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Lobbia PA, Rodríguez C, Remón C, Manteca-Acosta M. Reproductive consequences of the interaction Trypanosoma cruzi - Triatoma infestans and its trade-off with survival. J Invertebr Pathol 2024; 206:108183. [PMID: 39182644 DOI: 10.1016/j.jip.2024.108183] [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: 03/28/2024] [Revised: 07/04/2024] [Accepted: 08/20/2024] [Indexed: 08/27/2024]
Abstract
Relative little is known about fitness effects and life history trade-off of Trypanosoma cruzi in Triatoma infestans, the main vector of Chagas disease in Argentina. Previous studies revealed some costs related to development, excretion, and toxicology or their possible trade-offs, but none address effects on reproduction. To study the effect of T. cruzi infection on reproductive efficiency and survival of T. infestans we set up four treatments: both genders uninfected, both genders infected, female infected - males uninfected and female uninfected - males infected. The infection was induced during the third, fourth, and fifth nymphal instars. Reproductive efficiency and longevity variables were recorded. Our results showed that the infection by T. cruzi increased reproductive efficiency and reduced survival of T. infestans. Pairs where one or both individuals were infected presented a greater percentage copulation, of egg-laying females, the onset of copulation and oviposition occurred earlier, and age-specific fecundity was notably higher. Regarding fertility, infected females displayed higher rates irrespective of the infective status of the male counterpart. A reduction in longevity was observed in infected males and females. These findings highlighted that the infection significantly alters the trade-off reproductive efficiency-survival of T. infestans, with the impact differing according to the infection status of each gender, suggesting a complex interplay rather than a simple additive effect. This response corresponds to the reproductive compensation hypothesis.
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Affiliation(s)
- Patricia A Lobbia
- Unidad Operativa de Vectores y Ambiente (UnOVE), Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán", Ministerio de Salud de la Nación, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.
| | - Claudia Rodríguez
- Cátedra de Morfología animal, Facultad de Ciencias Exactas, Físicas y Naturales/Instituto de Investigaciones Biológicas y Tecnológicas (FCEFyN/IIByT- UNC/CONICET), Argentina
| | - Carolina Remón
- Unidad Operativa de Vectores y Ambiente (UnOVE), Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán", Ministerio de Salud de la Nación, Argentina
| | - Mariana Manteca-Acosta
- Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán", Ministerio de Salud de la Nación, Argentina
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2
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Girotti JR, Calderón-Fernández GM. Lipid Metabolism in Insect Vectors of Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024. [PMID: 38954247 DOI: 10.1007/5584_2024_811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
According to the World Health Organization vector-borne diseases account for more than 17% of all infectious diseases, causing more than 700,000 deaths annually. Vectors are organisms that are able to transmit infectious pathogens between humans, or from animals to humans. Many of these vectors are hematophagous insects, which ingest the pathogen from an infected host during a blood meal, and later transmit it into a new host. Malaria, dengue, African trypanosomiasis, yellow fever, leishmaniasis, Chagas disease, and many others are examples of diseases transmitted by insects.Both the diet and the infection with pathogens trigger changes in many metabolic pathways, including lipid metabolism, compared to other insects. Blood contains mostly proteins and is very poor in lipids and carbohydrates. Thus, hematophagous insects attempt to efficiently digest and absorb diet lipids and also rely on a large de novo lipid biosynthesis based on utilization of proteins and carbohydrates as carbon source. Blood meal triggers essential physiological processes as molting, excretion, and oogenesis; therefore, lipid metabolism and utilization of lipid storage should be finely synchronized and regulated regarding that, in order to provide the necessary energy source for these events. Also, pathogens have evolved mechanisms to hijack essential lipids from the insect host by interfering in the biosynthesis, catabolism, and transport of lipids, which pose challenges to reproduction, survival, fitness, and other insect traits.In this chapter, we have tried to collect and highlight the current knowledge and recent discoveries on the metabolism of lipids in insect vectors of diseases related to the hematophagous diet and pathogen infection.
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Affiliation(s)
- Juan R Girotti
- Instituto de Investigaciones Bioquímicas de La Plata (CONICET-UNLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
| | - Gustavo M Calderón-Fernández
- Instituto de Investigaciones Bioquímicas de La Plata (CONICET-UNLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
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3
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de Bona S, Chi H, Bustamante RO, Botto-Mahan C. Trypanosoma cruzi infection reduces the population fitness of Mepraia spinolai, a Chagas disease vector. MEDICAL AND VETERINARY ENTOMOLOGY 2024; 38:73-82. [PMID: 37877753 DOI: 10.1111/mve.12700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
The hematophagous insect Mepraia spinolai (Hemiptera: Reduviidae: Triatominae) is naturally infected with the protozoan parasite Trypanosoma cruzi, the agent of Chagas disease in humans. In this study, we compared the demographic parameters of M. spinolai with and without T. cruzi infection. We collected the immature life table data of 479 M. spinolai individuals of control cohort (reared on mice without T. cruzi infection) and 563 M. spinolai individuals of treatment cohort (reared on mice with T. cruzi infection). Nymphs were maintained in individual compartments inside a growth chamber (26°C; 65-75%) until adult emergence; moulting and survival were recorded daily. For the adult life table study of the control, we used 24 pairs of adults from the control cohort. For the adult life table study of T. cruzi-infected cohort, 25 infected females were paired with 25 males from the control cohort. Life table data were analysed using bootstrap-match technique based on the age-stage, two-sex life table. The preadult survival rate (0.5282) of the control cohort was significantly higher than that of the infected cohort (0.2913). However, the mean fecundity of reproductive females (Fr = 22.29 eggs/♀) and net reproductive rate of population (R0 = 5.07 offspring/individual) of the 0.5th percentile bootstrap-match control cohort were not significantly different from those of the infected cohort (Fr = 23.35 eggs/♀, R0 = 3.77 offspring/individual). Due to the shorter total preoviposition period and higher proportion of reproductive female, the intrinsic rate of increase (r = 0.0053 d-1 ) and finite rate of increase (λ = 1.0053 d-1 ) of control cohort of M. spinolai were significantly higher than those of the T. cruzi-infected cohort (r = 0.0035 d-1 , λ = 1.0035 d-1 ). These results suggest that T. cruzi infection reduces the population fitness of the Chagas disease vector M. spinolai.
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Affiliation(s)
- Sophie de Bona
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Hsin Chi
- Department of Entomology, National Chung Hsing University, Taichung, Taiwan
- College of Plant Protection, Shandong Agricultural University, Taian, China
- Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fujian, China
| | - Ramiro O Bustamante
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Carezza Botto-Mahan
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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Loshouarn H, Guarneri AA. The interplay between temperature, Trypanosoma cruzi parasite load, and nutrition: Their effects on the development and life-cycle of the Chagas disease vector Rhodnius prolixus. PLoS Negl Trop Dis 2024; 18:e0011937. [PMID: 38306403 PMCID: PMC10866482 DOI: 10.1371/journal.pntd.0011937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 02/14/2024] [Accepted: 01/23/2024] [Indexed: 02/04/2024] Open
Abstract
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi transmitted by blood-sucking insects of the subfamily Triatominae, is a major neglected tropical disease affecting 6 to 7 million of people worldwide. Rhodnius prolixus, one of the most important vectors of Chagas disease in Latin America, is known to be highly sensitive to environmental factors, including temperature. This study aimed to investigate the effects of different temperatures on R. prolixus development and life-cycle, its relationship with T. cruzi, and to gather information about the nutritional habits and energy consumption of R. prolixus. We exposed uninfected and infected R. prolixus to four different temperatures ranging from 24°C to 30°C, and monitored their survival, developmental rate, body and blood meal masses, urine production, and the temporal dynamics of parasite concentration in the excreted urine of the triatomines over the course of their development. Our results demonstrate that temperature significantly impacts R. prolixus development, life-cycle and their relationship with T. cruzi, as R. prolixus exposed to higher temperatures had a shorter developmental time and a higher mortality rate compared to those exposed to lower temperatures, as well as a lower ability to retain weight between blood meals. Infection also decreased the capacity of the triatomines to retain weight gained by blood-feeding to the next developmental stage, and this effect was proportional to parasite concentration in excreted urine. We also showed that T. cruzi multiplication varied depending on temperature, with the lowest temperature having the lowest parasite load. Our findings provide important insights into the potential impact of climate change on the epidemiology of Chagas disease, and can contribute to efforts to model the future distribution of this disease. Our study also raises new questions, highlighting the need for further research in order to understand the complex interactions between temperature, vector biology, and parasite transmission.
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Affiliation(s)
- Henri Loshouarn
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Brazil
| | - Alessandra A. Guarneri
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Brazil
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Sierra-Rosales C, San Juan E, Quiroga N, Araya-Donoso R, Correa JP, Solari A, Bacigalupo A, Botto-Mahan C. Diet of the sylvatic triatomine Mepraia spinolai: Association with Trypanosoma cruzi infection near human settlements. Acta Trop 2023; 248:107039. [PMID: 37839667 DOI: 10.1016/j.actatropica.2023.107039] [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: 08/30/2023] [Revised: 10/09/2023] [Accepted: 10/12/2023] [Indexed: 10/17/2023]
Abstract
The proximity between infectious disease vector populations and human settlements, and the infection prevalence of vector populations can determine the rate of encounters between vectors and humans and hence infection risk. The diet of sylvatic triatomine vectors (kissing bugs) provides evidence about the host species involved in the maintenance of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Here, we characterized the diet of the Chilean endemic triatomine Mepraia spinolai using Next Generation Sequencing (NGS), and evaluated the relation between T. cruzi infection status and proximity to human settlements, with the proportion of human and human-associated (domestic and synanthropic) vertebrates in the diet. We sampled 28 M. spinolai populations, covering a latitudinal range of ∼800 km in Chile. For each population, genomic DNA was obtained from M. spinolai intestinal content. We assessed T. cruzi infection individually, and sequenced vertebrate cytochrome b to characterize the diet from infected and uninfected pooled samples. Human and human-associated animals were present in the diet of both T. cruzi-infected (13.50 %) and uninfected (10.43 %) kissing bugs. The proportion of human and human-associated vertebrates in the diet of infected M. spinolai was negatively associated with the distance from surrounding human settlements, but no relationship was detected for uninfected kissing bugs. This pattern could be related to alterations of kissing bug feeding behavior when infected by the protozoan. Our results highlight the relevance of developing a deeper knowledge of the wild transmission cycle of T. cruzi, thus advancing in the surveillance of vectors present in the natural environment near human settlements.
