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No description available.

Throughout its range of South and Central America, visceral leishmaniasis due to Leishmania chagasi is transmitted by Lutzomyia longipalpis. Recently, a new vector, Lutzomyia evansi, has been discovered transmitting the parasite in the Caribbean Coast of Colombia. Field studies, using both experimental and observational methodologies were employed to elucidate the main ecological and behavioural factors affecting disease transmission in the focus of San Andres de Sotavento, northern Colombia. Nine species of Lutzomyia were present and Lu. evansi constituted 90% of all sandflies caught. Flies were most abundant in April, May June and September. Trapping in and around houses showed Lu. evansi to be endophilic but with exophagic behaviour, preferring houses near to forest edge as resting places. Host preference, measured using a newly designed trap in a rotational experimental design, showed that humans were preferred over dogs or opossums (reservoirs) during the peak abundance of Lu. evansi. This was supported by catches on tethered hosts and bloodmeal analysis although location of capture of resting flies was also a significant factor. Mark-release-recapture studies showed that Lu. evansi can move up to 800m after 5 days and that freshly fed flies move a few hundred metres to resting sites. Basic life history data on Lu. evansi was obtained from laboratory rearing. This species was bred under laboratory conditions though high mortalities were seen in first instars. In adults survival was associated with different types of sugar. Flagellate parasites resembling L. chagasi were found in 3 of 5326 wild caught Lu. evansi (0.05%) however, culturing and subsequent characterization of these isolates failed. Experimental infections with L. chagasi showed that at least one strain of the parasite grew more prolifically in Lu. longipalpis than in Lu. evansi. This, together with a limited vector range compared to the Old World L. infantum is suggested to be the result of a recent parasite-vector association. Morphologically no differences were seen between Colombian, Venezuelan and Costa Rican Lu. evansi populations. Some variation was seen however in one enzyme (6GPDH) of 18 isozymes tested. Mitochondrial DNA variation was seen between Central and South American populations.

No description available.

Lutzomyia longipalpis (Lutz & Neiva) is the vector of Leishmania infantum (Nicolle), the aetiological agent of visceral leishmaniasis in the New World. It has been shown by several authors that Lu. longipalpis represents a complex of at least three species. Adults of this species are known to mediate mating and oviposition using pheromones. This study aimed to investigate an aspect of their behaviour that had previously been neglected, namely the responses of female Lu. longipalpis to human kairomones. It was found that females could be lured by volatiles extracted from skin secretions. Pentane and ether extracts were equally effective in attracting female Lu. longipalpis. Whole pentane extracts were further fractionated by column chromatography into a polar fraction (ether-soluble) and a non-polar fraction (pentane-soluble). Testing both fractions for sandfly activity showed that only the pentane-soluble fraction was attractive to Lu. longipalpis. Host odours not only appeared to explain the variation in attraction of human volunteers, but were also found to be potentially responsible for sandfly biting distributions on a host. Female sandflies exhibited a marked biting preference for the ears of a human volunteer. Cross-mating experiments with putative members of the Lu. longipalpis complex, Jacobina (3-methyl-a-himachelene) and Marajo (Cembrene-producing pheromone type), provided direct evidence of prezygotic isolation between the two studied populations (i. e. by examining insemination rates and pheromone production in FI males). This result explains why two coexisting pheromone types are never detected in single male sandfiies collected in the wild. The cross-mating experiments additionally found partial post-zygotic barriers, with significantly reduced eggs production and egg hatching rates in F1 progeny. A series of independent bioassays provided evidence for innate differences in anthropophily between at least two allopatric populations of Lu. longipalpis. The main behavioural differences detected were in (1) the mean time to bite on a human host during a biting selection trial, (2) the behavioural response to ear washing extracts (landings on impregnated filter papers), and (3) the SAQ (Sandfly Activity Quotient) response (landings) to volatlles deposited onto handled glass Petri dishes (for the two most contrasting sandfly populations: Jacobina and Marajo). Finally, preliminary wind-tunnel studies undertaken with golden hamsters infected with Leishmania infantum suggested a change in the overall body odour composition of the host, making it more attractive to female Lu. longipalpis. Gas chromatography analysis of entrained volatile odours from infected and non-infected hamsters showed a large number of peaks in chromatograms from both animals. A total of 10 extra compounds, eluted from 10 to 16 minutes of retention time, were present in samples from infected hamsters, but were absent in those obtained from non-infected hamsters.

