Triatoma infestans e Triatoma brasiliensis: avaliação da resistência ao piretróide deltametrina e análise intraespecífica da variabilidade genética

Submitted by Nuzia Santos ([email protected]) on 2017-08-30T17:14:52Z No. of bitstreams: 1 Ivan Vieira Sonoda .pdf: 1065358 bytes, checksum: d25ad642f0b5ec9ef4eca1b0812fa587 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2017-08-30T17:19:45Z (GMT) No. of bitstreams: 1 Ivan Vieira Sonoda .pdf: 1065358 bytes, checksum: d25ad642f0b5ec9ef4eca1b0812fa587 (MD5)Made available in DSpace on 2017-08-30T17:19:45Z (GMT). No. of bitstreams: 1 Ivan Vieira Sonoda .pdf: 1065358 bytes, checksum: d25ad642f0b5ec9ef4eca1b0812fa587 (MD5) Previous issue date: 2009FapemigFiocruzFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.O Programa de Controle da Doença de Chagas (PCDCh) teve suas atividades iniciadas por volta da década de 1960 em âmbito nacional. Em 1991, com a Iniciativa dos Países do Cone Sul, o PCDCh passou a priorizar as áreas de ocorrência do Triatoma infestans , enquanto a vigilância epidemiológica era implantada nas áreas já s ob controle da transmissão vetorial. A utilização de inseticidas piretróides nas atividades de controle permitiram ao PCDCh obter resultados satisfatórios, como a interr upção da transmissão vetorial da doença de Chagas em amplas áreas. A preocupação atual refere-se á possibilidade de desenvolvimento de resistência aos insetici das utilizados devido à existência de uma região abrangendo o norte da Argentina e o sul da Bolívia onde T. infestans apresenta-se resistente aos piretróides. Al ém disso, outras espécies de triatomíneos já foram descritas com resistência inicial a estes inseticidas (ex. Rhodnius prolixus na Venezuela e Triatoma sordida em Minas Gerais). Estas informações nos impulsionaram a avaliar as populações remanescentes de T. infestans do Rio Grande do Sul, comparando-as com amostras resistentes da Argentina e Bolívia, e amostras de Triatoma brasiliensis do Ceará, através de ensaios com o piretróide deltametrina. Complementarmente, foi estudada a variabilidade genética das populações através de sequências do gene mitocondrial cytB e microssatélites. Os resultados dos ensaios com deltametrina demonstraram que todas as amostras de T. infestans e T. brasiliensis do Brasil apresentaram-se suscetíveis ao inseticida. A variabilidade genética para T. infestans foi baixa, com valores muito inferiores aos observados em T. brasiliensis . Também foi verificado que a variabilidade genética demonstrada através dos loci de microssatélites em T. infestans foi muito maior que a apresentada pelas sequências do gene cytB . Apesar disso, a análise das sequências deste gene se mostrou adequada para avaliar a diferenciação genética das populações. Em nosso trabalho foram observados valores de resistência menores dos já descritos para T. infestans do Rio Grande do Sul e da Bolívia. Estas diferenças indicam que o fenômeno de resistênc ia é muito mais complexo do que se imaginava, e por isso merece maior atenChagas disease control program (CDCP) had it s activities started about 1960 ́s. In 1991, based on the Southern Cone Initiati ve, the CDCP prioritized the areas of Triatoma infestans , while the epidemiologic vigil ance was established on areas under controlled vectorial transmission. The use of pyrethroids insecticides on control campaign allowed the CDCP to get great results, like the interruptio n of vectorial transmission of Chagas disease in wide areas. The current c oncern is related to the possibility of development of resistance to t he used insecticides, due to the existence of a region including the northern Argentine and southern Bolivia, were T. infestans present high resistance to pyrethroids. Moreover, other triatomine species were already described having initial resist ance to these insecticides (ex. Rhodnius prolixus from Venezuela and Triatoma sordida from Minas Gerais). These information stimulate us to evaluate the remainder T. infestans populations from Rio Grande do Sul, comparing them against the insectic ide resistant samples from Argentina and Bolivia, and samples from Triatoma brasiliensis from Ceara, through bioassays using the pyrethroid deltamethrin. Complement arily, was studied the genetic variability through mitochondrial cytB gene sequences and microsatelites. The results were encouraging, demonstrating that all evaluated samples of T. infestans and T. brasiliensis from Brazil presented su sceptibility to tested insecticides. The observed genetic variability to T. infestans were little, very lesser then that observed to T. brasiliensis . It was also observed that the genetic va riability of the microsatelite loci from T. infestans was very bigger than demonstrat ed by cytB gene sequences. In spite of this, the analysis of the cytB sequences was more indicated to analyze the genetic differentiation among populations. In this work was observed lower resistance ratios in T. infestans from Rio Grande do Sul and Bolivia, in comparison to the already observed. These differences indicated that the phenomenon of resistance is much more complex, and due to this it needs to have more attenti

