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12 resultados encontrados para: AUTOR: Ramsey Willoquet, Janine M.
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1.
Artículo
*Solicítelo con su bibliotecario/a
Behavioural and electrophysiological responses of Triatoma dimidiata nymphs to conspecific faecal volatiles
Gálvez Marroquín, Zitlalic ; Cruz López, Leopoldo Caridad (coaut.) ; Malo Rivera, Edi Álvaro (coaut.) ; Ramsey Willoquet, Janine M. (coaut.) ; Rojas, Julio C. (coaut.) ;
Contenido en: Medical and Veterinary Entomology Vol. 32, no. 1 (March 2018), p. 102–110 ISSN: 0269-283X
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Resumen en: Inglés |
Resumen en inglés

The behavioural and electrophysiological (electroantennography) responses of the first two instars of Triatoma dimidiata (Hemiptera: Reduviidae) Latreille to fresh and dry faecal headspace volatile extracts from fifth instar conspecific nymphs and synthetic compounds were analysed in this study. Recently emerged nymphs (3–5 days) aggregated around filter paper impregnated with dry faeces and around filter paper impregnated with extracts from both fresh and dry faeces. Older first instars (10–15 days) and second instars aggregated around filter paper impregnated with fresh and dry faeces, and their respective headspace extracts. Dry faecal volatile extracts elicited the strongest antennal responses, followed by fresh faecal extracts. Gas chromatography−mass spectrometry analysis of dried faecal headspace volatiles demonstrated the presence of 12 compounds: 2-ethyl-1-hexanol, 1,2,4-trimethylbenzene, n-octadecane, n-nonadecane, n-eicosane, n-heneicosane, n-tricosane, n-pentaeicosane, n-hexaeicosane, n-octaeicosane, nonanal, and 4-methyl quinazoline. In fresh faecal headspace extracts, only nonanal was clearly detected, although there were other trace compounds, including several unidentified sesquiterpenes. Four of the 11 compounds tested individually elicited aggregation behaviour at concentrations of 100 ng/μL and 1 μg/μL. A blend containing these four components also mediated the aggregation of nymphs. These volatiles may be valuable for developing monitoring methods and designing sensitive strategies to detect and measure T. dimidiata infestation.


2.
Artículo
Sweeter than a rose, at least to Triatoma phyllosoma complex males (Triatominae: Reduviidae)
May Concha, Irving Jesús ; Cruz López, Leopoldo Caridad (coaut.) ; Rojas, Julio C. (coaut.) ; Ramsey Willoquet, Janine M. (coaut.) ;
Contenido en: Parasites & Vectors Vol, 11, no. 95 (February 2018), p. 1-12 ISSN: 1756-3305
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Resumen en: Inglés |
Resumen en inglés

Background: The Triatoma phyllosoma complex of Trypanosoma cruzi vectors (Triatominae: Reduviidae) is distributed in both Neotropical and Nearctic bioregions of Mexico. Methods: Volatile organic compounds emitted by disturbed Triatoma longipennis, Triatoma pallidipennis and Triatoma phyllosoma, and from their Brindley’s and metasternal glands, were identified using solid-phase microextraction coupled with gas chromatography-mass spectrometry. Results: Disturbed bugs and the metasternal glands from T. phyllosoma released or had significantly fewer compounds than T. longipennis and T. pallidipennis. Isobutyric acid was the most abundant compound secreted by disturbed bugs of the three species, while Brindley’s glands of all species produced another four compounds: propanoic acid, isobutyric acid, pentyl butanoate, and 2-methyl hexanoic acid. Two novel compounds, both rose oxide isomers, were produced in MGs and released only by disturbed females of all three species, making this the first report in Triatominae of these monoterpenes. The principal compound in MGs of both sexes of T. longipennis and T. phyllosoma was 3-methyl-2-hexanone, while cis-rose oxide was the principal compound in T. pallidipennis females. The major components in male effluvia of T. pallidipennis were 2-decanol and 3-methyl-2-hexanone. Conclusion: Discriminant analysis of volatile organic compounds was significant, separating the three species and was consistent with morphological and genetic evidence for species distinctions within the complex.