Les phlébotomes sont des insectes hématophages appartenant à la famille des Psychodidae et à la sous-famille des Phlebotominae. Cet insecte diptère, jaunâtre, relativement petit (2 à 3 mm) compte environ 800 espèces. 70 de ces espèces ont été identifiées comme vecteurs potentiels dont une quarantaine sont des vecteurs prouvés. Ils peuvent transmettre différents pathogènes dont les principaux sont les leishmanies et les phlébovirus. Ce travail de thèse est focalisé sur les phlébotomes vecteurs de la leishmaniose. Les leishmanioses sont des maladies parasitaires causées par un protozoaire du genre Leishmania. Elles touchent un large panel d’hôtes vertébrés, dont l’homme et le chien. Elles sont toujours un problème de santé publique majeur dans de nombreux pays et sont actuellement en expansion. Bien que cette maladie soit largement étudiée, nous avons encore beaucoup apprendre sur son vecteur : le phlébotome. Par exemple, l’organisation des populations dans les écosystèmes et les paramètres qui les structurent, sont à l’heure actuelle très peu étudiés. Il est pourtant primordial de bien connaitre la biologie des différents acteurs d’un cycle parasitaire pour mieux comprendre la transmission du pathogène, évaluer les risques et enfin être capable de lutter efficacement contre la maladie. Dans ce contexte, le but de cette thèse est d’étudier l’écologie et la structure des populations de phlébotomes dans un foyer connu de leishmaniose et l’impact des facteurs biotiques et abiotiques sur leur organisation. Pour atteindre cet objectif, nous avons réalisé une collecte de phlébotomes le long d’un transect de 14km localisé dans la région de Montpellier, présentant une diversité altitudinale, climatique et environnementale. Les populations de phlébotomes ont été caractérisées d’un point de vue taxonomique, spatio-temporel, génétique (microsatellites), et morphométrique (géométrie morphométrie). Les résultats génétiques, morphométriques et de distribution des espèces ont été ensuite confrontés à des paramètres climatiques (température, humidité) ou environnementaux (altitude, versant, station, microhabitat).Durant ce travail, 4 espèces ont été capturées : Phlebotomus ariasi (93,23%), P. perniciosus (0,48%), P. mascittii (0,11%) et S. minuta (6,18%). Elles ont une activité saisonnière de Mai à Octobre avec un pic d’abondance en Juillet-Août quand les températures moyennes sont optimales pour les phlébotomes (20-30°C). Bien que l'environnement ait été considérablement transformé dans notre zone d'étude en 30 ans, l'abondance des phlébotomes ne semble pas avoir changé de façon significative, soulignant leur capacité d'adaptation aux modifications de l'écosystème à court et long terme. La présence et l’abondance des deux espèces prédominantes (P. ariasi et S. minuta) sont significativement influencées par l’altitude, la température, l’humidité relative, le versant ainsi que l’orientation des murs. Les analyses génétiques montrent que la diversité est conservée à toutes les échelles d’études et qu’il existe une structuration des phlébotomes en micropopulations. Les données de géométrie morphométrie révèlent un dimorphisme sexuel bien connu chez les insectes mais également une structuration phénotypique en fonction des facteurs environnementaux ou temporels (mois, versant, altitude et station). Ces deux types d’approches permettent grâce à leur complémentarité d’apporter des informations sur l’écologie et l’organisation des populations de phlébotomes et de discuter des conséquences sur la transmission de la leishmaniose. / Sandflies are hematophagous insects belonging to the family Psychodidae and the subfamily phlebotominae. This diptera, yellowish, relatively small (2-3 mm) has about 800 species. 70 of these species have been identified as potential vectors of which forty are proven ones. They can transmit different pathogens; the main ones are Leishmania and phlebovirus.This thesis focused on sandflies, vectors of leishmaniasis. Leishmaniases are parasitic diseases caused by protozoa of the genus Leishmania. They affect a wide range of vertebrate hosts, including humans and dogs. They are still a major problem of public health in many countries and are currently in expansion. Although this disease is widely studied, we still have a lot to learn about its vector: the sandfly. For example, the organization of populations in ecosystems and the parameters which structure them are very little studied up to now. It is therefore essential to know the biology of the different actors of a parasite cycle to better understand the transmission of pathogens, to assess risks of transmission, and finally to be able to effectively fight against the disease.In this context, the aim of this thesis is to study the ecology and the structuring of sandfly populations in a known endemic area of leishmaniasis and the impact of biotic and abiotic factors on their organization. To reach this objective, we performed captures of sandflies along a 14km transect located in the Montpellier region which presents an altitudinal, climate and environmental diversity. Sandfly populations have been characterized by taxonomic, spatio-temporal, genetic (microsatellites) and morphometric (geometry morphometry) approaches. The genetic, morphometric and species distribution results were then confronted with climatic (temperature, relative humidity) or environmental parameters (altitude, slope, station, microhabitat).During this work, four species were captured: Phlebotomus ariasi (93.23%), P. perniciosus (0.48%), P. mascittii (0.11%) and S. minuta (6.18%). They have a seasonal activity from May to October with an abundance peak in July-August when average temperatures are optimal for sandflies (20-30°C). Although the environment has been considerably transformed in our study area in 30 years, the abundance of sandflies does not seem to have changed significantly, highlighting their ability to adapt to ecosystem modifications in short and long-term. The presence and abundance of the two predominant species (P. ariasi and S. minuta) are significantly influenced by altitude, temperature, relative humidity, slope and wall orientation.The genetic analyses show that diversity is maintained at all scales of study and that sandflies are organized in micropopulations. The morphometric geometry data reveal a sexual dimorphism, well known in insects but also a phenotypic structuring correlated to environmental or temporal factors (month, slope, altitude and station).Both of these approaches, because of their complementarity, help provide information on the ecology and organization of sandfly populations and to discuss about the consequences in terms of leishmaniasis transmission.