Variabilidade genética de populações naturais de Lutzomyia longipalpis (Diptera : Psychodidae) de Pernambuco

Lutzomvia Iongipalpis, o principal vetor de Leishmania chagasi possui distribuição geográfica ampla na Região Neotropical. Devido à existência de barreiras climáticas e geogr|ficas nesta região, bem come pela capacidade de voo reduzida deste flebotomíneo, as populações desta espécie encontram-se isoladas geograficamente. Este isolamento possibilita o surgimento de diferenças genéticas entre as populações. Evidência disto são os diferentes padrões de manchas abdominais apresentados pelos machos desta espécie, alguns dos quais possuem um par (1M) enquanto outros possuem dois pares (2M) de manchas. Com o objetivo de estudar a variabilidade genética populações naturais de L. longipalpis do Estado de Pernambuco que exibissem machos 1M e 2M em simpatria, um fragmento do gene mitocondrial nd4 foi utilizado como marcador molecular. Foram detectados 28 haplótipos nos 71 espécimes analisados, o que corresponde a uma diversidade haplotípica de 0,944. Sete destes haplótipos (25%) foram comuns a ambos os fenótipos ( 1M e 2M), dando indícios de introgressão gênica nestas populações. Apesar da diversidade haplotípica elevada, as distâncias genéticas entre as populações analisadas foram muito baixas, variando de 0,0029 a 0,0092, o que é característico de populações panmíticas. Através de análise filogenética destes haplótipos juntamente com outros obtidos no banco de dados do GenBank pode-se considerar a influência do Rio São Francisco como barreira geográfica entre populações de L. longipalpis do Nordeste brasileir

Assessing the mitochondrial DNA diversity of the Chagas disease vector Triatoma sordida (Hemiptera: Reduviidae)

Submitted by Nuzia Santos ([email protected]) on 2016-08-24T17:46:49Z No. of bitstreams: 1 ve_Pessoa_Grasielle_Assessing_CPqRR_2016.pdf: 862246 bytes, checksum: 83c92e6ad9287a3fdd0fbc3c95d3ddb3 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-08-24T17:53:31Z (GMT) No. of bitstreams: 1 ve_Pessoa_Grasielle_Assessing_CPqRR_2016.pdf: 862246 bytes, checksum: 83c92e6ad9287a3fdd0fbc3c95d3ddb3 (MD5)Made available in DSpace on 2016-08-24T17:53:31Z (GMT). No. of bitstreams: 1 ve_Pessoa_Grasielle_Assessing_CPqRR_2016.pdf: 862246 bytes, checksum: 83c92e6ad9287a3fdd0fbc3c95d3ddb3 (MD5) Previous issue date: 2016Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Malária. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilTriatoma sordida is a species that transmits Trypanosoma cruzi to humans. In Brazil, T. sordida currently deserves special attention because of its wide distribution, tendency to invade domestic environments and vectorial competence. For the planning and execution of control protocols to be effective against Triatominae, they must consider its population structure. In this context, this study aimed to characterise the genetic variability of T. sordida populations collected in areas with persistent infestations from Minas Gerais, Brazil. Levels of genetic variation and population structure were determined in peridomestic T. sordida by sequencing a polymorphic region of the mitochondrial cytochrome b gene. Low nucleotide and haplotype diversity were observed for all 14 sampled areas; π values ranged from 0.002-0.006. Most obtained haplotypes occurred at low frequencies, and some were exclusive to only one of the studied populations. Interpopulation genetic diversity analysis revealed strong genetic structuring. Furthermore, the genetic variability of Brazilian populations is small compared to that of Argentinean and Bolivian specimens. The possible factors related to the reduced genetic variability and strong genetic structuring obtained for studied populations are discussed in this paper

Susceptibility of Triatoma brasiliensis from state of Ceará, Northeastern Brazil, to the pyrethroid deltamethrin