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Affiliation(s)
| | | | - Nicol Quiroga
- Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Raúl Araya-Donoso
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Juana P Correa
- Facultad de Ciencias de la Naturaleza, Universidad San Sebastián, Concepción, Chile
| | - Aldo Solari
- ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Antonella Bacigalupo
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, United Kingdom
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Lobbia PA, Rodríguez C, Mougabure-Cueto G. Can infection with Trypanosoma cruzi modify the toxicological response of Triatoma infestans susceptible and resistant to deltamethrin? Acta Trop 2023; 245:106969. [PMID: 37328120 DOI: 10.1016/j.actatropica.2023.106969] [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: 04/25/2023] [Revised: 06/05/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
Chemical control plays a central role in interrupting the vector transmission of Chagas disease. In recent years, high levels of resistance to pyrethroids have been detected in the main vector Triatoma infestans, which were associated with less effectiveness in chemical control campaigns in different regions of Argentina and Bolivia. The presence of the parasite within its vector can modify a wide range of insect physiological processes, including toxicological susceptibility and the expression of resistance to insecticides. This study examined for the first time the possible effects of Trypanosoma cruzi infection on susceptibility and resistance to deltamethrin in T. infestans. Using WHO protocol resistance monitoring assays, we exposed resistant and susceptible strains of T. infestans, uninfected and infected with T. cruzi to different concentrations of deltamethrin in fourth-instar nymphs at days 10-20 post-emergence and monitored survival at 24, 48, and 72 h. Our findings suggest that the infection affected the toxicological susceptibility of the susceptible strain, showing higher mortality than uninfected susceptible insects when exposed to both deltamethrin and acetone. On the other hand, the infection did not affect the toxicological susceptibility of the resistant strain, infected and uninfected showed similar toxic responses and the resistance ratios was not modified. This is the first report of the effect of T. cruzi on the toxicological susceptibility of T. infestans and triatomines in general and, to our knowledge, one of the few on the effect of a parasite on the insecticide susceptibility of its insect vector.
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Affiliation(s)
- Patricia A Lobbia
- Unidad Operativa de Vectores y Ambiente (UnOVE), Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán", Ministerio de Salud de la Nación, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Claudia Rodríguez
- Cátedra de Morfología animal, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas (IIByT/CONICET), Argentina
| | - Gastón 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), Argentina.
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7
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Botzotz J, Méndez-Valdés G, Ortiz S, López A, Botto-Mahan C, Solari A. Natural Trypanosoma cruzi Infection and Climatic Season Influence the Developmental Capacity in Field-Caught Mepraia spinolai Nymphs. INSECTS 2023; 14:272. [PMID: 36975957 PMCID: PMC10058416 DOI: 10.3390/insects14030272] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
In this study, we evaluated the effect of the climatic season and infection by Trypanosoma cruzi, etiological agent of Chagas disease, on the molting capacity of the triatomine vector Mepraia spinolai endemic to Chile. We used wild-caught first-to-fourth instar nymphs during cooling (fall and winter) and warming (spring) periods. After capturing, nymphs were fed at the laboratory, and maintained under optimal rearing conditions. Feeding was repeated 40 days later. We followed-up the molting events on 709 nymphs, recording one, two or the absence of molts after two feeding opportunities. Within the same climatic period, only infected second- and fourth-instar nymphs from the warming period showed a larger proportion of double molting compared to uninfected nymphs. Regarding the climatic period, infected and uninfected first- and fourth-instar nymphs exhibited a larger proportion of double molting in the warming and cooling periods, respectively. The pattern of non-molting nymph occurrence suggests they probably reach diapause by environmental stochasticity. The effect of the climatic period and T. cruzi infection on the development of M. spinolai is an instar-dependent phenomenon, highlighting the occurrence of finely synchronized processes at different moments of the life cycle of such an hemimetabolous insect as triatomines.
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Affiliation(s)
- Juan Botzotz
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Gabriel Méndez-Valdés
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Sylvia Ortiz
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Angélica López
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Carezza Botto-Mahan
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
| | - Aldo Solari
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
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De Bona S, Correa JP, San Juan E, Estay-Olea D, Quiroga N, Bacigalupo A, Araya-Donoso R, Botto-Mahan C. Opportunistic or selective? Stage-dependent feeding behavior in a wild vector of Chagas disease. Int J Parasitol 2023; 53:55-64. [PMID: 36462561 DOI: 10.1016/j.ijpara.2022.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 12/03/2022]
Abstract
The composition and contribution of different host species in the dynamics of vector-borne zoonotic parasites are particularly relevant for public health. Hence, the study of host selection by vectors is fundamental. Developmental stage and infection status are factors that may modulate vector feeding behavior. In the semi-arid Mediterranean ecosystem of South America, the transmission of Trypanosoma cruzi, the protozoan causing Chagas disease, includes the triatomine vector Mepraia spinolai and several vertebrate species. In this field study, we examined whether M. spinolai exhibits an opportunistic feeding behavior dependent upon developmental stage and/or infection status. We found that M. spinolai does not feed according to the relative availability of vertebrate species. In addition, early stage nymphs (first/second instars) fed on twice as many different species as middle (third/fourth instars) and late (fifth instars and adults) M. spinolai, with the former feeding on native rodents and lizards and the latter mostly on rabbits. Infected and uninfected M. spinolai showed similar feeding profiles. Wild triatomine species might be described as stage-dependent selective blood feeders, as a consequence of the temporal and spatial scale at which host-vector interactions occur, highlighting that all developmental stages might be infected and capable of transmitting T. cruzi.
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Affiliation(s)
- Sophie De Bona
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, P.O. Box 653, Santiago, Chile
| | - Juana P Correa
- Escuela de Medicina Veterinaria, Facultad de Ciencias de la Naturaleza, Universidad San Sebastián, Concepción, Chile
| | - Esteban San Juan
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, P.O. Box 653, Santiago, Chile
| | - Daniela Estay-Olea
- Instituto de Ciencias Agroalimentarias, Animales y Ambientales (ICA3), Universidad de O'Higgins, San Fernando, Chile
| | - Nicol Quiroga
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, P.O. Box 653, Santiago, Chile
| | - Antonella Bacigalupo
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - Carezza Botto-Mahan
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, P.O. Box 653, Santiago, Chile.
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May-Concha IJ, Escalante-Talavera MJ, Dujardin JP, Waleckx E. Does Trypanosoma cruzi (Chagas, 1909) (Kinetoplastida: Trypanosomatidae) modify the antennal phenotype of Triatoma dimidiata (Latreille, 1811) (Hemiptera: Triatominae)? Parasit Vectors 2022; 15:466. [PMCID: PMC9749310 DOI: 10.1186/s13071-022-05587-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 11/11/2022] [Indexed: 12/15/2022] Open
Abstract
Abstract
Background
Triatoma dimidiata is a vector of the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. Phenotypic plasticity allows an organism to adjust its phenotype in response to stimuli or environmental conditions. Understanding the effect of T. cruzi on the phenotypic plasticity of its vectors, known as triatomines, has attracted great interest because of the implications of the parasite–triatomine interactions in the eco-epidemiology and transmission of the etiologic agent of Chagas disease. We investigated if the infection of the vector with T. cruzi may be associated with a change in the antennal phenotype of sylvatic, domestic, and laboratory-reared populations of T. dimidiata.
Methods
The abundance of each type of sensillum (bristles, basiconic, thick- and thin-walled trichoid) on the antennae of T.cruzi-infected and non-infected T.dimidiata reared in the laboratory or collected in sylvatic and domestic ecotopes were measured under light microscopy and compared using Kruskal–Wallis non-parametric tests and permutational multivariate analysis of variance.
Results
We found significant differences between sensilla patterns of infected and non-infected insects within sylvatic and domestic populations. Conversely, we found no significant differences between sensilla patterns of infected and non-infected insects within the laboratory-reared population. Besides, for sylvatic and domestic populations, sexual dimorphism tended to be increased in infected insects.
Conclusion
The differences observed in infected insects could be linked to higher efficiency in the perception of odor molecules related to the search for distant mates and hosts and the flight dispersal in search of new habitats. In addition, these insects could have a positive effect on population dynamics and the transmission of T.cruzi.
Graphical Abstract
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Chacón F, Bacigalupo A, Álvarez-Duhart B, Cattan PE, Solís R, Muñoz-San Martín C. The Parasite Load of Trypanosoma cruzi Modulates Feeding and Defecation Patterns of the Chagas Disease Vector Triatoma infestans. Microorganisms 2022; 10:microorganisms10051003. [PMID: 35630447 PMCID: PMC9143535 DOI: 10.3390/microorganisms10051003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 12/04/2022] Open
Abstract
Trypanosoma cruzi is the causal agent of Chagas disease, a parasitic zoonosis transmitted mainly through the feces of triatomine insects. Triatoma infestans is the main triatomine vector of this disease in South America. Previous research has shown that T. cruzi infection modifies the behavior of triatomines. We evaluated, for the first time, the effect of parasite load on feeding and defecation behavior, which we quantified by using real-time PCR. The detection time of the host was shorter in infected individuals, and the number of bites increased, while the dejection time was reduced when compared with the non-infected group. A significant correlation between the parasite load and the behavioral changes registered in the infected triatomines was found. These results would indicate that the intensity of T. cruzi infection modulates the feeding and defecation behavior of T. infestans, increasing the vector competence of this triatomine vector.
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Affiliation(s)
- Francisco Chacón
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (A.B.); (B.Á.-D.); (P.E.C.)
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur, Universidad de Chile, Santiago 8820808, Chile
| | - Antonella Bacigalupo
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (A.B.); (B.Á.-D.); (P.E.C.)
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Bárbara Álvarez-Duhart
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (A.B.); (B.Á.-D.); (P.E.C.)
| | - Pedro E. Cattan
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (A.B.); (B.Á.-D.); (P.E.C.)
| | - Rigoberto Solís
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (A.B.); (B.Á.-D.); (P.E.C.)
