial transmission. Despite this, there is a lack of data demonstrating the bionomic aspects, the vectorial competence or the natural ecotope and the wild hosts of T. williami. This study describes for the first time the life cycle of T. williami under the influence of two blood meal sources and also evaluates the vectorial potential of the species. The development of two groups of hundred triatomines was followed over the nymphal stages and adulthood. Each group was exposed to a sole blood meal source, mammalian or bird. The average egg-to-adult development time in both groups was similar, except by shorter stages of N3 and N4 in triatomines fed on mammals. The group fed on birds needed more blood feedings to suffer the ecdysis and had higher cumulative mortality in the nymphal stages. Although the observed delay at defecation of adults after feeding, our results suggest that T. williami in the third and fifth nymphal stages may be good vectors.
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Sandoval CM, Medone P, Nieves EE, Jaimes DA, Ortiz N, Rabinovich JE. Demographic fitness of Belminus ferroae (Hemiptera: Triatominae) on three different hosts under laboratory conditions. Mem Inst Oswaldo Cruz 2013; 108:854-64. [PMID: 24141961 PMCID: PMC3970645 DOI: 10.1590/0074-0276130211] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 08/06/2013] [Indexed: 11/22/2022] Open
Abstract
Triatominae are widely recognised for their role as vectors of Trypanosoma cruzi. One of the main biological characteristics of this subfamily is their obligate haematophagous condition. However, previous studies on Belminus herreri and Belminus ferroae suggested that cockroaches are their principal hosts in domiciles. Due to this peculiar behaviour, the aim of this study was to analyse several demographic and reproductive parameters of B. ferroae fed on three different hosts (mice, cockroaches and Rhodnius prolixus) and relate B. ferroae fitness to these alternative hosts. The cohorts were reared under constant conditions. The egg hatching rate was similar for cohorts fed on cockroaches (69.4%) and R. prolixus (63.8%), but was much lower for the cohort fed on mice (16%). The development time from the nymph to adult stage and the average age of first reproduction (α) presented lower values in the cohort fed on cockroaches, which is consistent with the higher population growth rate associated with this host. Demographic parameters [intrinsic rate of natural increase, finite rate of population growth, net reproductive rate and damping ratio] showed statistically significant differences between the cohorts. Analysis of the life history of B. ferroae revealed a higher fitness related to the cockroach. The implications of these results for the origin of the subfamily are discussed.
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Affiliation(s)
- Claudia Magaly Sandoval
- Laboratorio de Parasitología Experimental, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Paula Medone
- Centro de Estudios Parasitológicos y de Vectores, Consejo Nacional de Investigaciones Científicas y Técnicas, La Plata, Argentina
| | - Elsa Evelia Nieves
- Laboratorio de Parasitología Experimental, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Diego Alexander Jaimes
- Laboratorio de Investigación en Ciencias Biomédicas, Universidad de Pamplona, Pamplona, Norte de Santander, Colombia
| | - Nelcy Ortiz
- Laboratorio de Investigación en Ciencias Biomédicas, Universidad de Pamplona, Pamplona, Norte de Santander, Colombia
| | - Jorge Eduardo Rabinovich
- Centro de Estudios Parasitológicos y de Vectores, Consejo Nacional de Investigaciones Científicas y Técnicas, La Plata, Argentina
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Nattero J, Rodríguez CS, Crocco L. Effects of blood meal source on food resource use and reproduction in Triatoma patagonica Del Ponte (Hemiptera, Reduviidae). J Vector Ecol 2013; 38:127-133. [PMID: 23701617 DOI: 10.1111/j.1948-7134.2013.12018.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Triatoma patagonica (Del Ponte, 1929) (Hemiptera-Reduviidae) is a peridomestic vector of Chagas disease that has been frequently found colonizing peridomestic structures in several localities in Argentina. Studying relationships between feeding and reproductive factors is important because these traits regulate population density and define vectorial capacity. Since T. patagonica can circulate among peridomestic structures taking blood from both bird and mammal hosts, we evaluated the extent to which different blood meal sources affect food resource use and reproductive parameters. We used 5(th) instar nymphs and females that fed on either guinea pigs or pigeons to estimate food resource use. We estimated reproductive parameters in adults that fed on these sources. Nymphs and adults showed differences in blood consumption between feeding sources. Females fed on pigeons ingested more blood and needed a higher amount of blood to produce an egg than females fed on guinea pigs. There were no differences in the number of eggs laid and hatched between insects fed on different feeding sources. The higher amount of blood ingested and consumed by T. patagonica fed on pigeons did not translate into higher fecundity or fertility. The lower amount of guinea pig blood ingested was offset by its high nutritional quality.