3.
- Artículo con arbitraje
Antennal phenotype of Mexican haplogroups of the Triatoma dimidiata complex, vectors of Chagas disease
May Concha, Irving Jesús (autor) ; Guerenstein, Pablo G. (autor) ; Ramsey Willoquet, Janine M. (autor) ; Rojas, Julio C. (autor) ; Catalá, Silvia S. (autora) ;
Contenido en: Infection, Genetics and Evolution Vol. 40 (June 2016), p. 73–79 ISSN: 1567-1348
Resumen en: Inglés |
Resumen en inglés

Triatoma dimidiata (Latreille) is a species complex that spans North, Central, and South America and which is a key vector of all known discrete typing units (DTU) of Trypanosoma cruzi, the etiologic agent of Chagas disease. Morphological and genetic studies indicate that T. dimidiata is a species complex with three principal haplogroups (hg) in Mexico. Different markers and traits are still inconclusive regarding if other morphological differentiation may indicate probable behavioral and vectorial divergences within this complex. In this paper we compared the antennae of three Mexican haplogroups (previously verified by molecular markers ND4 and ITS-2) and discussed possible relationships with their capacity to disperse and colonized new habitats. The abundance of each type of sensillum (bristles, basiconics, thick- and thin-walled trichoids) on the antennae of the three haplogroups, were measured under light microscopy and compared using Kruskal–Wallis non-parametric and multivariate non-parametric analyses. Discriminant analyses indicate significant differences among the antennal phenotype of haplogroups either for adults and some nymphal stages, indicating consistency of the character to analyze intraspecific variability within the complex. The present study shows that the adult antennal pedicel of the T. dimidiata complex have abundant chemosensory sensilla, according with good capacity for dispersal and invasion of different habitats also related to their high capacity to adapt to conserved as well as modified habitats.

However, the numerical differences among the haplogroups are suggesting variations in that capacity. The results here presented support the evidence of T. dimidiata as a species complex but show females and males in a different way. Given the close link between the bug's sensory system and its habitat and host-seeking behavior, AP characterization could be useful to complement genetic, neurological and ethological studies of the closely related Dimidiata Complex haplogroups for a better knowledge of their vectorial capacity and a more robust species differentiation.


4.
Artículo
Geographical, landscape and host associations of Trypanosoma cruzi DTUs and lineages
Izeta Alberdi, Amaia (autor) ; Ibarra Cerdeña, Carlos Napoleón (autor) ; Moo Llanes, David Alejandro (autor) ; Ramsey Willoquet, Janine M. (autor) ;
Contenido en: Parasites & Vectors Vol. 9, no. 1 (December 2016), p. 1-20 ISSN: 1756-3305
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Resumen en: Inglés |
Resumen en inglés

Background: The evolutionary history and ecological associations of Trypanosoma cruzi, the need to identify genetic markers that can distinguish parasite subpopulations, and understanding the parasite’s evolutionary and selective processes have been the subject of a significant number of publications since 1998, the year when the first DNA sequence analysis for the species was published. Methods: The current analysis systematizes and re-analyzes this original research, focusing on critical methodological and analytical variables and results that have given rise to interpretations of putative patterns of genetic diversity and diversification of T. cruzi lineages, discrete typing units (DTUs), and populations, and their associations with hosts, vectors, and geographical distribution that have been interpreted as evidence for parasite subpopulation specificities. Results: Few studies use hypothesis-driven or quantitative analysis for T. cruzi phylogeny (16/58 studies) or phylogeography (10/13). Among these, only one phylogenetic and five phylogeographic studies analyzed molecular markers directly from tissues (i.e. not from isolates). Analysis of T. cruzi DTU or lineage niche and its geographical projection demonstrate extensive sympatry among all clades across the continent and no significant niche differences among DTUs. DTU beta-diversity was high, indicating diverse host assemblages across regions, while host dissimilarity was principally due to host species turnover and to a much lesser degree to nestedness. DTU-host order specificities appear related to trophic or microenvironmental interactions. Conclusions: More rigorous study designs and analyses will be required to discern evolutionary processes and the impact of landscape modification on population dynamics and risk for T. cruzi transmission to humans.