- Correspondence: (R.S.); (C.M.-S.M.); Tel.: +56-229-785-527 (R.S.); +56-229-785-637 (C.M.-S.M.)
| | - Catalina Muñoz-San Martín
- Escuela de Medicina Veterinaria, Facultad de Ciencias Médicas, Universidad Bernardo O’Higgins, Santiago 8370854, Chile
- Núcleo de Investigaciones Aplicadas en Ciencias Veterinarias y Agronómicas, Universidad de las Américas, Campus Providencia, Santiago 7500975, Chile
- Correspondence: (R.S.); (C.M.-S.M.); Tel.: +56-229-785-527 (R.S.); +56-229-785-637 (C.M.-S.M.)
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Marliére NP, Lorenzo MG, Guarneri AA. Trypanosoma cruzi-infected Rhodnius prolixus endure increased predation facilitating parasite transmission to mammal hosts. PLoS Negl Trop Dis 2021; 15:e0009570. [PMID: 34197458 PMCID: PMC8279422 DOI: 10.1371/journal.pntd.0009570] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/14/2021] [Accepted: 06/16/2021] [Indexed: 11/19/2022] Open
Abstract
Triatomine bugs aggregate with conspecifics inside shelters during daylight hours. At dusk, they leave their refuges searching for hosts on which to blood feed. After finding a host, triatomines face the threat of being killed, because hosts often prey on them. As it is known that many parasites induce the predation of intermediate hosts to promote transmission, and that ingestion of Trypanosoma cruzi-infected bugs represents a very effective means for mammal infection, we hypothesized that trypanosomes induce infected bugs to take increased risk, and, as a consequence, be predated when approaching a host. Therefore, we evaluated whether the predation risk and predation rates endured by Rhodnius prolixus increase when infected with T. cruzi. Assays were performed in square glass arenas offering one central refuge to infected and uninfected 5th instar nymphs. A caged mouse was introduced in each arena after a three-day acclimation interval to activate sheltered insects and induce them to approach it. As hypothesized, a significantly higher proportion of infected insects was predated when compared with uninfected ones (36% and 19%, respectively). Indeed, T. cruzi-infected bugs took higher risk (Approximation Index = 0.642) when compared with healthy ones (Approximation Index = 0.302) and remained outside the shelters when the host was removed from the arena. Our results show that infection by T. cruzi induces bugs to assume higher risk and endure higher predation rates. We reveal a hitherto unknown trypanosome-vector interaction process that increases infected bug predation, promoting increased rates of robust oral transmission. The significant consequences of the mechanism revealed here make it a fundamental component for the resilient maintenance of sylvatic, peridomestic and domestic cycles.
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Affiliation(s)
- Newmar Pinto Marliére
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Brazil
| | - Marcelo Gustavo Lorenzo
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Brazil
| | - Alessandra Aparecida Guarneri
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Brazil
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Carmona-Galindo VD, Sheppard CC, Bastin ML, Kehrig MR, Marín-Recinos MF, Choi JJ, Castañeda de Abrego V. Chromatic and Morphological Differentiation of Triatoma dimidiata (Hemiptera: Reduviidae) with Land Use Diversity in El Salvador. Pathogens 2021; 10:pathogens10060753. [PMID: 34198542 PMCID: PMC8231922 DOI: 10.3390/pathogens10060753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 05/24/2021] [Accepted: 06/09/2021] [Indexed: 12/03/2022] Open
Abstract
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted by insect-vectors in the taxonomic subfamily Triatominae and affects approximately 8,000,000 people world-wide. Current mitigation strategies for Chagas focus on insecticides, infrastructure improvements, and management of symptoms, which are largely unsustainable in underserved communities where the disease is widespread. Transmission patterns of vector-borne diseases are known to adaptively respond to habitat change; as such, the objective of our study was to evaluate how the physical characteristics of Triatoma dimidiata would vary in relation to land use in El Salvador. We hypothesized that the color and morphology of T. dimidiata would change with municipal levels of urban and natural green space, natural green space, and agricultural space, as well as municipal diversity, richness, and evenness of land use types. Our results characterize how T. dimidiata color and morphology vary directly with anthropogenic changes to natural and agricultural environments, which are reflective of a highly adaptable population primed to respond to environmental change. Mitigation studies of Chagas disease should exploit the relationships between anthropogenic land use and T. dimidiata morphology to evaluate how the transmission pattern of T. cruzi and Chagas disease symptomology are impacted.
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Affiliation(s)
- Víctor D. Carmona-Galindo
- Biology Department, University of Detroit Mercy, Detroit, MI 48221, USA; (C.C.S.); (M.L.B.); (M.R.K.)
- Centro de Investigación y Desarrollo en Salud, Universidad de El Salvador, San Salvador CP1101, El Salvador;
- Correspondence: ; Tel.: +1-313-993-1182
| | - Claire C. Sheppard
- Biology Department, University of Detroit Mercy, Detroit, MI 48221, USA; (C.C.S.); (M.L.B.); (M.R.K.)
| | - Madelyn L. Bastin
- Biology Department, University of Detroit Mercy, Detroit, MI 48221, USA; (C.C.S.); (M.L.B.); (M.R.K.)
| | - Megan R. Kehrig
- Biology Department, University of Detroit Mercy, Detroit, MI 48221, USA; (C.C.S.); (M.L.B.); (M.R.K.)
| | | | - Joyce J. Choi
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Vianney Castañeda de Abrego
- Centro de Investigación y Desarrollo en Salud, Universidad de El Salvador, San Salvador CP1101, El Salvador;
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Schaub GA. An Update on the Knowledge of Parasite-Vector Interactions of Chagas Disease. Res Rep Trop Med 2021; 12:63-76. [PMID: 34093053 PMCID: PMC8169816 DOI: 10.2147/rrtm.s274681] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/15/2021] [Indexed: 11/23/2022] Open
Abstract
This review focusses on the interactions between the etiologic agent of Chagas disease, Trypanosoma cruzi, and its triatomine vector. The flagellate mainly colonizes the intestinal tract of the insect. The effect of triatomines on trypanosomes is indicated by susceptibility and refractoriness phenomena that vary according to the combination of the strains. Other effects are apparent in the different regions of the gut. In the stomach, the majority of ingested blood trypomastigotes are killed while the remaining transform to round stages. In the small intestine, these develop into epimastigotes, the main replicative stage. In the rectum, the population density is the highest and is where the infectious stage develops, the metacyclic trypomastigote. In all regions of the gut, starvation and feeding of the triatomine affect T. cruzi. In the small intestine and rectum, starvation reduces the population density and more spheromastigotes develop. In the rectum, feeding after short-term starvation induces metacyclogenesis and after long-term starvation the development of specific cells, containing several nuclei, kinetoplasts and flagella. When considering the effects of T. cruzi on triatomines, the flagellate seems to be of low pathogenicity. However, during stressful periods, which are normal in natural populations, effects occur often on the behaviour, eg, in readiness to approach the host, the period of time before defecation, dispersal and aggregation. In nymphs, the duration of the different instars and the mortality rates increase, but this seems to be induced by repeated infections or blood quality by the feeding on infected hosts. Starvation resistance is often reduced by infection. Longevity and reproduction of adults is reduced, but only after infection with some strains of T. cruzi. Only components of the surface coat of blood trypomastigotes induce an immune reaction. However, this seems to act against gut bacteria and favours the development of T. cruzi.
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Affiliation(s)
- Günter A Schaub
- Zoology/Parasitology, Ruhr-University Bochum, Bochum, Germany
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Eberhard FE, Klimpel S, Guarneri AA, Tobias NJ. Metabolites as predictive biomarkers for Trypanosoma cruzi exposure in triatomine bugs. Comput Struct Biotechnol J 2021; 19:3051-3057. [PMID: 34136103 PMCID: PMC8178018 DOI: 10.1016/j.csbj.2021.05.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/10/2021] [Accepted: 05/19/2021] [Indexed: 11/17/2022] Open
Abstract
Trypanosoma cruzi, the causative agent of Chagas disease (American trypanosomiasis), colonizes the intestinal tract of triatomines. Triatomine bugs act as vectors in the life cycle of the parasite and transmit infective parasite stages to animals and humans. Contact of the vector with T. cruzi alters its intestinal microbial composition, which may also affect the associated metabolic patterns of the insect. Earlier studies suggest that the complexity of the triatomine fecal metabolome may play a role in vector competence for different T. cruzi strains. Using high-resolution mass spectrometry and supervised machine learning, we aimed to detect differences in the intestinal metabolome of the triatomine Rhodnius prolixus and predict whether the insect had been exposed to T. cruzi or not based solely upon their metabolic profile. We were able to predict the exposure status of R. prolixus to T. cruzi with accuracies of 93.6%, 94.2% and 91.8% using logistic regression, a random forest classifier and a gradient boosting machine model, respectively. We extracted the most important features in producing the models and identified the major metabolites which assist in positive classification. This work highlights the complex interactions between triatomine vector and parasite including effects on the metabolic signature of the insect.
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Affiliation(s)
- Fanny E. Eberhard
- Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt, Frankfurt/Main, Germany
| | - Sven Klimpel
- Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt, Frankfurt/Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE TBG), Frankfurt/Main, Germany
- Senckenberg Gesellschaft für Naturforschung, Senckenberg Biodiversity and Climate Research Centre, Frankfurt/Main, Germany
| | - Alessandra A. Guarneri
- Vector Behaviour and Pathogen Interaction Group, Instituto René Rachou, Avenida Augusto de Lima,1715, Belo Horizonte, MG CEP 30190-009, Brazil
| | - Nicholas J. Tobias
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE TBG), Frankfurt/Main, Germany
- Senckenberg Gesellschaft für Naturforschung, Senckenberg Biodiversity and Climate Research Centre, Frankfurt/Main, Germany
- Corresponding author at: LOEWE Centre for Translational Biodiversity Genomics (LOEWE TBG), Frankfurt/Main, Germany.
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Córdoba-Aguilar A. Chagas bugs and trypanosoma cruzi: Puppets and puppeteer? Acta Trop 2020; 211:105600. [PMID: 32592685 DOI: 10.1016/j.actatropica.2020.105600] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 06/23/2020] [Indexed: 01/15/2023]
Abstract
A widely accepted idea in parasite-host relationships is that the former manipulates the latter so that it increases its own success. In the case of complex life cycles, this means that the parasite is able to manipulate the first host which allows its transmission to the second host. In this paper, I formalize the idea that this may be the case for the Trypanosoma cruzi parasite and its vectors, bugs of the subfamily Triatominae. I discuss the sources of existing evidence and propose some types of manipulation. This manipulation could also occur in the second host, that is, a vertebrate. Here, I emphasize humans and domesticated animals. I also discuss how global change and insecticide resistance may drive the arms race between both, triatomines and T. cruzi, and host manipulation.