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Affiliation(s)
- Julieta Nattero
- Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas (IIByT) CONICET. Universidad Nacional de Córdoba, Córdoba, Argentina.
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Rabinovich JE, Kitron UD, Obed Y, Yoshioka M, Gottdenker N, Chaves LF. Ecological patterns of blood-feeding by kissing-bugs (Hemiptera: Reduviidae: Triatominae). Mem Inst Oswaldo Cruz 2012; 106:479-94. [PMID: 21739038 DOI: 10.1590/s0074-02762011000400016] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Accepted: 05/06/2011] [Indexed: 11/21/2022] Open
Abstract
Host use by vectors is important in understanding the transmission of zoonotic diseases, which can affect humans, wildlife and domestic animals. Here, a synthesis of host exploitation patterns by kissing-bugs, vectors of Chagas disease, is presented. For this synthesis, an extensive literature review restricted to feeding sources analysed by precipitin tests was conducted. Modern tools from community ecology and multivariate statistics were used to determine patterns of segregation in host use. Rather than innate preferences for host species, host use by kissing-bugs is influenced by the habitats they colonise. One of the major limitations of studies on kissing-bug foraging has been the exclusive focus on the dominant vector species. We propose that expanding foraging studies to consider the community of vectors will substantially increase the understanding of Chagas disease transmission ecology. Our results indicate that host accessibility is a major factor that shapes the blood-foraging patterns of kissing-bugs. Therefore, from an applied perspective, measures that are directed at disrupting the contact between humans and kissing-bugs, such as housing improvement, are among the most desirable strategies for Chagas disease control.
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Affiliation(s)
- Jorge Eduardo Rabinovich
- Centro de Estudios Parasitológicos y de Vectores, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina.
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Alves CL, Araujo RN, Gontijo NF, Pereira MH. Importance and physiological effects of hemolymphagy in triatomines (Hemiptera: Reduviidae). J Med Entomol 2011; 48:372-81. [PMID: 21485376 DOI: 10.1603/me10151] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Triatomines are hematophagous insects and the vectors for Trypanosoma cruzi in the Americas. Although their preferred meal is blood from vertebrate hosts, unfed triatomine nymphs are often seen feeding on different arthropod species. Triatomine saliva has a wide range of activities that aid the hematophagic process. However, nothing is known about its role during hemolymphagy. In the current study, we reproduced hemolymphagy under laboratory conditions and evaluated the influence of hemolymphagy on the survival of Triatoma infestans nymphs. The effects of saliva on the activation of the prophenoloxidase cascade in the invertebrate host and the influence of the saliva on the motility of the bugs and contractions of the dorsal vessels were assessed. Hemolymphagy prolonged the survival rate of T. infestans first instars from 60 to >120 d compared with unfed nymphs. The saliva from T. infestans caused a 50% reduction in the amplitude and frequency of the dorsal vessel contractions of adult Rhodnius prolixus and induced paralysis for >10 min when the saliva was injected into second instars. T. infestans saliva was able to inhibit the activation of the prophenoloxidase cascade from a R. prolixus hemolymph, but had no effect on the phenoloxidase activity after the cascade was activated. The paralyzing molecule in the saliva was <5 kDa and probably had no proteic or lipidic characteristics. These results suggest that triatomine saliva may play an important role during hemolymphagy by inducing paralysis and suppressing immune responses in the invertebrate host. The importance of hemolymphagy for the survival of nymphs in periods when vertebrate blood is scarce is also discussed.
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Affiliation(s)
- Ceres L Alves
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Bloco I4, Sala 177, Av. Antônio Carlos 6627, Belo Horizonte, MG, Brazil
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Zeledón R, Cordero M, Marroquín R, Lorosa ES. Life cycle of Triatoma ryckmani (Hemiptera: Reduviidae) in the laboratory, feeding patterns in nature and experimental infection with Trypanosoma cruzi. Mem Inst Oswaldo Cruz 2010; 105:99-102. [PMID: 20209337 DOI: 10.1590/s0074-02762010000100015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 01/26/2010] [Indexed: 11/22/2022] Open
Abstract
A cohort initiated with 121 eggs, yielding 105 first instar nymphs (eclosion rate: 86.78%), allowed us to observe the entire life cycle of Triatoma ryckmani under laboratory conditions (24 degrees C and 62% relative humidity), by feeding them on anesthetized hamsters. It was possible to obtain 62 adults and the cycle from egg to adult took a mean of 359.69 days with a range of 176-529 days (mortality rate of nymphs: 40.95%). Mean life span of adults was of 81 days for females and 148 days for males. The developmental periods of 4th and 5th nymphs were longer than those of the other instars. This suggests that young siblings have a better chance of taking a hemolymph meal from older ones, in order to survive during fasting periods during prolonged absences of vertebrate hosts from natural ecotopes. The stomach contents of 37 insects showed blood from rodents (15 cases), lizards (7 cases), birds (6 cases) and insect hemolymph (7 cases). Out of 10 insects fed by xenodiagnosis on a Trypanosoma cruzi infected mouse, all but one became infected with the parasite.
