Made available in DSpace on 2015-05-07T14:49:23Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2716493 bytes, checksum: 45124bd2a0783bf2deef175a9d510b95 (MD5) Previous issue date: 2012-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Artificial chemical larvicides are a commonly used solution to control larvae of mosquitoes. However, these substances can have health and environmental impacts. We tested the efficacy of two biological methods to control mosquitoes larvae, the copepod (Mesocyclops oggunus) and entomotoxic bacteria Bacillus thuringiensis var, israelensis (Bti). These biological agents were used in isolation and consociated. We also interview endemic control agents that work with Aedes aegpty control in the city of João Pessoa-PB in order to access their perceptions about the uses of biological control against mosquito larvae. We found that the consociation between M. oggunus and Bti is more effective that each method in isolation to control larvae of A. albopictus (a species with similar biology with A. aegpity). Consequently the consociation between copepods and Bti represent a low operational cost and low environmental impact alternative to chemical larvicides in order to control mosquito larvae. Our interviews with endemic control agents involved with Aedes control showed that more efforts are need to inform them about the consequences and precautions associated to the use of chemical larvicides. / Larvicidas químicos artificiais são uma solução comumente utilizada para controlar as larvas de mosquitos. No entanto, essas substâncias podem causar impactos na saúde e no meio ambiente. Testamos a eficácia de dois controladores biológicos para controlar larvas de mosquitos, o copépodo (Mesocyclops ogunnus) e a bactéria entomotóxica Bacillus thuringiensis var. israelensis (Bti). Esses agentes biológicos foram utilizados isoladamente e em consorciação. Foram também realizadas entrevistas com os agentes de controle de endemias que trabalham no controle do Aedes aegypti na cidade de João Pessoa PB a fim de saber suas percepções sobre o uso de controladores biológicos no controle de larvas de mosquitos. Verificamos que a consorciação entre M. ogunnus e o Bti é mais eficaz do que a utilização dessas ferramentas isoladamente para controlar larvas de A. albopictus (uma espécie com a biologia semelhante ao A. aegypti). Dessa forma, a consorciação de copépodos com Bti representa uma alternativa de baixo custo operacional e baixo impacto ambiental a utilização de larvicidas químicos no controle de larvas de mosquitos. As entrevistas com agentes de controle de endemias mostraram que são necessários mais esforços para informá-los sobre as consequências e as precauções associadas ao uso de larvicidas químicos.

Le moustigre tigre Aedes albopictus, un des vecteurs de la Dengue et du Chikungunya, est une espèce invasive qui a colonisé le monde entier en 30 ans à partir de son berceau asiatique. Les éventuelles bases génétiques de ce succès sont inconnues. Afin d’étudier l’ampleur de la différenciation génétique entre populations asiatiques et européennes et la part prise par la sélection naturelle dans cette différenciation, nous avons développé de nouveaux marqueurs génétiques reposant sur le polymorphisme d’insertion des éléments transposables. Pour cela, nous avons dans un premier temps conçu un outil bioinformatique –dnaPipeTE— nous permettant de dresser le portrait de la fraction répétée du génome d’Ae. albopictus à partir d’une faible proportion des lectures brutes issues d’un projet de séquençage en cours. Le polymorphisme d’insertion de cinq des familles d’ET décrites a ensuite été étudié par la technique de transposon display couplée à du séquençage Illumina, chez 140 individus issus de trois populations vietnamiennes et cinq populations européennes. L’immense majorité des 128 000 marqueurs analysés montre une différenciation génétique très faible entre Europe et Asie. Nous avons néanmoins pu mettre en évidence un centaine d’insertions ayant des fréquences extrêmement différentes entre ces continents. La majorité d’entre elles ségrège à forte fréquence en Europe, suggérant une adaptation du moustique à son environnement tempéré / The Asian tiger mosquito, one of the main vectors of Dengue and Chikungunya, is an invasive species that colonized the world during the last 30 years from its cradle in Asia. Whether this success has an underlying genetic basis remains to be investigated. In order to study the extent of the genetic differentiation between Asian and European populations and the contribution of natural selection to this differentiation, we developed new genetic markers based on transposable elements insertion polymorphism. We first conceived a bioinformatic pipeline –dnaPipeTE— that allowed to grasp a comprehensive picture of the repetitive fraction of the Tiger’s genome through the analysis of a low proportion of raw reads from a ongoing sequencing project. The insertion polymorphism of five transposable element families was then studied by Illumina based transposon display, in 140 individuals from three Vietnamese populations and five European populations. The vast majority of the 128,000 markers showed a very low genetic differentiation between Europe and Asia. However 92 of them displayed extreme frequency differences between the continents. The majority of them segregate at high frequencies in Europe, a pattern suggestive of adaptive evolution towards temperate environments