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Affiliation(s)
- Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, México.
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16
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Estay-Olea D, Correa JP, de Bona S, Bacigalupo A, Quiroga N, San Juan E, Solari A, Botto-Mahan C. Trypanosoma cruzi could affect wild triatomine approaching behaviour to humans by altering vector nutritional status: A field test. Acta Trop 2020; 210:105574. [PMID: 32504588 DOI: 10.1016/j.actatropica.2020.105574] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/01/2020] [Accepted: 06/01/2020] [Indexed: 01/27/2023]
Abstract
Hematophagous insects exhibit complex behaviour when searching for blood-meals, responding to several host stimuli. The hematophagous insect Mepraia spinolai is a wild vector of Trypanosoma cruzi, causative agent of Chagas disease in humans, in the semiarid-Mediterranean ecosystem of Chile. In this study, we evaluated the association between the approaching behaviour to a human host, with T. cruzi infection status and nutritional condition of M. spinolai. To this end, we captured 501 individuals in six consecutive 10 min-timespan, using a human as bait. Captured vectors were weighed, photographed and measured to calculate their nutritional status by means of a Standardized Body Mass Index. Trypanosoma cruzi infection was assessed in the intestinal content by using a real-time PCR assay. Ordinal logistic regressions were performed separately for infected and uninfected groups to evaluate if the nutritional status was associated with the approaching behaviour to a human host, recorded as the time-span of capture. Nutritional status of uninfected triatomines was higher than that from infected ones (p < 0.005). Among the infected, those with higher nutritional status approached first (p < 0.01); there was no effect of nutritional status in the uninfected group. Trypanosoma cruzi infection might affect the foraging behaviour of M. spinolai under natural conditions, probably deteriorating nutritional status and/or altering vector detection abilities.
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Verly T, Costa S, Lima N, Mallet J, Odêncio F, Pereira M, Moreira CJDC, Britto C, Pavan MG. Vector competence and feeding-excretion behavior of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera: Reduviidae) infected with Trypanosoma cruzi TcVI. PLoS Negl Trop Dis 2020; 14:e0008712. [PMID: 32970687 PMCID: PMC7544132 DOI: 10.1371/journal.pntd.0008712] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/08/2020] [Accepted: 08/13/2020] [Indexed: 01/22/2023] Open
Abstract
Background Several studies addressed changes on the insect vector behavior due to parasite infection, but little is known for triatomine bugs, vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. We assessed infection rates and metacyclogenesis of T. cruzi (TcVI) in fifth-instar nymphs of Triatoma rubrovaria comparing with the primary vector Triatoma infestans. Also, biological parameters related to feeding-excretion behavior were evaluated aiming to identify which variables are most influenced by T. cruzi infection. Methodology/principal findings Fifth-instar nymphs of T. rubrovaria and T. infestans were fed on mice infected with T. cruzi (TcVI). We compared the presence and the number of parasite evolutive forms in excreta of both triatomine species at 30, 60 and 90 days post-infection (dpi) with traditional statistical analyses. Moreover, both species were analyzed through generalized linear models and multinomial logistic regression hypotheses for seven behavioral parameters related to host-seeking and feeding-excretion. Triatoma rubrovaria and T. infestans had similar overall infection and metacyclogenesis rates of T. cruzi TcVI in laboratory conditions. Regarding vector behavior, we confirmed that the triatomine’s tendency is to move away from the bite region after a blood meal, probably to avoid being noticed by the vertebrate host. Interspecific differences were observed on the volume of blood ingested and on the proportion of individuals that excreted after the blood meal, revealing the higher feeding efficiency and dejection rates of T. infestans. The amount of ingested blood and the bite behavior of T. rubrovaria seems to be influenced by TcVI infection. Infected specimens tended to ingest ~25% more blood and to bite more the head of the host. Noteworthy, in two occasions, kleptohematophagy and coprophagy behaviors were also observed in T. rubrovaria. Conclusions/significance Laboratory infections revealed similar rate of T. cruzi TcVI trypomatigotes in excreta of T. rubrovaria and T. infestans, one of the most epidemiological important vectors of T. cruzi. Therefore, TcVI DTU was able to complete its life cycle in T. rubrovaria under laboratory conditions, and this infection changed the feeding behavior of T. rubrovaria. Considering these results, T. rubrovaria must be kept under constant entomological surveillance in Rio Grande do Sul, Brazil. Chagas disease is caused by the etiological agent Trypanosoma cruzi and is mainly transmitted through the excreta of triatomine vectors. It is endemic in Latin America and the Caribbean, affecting ~8 million people. Control programs are based on the elimination of domestic vectors through insecticide-spraying indoors, since there is no vaccine or efficient treatment for chronic patients. However, this strategy is not sustainable where native triatomine species are capable of colonizing peridomestic structures and reinvading human dwellings. Since the ‘virtual’ elimination of Triatomainfestans in Brazil (residual foci remain in Rio Grande do Sul and Bahia), specimens of the native Triatoma rubrovaria have been constantly collected inside human dwellings and peridomiciliary ecotopes in Rio Grande do Sul, southern Brazil, which might represent a real risk for human infections. Here we analyzed a unique and large dataset through classical and modern statistical methods to evaluate T. cruzi infection in T. rubrovaria and to identify host-seeking, and also feeding/excretion behavioral traits that could be influenced by the parasite. Our results indicated that the parasite infection caused changes in T. rubrovaria feeding behavior that could increase T. cruzi TcVI transmission. Moreover, this vector species had similar infection rate to one of the main important Chagas disease vectors in South America, T. infestans. Therefore, T. rubrovaria must be kept under constant entomological surveillance in Rio Grande do Sul, Brazil.
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Affiliation(s)
- Thaiane Verly
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Stephanie Costa
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Nathanielly Lima
- Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Jacenir Mallet
- Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
- Universidade Iguaçu - UNIG, Rio de Janeiro, Brazil
| | - Francisco Odêncio
- Laboratório de Ultraestrutura Celular, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Mirian Pereira
- Laboratório de Ultraestrutura Celular, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | | | - Constança Britto
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Márcio G. Pavan
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
- * E-mail:
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May-Concha I, Remón C, Mougabure-Cueto G. Behavioral response mediated by feces in Triatoma infestans (Hemiptera: Reduviidae: triatominae) susceptible and resistant to deltamethrin. Acta Trop 2020; 206:105442. [PMID: 32171756 DOI: 10.1016/j.actatropica.2020.105442] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 03/10/2020] [Accepted: 03/10/2020] [Indexed: 12/21/2022]
Abstract
Chemical cues from feces promote aggregation behavior in Triatoma infestans nymphs and adults. Given the importance of T. infestans resistant to pyrethroids in several areas of Argentina and Bolivia, it would be important to know if there is an association with specific attraction and aggregation behaviors. These behaviors, to and surrounding refuges, play an important role in triatomine population dynamics, an important factor to consider and model for vector control strategies. The aim of the present study was to analyze the behavior of orientation to chemical signals emitted by feces from deltamethrin resistant (R) and susceptible (S) T. infestans. The behavioral assays were performed in a circular glass arena divided in two equal sectors. Fecal signals emitted by both S and R feces are attractants to fifth-instar nymphs of both S and R populations. Both toxicological phenotypes remained significantly longer on R feces, as compared to S feces. This is the first evidence in a triatomine, for the association of an aggregation behavior and insecticide resistance and may be the result of pleiotropic effects surrounding resistance genes.
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Pereyra N, Lobbia PA, Mougabure-Cueto G. Effects of the infection with Trypanosoma cruzi on the feeding and excretion/defecation patterns of Triatoma infestans. BULLETIN OF ENTOMOLOGICAL RESEARCH 2020; 110:169-176. [PMID: 31337451 DOI: 10.1017/s0007485319000464] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Transmission of Trypanosma cruzi (Kinetoplastida: Trypanosomatidae) occurs when feces/urine of infected triatomines come into contact with mucous membranes or damaged skin, and this occurs mainly when insects defecate while feeding on the host. Thus, the vector competence of the triatomines is associated with their feeding and excretion/defecation behavior. This work studied for the first time the effect of T. cruzi infection on feeding and excretion/defecation patterns of Triatoma infestans (Hemiptera: Reduviidae). Uninfected and infected fifth-instar nymphs were fed ad libitum and their feeding behavior and defecations were registered during and after feeding. The feeding pattern did not show differences between the experimental groups. However, the infected nymphs began to defecate earlier, defecated in greater quantity and there was a greater proportion of defecating individuals compared to uninfected nymphs. These results show that T. cruzi affected the excretion/defecation pattern of T. infestans in a way that would increase the probability of contact between infective feces and the mammalian host.
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Affiliation(s)
- N Pereyra
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Coordinación de Vectores, Ministerio de Salud y Desarrollo Social de la Nación. Hospital Colonia-Pabellón Rawson calle s/n, Santa María de Punilla, Córdoba, Argentina
| | - P A Lobbia
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Coordinación de Vectores, Ministerio de Salud y Desarrollo Social de la Nación. Hospital Colonia-Pabellón Rawson calle s/n, Santa María de Punilla, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - G Mougabure-Cueto
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Coordinación de Vectores, Ministerio de Salud y Desarrollo Social de la Nación. Hospital Colonia-Pabellón Rawson calle s/n, Santa María de Punilla, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
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Ramírez-González MG, Flores-Villegas AL, Salazar-Schettino PM, Gutiérrez-Cabrera AE, Rojas-Ortega E, Córdoba-Aguilar A. Zombie bugs? Manipulation of kissing bug behavior by the parasite Trypanosoma cruzi. Acta Trop 2019; 200:105177. [PMID: 31539526 DOI: 10.1016/j.actatropica.2019.105177] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/13/2019] [Accepted: 09/13/2019] [Indexed: 01/06/2023]
Abstract
The parasite manipulation hypothesis states that the parasite modifies host's behavior thereby increasing the probability that the parasite will pass from an intermediate host to its final host. We used the kissing bugs Triatoma pallidipennis and T. longipennis and two isolates of the Trypanosoma cruzi parasite (Chilpancingo and Morelos) to test these ideas. These insects are intermediate hosts of this parasite, which is the causal agent of Chagas disease. The Chilpancingo isolate is more pathogenic than the Morelos isolate, in the bugs. We expected that infected bugs would be more active and likely at detecting human-like odors. Given the differences in pathogenicity between isolates, we expected the Chilpancingo isolate to induce these effects more strongly and lead to higher parasite number than the Morelos isolate. Finally, infected bugs would gain less mass (a mechanism thought to increase bite rate, and thus transmission) than non-infected bugs. Having determined that both isolate haplotypes belong to the Tc1a group, we found that: (a) young instars of both species were more active and likely to detect human odor when they were infected, regardless of the isolate; (b) there was no difference in parasite abundance depending on isolate; and, (c) infected bugs did not end up with less weight than uninfected bugs. These results suggest that T. cruzi can manipulate the bugs, which implies a higher risk to contract Chagas disease than previously thought.