5.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata.

Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in parasite transmission related to lineage sorting within the matrix. Intriguingly, TcIa is dominant in terrestrial small wildlife in the sylvatic habitat and is the only parasite DTU found in D. virginiana in the domestic habitat, although its frequency remained constant in sylvatic and ecotone vectors. Bats have a key role in TcVI dispersal from the sylvatic habitat, while dogs, sheep, and humans are drivers of TcVI between domestic and ecotone habitats. Overall, our results allow us to conclude that T. cruzi transmission is dependent on host availability within a highly permeable landscape in Zoh Laguna.


6.
Tesis - Doctorado
Prácticas y representaciones sociales asociadas a la transmisión vectorial de la enfermedad de chagas en Zoh-Laguna, Calakmul, México / Alba Rocío Valdez Tah
Valdez Tah, Alba Rocío (autor) ; Huicochea Gómez, Laura (directora) ; Ramsey Willoquet, Janine M. (co-directora) ; Nazar Beutelspacher, Austreberta (asesora) (1960-) ; Ortega Canto, Judith Elena (asesora) ;
Lerma, Campeche, México : El Colegio de la Frontera Sur , 2015
Clasificación: TE/614.533097265 / V3
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SIBE Campeche
ECO040006002 (Disponible)
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SIBE Chetumal
ECO030008236 (Disponible)
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SIBE San Cristóbal
ECO010017780 (Disponible)
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Resumen en español

Se identificó y caracterizó las representaciones sociales y prácticas que generan vulnerabilidad humana ante la transmisión vectorial del agente infeccioso de la enfermedad de Chagas. Se expone la concomitancia de los factores bio-ecológicos con los socioculturales en el riesgo de infección con el propósito de profundizar en el entendimiento de los escenarios de contacto humano-vector en el paisaje de Zoh- Laguna, Calakmul, Campeche. Con el análisis sistemático de la literatura y un primer acercamiento etnográfico se identificó los componentes de peligro y vulnerabilidad en la transmisión vectorial de la enfermedad. La vulnerabilidad humana, desde los procesos de salud-enfermedad-atención y de la apropiación social del territorio, se indagó por el método etnográfico en 2011-2012. La “normalización” de las picaduras de los triatominos, su tratamiento doméstico ante la demanda de atención de otros padecimientos percibidos de mayor gravedad y la desatención institucional impactan en el reconocimiento social del riesgo en la comunidad de estudio. Las prácticas ecológicas de la población muestran la posibilidad de exposición humano-vector en espacios extra-domésticos. La dinámica comunitaria en las actividades económicas durante la temporada seca, paralelo al relajamiento de los métodos de protección contra la picadura de insectos, se traduce en una mayor vulnerabilidad para la población durante esta época. Por su distanciamiento simbólico al riesgo, por sus prácticas productivas por las cuales introducen y transportan triatominos hacia el espacio doméstico y por ser excluidos en los esfuerzos de prevención en salud pública los varones son centrales en la comprensión de la vulnerabilidad humana ante el fenómeno.

La pluralidad en las representaciones sociales y su articulación con las prácticas que la investigación encontró debe ser considerada en el diseño de programas de prevención y atención de la enfermedad de Chagas con el objetivo de garantizar la accesibilidad sociocultural a los diferentes usuarios en los diferentes escenarios de transmisión.