Les femelles moustiques peuvent être vectrices de nombreux agents infectieux (virus, protozoaires, helminthes) pour l'Homme, qui peuvent être la cause de maladies graves comme le paludisme et la dengue. Ces maladies menacent respectivement 50 et 40% de la population mondiale ; le paludisme étant responsable de près d'un million de décès par an. Les méthodes de lutte anti-vectorielle destinées à limiter les populations vectrices et stopper la transmission de maladies, se heurtent au développement incessant de résistances de la part des moustiques et des agents infectieux vis-à-vis des traitements employés. Bien que certaines régions du monde aient réussi à stopper efficacement la transmission de certaines de ces maladies, une grande partie des régions tropicales reste menacée. De plus l'expansion rapide de certaines espèces vectrices, telles qu'Aedes albopictus, accroît les risques sanitaires dans de nouvelles régions du globe. La technique de l'insecte stérile (TIS), qui a permis l'éradication ou la suppression des populations de nombreux insectes nuisibles aux cultures et à l'Homme, représente un moyen de lutte prometteur contre les moustiques. Cette technique s'appuie sur le lâcher en masse de mâles stérilisés par rayonnements ionisants qui, en transférant un sperme stérile aux femelles sauvages, vont permettre une diminution progressive de la population cible. Suite à l'épidémie de chikungunya à l'île de la Réunion en 2005 et face aux menaces permanentes de recrudescence de la dengue et du paludisme, les services de lutte anti-vectorielle réunionnais mettent en place d'importants moyens de lutte contre les populations de moustiques concernées. Toutefois, ces mesures ne permettant pas une diminution durable des densités de vecteurs, une étude de faisabilité est en cours quant à l'utilisation de la TIS pour diminuer et contrôler les populations d’Aedes albopictus, vecteur de la dengue et du chikungunya, et d’Anopheles arabiensis, vecteur du paludisme.Ce travail de thèse s'inscrit dans le cadre du projet TIS Réunion, dans le but d'étudier la biologie et le comportement des souches destinées aux lâchers de mâles stériles. Dans un premier temps, cette étude s'intéresse à la comparaison entre les souches d'élevage d’Anopheles arabiensis et les souches sauvages, ainsi qu'aux modalités de stérilisation des mâles de la souche à sexage génétique. Une seconde partie est consacrée à l'étude de l'effet de l'irradiation sur les mâles d’Aedes albopictus, en étudiant plus particulièrement leur stratégie de reproduction, leur capacité d'insémination en laboratoire, ainsi que leur compétitivité sexuelle et longévité face aux mâles sauvages en conditions semi-contrôlées. / Mosquito females are potential vectors of numerous pathogens (viruses, protozoa, helminths), which can cause serious diseases such as malaria and dengue in humans. These two infectious diseases are threatening 50 and 40% of the world population respectively. Malaria is responsible for nearly one million deaths per year, and is considered by many experts as the most important insect-transmitted disease. Antivectorial control methods, intended to limit the vector populations and to stop the disease transmission have to face many challenges such as the development of mosquitoes' and pathogens' resistance to the treatments employed to control them. Although various regions of the world have succeeded in efficiently stopping the transmission of some diseases, most of the tropical regions remain under threat. In addition, the rapid expansion of some vector species, such as Aedes albopictus, increases the risks in previously safe areas of the world. The sterile insect technique (SIT) has allowed the eradication or suppression of various insect pest populations threatening crops, animal, and human health, and could offer a promising control tool against mosquitoes. The classical SIT relies on the mass releases of males sterilized by ionizing radiation;they transfer sterile sperm to wild females, which results in a progressive reduction of the target population.Following the chikungunya outbreak in Reunion Island in 2005 and considering the constant threat of arecrudescence of dengue and malaria, the anti-vectorial services in Reunion Island are deploying important means to control the relevant mosquito populations. However, these measures do not confer a permanent, or long-lasting reduction of vector densities. A feasibility study is ongoing, evaluating the use of the SIT to diminish and control the populations of Ae. albopictus, a vector of dengue and chikungunya, and Anopheles arabiensis, a vector of malaria. This PhD work was developed in the context of the SIT Reunion project, with the aim of studying the biology and the behaviour of some strains intended for the sterile male releases. Firstly, this study endeavours to compare colonized and wild strains of An. arabiensis, and to determine the sterilisation procedures of the genetic sexing strain males. The second part of this work studies the effect of irradiation on male Ae. albopictus, and most notably their reproductive strategy, the insemination capacity in laboratory, and finally their sexual competitiveness and longevity against wild males under semi-field conditions.