Les insectes hématophages impactent sur la santé humaine et animale par la nuisance et l’allergie induite par la piqûre ou par leur risque de transmission d’agents pathogènes. Les étudier permet de mieux prévenir, gérer ou traiter l’ensemble des pathologies induites. Au cours de cette thèse, nous avons étudié deux insectes que sont la punaise de lit et le phlébotome.- Pour les punaises de lit une revue de la littérature sur les méthodes d'élevage a été rédigée. Nous avons déterminé deux aspects que sont les facteurs physiques (température, humidité relative, photopériode) et physiologiques (type, fréquence des repas) à prendre en considération. Un travail de terrain de recueil de spécimens a permis d’étudier la génétique des spécimens par localités et d’évaluer le portage de pathogènes notamment la bactérie Wolbachia sp.- Pour le phlébotome, un élevage de l’espèce Phlebotomus perniciosus a été mis en place permettant d'évaluer deux modèles infectieux expérimentaux à Leishmania infantum sur souris BALB/c et sur gorgeur artificiel. Des captures de terrain ont été réalisées et une étude de la génétique de population de Phlebotomus ariasi a été publiée. Une revue de la littérature sur les principaux événements historiques et évolutifs des Leishmanies, des phlébotomes et des réservoirs animaux associés a été publiée.- Dans le cadre de cette thèse nous avons collaboré à un nouveau mode d’identification des diptères hématophages (dépôt d’un brevet).- Au cours de ces 3 années de thèse, nos activités entomologiques hospitalières ont permis la description de cas entomologiques originaux.Cette thèse a fait l'objet d'une bourse CIFRE financée par les Laboratoires VIRBAC. / Bloodsucking insects have an impact on the human and animal health particularly for the risk of pathogens transmission and the nuisance caused by their bite. To have knowledge on these insects can help and apply to prevent, manage or treat the diseases. In this thesis, we mainly focused on two insects: bedbugs and sandflies.- For bedbug, a literature review was carried out to classify the published data demonstrating preferred bedbug colony conditions. We showed that physical factors (temperature, relative humidity, photoperiod), and physiological factors (type, frequency of blood meals) play important roles in the laboratory colonies. A huge number of Cimex lectularius species was sampled from infested regions to study the spatial genetic structure and restricted gene flow in bed bugs in France and to evaluate the symbiotic flora including Wolbachia bacteria.- For sandfly, Phlebotomus perniciosus species was colonized for experimental infections by Leishmania infantum using murine model and artificial feeder. A local sandfly sampling was carried out in the rural regions of Nice city and were served in a study targeting the genetic population structure of Phlebotomus ariasi. Moreover, a historical study was conducted on the classification, evolution and dispersion of Leishmania parasites, sandflies and animals reservoirs.- A new identification method of bloodsucking Diptera was invented (submitted patent).- Thanks to the hospital-entomological activities, an original case report of phthiriasis on an old person was reported.- During this thesis with a scholarship CIFRE funded by Virbac Laboratories, I succeeded tosubmit and publish 7 articles and 1 patent.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-09-13T13:48:58Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) amanda_oliveira_baracho.pdf: 1018229 bytes, checksum: 7da405c92d90a6056df94d878fc77113 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-02T16:26:57Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) amanda_oliveira_baracho.pdf: 1018229 bytes, checksum: 7da405c92d90a6056df94d878fc77113 (MD5) / Made available in DSpace on 2018-10-02T16:27:10Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) amanda_oliveira_baracho.pdf: 1018229 bytes, checksum: 7da405c92d90a6056df94d878fc77113 (MD5) Previous issue date: 2018 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / A leishmaniose visceral ? uma doen?a parasit?ria de transmiss?o vetorial causada por protozo?rios do g?nero Leishmania, com elevado grau de letalidade e que atinge milh?es de pessoas no mundo. A busca por produtos alternativos para a elimina??o do vetor tem como objetivo minimizar os impactos causados pelos inseticidas qu?micos sint?ticos utilizados pelos