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Affiliation(s)
- María Guadalupe Ramírez-González
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510 Coyoacán, Distrito Federal, Mexico
| | - A Laura Flores-Villegas
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, Ciudad de México, Mexico
| | - Paz María Salazar-Schettino
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, Ciudad de México, Mexico
| | - Ana E Gutiérrez-Cabrera
- CONACYT y Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Avenida Universidad 655, Col. Santa María Ahuacatitlán, Cerrada Los Pinos y Caminera, 62100 Cuernavaca, Morelos, Mexico
| | - Eréndira Rojas-Ortega
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, México, Ciudad de México, Mexico
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510 Coyoacán, Distrito Federal, Mexico.
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21
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Depickère S, Ramírez-Ávila GM, Deneubourg JL. Alteration of the aggregation and spatial organization of the vector of Chagas disease, Triatoma infestans, by the parasite Trypanosoma cruzi. Sci Rep 2019; 9:17432. [PMID: 31758071 PMCID: PMC6874570 DOI: 10.1038/s41598-019-53966-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 10/23/2019] [Indexed: 11/30/2022] Open
Abstract
Triatominae insects are vectors of the parasite Trypanosoma cruzi, the etiological agent of Chagas disease affecting millions of people in Latin America. Some species, such as Triatoma infestans, live in the human neighborhood, aggregating in walls or roof cracks during the day and going out to feed blood at night. The comprehension of how sex and T. cruzi infection affect their aggregation and geotaxis is essential for understanding their spatial organization and the parasite dispersion. Experiments in laboratory-controlled conditions were carried out with groups of ten adults of T. infestans able to explore and aggregate on a vertical surface. The influence of the sex (male vs. female) and the proportion of infected insects in the group were tested (100% of infected insects vs. a small proportion of infected insects, named infected and potentially weakly infected groups, respectively). Therefore, four distinct groups of insects were tested: infected males, infected females, potentially weakly infected males, and potentially weakly infected females, with 12, 9, 15, and 16 replicates, respectively. The insects presented a high negative geotaxis and a strong aggregation behavior whatever the sex or their infection. After an exploration phase, these behaviors were stable in time. The insects exhibited a preferential vertical position, head toward the top of the setup. Males had a higher negative geotaxis and a higher aggregation level than females. Both behaviors were enhanced in groups of 100% infected insects, the difference between sexes being maintained. According to a comparison between experimental and theoretical results, geotaxis favors the aggregation that mainly results from the inter-attraction between individuals.
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Affiliation(s)
- Stéphanie Depickère
- Laboratorio Entomología Médica, INLASA, La Paz, Bolivia.
- Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz, Bolivia.
- The Abdus Salam, International Centre for Theoretical Physics (ICTP), Trieste, Italy.
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Garcia V, Graterol J, López A, Ortiz S, Solari A. Influence of Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) Infection on Mortality of the Sylvatic Triatomine Vector, Mepraia spinolai (Heteroptera: Reuviidae), Under Fasting. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1384-1388. [PMID: 31322659 DOI: 10.1093/jme/tjz124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Indexed: 06/10/2023]
Abstract
The etiologic agent of Chagas disease, Trypanosoma cruzi, is transmitted by hematophagous insect vectors that subsist on repeated blood meals over their lives separated by periods of fasting. Using naturally infected Mepraia spinolai, we measured the influence of parasite infection on this host vector's mortality during regular feeding and after fasting. After their capture, the insects were fed twice with uninfected mice to evaluate parasitic infection in their fecal samples by microscopic observation and PCR. Then the insects were subjected to a fasting period, followed by a third (final) feeding. After each feeding, a fecal sample was obtained to evaluate T. cruzi infection. To determine its progress through ontogeny, mortality and ecdysis of the infected and uninfected nymphs and adults were recorded on three occasions, over 140 d, and analyzed. Detections of infection by T. cruzi between the two first feedings increased, but this detection level was generally reduced after final feeding unless reinfected. For nymphs (stages III-V), their mortality was highest when infected after the fasting period, whereas adults were equally resistant to death after fasting when infected with T. cruzi. Metacyclic trypomastigotes were principally excreted in the fecal samples. Our results confirm that T. cruzi is pathogenic to its invertebrate hosts under nutritional stress conditions, when nymphs' mortality is higher while infected than uninfected when they were hungry. These results are epidemiologically important because T. cruzi harms the fasting vector M. spinolai, reducing its lifespan and competence as a disease vector, and thereby its rates of parasite transmission.
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Affiliation(s)
- Vanessa Garcia
- Cellular and Molecular Biology Program, ICBM, Faculty of Medicine, University of Chile, Casilla, Santiago, Chile
| | - Johsmar Graterol
- Cellular and Molecular Biology Program, ICBM, Faculty of Medicine, University of Chile, Casilla, Santiago, Chile
| | - Angélica López
- Cellular and Molecular Biology Program, ICBM, Faculty of Medicine, University of Chile, Casilla, Santiago, Chile
| | - Sylvia Ortiz
- Cellular and Molecular Biology Program, ICBM, Faculty of Medicine, University of Chile, Casilla, Santiago, Chile
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23
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Villalobos G, Nava-Bolaños A, De Fuentes-Vicente JA, Téllez-Rendón JL, Huerta H, Martínez-Hernández F, Rocha-Ortega M, Gutiérrez-Cabrera AE, Ibarra-Cerdeña CN, Córdoba-Aguilar A. A reduction in ecological niche for Trypanosoma cruzi-infected triatomine bugs. Parasit Vectors 2019; 12:240. [PMID: 31097007 PMCID: PMC6524312 DOI: 10.1186/s13071-019-3489-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/06/2019] [Indexed: 01/20/2023] Open
Abstract
Background Theory predicts that parasites can affect and thus drive their hosts’ niche. Testing this prediction is key, especially for vector-borne diseases including Chagas disease. Here, we examined the niche use of seven triatomine species that occur in Mexico, based on whether they are infected or not with Trypanosoma cruzi, the vectors and causative parasites of Chagas disease, respectively. Presence data for seven species of triatomines (Triatoma barberi, T. dimidiata, T. longipennis, T. mazzottii, T. pallidipennis, T. phyllosoma and T. picturata) were used and divided into populations infected and not infected by T. cruzi. Species distribution models were generated with Maxent 3.3.3k. Using distribution models, niche analysis tests of amplitude and distance to centroids were carried out for infected vs non-infected populations within species. Results Infected populations of bugs of six out of the seven triatomine species showed a reduced ecological space compared to non-infected populations. In all but one case (T. pallidipennis), the niche used by infected populations was close to the niche centroid of its insect host. Conclusions Trypanosoma cruzi may have selected for a restricted niche amplitude in triatomines, although we are unaware of the underlying reasons. Possibly the fact that T. cruzi infection bears a fitness cost for triatomines is what narrows the niche breadth of the insects. Our results imply that Chagas control programmes should consider whether bugs are infected in models of triatomine distribution. Electronic supplementary material The online version of this article (10.1186/s13071-019-3489-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guiehdani Villalobos
- Hospital General "Dr. Manuel Gea González", Secretaría de Salud, Mexico City, Mexico.,Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Angela Nava-Bolaños
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - José A De Fuentes-Vicente
- Instituto de Ciencias Biológicas, Universidad de Ciencias y Artes de Chiapas, Tuxtla Gutiérrez, Chiapas, Mexico
| | - Juan Luis Téllez-Rendón
- Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico
| | - Herón Huerta
- Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico
| | | | - Maya Rocha-Ortega
- Hospital General "Dr. Manuel Gea González", Secretaría de Salud, Mexico City, Mexico
| | - Ana E Gutiérrez-Cabrera
- CONACyT-Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
| | - Carlos N Ibarra-Cerdeña
- Departamento de Ecología Humana, Centro de Investigación y Estudios Avanzados del IPN (Cinvestav), Unidad Mérida, 97310, Mérida, Yucatán, Mexico
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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24
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González-Rete B, Salazar-Schettino PM, Bucio-Torres MI, Córdoba-Aguilar A, Cabrera-Bravo M. Activity of the prophenoloxidase system and survival of triatomines infected with different Trypanosoma cruzi strains under different temperatures: understanding Chagas disease in the face of climate change. Parasit Vectors 2019; 12:219. [PMID: 31068226 PMCID: PMC6507061 DOI: 10.1186/s13071-019-3477-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 05/03/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Little is known about how human disease vectors will modify their life history patterns and survival capacity as a result of climate change. One case is that of Chagas disease, which has triatomine bugs and Trypanosoma cruzi as vectors and parasite, respectively. This work aimed to determine: (i) the activity of the prophenoloxidase system (prophenoloxidase and phenoloxidase activity, two indicators of immune ability) in three intestine regions (anterior midgut, posterior midgutand rectum) of the triatomine bug Meccus pallidipennis under three temperature conditions (20 °C, 30 °C and 34 °C) against two T. cruzi strains [ITRI/MX/14/CHIL (Chilpancingo) and ITRI/MX/12/MOR (Morelos)], and (ii) whether vector survival varies under these three temperatures after infection by these T. cruzi strains. RESULTS Our results indicate that prophenoloxidase activity was lower at higher temperatures, that the level of prophenoloxidase activity elicited by each strain was different (higher in Chilpancingo than in Morelos strains), and that prophenoloxidase activity was more intense in the anterior midgut than in the posterior midgut or rectum. Survival rates were lower in insects maintained at higher temperatures and infected by Chilpancingo strains. CONCLUSIONS These results indicate that climate change could lead to lower prophenoloxidase activity and survival rates in triatomines when infected with different T. cruzi strains, which could reduce the vector capacity of M. pallidipennis.