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Affiliation(s)
- Rodrigo Zeledón
- Laboratorio de Zoonosis, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica.
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Ferguson HM, Ng'habi KR, Walder T, Kadungula D, Moore SJ, Lyimo I, Russell TL, Urassa H, Mshinda H, Killeen GF, Knols BG. Establishment of a large semi-field system for experimental study of African malaria vector ecology and control in Tanzania. Malar J 2008; 7:158. [PMID: 18715508 PMCID: PMC2543042 DOI: 10.1186/1475-2875-7-158] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 08/20/2008] [Indexed: 01/08/2023] Open
Abstract
Background Medical entomologists increasingly recognize that the ability to make inferences between laboratory experiments of vector biology and epidemiological trends observed in the field is hindered by a conceptual and methodological gap occurring between these approaches which prevents hypothesis-driven empirical research from being conducted on relatively large and environmentally realistic scales. The development of Semi-Field Systems (SFS) has been proposed as the best mechanism for bridging this gap. Semi-field systems are defined as enclosed environments, ideally situated within the natural ecosystem of a target disease vector and exposed to ambient environmental conditions, in which all features necessary for its life cycle completion are present. Although the value of SFS as a research tool for malaria vector biology is gaining recognition, only a few such facilities exist worldwide and are relatively small in size (< 100 m2). Methods The establishment of a 625 m2 state-of-the-art SFS for large-scale experimentation on anopheline mosquito ecology and control within a rural area of southern Tanzania, where malaria transmission intensities are amongst the highest ever recorded, is described. Results A greenhouse frame with walls of mosquito netting and a polyethylene roof was mounted on a raised concrete platform at the Ifakara Health Institute. The interior of the SFS was divided into four separate work areas that have been set up for a variety of research activities including mass-rearing for African malaria vectors under natural conditions, high throughput evaluation of novel mosquito control and trapping techniques, short-term assays of host-seeking behaviour and olfaction, and longer-term experimental investigation of anopheline population dynamics and gene flow within a contained environment that simulates a local village domestic setting. Conclusion The SFS at Ifakara was completed and ready for use in under two years. Preliminary observations indicate that realistic and repeatable observations of anopheline behaviour are obtainable within the SFS, and that habitat and climatic features representative of field conditions can be simulated within it. As work begins in the SFS in Ifakara and others around the world, the major opportunities and challenges to the successful application of this tool for malaria vector research and control are discussed.
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Affiliation(s)
- Heather M Ferguson
- Division of Infection and Immunity, University of Glasgow, G128TA Glasgow, UK.
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Affiliation(s)
| | | | - Ester Tartarotti
- Universidade Estadual Paulista ‘Julio de Mesquita Filho’, Brazil
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Pelli A, da Silva MA, Sarmento FR, Martins E, da Mata SA, Domingues MA, Ramirez LE. Parâmetros populacionais para Triatoma sordida Stal, 1859, o vetor mais freqüente da doença de Chagas no Triângulo Mineiro (Heteroptera, Triatominae). Rev Soc Bras Med Trop 2007; 40:25-8. [PMID: 17486249 DOI: 10.1590/s0037-86822007000100005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Accepted: 01/12/2007] [Indexed: 11/22/2022] Open
Abstract
O Triatoma sordida é o mais freqüente vetor do Trypanosoma cruzi, Chagas, 1909, em Uberaba, MG. O objetivo deste trabalho foi construir uma tabela de vida dinâmica para o Triatoma sordida visando fornecer dados para subsidiar o controle de suas populações.
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Affiliation(s)
- Afonso Pelli
- Departamento de Ciências Biológicas, Universidade Federal do Triângulo Mineiro, Uberaba, MG.
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