programas de controle, sendo cada vez mais frequente a pesquisa em produtos de origem bot?nica com atividade inseticida. Organismos vegetais s?o capazes de produzir compostos org?nicos de comprovada toxicidade frente aos insetos e, diante disto, avaliou-se neste trabalho a atividade inseticida de extratos de Caryocar brasiliense, planta nativa do Cerrado popularmente conhecida como ?pequi?, sobre flebotom?neos da esp?cie Lutzomyia longipalpis, principal transmissora da leishmaniose visceral. Extratos hidroetan?licos, etan?licos e ciclohex?nicos de folhas e cascas de C. brasiliense foram preparados e dilu?dos em solu??o de Tween 80 a 3% para a obten??o de concentra??es a 50, 100, 200 e 400 mg.mL-1, para a realiza??o dos ensaios biol?gicos. Os flebotom?neos foram coletados em uma localidade rural do munic?pio de Diamantina/MG. Um n?mero amostral de 30 flebotom?neos foi posto em contato com os extratos e a mortalidade foi avaliada ap?s 1, 2, 4, 16, 24 48 e 72 horas de exposi??o, bem como grupos controle negativos (?gua destilada e Tween) e positivo (cipermetrina). A identifica??o dos constituintes qu?micos dos extratos tamb?m foi avaliada. Ap?s 72h de experimento, foram registradas mortalidades de 93,3% pelo extrato hidroetan?lico da casca a 400 mg.mL-1, 66,3% pelo etan?lico da casca a 50 mg.mL-1 e 81,1% pelo ciclohex?nico de folhas a 200 mg.mL-1. Os extratos hidroetan?licos da casca mostraram-se estatisticamente semelhantes ? a??o da cipermetrina em 72h de experimento, indicando que este extrato foi o mais eficiente quanto ? atividade inseticida. Foram identificados triterpenos, esteroides, taninos, flavonoides, alcaloides e saponinas nos extratos. Os resultados obtidos sugerem que os extratos hidroetan?licos de C. brasiliense, sobretudo das cascas, s?o promissores na busca por compostos naturais com atividade inseticida sobre Lu. longipalpis. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biologia Animal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018. / Visceral leishmaniasis is a vector-borne disease caused by a protozoan of the genus Leishmania with high lethality rate that reaches millions of people worldwide. The impacts caused by synthetic insecticides used in control programs are well known. In this context, research on alternative products for vector control, especially products of botanical origin, has been frequent in order to minimize the impacts of synthetic ones. Plants are capable to produce organic compounds with insect toxicity. Here, the insecticidal activity of Caryocar brasiliense extracts, a native plant of Brazilian savannah, popularly known as "pequi", on Lutzomyia longipalpis, the main vector of visceral leishmaniasis, was tested. Hydroethanolic, ethanolic and cyclohexanic extracts of leaves and barks of C. brasiliense were prepared and diluted in Tween 80 (3%) to obtain concentrations of 50, 100, 200 and 400 mg.mL-1 for the biological tests. Phlebotomine sandflies were collected in a rural locality of Diamantina (Minas Gerais state, Brazil). Thirty sand flies were exposed to the extracts and mortality was evaluated after 1, 2, 4, 16, 24 48 and 72 hours of exposure, as well as negative control groups (distilled water and Tween) and positive (cypermethrin). Chemical compounds of the extracts were also evaluated. Mortalities rates of 93.3% were observed for the hydroethanolic extract of the bark at 400 mg.mL-1, 66.3% for the ethanolic bark at 50 mg.mL-1 and 81.1% for the cyclohexane of leaves at 200 mg.mL-1. The hydroethanolic extracts of the bark showed to be statistically similar to the action of cypermethrin in 72h of the experiment, indicating that this extract was the most efficient as an insecticide. Triterpenes, steroids, tannins, flavonoids, alkaloids and saponins were identified in the extracts. The results obtained suggest that the hydroethanolic extracts of C. brasiliense, especially of the bark, are promising for the use of natural compounds to control Lu. longipalpis.