Originaire d'Asie du Sud et de l'Est, le moustique tigre Aedes albopictus est aujourd'hui implanté sur 5 des 6 continents et les moyens de lutte mis en place pour l'éliminer peinent à freiner son expansion. Ces dernières années, l'étude des communautés microbiennes associées aux insectes a permis de démontrer leur implication dans des fonctions clefs de la biologie de leurs hôtes (nutrition, immunité, résistance aux stress biotiques et abiotiques …). Ensemble, ils constituent un super-organisme appelé holobionte. Ainsi, une meilleure connaissance de l'écologie microbienne d'Ae. albopictus pourrait nous apporter de nouvelles perspectives dans la compréhension du fonctionnement du pathosystème vectoriel. C'est dans ce contexte que s'est inscrit mon projet de thèse qui a consisté à décrire le microbiote bactérien du moustique tigre en lien avec son écologie et la génétique de ses populations. Nos travaux se sont tout d'abord portés sur des exemples précis d'interactions avec des symbiotes d'intérêts puis nous avons élargi cette étude à l'ensemble des communautés bactériennes et leurs facteurs de variation, en bénéficiant du développement des nouvelles technologies de séquençage. Les résultats obtenus ouvrent la voie vers de nouvelles hypothèses sur le fonctionnement et la dynamique de l'holobionte moustique avec la prise en compte des interactions symbiotiques comme un élément majeur du pathosystème vectoriel / Originated from South East Asia, the Asian tiger mosquito Aedes albopictus is now established on 5 of the 6 continents. Control strategies to limit its introduction and expansion remain restricted. Those last years, studies on insect microbial communities highlighted the key role of symbionts in the biology of their hosts (nutrition, immunity, resistance to biotic and abiotic stresses…). Together, they constitute a super-organism called the holobiont. Therefore, a better knowledge of microbial ecology of Ae. Albopictus should increase the understanding of vectorial pathosystem. In this context, my thesis project consisted to improve the description of bacterial microbiota associated with the Asian tiger mosquito in relation with its ecology and population genetics. We first based our attention on specific models of symbiotic interactions and then we extended our study to the whole bacterial community and its variation factors using high throughput sequencing technologies. Our results open the way to new hypotheses about the function and dynamics of mosquito holobionte taking into account the symbiotic interactions as a major component of the vectorial pathosystem

No presente trabalho procura-se caracterizar biológica e ecologicamente o Aedes albopictus (Skuse) (Diptera: Culicidae) no seu mais recente ambiente geográfico, isto é, nas Américas. São descritos aspectos relacionados com a chegada e dispersão da espécie no Continente Americano. Paralelamente, são discutidos aspectos relativos ao comportamento, biologia, bionomia, ecologia, hematofagia, interação com outras espécies do gênero Aedes, bem como a importância epidemiológica do Ae. albopictus. Esses aspectos foram descritos, por serem considerados importantes pela influência que exercem na competência vetora da espécie, bem como na sua adaptação ao ambiente antrópico. Ressaltando a importância epidemiológica deste vetor para a espécie humana, citam-se dados referentes à potencialidade do Ae. albopictus participar na transmissão de arboviroses. Assim, procura-se caracterizar a importância da possível participação do Ae. albopictus na veiculação do vírus dengue, febre amarela, bem como outros arbovírus que afetam o ser humano nas Américas. Paralelamente, discute-se a possibilidade do Ae. albopictus atuar como vetor da Dirofilaria immitis (Leidy) ao homem. / In the present work, biological and ecological features of Aedes albopictus (Skuse) (Diptera: Culicidae) are discussed based on literature records. The main focus of this study is the epidemiological importance of the presence of this species in Americas. Aspects