Índice

Capítulo 1
Introducción General
La dimensión sociocultural en las enfermedades transmitidas por vector
La vulnerabilidad humana ante la transmisión vectorial de Trypanosoma cruzi
Premisas de Investigación
Enfoque Teórico
Las representaciones sociales y las prácticas
El riesgo: peligro y vulnerabilidad
Pregunta de Investigación:
Objetivos:
Sitio y Población de Estudio
La transmisión de Trypanosoma cruzi en el paisaje de Zoh-Laguna
Metodología
Aspectos éticos de la investigación
Primera aproximación
El proceso de síntesis y sistematización de la literatura
Profundizando en el tema
Estructura de la Tesis
Capítulo 2
Resumen
Abstract
Introducción
. Marco Conceptual y Metodología
Resultados
Matriz de riesgo de peligro y vulnerabilidad de la transmisión vectorial de T. cruzi
El peligro en la transmisión vectorial de T. cruzi
La vulnerabilidad a la transmisión vectorial de T. cruzi
. La vulnerabilidad a través del análisis etnográfico en Zoh-Laguna, Calakmul
. Discusión
Referencias
Capítulo 3
Abstract
Introduction
Materials and Methods
Ethics statement
Study setting: Zoh-Laguna landscape and inhabitants
Study participants
Data collection and analysis
Results
A dual and antagonistic relationship between environment and human health
“Normalization” of insects and triatomine bites
Housing materials, lot arrangement and gender
Increase in landscape modifications and inter-habitat movement in the dry season
Triatomines associated with humidity-darkness-monte
Sleep and protection practices over entire landscape
Discussion
The ethno-ecology of vector-borne transmission of Trypanosoma cruzi
Disease and chinchoma perception and care-seeking practices
Livelihoods and differential exposure in the landscape
Seasons and human activity
Triatomine exposure and gender
Referencias

Capítulo 4
Conclusiones Generales
Literatura Citada
Anexos


7.
- Artículo con arbitraje
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Resumen en: Inglés |
Resumen en inglés

Vector-borne transmission of Trypanosoma cruzi (VBTTc) is dependent on the concomitant interaction between biological and environmental hazard over the entire landscape, and human vulnerability. Representations and practices of health-disease-care-seeking and territorial appropriation and use were analyzed for VBTTc in a qualitative ethnographic study in the Zoh-Laguna landscape, Campeche, Mexico. In-depth interviews and participatory observation explored representations and practices regarding ethno-ecological knowledge related to vector-transmission, health-disease-care-seeking, and land use processes. The population has a broad knowledge of biting insects, which they believe are all most abundant in the rainy season; the community´s proximity to natural areas is perceived as a barrier to control their abundance. Triatomines are mostly recognized by men, who have detailed knowledge regarding their occurrence and association with mammals in non-domestic fragments, where they report being bitten. Women emphasize the dermal consequences of triatomine bites, but have little knowledge about the disease. Triatomine bites and the chinchoma are “normalized” events which are treated using home remedies, if at all. The neglected condition of Chagas disease in Mexican public health policies, livelihoods which are dependent on primary production, and gender-related knowledge (or lack thereof) are structural circumstances which influence the environment and inhabitants´ living conditions; in turn, these trigger triatomine-human contact. The most important landscape practices producing vulnerability are the activities and mobility within and between landscape fragments causing greater exposure of inhabitants primarily in the dry season.

A landscape approach to understanding vulnerability components of VBTTc from health-disease-care-seeking perspectives and based on territorial appropriation and use, is essential where there is continuous movement of vectors between and within all habitats. An understanding of the structural factors which motivate the population´s perceptions, beliefs, and practices and which create and maintain vulnerability is essential to develop culturally relevant and sustainable community-based VBTTc prevention and control.


8.
- Artículo con arbitraje
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Resumen en: Inglés |
Resumen en inglés

Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously “presumed” monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups. Methods: Volatiles emitted by disturbed bugs, Brindley’s (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer.

Results: Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup specific, while those from the MG were not. Conclusions: Discriminant and cluster analysis of BG + MG compounds indicate significant separation among the three haplogroups, while alarm response compounds were similar between h2 and h3, both distinct from h1. This latter haplogroup is ancestral phylogenetically to the other two. Our results suggest that alarm responses are a conserved behaviour in the Triatoma dimidiata complex.