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Affiliation(s)
| | - Paz María Salazar-Schettino
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Martha I Bucio-Torres
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, Coyoacán, 04510, Ciudad de México, Mexico.
| | - Margarita Cabrera-Bravo
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
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25
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Cabe AM, Yañez F, Pinto R, López A, Ortiz S, Martin CMS, Botto-Mahan C, Solari A. Survivorship of wild caught Mepraia spinolai nymphs: The effect of seasonality and Trypanosoma cruzi infection after feeding and fasting in the laboratory. INFECTION GENETICS AND EVOLUTION 2019; 71:197-204. [PMID: 30953715 DOI: 10.1016/j.meegid.2019.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/08/2019] [Accepted: 04/02/2019] [Indexed: 11/17/2022]
Abstract
Chagas disease is caused by Trypanosoma cruzi. Vector survival is an important variable affecting vectorial capacity to determine parasite transmission risk. The aims of this study are to evaluate vector survival under fasting/starvation conditions of wild-caught Mepraia spinolai after feeding and fasting, the pathogenicity of T. cruzi infection, the parasite burden and seasonal variation in parasite discrete typing units (DTU). The survivorship of M. spinolai nymphs after two continuous artificial feedings was evaluated, assessing their infection with microscopic observation of fecal samples and PCR. Later, insects were fasted/starved until death. We performed qPCR analyses of parasite load in the fecal samples and dead specimens. T. cruzi genotyping was performed using conventional PCR amplicons and hybridization tests. Infection rate was higher in M. spinolai nymphs in summer and spring than in fall. Parasite burden varied from 3 to 250,000 parasites/drop. Survival rate for starved nymph stage II was lower in insects collected in the spring compared to summer and fall. TcII was the most frequent DTU. Mainly metacyclic trypomastigotes were excreted. We conclude that M. spinolai infection rate in nymphs varies among seasons, suggesting higher transmission risk in warmer seasons. However, nymphs stage II collected in spring are more sensitive to starvation compared to other seasons. TcII in single or mixed infection does not seem relevant to determine vector pathogenicity. These results of vector survivorship after fasting/starvation are important to determine the competence of M. spinolai as a vector of T. cruzi, since they excrete metacyclic trypomastigotes and the parasitism with T. cruzi seems to be poorly pathogenic to the vector under a severe fasting/starvation condition.
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Affiliation(s)
- A Mc Cabe
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Chile
| | - F Yañez
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Chile
| | - R Pinto
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Chile
| | - A López
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Chile
| | - S Ortiz
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Chile.
| | - C Muñoz-San Martin
- Ecology Laboratory, Faculty of Veterinary Sciences and Livestock, University of Chile, Chile.
| | - C Botto-Mahan
- Department of Ecological Sciences, Faculty of Science, University of Chile, Chile.
| | - A Solari
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Chile.
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26
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Peterson JK, Salazar R, Castillo-Neyra R, Borrini-Mayori K, Condori C, Bartow-McKenney C, Tracy D, Náquira C, Levy MZ. Trypanosoma cruzi Infection Does Not Decrease Survival or Reproduction of the Common Bed Bug, Cimex lectularius. Am J Trop Med Hyg 2018; 98:724-734. [PMID: 29363461 DOI: 10.4269/ajtmh.17-0593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Although not presently implicated as a vector of human pathogens, the common bed bug, Cimex lectularius, has been suspected of carrying human pathogens because of its close association with humans and its obligate hematophagy. Recently, we characterized the vectorial competence of C. lectularius for the parasite Trypanosoma cruzi, the causative agent of Chagas disease. We observed that C. lectularius can acquire T. cruzi infection when fed on T. cruzi-carrying mice, and subsequently transmit T. cruzi to uninfected mice. This led us to ask why has C. lectularius not been implicated in the transmission of T. cruzi outside of the laboratory? We hypothesized that T. cruzi reduces C. lectularius fitness (i.e., survival and/or reproduction) as an explanation for why C. lectularius does not to transmit T. cruzi in natural settings. We tested this hypothesis by comparing the survival and reproduction of uninfected and T. cruzi-infected C. lectularius. We observed that T. cruzi had a variable effect on C. lectularius survival and reproduction. There were negligible differences between treatments in juveniles. Infected adult females tended to live longer and produce more eggs. However, no effect was consistent, and infected bugs showed more variation in survival and reproduction metrics than control bugs. We did not observe any negative effects of T. cruzi infection on C. lectularius survival or reproduction, suggesting that decreased fitness in T. cruzi-infected C. lectularius is not why bed bugs have not been observed to transmit T. cruzi in natural settings.
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Affiliation(s)
- Jennifer K Peterson
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Renzo Salazar
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Ricardo Castillo-Neyra
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Katty Borrini-Mayori
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Carlos Condori
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Casey Bartow-McKenney
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Dylan Tracy
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - César Náquira
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Michael Z Levy
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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27
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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: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [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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28
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Modeling Chagas disease in Chile: From vector to congenital transmission. Biosystems 2017; 156-157:63-71. [PMID: 28435013 DOI: 10.1016/j.biosystems.2017.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 03/27/2017] [Accepted: 04/14/2017] [Indexed: 11/30/2022]
Abstract
Chagaś disease is a human health problem in Latin America. It is highly prevalent in northern Chile between the Arica-Parinacota and Coquimbo regions, with reported incidence of 3-11/100000 inhabitants and mortality of 0.3-0.4/100000. The interruption of vector transmission was reported in 1999 by means of the elimination of the primary vector, Triatoma infestans, from human dwellings, thus the epidemiologic dynamics of this disease should be modified. Here we model the dynamics of Chagaś disease based on previous models for vector and congenital transmission, propose a model that includes both transmission forms and perform simulations. We derive useful relationships for the reproductive number (R0) showing that it may be expressed as the sum of the vector (R0V) and congenital (R0C) contributions. The vector contribution is larger than the congenital one; without the former Chagaś disease vanishes exponentially in two to three generations. Sensitivity analyses showed that the main parameters that intervene are the human bite rate, the density of vectors per human and the mortality rate of the insect vectors. Our model showed that the success of the eradication of Chagaś disease is based on the interruption of domestic transmission. Once this is obtained, the control strategies should focus on avoiding the domiciliation of wild vectors, re-colonization by the primary vector, and an adequate coverage of congenital case treatment.
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29
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Botto-Mahan C, Campos V, Medel R. Sex-dependent infection causes nonadditive effects on kissing bug fecundity. Ecol Evol 2017; 7:3552-3557. [PMID: 28515890 PMCID: PMC5433981 DOI: 10.1002/ece3.2956] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 03/14/2017] [Indexed: 11/28/2022] Open
Abstract
The influence of parasites on host reproduction has been widely studied in natural and experimental conditions. Most studies, however, have evaluated the parasite impact on female hosts only, neglecting the contribution of males for host reproduction. This omission is unfortunate as sex‐dependent infection may have important implications for host–parasite associations. Here, we evaluate for the first time the independent and nonindependent effects of gender infection on host reproductive success using the kissing bug Mepraia spinolai and the protozoan Trypanosoma cruzi as model system. We set up four crossing treatments including the following: (1) both genders infected, (2) both genders uninfected, (3) males infected—females uninfected, and (4) males uninfected—females infected, using fecundity measures as response variables. Interactive effects of infection between sexes were prevalent. Uninfected females produced more and heavier eggs when crossed with uninfected than infected males. Uninfected males, in turn, sired more eggs and nymphs when crossed with uninfected than infected females. Unexpectedly, infected males sired more nymphs when crossed with infected than uninfected females. These results can be explained by the effect of parasitism on host body size. As infection reduced size in both genders, infection on one sex only creates body size mismatches and mating constraints that are not present in pairs with the same infection status. Our results indicate the fitness impact of parasitism was contingent on the infection status of genders and mediated by body size. As the fecundity impact of parasitism cannot be estimated independently for each gender, inferences based only on female host infection run the risk of providing biased estimates of parasite‐mediated impact on host reproduction.
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Affiliation(s)
- Carezza Botto-Mahan
- Departamento de Ciencias Ecológicas Facultad de Ciencias Universidad de Chile Santiago Chile
| | - Verónica Campos
- Department of Entomology Purdue University West Lafayette IN USA
| | - Rodrigo Medel
- Departamento de Ciencias Ecológicas Facultad de Ciencias Universidad de Chile Santiago Chile
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30
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Guarneri AA, Lorenzo MG. Triatomine physiology in the context of trypanosome infection. JOURNAL OF INSECT PHYSIOLOGY 2017; 97:66-76. [PMID: 27401496 DOI: 10.1016/j.jinsphys.2016.07.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/24/2016] [Accepted: 07/07/2016] [Indexed: 06/06/2023]
Abstract
Triatomines are hematophagous insects that feed on the blood of vertebrates from different taxa, but can occasionally also take fluids from invertebrate hosts, including other insects. During the blood ingestion process, these insects can acquire diverse parasites that can later be transmitted to susceptible vertebrates if they complete their development inside bugs. Trypanosoma cruzi, the etiological agent of Chagas disease, and Trypanosoma rangeli are protozoan parasites transmitted by triatomines, the latter only transmitted by Rhodnius spp. The present work makes an extensive revision of studies evaluating triatomine-trypanosome interaction, with special focus on Rhodnius prolixus interacting with the two parasites. The sequences of events encompassing the development of these trypanosomes inside bugs and the consequent responses of insects to this infection, as well as many pathological effects produced by the parasites are discussed.