relative to colonization and dispersion of Ae. albopictus in Americas are discussed. Dispersion, ethology, biology, ecology, haematophagy, bionomics as well as epidemiological importance, and relationships among Ae. albopictus and other members of the genus Aedes are discussed. These aspects are included because of their influence in the vector competence of Ae. albopictus, and also in its adaptation to the human environment. Because of the epidemiological importance of Ae. albopictus to humans, data relative to the potentiality of this species to participate in the transmission of arboviruses are discussed. In this sense, the importance of Ae. albopictus as vector of dengue, yellow fever, and other arboviruses that cause human diseases is described. Besides, it is discussed the potentiality of Ae. albopictus to act as a vector of Dirofilaria immitis (Leidy) to humans.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-06-27T15:06:48Z No. of bitstreams: 1 texto completo.pdf: 717860 bytes, checksum: d71c1053a82b292b3ab10f06c3e68ce6 (MD5) / Made available in DSpace on 2016-06-27T15:06:48Z (GMT). No. of bitstreams: 1 texto completo.pdf: 717860 bytes, checksum: d71c1053a82b292b3ab10f06c3e68ce6 (MD5) Previous issue date: 2004-04-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A avaliação de viabilidade de uso da técnica de immuno-dot blot para a detecção do vírus da dengue em homogenatos de larvas e de mosquitos Aedes aegypti e larvas de Aedes albopictus foi realizada utilizando-se soros humanos reativos para dengue e soros policlonais antidengue, produzidos em coelhos da raça Nova Zelândia imunizados com suspensões de vírus DEN-1 (Havaí) e DEN-2 (Nova Guiné) purificados e emulsificadas em adjuvante incompleto de Freund. Os resultados demonstraram que a técnica apresenta sensibilidade adequada para a detecção do vírus da dengue em homogenatos de larvas e de mosquitos A. aegypti e larvas de A. albopictus ainda que os títulos dos anti- soros sejam baixos. A presença do vírus foi detectada em larvas do mosquito A. albopictus, o que pode contribuir para o monitoramento do vírus mesmo na ausência de surtos da doença. Pode, inclusive, contribuir para estudos epidemiológicos mais amplos desse vírus por fornecer ferramenta para esses estudos. / The immuno-dot blot technique was tested and standardized for detection of dengue viruses in Aedes aegypti and Aedes albopictus larvae and mosquitoes homogenates. The experiments were carried out with dengue-reactive human sera and with anti-dengue polyclonal antisera prepared in New Zealand male rabbits immunized with DEN-1 (Hawai) and DEN-2 (New Guinea) purified virus suspensions emulsified in Freund incomplete adjuvant. Results showed that the virus can be easily detected by immuno-dot blot in A. aegypti and A. albopictus larvae and mosquitoes homogenates and suggest that this technique, for its simple procedure and easy reading, could be useful for field virus detection. Although it was recently established that these viruses can multiply in A. albopictus larvae, it is not known whether A. albopictus can indeed vector the DEN-1 and DEN-2 viruses in Brazil and, if so, under what percentages, relatively to A. aegypti mosquitoes. This study provides a tool for broader epidemiological studies of these viruses. / Dissertação antiga

Made available in DSpace on 2014-12-17T14:13:44Z (GMT). No. of bitstreams: 1 ArlineteSM_Dissert.pdf: 1812083 bytes, checksum: 376b552fc90bb11b8b551d6db7f2d45f (MD5) Previous issue date: 2009-08-26 / Desenvolvido no Parque das Dunas, segunda reserva ambiental urbana do Brasil, ocupando uma ?rea de 1.172,80 hectares, com caracter?stica de mata atl?ntica de dunas, situada numa faixa litor?nea na regi?o urbana do munic?pio de Natal (05? 46 S, 35? 