After controlling Triatoma infestans in Brazil, other species of triatomine that were considered minor in the transmission of Chagas disease became important. The persistence of Triatoma brasiliensis in Northeastern Brazil, associated with reinfection of domestic environments recently sprayed with pyrethroids, may be a signal of susceptibility alteration of this species to this insecticide. Specimens of T. brasiliensis from the municipality of Tauá, state of Ceará, were captured before and one year after spraying. They were submitted to bioassays using deltamethrin. The LD50 ranged from 0.19-0.33 ng of deltamethrin/nymph. The resistance ratio among samples from Tauá varied from 1.16-1.79 in the samples captured before the spraying and 1.00-1.74 in the samples captured one year after spraying, demonstrating that the two populations were equally susceptible to deltamethrin. The small difference in susceptibility between the two captures suggests that T. brasiliensis obtained in the second capture are from new invasions of the domestic environment and that the insecticide did not select resistant individuals. Therefore, it is suggested that T. brasiliensis control be carried out supplementing the regular use of pyrethroids with complementary measures, such as improvement of the dwellings and health education

Susceptibility of Triatoma infestans to deltamethrin in Rio Grande do Sul, Brazil

Strategies for controlling Chagas disease are based on spraying infested houses with pyrethroid insecticides. However, the intense use of these insecticides has promoted resistance of Triatoma infestans and, in Argentina, Bolivia and Southern Brazil, low levels of resistance have been reported. Due to the persistence of T. infestans in the state of Rio Grande do Sul (RS), we evaluated the occurrence of deltamethrin resistance in four strains from different municipalities in comparison to two susceptible strains from Brazil and one resistant strain from Bolivia. The results indicated the absence of resistance in T. infestans from RS

Genetic variability in the 5' UTR and NS5A regions of hepatitis C virus RNA isolated from non-responding and responding patients with chronic HCV genotype 1 infection

Submitted by Nuzia Santos ([email protected]) on 2013-07-03T18:27:33Z No. of bitstreams: 1 8. ARAUJO FMG, SONODA IV.pdf: 390202 bytes, checksum: 12579764f3ec1d032cea575fc9365b80 (MD5)Made available in DSpace on 2013-07-03T18:27:33Z (GMT). No. of bitstreams: 1 8. ARAUJO FMG, SONODA IV.pdf: 390202 bytes, checksum: 12579764f3ec1d032cea575fc9365b80 (MD5) Previous issue date: 2008Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilHospital das Clínicas. Instituto Alfa de GastroenterologiaUniversidade Federal de Minas Gerais. Instituto de Ciencias Biológicas. Laboratório de Biodiversidade e Evolução Molecular Departamento de Biologia Geral. Belo Horizonte, MG, BrasilSanta Casa de Belo Horizonte. Programa de Pós-Graduação e Pesquisa. Belo Horizonte, MG, BrasilSequence variation among different hepatitis C virus (HCV) isolates has adaptive significance and reflects the modes and intensities of selection mechanisms operating on the virus. In this work, we sought to investigate using classical population genetics parameters, the genetic variability of HCV genotype 1 using the 5' UTR and NS5A regions from treatment non-responding and responding groups of patients. Both regions showed low genetic varia-bility and the 5' UTR showed neutral deviation. No differences were observed in the nonsynonymous/synonymous nucleotide substitution ratio among groups for NS5A. The analysis of molecular variance test of the 5' UTR region showed an 11.94% variation among groups. Phylogenetic analysis showed no correlation between sequence variations and therapeutic response

Population dynamics of Triatoma vitticeps (Stål, 1859) in Itanhomi, Minas Gerais, Brazil

Taxonomic markers (head structure morphometry, isoenzymes and randon amplified polymorphism of DNA - RAPD) were used to understand the population dynamics of Triatoma vitticeps , predominant triatomine species in Itanhomi district, using samples obtained from domestic, peridomiciliary and sylvatic habitats. Morphometric analysis revealed sexual dimorphism within the three samples although specimens could not be separated according to the habitat in which they were captured. Forty-two bands were analyzed from RAPD profiles generated using four primers. A dendrogram constructed from Dice's similarity coefficient values showed that migration of the insects between the habitats has occurred, without structuring of populations. Moreover, the dendrogram obtained from the genetic distance values showed an important gene flow between the sylvatic and domestic habitats. No polymorphism was found in the electrophoretic mobility of proteins for the ten enzymes studied. Our results revealed movement of triatomines between the three habitats, suggesting that the presence of T. vitticeps in houses should not be ignored. As invasion of houses by sylvatic insects is frequent and the natural infection indices of this species are among the highest known, epidemiological vigilance studies may reveal possible changes in T. vitticeps behaviour which could present future risks to public health