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Affiliation(s)
- Alessandra Aparecida Guarneri
- Vector Behavior and Pathogen Interaction Group, Centro de Pesquisas René Rachou, Fiocruz, Av. Augusto de Lima, 1715 Belo Horizonte, Minas Gerais, Brazil.
| | - Marcelo Gustavo Lorenzo
- Vector Behavior and Pathogen Interaction Group, Centro de Pesquisas René Rachou, Fiocruz, Av. Augusto de Lima, 1715 Belo Horizonte, Minas Gerais, Brazil
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31
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Egaña C, Pinto R, Vergara F, Ortiz S, Campos R, Solari A. Fluctuations in Trypanosoma cruzi discrete typing unit composition in two naturally infected triatomines: Mepraia gajardoi and M. spinolai after laboratory feeding. Acta Trop 2016; 160:9-14. [PMID: 27109041 DOI: 10.1016/j.actatropica.2016.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 03/22/2016] [Accepted: 04/19/2016] [Indexed: 11/29/2022]
Abstract
Mepraia species are hematophagous insects and the most important wild vectors of Trypanosoma cruzi, the causative agent of Chagas disease in southeastern South America. Because the domestic Triatoma infestans is already controlled, the transmission of different T. cruzi discrete typing units (DTUs) by Mepraia species deserves attention. Our aim is to gather information on the diversity of T. cruzi DTUs circulating in natural insect populations. Two groups of naturally infected bugs 21 Mepraia gajardoi and 26 Mepraia spinolai were followed-up after two or more laboratory feedings by means of minicircle-PCR assays to evaluate the composition of four T. cruzi DTUs by hybridization tests. Fluctuations from positive T. cruzi detection to negative and the converse, as well as single to mixed infections with different T. cruzi DTUs and the opposite were frequent observations after laboratory feeding in both Mepraia species. Single and mixed infections with more than two T. cruzi DTUs were detected after the first feeding; however mainly mixed infections prevailed after the second feeding. Laboratory feeding on three or more occasions resulted in a decreasing trend of the parasite burden. In a comparison with 28 infected and fed M. gajardoi collected one year before from the same vector colony T. cruzi DTUs composition changed, indicating that temporal variations occur in T. cruzi. Natural populations of Mepraia species can transmit complex mixtures T. cruzi DTUs which fluctuate over time after feeding, with a tendency to eliminate the parasitism after prolonged feeding.
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Affiliation(s)
- Camila Egaña
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Raquel Pinto
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Fernanda Vergara
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Sylvia Ortiz
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Ricardo Campos
- Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Aldo Solari
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.
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Trypanosoma cruzi-Trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected Rhodnius prolixus. Parasitology 2016; 143:1157-67. [PMID: 27174360 DOI: 10.1017/s0031182016000615] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Trypanosoma cruzi, causative agent of Chagas disease, co-infects its triatomine vector with its sister species Trypanosoma rangeli, which shares 60% of its antigens with T. cruzi. Additionally, T. rangeli has been observed to be pathogenic in some of its vector species. Although T. cruzi-T. rangeli co-infections are common, their effect on the vector has rarely been investigated. Therefore, we measured the fitness (survival and reproduction) of triatomine species Rhodnius prolixus infected with just T. cruzi, just T. rangeli, or both T. cruzi and T. rangeli. We found that survival (as estimated by survival probability and hazard ratios) was significantly different between treatments, with the T. cruzi treatment group having lower survival than the co-infected treatment. Reproduction and total fitness estimates in the T. cruzi and T. rangeli treatments were significantly lower than in the co-infected and control groups. The T. cruzi and T. rangeli treatment group fitness estimates were not significantly different from each other. Additionally, co-infected insects appeared to tolerate higher doses of parasites than insects with single-species infections. Our results suggest that T. cruzi-T. rangeli co-infection could ameliorate negative effects of single infections of either parasite on R. prolixus and potentially help it to tolerate higher parasite doses.
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Colonization of Rhodnius prolixus gut by Trypanosoma cruzi involves an extensive parasite killing. Parasitology 2016; 143:434-43. [PMID: 26818093 DOI: 10.1017/s0031182015001857] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, is ingested by triatomines during their bloodmeal on an infected mammal. Aiming to investigate the development and differentiation of T. cruzi inside the intestinal tract of Rhodnius prolixus at the beginning of infection we fed insects with cultured epimastigotes and blood trypomastigotes from infected mice to determine the amount of recovered parasites after ingestion. Approximately 20% of the ingested parasites was found in the insect anterior midgut (AM) 3 h after feeding. Interestingly, a significant reduction (80%) in the numbers of trypomastigotes was observed after 24 h of infection suggesting that parasites were killed in the AM. Moreover, few parasites were found in that intestinal portion after 96 h of infection. The evaluation of the numbers of parasites in the posterior midgut (PM) at the same periods showed a reduced parasite load, indicating that parasites were not moving from the AM. Additionally, incubation of blood trypomastigotes with extracts from R. prolixus AMs revealed that components of this tissue could induce significant death of T. cruzi. Finally, we observed that differentiation from trypomastigotes to epimastigotes is not completed in the AM; instead we suggest that trypomastigotes change to intermediary forms before their migration to the PM, where differentiation to epimastigotes takes place. The present work clarifies controversial points concerning T. cruzi development in insect vector, showing that parasite suffers a drastic decrease in population size before epimastigonesis accomplishment in PM.
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Wozniak EJ, Lawrence G, Gorchakov R, Alamgir H, Dotson E, Sissel B, Sarkar S, Murray KO. The Biology of the Triatomine Bugs Native to South Central Texas and Assessment of the Risk They Pose for Autochthonous Chagas Disease Exposure. J Parasitol 2015; 101:520-8. [DOI: 10.1645/15-748] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Marliére NP, Latorre-Estivalis JM, Lorenzo MG, Carrasco D, Alves-Silva J, Rodrigues JDO, Ferreira LDL, Lara LDM, Lowenberger C, Guarneri AA. Trypanosomes Modify the Behavior of Their Insect Hosts: Effects on Locomotion and on the Expression of a Related Gene. PLoS Negl Trop Dis 2015; 9:e0003973. [PMID: 26291723 PMCID: PMC4546274 DOI: 10.1371/journal.pntd.0003973] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 07/12/2015] [Indexed: 11/23/2022] Open
Abstract
Background As a result of evolution, the biology of triatomines must have been significantly adapted to accommodate trypanosome infection in a complex network of vector-vertebrate-parasite interactions. Arthropod-borne parasites have probably developed mechanisms, largely still unknown, to exploit the vector-vertebrate host interactions to ensure their transmission to suitable hosts. Triatomines exhibit a strong negative phototaxis and nocturnal activity, believed to be important for insect survival against its predators. Methodology/Principal Findings In this study we quantified phototaxis and locomotion in starved fifth instar nymphs of Rhodnius prolixus infected with Trypanosoma cruzi or Trypanosoma rangeli. T. cruzi infection did not alter insect phototaxis, but induced an overall 20% decrease in the number of bug locomotory events. Furthermore, the significant differences induced by this parasite were concentrated at the beginning of the scotophase. Conversely, T. rangeli modified both behaviors, as it significantly decreased bug negative phototaxis, while it induced a 23% increase in the number of locomotory events in infected bugs. In this case, the significant effects were observed during the photophase. We also investigated the expression of Rpfor, the triatomine ortholog of the foraging gene known to modulate locomotion in other insects, and found a 4.8 fold increase for T. rangeli infected insects. Conclusions/Significance We demonstrated for the first time that trypanosome infection modulates the locomotory activity of the invertebrate host. T. rangeli infection seems to be more broadly effective, as besides affecting the intensity of locomotion this parasite also diminished negative phototaxis and the expression of a behavior-associated gene in the triatomine vector. The control of Chagas disease, an infection that affects ca. 8 million people in Latin America, is mostly based on vector control activities. Understanding vector biology and how these insects interact with their environment, hosts and pathogens is crucial to improve vector control strategies. The behavior of triatomines has been largely studied, yet few reports have focused on the behavioral effects of the interaction that these insects endure with their natural parasites. Trypanosoma cruzi and Trypanosoma rangeli are two protozoan parasites found naturally infecting Rhodnius species. In this study, we showed for the first time that the locomotory activity of Rhodnius prolixus, a relevant vector of Chagas disease, is affected by trypanosome infection. T. cruzi was found to decrease bug locomotory activity during night hours, while T. rangeli promoted a generally increased insect locomotion. In addition, we searched for the R. prolixus orthologue (Rpfor) of a gene associated with the modulation of insect activity (foraging gene) and found that Rpfor expression was also affected by trypanosome infection.
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Affiliation(s)
- Newmar Pinto Marliére
- Centro de Pesquisas René Rachou, Avenida Augusto de Lima, Belo Horizonte, Minas Gerais, Brazil
| | | | - Marcelo Gustavo Lorenzo
- Centro de Pesquisas René Rachou, Avenida Augusto de Lima, Belo Horizonte, Minas Gerais, Brazil
| | - David Carrasco
- Chemical Ecology Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Juliana Alves-Silva
- Centro de Pesquisas René Rachou, Avenida Augusto de Lima, Belo Horizonte, Minas Gerais, Brazil
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Luisa de Melo Lara
- Centro de Pesquisas René Rachou, Avenida Augusto de Lima, Belo Horizonte, Minas Gerais, Brazil
| | - Carl Lowenberger
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Alessandra Aparecida Guarneri
- Centro de Pesquisas René Rachou, Avenida Augusto de Lima, Belo Horizonte, Minas Gerais, Brazil
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail:
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Peterson JK, Graham AL, Dobson AP, Chávez OT. Rhodnius prolixus Life History Outcomes Differ when Infected with Different Trypanosoma cruzi I Strains. Am J Trop Med Hyg 2015; 93:564-72. [PMID: 26078316 DOI: 10.4269/ajtmh.15-0218] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/02/2015] [Indexed: 12/20/2022] Open
Abstract
The effect of a parasite on the life history of its vector is important for understanding and predicting disease transmission. Chagas disease agent Trypanosoma cruzi is a generalist parasite that is diverse across scales from its genetic diversity to the 100s of mammal and vector species it infects. Its vertebrate hosts show quite variable responses to infection, however, to date there are no studies looking at how T. cruzi variability might result in variable outcomes in its invertebrate host. Therefore, we investigated the effect of different T. cruzi I strains on Rhodnius prolixus survival and development. We found significant variation between insects infected with different strains, with some strains having no effect, as compared with uninfected insects, and others with significantly lower survival and development. We also found that different variables had varying importance between strains, with the effect of time postinfection and the blood:weight ratio of the infective meal significantly affecting the survival of insects infected with some strains, but not others. Our results suggest that T. cruzi can be pathogenic not only to its vertebrate hosts but also to its invertebrate hosts.