12 W), o presente estudo, realizado durante os anos de 2004 a 2006, teve como objetivo identificar as esp?cies de culic?deos existentes no Parque das Dunas, capazes de transmitir arbov?rus, tendo em vista que em 2004 houve uma epizootia de saguis (Callitrix jacchus), que causou grande mortandade, sem defini??o do agente etiol?gico. No ano de 2004, foram pesquisados sete pontos no interior da mata, com instala??o de 20 armadilhas de ovitrampas e 20 de bambu para coleta dos imaturos. Para os adultos, durante quatro vezes por semana, foram usadas as armadilhas de Sannhon. Foram coletados 5.691 imaturos, sendo 839 Ae. aegypti, 3.184 Ae. albopictus e 1.668 Hg. leucocelaenus. A coleta dos adultos foi realizada de 2004 a 2006, etapa em que se recolheu 17.506 culic?deos adultos, sendo 17.244 Wy. bourrouli, 255 Ae. aegypti, 593 Ae. albopictus, 1.275 Hg. leucocelaenus, 294 Oc. scapularis, 05 Oc. taeniorynchus, 02 Oc. serratus e 3 Li. durhami. Para os imaturos houve correla??o significativa entre Ae. aegypti e umidade relativa do ar p = 0, 049 e pluviometria p = 0,00, Ae. albopictus apresentou correla??o significativa positiva com a pluviometria, enquanto Hg. leucocelaenus n?o apresentou nenhuma das vari?veis clim?ticas. Para os adultos, a an?lise de s?rie temporal aponta flutua??o sazonal significativa para Ae. aegypti (p = 0,003); Ae. albopictus (p = 0,04); Oc. scapularis (p = 0,008 ) e Hg. leucocelaenus (p = 0,003). Uma correla??o significativa negativa foi observada entre o n?mero de Ae. albopictus coletado e a temperatura (Corr= - 0,50, p = 0,01); isto ?, para cada 1?C a mais h? diminui??o de 7 esp?cimes. Este estudo teve a participa??o de uma equipe multidisciplinar: bi?logos, entomologistas, para confirma??o das esp?cies; t?cnicos de laborat?rio, para acompanhamento di?rio das larvas eclodidas das armadilhas de ovitrampas. Teve a importante colabora??o de profissionais da Funda??o Oswaldo Cruz FIOCRUZ/Rio de Janeiro, da Universidade de S?o Paulo USP para identifica??o do grupo Wyeomyia.

No presente trabalho procura-se caracterizar biológica e ecologicamente o Aedes albopictus (Skuse) (Diptera: Culicidae) no seu mais recente ambiente geográfico, isto é, nas Américas. São descritos aspectos relacionados com a chegada e dispersão da espécie no Continente Americano. Paralelamente, são discutidos aspectos relativos ao comportamento, biologia, bionomia, ecologia, hematofagia, interação com outras espécies do gênero Aedes, bem como a importância epidemiológica do Ae. albopictus. Esses aspectos foram descritos, por serem considerados importantes pela influência que exercem na competência vetora da espécie, bem como na sua adaptação ao ambiente antrópico. Ressaltando a importância epidemiológica deste vetor para a espécie humana, citam-se dados referentes à potencialidade do Ae. albopictus participar na transmissão de arboviroses. Assim, procura-se caracterizar a importância da possível participação do Ae. albopictus na veiculação do vírus dengue, febre amarela, bem como outros arbovírus que afetam o ser humano nas Américas. Paralelamente, discute-se a possibilidade do Ae. albopictus atuar como vetor da Dirofilaria immitis (Leidy) ao homem. / In the present work, biological and ecological features of Aedes albopictus (Skuse) (Diptera: Culicidae) are discussed based on literature records. The main focus of this study is the epidemiological importance of the presence of this species in Americas. Aspects relative to colonization and dispersion of Ae. albopictus in Americas are discussed. Dispersion, ethology, biology, ecology, haematophagy, bionomics as well as epidemiological importance, and relationships among Ae. albopictus and other members of the genus Aedes are discussed. These aspects are included because of their influence in the vector competence of Ae. albopictus, and also in its adaptation to the human environment. Because of the epidemiological importance of Ae. albopictus to humans, data relative to the potentiality of this species to participate in the transmission of arboviruses are discussed. In this sense, the importance of Ae. albopictus as vector of dengue, yellow fever, and other arboviruses that cause human diseases is described. Besides, it is discussed the potentiality of Ae. albopictus to act as a vector of Dirofilaria immitis (Leidy) to humans.