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-06-09T12:16:08Z No. of bitstreams: 1 Debora Elienai de Oliveira Miranda.pdf: 1609187 bytes, checksum: aae427fd4f090fe99e6a29edda199af1 (MD5) / Made available in DSpace on 2016-06-09T12:16:08Z (GMT). No. of bitstreams: 1 Debora Elienai de Oliveira Miranda.pdf: 1609187 bytes, checksum: aae427fd4f090fe99e6a29edda199af1 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Sand flies belonging to the genus Lutzomyia (Diptera: Psychodidae) are spread over several zoogeographic regions of the world, being represented by several species found in greater abundance in tropical and subtropical regions. These flies have great relevance to public health, because they are involved in the transmission of the causative agents of American cutaneous leishmaniasis (ACL) and visceral leishmaniasis (VL), which are among the most important tropical diseases in Brazil and in many countries worldwide. This study aimed to study the ecology of sandflies in an endemic rural area for American cutaneous leishmaniasis in the state of Pernambuco Sandfly collections were conducted from August 2013 to August 2014, with CDC light traps, type on a monthly basis for three consecutive nights, from 5:00 pm to 6:00 am totaling seven traps. Each trap was placed at 1.5m, being installed in three different environments: indoors, outside the home and kills. The capture sites were selected near dens of wild animals, large tree trunks, in shaded and humid places. The specimens captured were examined, separated according to sex and kept in 70% ethanol. Collected sand flies were identified based on morphology and females of Lutzomyia whitmani (n = 169), Lutzomyia amazonensis (n = 134) and Lutzomyia complexa (n = 21) were selected and evaluated by PCR for the presence of Leishmania (Viannia) spp. In total, 5,167 sand flies belonging to 19 species were identified, being that Lutzomyia choti (43.2%) was the most frequent species, followed by Lu. amazonensis (16.6%), Lu. whitmani (15.8%), Lutzomyia sordellii (10.7%) and Lutzomyia quinquefer (5.8%), which together represented over 90% of the collected sand flies. Females assessed by PCR were negative for Leishmania (Viannia) spp. The study showed that there is an important variety of species in the above area, although some of these species are associated with human cases reported of ACL. The meeting of the species Lu. whitmani proven vector of cutaneous leishmaniasis in several Brazilian regions, may suggest their participation in the ACL in Ipojuca. / Os flebotomíneos pertencentes ao gênero Lutzomyia (Diptera: Psychodidae) estão distribuídos por diversas regiões zoogeográficas do mundo, sendo representados por várias espécies encontradas em maior abundância, nas regiões tropicais e subtropicais. Estes dípteros apresentam grande relevância na saúde pública, porque estão envolvidos na transmissão dos agentes causadores da leishmaniose tegumentar americana (LTA) e leishmaniose visceral (LV), as quais estão entre as doenças tropicais de maior importância no Brasil e em muitos países do mundo. O presente estudo teve como objetivo estudar a ecologia de flebotomíneos em uma área rural endêmica para leishmaniose tegumentar americana no estado de Pernambuco. As coletas de flebotomíneos foram realizadas no período de agosto de 2013 a agosto de 2014, com armadilhas luminosas do tipo CDC, mensalmente, durante três noites consecutivas, das 17:00 horas às 6:00 horas, totalizando sete armadilhas. Cada armadilha foi posicionada a 1,5m do solo, sendo instalada em três diferentes ambientes: intradomicílio, peridomicílio e mata. Os locais de captura foram selecionados próximos a tocas de animais silvestres, troncos de árvores de grande porte, em locais sombreados e úmidos. Os exemplares capturados foram examinados, separados de acordo com sexo e mantidos em etanol 70%. Os flebotomíneos coletados foram identificados com base na morfologia e fêmeas de Lutzomyia whitmani (n = 169), Lutzomyia amazonensis (n = 134) e Lutzomyia complexa (n = 21) foram selecionadas e avaliadas por PCR para a presença de Leishmania (Viannia) spp. No total, foram identificados 5.167 espécimes de flebotomíneos de 19 espécies, sendo que Lutzomyia choti (43,2%) foi a espécie mais frequente, seguido por Lu. amazonensis (16,6%), Lu. whitmani (15,8%), Lutzomyia sordellii (10,7%) e Lutzomyia quinquefer (5,8%), que juntos representaram mais de 90% dos flebotomíneos coletados. As fêmeas avaliadas por PCR foram negativas para Leishmania (Viannia) spp. O estudo demonstrou que há uma variedade importante de espécies na área supracitada, podendo algumas dessas espécies estarem associadas a casos humanos notificados de LTA. O encontro da espécie Lu. whitmani, comprovadamente vetora de leishmaniose tegumentar em diversas regiões brasileiras, pode sugerir sua participação na transmissão de LTA em Ipojuca.