9.
- Artículo con arbitraje
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Resumen en: Español | Inglés |
Resumen en español

Los estudios sobre el riesgo de la transmisión vectorial de Trypanosoma cruzi a población humana han desatendido el rol del comportamiento y de la subjetividad de las relaciones sociales en el marco del paisaje natural y el contexto social. A través de una revisión y síntesis de la bibliografía sobre los factores biológicos, ecoepidemiológicos y socioculturales que intervienen en el fenómeno, en conjunto con un estudio etnográfico, se propone un modelo de análisis del riesgo que distingue los componentes de peligro y de la vulnerabilidad humana. Los conocimientos, prácticas y representaciones sociales respecto del proceso salud-enfermedad-atención y de la apropiación social del territorio se plantean como elementos explicativos de la vulnerabilidad humana. Los componentes de la vulnerabilidad propuestos se exploran en el marco de un análisis etnográfico, que permite identificar opciones y medidas preventivas o de control integral del riesgo más adecuadas.

Resumen en inglés

Risk studies of Trypanosoma cruzi vector transmission have classically overlooked the role of social behaviors and subjectivities within the natural landscape and social environment. A review and analysis of the literature on relevant biological, eco-epidemiological and sociocultural factors was combined with an ethnographic study in order to develop a risk model framework identifying the components of hazard and human vulnerability. Social practices, representations and knowledge regarding the health-disease-care process and the social appropriation of the territory are considered as elements explicative of human vulnerability. Exploring these components within an ethnographic analysis allows new options and more adequate prevention or comprehensive risk control measures to be identified.


10.
Tesis - Maestría
Respuesta comportamental y electrofisiológica de ninfas de Triatoma dimidiata Latreille (Hemiptera: reduviidae) a volátiles de heces de conespecíficos / Zitlalic Gálvez Marroquín
Gálvez Marroquín, Zitlalic ; Cruz López, Leopoldo Caridad (tutor) ; Malo Rivera, Edi Álvaro (asesor) ; Rojas, Julio C. (asesor) ; Ramsey Willoquet, Janine M. (asesora) ;
Tapachula, Chiapas, México : El Colegio de la Frontera Sur , 2014
Clasificación: TE/595.754097275 / G3
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SIBE Campeche
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SIBE Chetumal
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Índice | Resumen en: Español |
Resumen en español

La enfermedad de Chagas es una padecimiento potencialmente mortal causado por el parásito Trypanosoma cruzi Chagas (Protozoa, Mastigophora). Esta enfermedad está distribuida principalmente en América Latina, donde se transmite a los humanos principalmente por las heces de insectos triatominos. A nivel mundial, existen cerca de diez millones de personas infectadas y más de 25 millones están en riesgo de adquirir la enfermedad (OMS, 2012). Triatoma dimidiata Latreille (Hemiptera: Reduviidae) es considerado uno de los vectores más importantes en la propagación de la enfermedad de Chagas y se distribuye desde el norte de América del Sur (Colombia, Venezuela, Ecuador y Perú), en todos los países de América Central y en las zonas costeras de México (Pacífico y Golfo) (Ibarra- Cerdeña et al., 2009). Es la única especie que abarca naturalmente, Norte, Centro y el sur de América, reconociéndose tres genotipos del complejo dimidiata en México (Lehmann et al., 2005; Bargues et al., 2008). Esta especie ha sido encontrada en hábitats domésticos en 14 estados de la Republica (Salazar- Schettino et al., 2005), y se sabe que entre 19 y 34% de los individuos de T. dimidiata que infestan las viviendas se encuentran infectados con T. cruzi (Dumonteil et al., 2004; Monroy et al., 2003; Nakagawa et al., 2005).

Índice

Introducción
Respuesta comportamental y electrofisiológica de ninfas de Triatoma dimidiata a volátiles de heces de conespecíficos (Artículo enviado)
Conclusiones
Literatura citada
Anexos