Le virus chikungunya (CHIKV), transmis par les moustiques Aedes aegypti et Aedes albopictus, constitue un problème majeur de santé publique. Depuis 2004, des épidémies de CHIKV ont été rapportées en Afrique, en Asie, dans les îles de l'Océan Indien, et en Europe. Seule l'Amérique semblait épargnée malgré la présence de fortes densités de moustiques vecteurs et de multiples importations du virus dans le continent par des voyageurs de retour de pays où le virus circulait. Nous avons abordé dans cette thèse le risque d'émergence du CHIKV en Amérique à partir d'une évaluation de la compétence vectorielle de 35 populations d'Ae. aegypti et Ae. albopictus locaux avec différentes souches de CHIKV. Ces populations sont compétentes vis-à-vis du CHIKV avec un rôle des glandes salivaires comme "filtre" de la transmission. De plus, le génotypage des Ae. albopictus d'Amérique par microsatellites a permis d'identifier un cluster génétique de populations se caractérisant par une faible transmission des souches de CHIKV de génotype Est-Centre-Sud-africain. En octobre 2013, des souches asiatiques de CHIKV ont été signalées dans la Caraïbe. Nous avons alors évalué la réceptivité de 11 populations d'Ae. aegypti et Ae. albopictus d'Amérique vis-à-vis de CHIKV de génotype asiatique et avons mis en évidence que les deux espèces étaient compétents pour assurer la diffusion du virus sur le continent. On note aussi qu'Ae. albopictus peut faciliter la propagation du CHIKV vers l'Europe. Néanmoins, la compétence vectorielle d'Ae. albopictus de France vis-à-vis de CHIKV asiatique est affectée négativement par des températures plus basses que celles habituellement observées dans les pays tropicaux. / Chikungunya virus (CHIKV), transmitted mainly by the mosquitoes Aedes aegypti and Aedes albopictus, is a major public health problem. Since 2004, CHIKV epidemics have been reported in Africa, Asia, the Indian Ocean Islands, and Europe. Only the Americas seemed spared despite high densities of mosquitoes and multiple introductions of the virus to the continent by travelers returning from countries where CHIKV was circulating. We have assessed the risk of CHIKV emergence in the Americas by evaluating the vector competence of 35 local populations of Ae. aegypti and Ae. albopictus infected with different strains of CHIKV. These populations were shown to be susceptible to CHIKV infection, highlighting the predominant role of salivary glands as a "filter" of transmission. Genotyping of Ae. albopictus from the Americas using microsatellites allowed the identification of a genetic cluster of populations characterized by a low transmission of CHIKV strains of the East-Central-South-African genotype. In October 2013, Asian strains of CHIKV began circulating in the Caribbean. Thus, we evaluated the susceptibility of 11 populations of Ae. aegypti and Ae. albopictus to the Asian CHIKV genotype and showed that the two species were sufficiently competent to ensure dissemination of the virus throughout the continent. Furthermore, we showed that Ae. albopictus was likely to facilitate the spread of CHIKV to Europe. However, the vector competence of French Ae. albopictus to the Asian CHIKV genotype was negatively affected by temperatures lower than those usually found in tropical countries.

No description available.