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Affiliation(s)
- Jennifer K Peterson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey; Grupo BCEI, Universidad de Antioquia, Medellín, Colombia
| | - Andrea L Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey; Grupo BCEI, Universidad de Antioquia, Medellín, Colombia
| | - Andrew P Dobson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey; Grupo BCEI, Universidad de Antioquia, Medellín, Colombia
| | - Omar Triana Chávez
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey; Grupo BCEI, Universidad de Antioquia, Medellín, Colombia
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Trypanosoma cruzi, etiological agent of Chagas disease, is virulent to its triatomine vector Rhodnius prolixus in a temperature-dependent manner. PLoS Negl Trop Dis 2015; 9:e0003646. [PMID: 25793495 PMCID: PMC4368190 DOI: 10.1371/journal.pntd.0003646] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 02/25/2015] [Indexed: 12/05/2022] Open
Abstract
It is often assumed that parasites are not virulent to their vectors. Nevertheless, parasites commonly exploit their vectors (nutritionally for example) so these can be considered a form of host. Trypanosoma cruzi, a protozoan found in mammals and triatomine bugs in the Americas, is the etiological agent of Chagas disease that affects man and domestic animals. While it has long been considered avirulent to its vectors, a few reports have indicated that it can affect triatomine fecundity. We tested whether infection imposed a temperature-dependent cost on triatomine fitness. We held infected insects at four temperatures between 21 and 30°C and measured T. cruzi growth in vitro at the same temperatures in parallel. Trypanosoma cruzi infection caused a considerable delay in the time the insects took to moult (against a background effect of temperature accelerating moult irrespective of infection status). Trypanosoma cruzi also reduced the insects’ survival, but only at the intermediate temperatures of 24 and 27°C (against a background of increased mortality with increasing temperatures). Meanwhile, in vitro growth of T. cruzi increased with temperature. Our results demonstrate virulence of a protozoan agent of human disease to its insect vector under these conditions. It is of particular note that parasite-induced mortality was greatest over the range of temperatures normally preferred by these insects, probably implying adaptation of the parasite to perform well at these temperatures. Therefore we propose that triggering this delay in moulting is adaptive for the parasites, as it will delay the next bloodmeal taken by the bug, thus allowing the parasites time to develop and reach the insect rectum in order to make transmission to a new vertebrate host possible. Parasites are often assumed to cause little harm to their arthropod vectors, even though they commonly reproduce inside the arthropods and exploit their nutrients, even causing lesions when crossing internal barriers. Thus, the interests of parasite and vector may well not be aligned and we can expect the parasite to exploit its vector just as it does with its main host, with consequent negative effects on the vector’s fitness. Here, we show that this occurs with Trypanosoma cruzi in its bug vector (T. cruzi causes Chagas disease, affecting ca. 8 million people and disease management is principally attained via vector control). Our results indicate that the parasites delay insect moulting, which is likely beneficial to them as they need time to develop in the insect before the next bloodmeal (that only occurs post-moult). We also show parasite-induced mortality over the narrow range of temperatures which the insect prefers and over which it performs best. In vitro growth of the parasite increases with temperature and we discuss how this may help explain the effects in vivo. Overall, these results will be important to understand the epidemiology of Chagas disease and provide an evolutionary context to explain the parasite′s interaction with its vector.
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Klotz SA, Dorn PL, Mosbacher M, Schmidt JO. Kissing bugs in the United States: risk for vector-borne disease in humans. ENVIRONMENTAL HEALTH INSIGHTS 2014; 8:49-59. [PMID: 25574143 PMCID: PMC4264683 DOI: 10.4137/ehi.s16003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/16/2014] [Accepted: 09/22/2014] [Indexed: 05/11/2023]
Abstract
Eleven species of kissing bugs are found in the United States. Their home ranges may be expanding northward, perhaps as a consequence of climate change. At least eight of the species, perhaps all, are reported to harbor Trypanosoma cruzi, the parasite that causes Chagas disease. Because humans are encroaching on kissing bug habitat, there is concern for vector-transmitted Chagas disease in the United States. To date, documented autochthonous cases of Chagas in humans in the United States are rare. Kissing bugs are capable of adapting to new habitats such as human domiciles; however, they do not colonize homes in the United States as in Central and South America. We review the biology, behavior, and medical importance of kissing bugs and the risk they pose for transmission of Chagas disease in the United States. Where possible, descriptions of US species are compared to the epidemiologically important Latin American species.
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Affiliation(s)
- Stephen A Klotz
- Division of Infectious Diseases, University of Arizona, Tucson, USA
- CORRESPONDENCE: , , ,
| | - Patricia L Dorn
- Department of Biological Sciences, Loyola University New Orleans, New Orleans, USA
- CORRESPONDENCE: , , ,
| | - Mark Mosbacher
- School of Veterinary Medicine, MPVM Program, University of California, Davis, USA
- CORRESPONDENCE: , , ,
| | - Justin O Schmidt
- Southwestern Biological Institute, Tucson, USA
- CORRESPONDENCE: , , ,
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Genetics and evolution of triatomines: from phylogeny to vector control. Heredity (Edinb) 2011; 108:190-202. [PMID: 21897436 DOI: 10.1038/hdy.2011.71] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Triatomines are hemipteran bugs acting as vectors of the protozoan parasite Trypanosoma cruzi. This parasite causes Chagas disease, one of the major parasitic diseases in the Americas. Studies of triatomine genetics and evolution have been particularly useful in the design of rational vector control strategies, and are reviewed here. The phylogeography of several triatomine species is now slowly emerging, and the struggle to reconcile the phenotypic, phylogenetic, ecological and epidemiological species concepts makes for a very dynamic field. Population genetic studies using different markers indicate a wide range of population structures, depending on the triatomine species, ranging from highly fragmented to mobile, interbreeding populations. Triatomines transmit T. cruzi in the context of complex interactions between the insect vectors, their bacterial symbionts and the parasites; however, an integrated view of the significance of these interactions in triatomine biology, evolution and in disease transmission is still lacking. The development of novel genetic markers, together with the ongoing sequencing of the Rhodnius prolixus genome and more integrative studies, will provide key tools to expanding our understanding of these important insect vectors and allow the design of improved vector control strategies.
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Nouvellet P, Ramirez-Sierra MJ, Dumonteil E, Gourbière S. Effects of genetic factors and infection status on wing morphology of Triatoma dimidiata species complex in the Yucatán peninsula, Mexico. INFECTION GENETICS AND EVOLUTION 2011; 11:1243-9. [PMID: 21515410 DOI: 10.1016/j.meegid.2011.04.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/05/2011] [Accepted: 04/07/2011] [Indexed: 10/18/2022]
Abstract
Triatoma dimidiata is one of the main vectors of Chagas disease, and it has been shown to be a species complex. In the Yucatán peninsula, Mexico, vector populations are non-domiciliated, and the transmission of Trypanosoma cruzi thus critically relies on vector dispersal. This leads us to study the morphologic variations in T. dimidiata wings with respect to genetic factors (sex and genotype at the ITS-2 locus), geographic location, and T. cruzi-infection status. Females were found to have larger and more symmetrical wings than males. Wing shape was influenced by ITS-2 genotypes, although differences are unlikely sufficient to allow taxonomic discrimination of the sibling species. Hybrids were shown to have similar fluctuating asymmetries in wing size and shape as parental species, but the level of asymmetry in shape varied slightly between villages. The two later findings are consistent with a high level of gene flow between parental species, and the high dispersal potential of these non-domiciliated vectors. More surprisingly, individuals infected with T. cruzi were found to have larger wings than non-infected ones. This effect, which was consistently observed across sexes, genotypes and villages, is likely to be due to a direct impact of T. cruzi on insect development. Sex and infection status are thus likely to be key factors influencing vector dispersal with important impacts on disease transmission, since dispersal directly controls the domestic abundance of these vectors. These aspects should be investigated further to fully capture the ecology and evolution of Chagas disease transmission by non-domiciliated vectors.
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Affiliation(s)
- Pierre Nouvellet
- Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
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Campos R, Botto-Mahan C, Coronado X, Jaramillo N, Panzera F, Solari A. Wing shape differentiation of Mepraia species (Hemiptera: Reduviidae). INFECTION GENETICS AND EVOLUTION 2011; 11:329-33. [DOI: 10.1016/j.meegid.2010.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 11/03/2010] [Accepted: 11/05/2010] [Indexed: 11/30/2022]
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Ramirez-Sierra MJ, Herrera-Aguilar M, Gourbière S, Dumonteil E. Patterns of house infestation dynamics by non-domiciliated Triatoma dimidiata reveal a spatial gradient of infestation in rural villages and potential insect manipulation by Trypanosoma cruzi. Trop Med Int Health 2009; 15:77-86. [PMID: 19912593 DOI: 10.1111/j.1365-3156.2009.02422.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Chagas disease is a major vector-borne parasitic disease in Latin America, primarily transmitted to humans by triatomine vectors. Non-domiciliated triatomine species such as Triatoma dimidiata in the Yucatan peninsula, Mexico, can transiently invade houses and are emerging as a major challenge to control Trypanosoma cruzi transmission to humans. We analyzed the spatio-temporal spreading of house infestation by T. dimidiata in four rural villages. METHODS Triatomines were collected in four rural villages over a 2 years period, and the spatio-temporal patterns of infestation were analyzed. RESULTS Triatomines were consistently more abundant at the periphery of villages than in centers, indicating a much higher risk of T. cruzi transmission at the periphery. Male T. dimidiata were found further in the center of the village, while females remained closer to the periphery, suggesting differential dispersal capabilities between sexes, although the timing of dispersal appeared identical. Surprisingly, infected females were consistently collected in houses much further from the surrounding bushes than non-infected females, while the distribution of males was unaffected by their T. cruzi infection status, suggesting an increased dispersal capability in infected females. CONCLUSION The spatial structure of infestation should be taken into account for the prioritization of vector control activities within villages, and spatially targeted interventions may be explored. A potential vector manipulation by T. cruzi, observed for the first time in triatomines, may favor parasite transmission to new hosts.
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Affiliation(s)
- Maria Jesus Ramirez-Sierra
- Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Yucatan, Mexico
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