Monitoramento da suscetibilidade ao piretróide Deltametrina em populações de Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae)

Submitted by Nuzia Santos ([email protected]) on 2017-08-28T16:49:55Z No. of bitstreams: 1 Grasielle Caldas.pdf: 19164798 bytes, checksum: 4679a134eb72a6182c329578d4f03329 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2017-08-28T16:55:50Z (GMT) No. of bitstreams: 1 Grasielle Caldas.pdf: 19164798 bytes, checksum: 4679a134eb72a6182c329578d4f03329 (MD5)Made available in DSpace on 2017-08-28T16:55:50Z (GMT). No. of bitstreams: 1 Grasielle Caldas.pdf: 19164798 bytes, checksum: 4679a134eb72a6182c329578d4f03329 (MD5) Previous issue date: 2008CNPqFAPEMIGFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.A resistência de triatomíneos a inseticidas já foi relatada na Venezuela, Argentina e Bolívia, sendo possível a existência de out ros focos em regiões ainda mais amplas. Deste modo, torna-se necessário desenv olver estudos que investiguem a dispersão geográfica desses vet ores resistentes, bem como os mecanismos envolv idos, com vistas a elaborar estratégias adequadas às necessidades locais , ou até mesmo que impeçam o aparecimento deste fenômeno. O objetivo deste estudo foi padronizar ensaios biológicos para monitoramento de resistência de triatomíneos a inseticidas em laborat ório e caracterizar a su scetibilidade de quat orze populações de Tri atom a sordida Stal, 1859 de Minas Gerais (Sudest e do Bras il) ao piretróide Deltametrina. A área em que os triatomíneos foram coletados foi submetida ao controle químico por cerca de 30 anos. A linhagem referência de suscetibilid ade é oriunda de Uberaba. A metodologia foi orientada pelas recom endações da WHO (1994) e OPS (2005), tendo sido redefinidos alguns detalhes técnicos (dose diagnóstica adequada para triagem de resistência em triatomíneos, lo cal ideal de aplicaçã o do ins eticida nas ninfas I, idade e gera ção dos in setos utiliz ados). A linha base d e suscetibilidade da linhagem r eferência f oi inic ialm ente det erminada. A Deltametrina, solubilizada em acetona, foi aplicada topica ment e no dorso do abdômen de ninf as I da ger ação F 2 (cinco dias de idade, j ejum, ± 1,2 mg. de pes o) com auxílio de um a microseringa. Os resultados dos ensaios dose-resposta foram analisados com auxílio do programa PROBIT (Finney, 1971). Em seguida, as populações de campo foram submetidas a dose diagnóstica de 1XDL99 da linhagem re ferência de s uscetibi lidade e 2XDD99 da linhagem referência de susc etibilidad e. Todas as populações apresentaram-se menos sus cetíveis ao insetic ida quando co mparadas com a linhagem referência de suscetibilidade. As razões de r esistência encontradas variaram de 2,6 a 6,8. A comparação de um fragmento de DNA de 317 pb do gene mitocondrial do citocromo b (mtCytB) foi usada para inferir sobr e a varia bilidade genética das quatorze populações de T. sordida estudadas. Inferências filogenéticas, usando P. megistu s como grupo externo, não revelaram a formação de clados. O s 150 es pécimes analisados apresentaram 50 haplótipos gerando uma divers idade (Hd) de 0,831. Foi possível distinguir seis populaçõ es genet icamente diferentes. Anális e do Network revelou a presença de vários loops , demonstrando homoplas ia e a ocorrência de mutações reversas/paralelas. Com o ma rcador genético utiliz ado não foi possível estabelecer correlação entre a variabilid ade genética das populaç ões estudadas e a resistência a Deltametrina. Giordano et al. (2005) sugerem que os microssatélites podem ser uma ferramenta mais sensível e eficiente para este objetivo. A possível natureza bioquímica da resistência encontrada está sendo verificada.The resistance of triatomines to insectici de was reported in Vene zuela, Argentina and Boliv ia, being possib le the existe nce of other fo cus in still more ample regio ns. In this way, it becomes necessary to realize studie s to investigate the state of resistance of these vectors to insecticides, as well as its mechanisms, in order to develop adequate s trategies to the local necessities, or even to prevent t he emergence of this phenomenon. The objective of this study was standardized b iological assays for monitoring the triatomi nes resistance to inse cticide in laboratory, and to monitor the susceptibility of f ourteen populations of Triatoma sordida Stal, 1859 of Minas Gerais State (Southeast Brazil) to the pirethroid Deltamethrin . The area where the triatomines were collected was submitted to chemical c ontrol for about 30 years.The susceptibility reference strain is the U beraba. The methodology has been g uided by the OPS recommendations (2005) and WHO (1994), being redefined some technical details (ideal diagnost ic dose for resistance selection of triatomines, ideal place of application of the insecticide of nymphs I, age and generation of used insects). The baseline of the susceptibilit y of the reference strain was initially determined. Deltamethrin diluted in acetone was appli ed topically on the back of the abdomen of nymphs I of the F2 generation (five days of age, fasting, 1.0 ± 0. 2 mg. of weight) with the aid of a microsyringe. The r esults of the dose-response tes ts were analyzed using the program PROBIT (Finney, 1971). After that, the fi eld populations were submitted to the two diagnostic doses (1 XDL99 and 2XDL99 of the susceptibility reference strain) . All the populations were less susceptible to the insecticide when compared with the susceptibilit y reference strain. The resistance rate ranged from 2.6 to 6.8. The comparison of a DNA fragment of 317 pb of the DNA mitoc hondria l cytochrome b (mtCytB) gene has been used to infer the genetic variability of the fourteen T. sordida populations studi ed. Phylogenetics inferences , with P. megistus as external group, had not shown the formation of clades. The 150 s pecimens analyzed showed 50 haplotypes resulting a divers ity (Hd) of 0,831. It was possible to distinguish six different genetic populations. Analys is of the Network reveled several loops , dem onstrating homoplas ia and the occurrenc e of reverses/parallels mutations. With the genetic marker used it was not po ssible to es tablish correlation between the genetic var iability of t he ins ects and the resistance to the De ltamethrin. Giordano et al. (2005) suggests that the mi crosatellite s wou ld be a more s ensib le an d efficient tool to define this obj ective. The possible bi ochemical nature for the resistance ratios encountered is being v erifie

Deltamethrin pyrethroid susceptibility characterization of Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae) populations in the Northern Region of Minas Gerais, Brazil

Submitted by Nuzia Santos ([email protected]) on 2015-03-26T16:49:39Z No. of bitstreams: 1 2014_174.pdf: 736569 bytes, checksum: a487d3f862f8997b06a5dc09cb460c64 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-03-26T16:49:46Z (GMT) No. of bitstreams: 1 2014_174.pdf: 736569 bytes, checksum: a487d3f862f8997b06a5dc09cb460c64 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-03-26T16:51:47Z (GMT) No. of bitstreams: 1 2014_174.pdf: 736569 bytes, checksum: a487d3f862f8997b06a5dc09cb460c64 (MD5)Made available in DSpace on 2015-03-26T16:51:47Z (GMT). No. of bitstreams: 1 2014_174.pdf: 736569 bytes, checksum: a487d3f862f8997b06a5dc09cb460c64 (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilIntroduction: Triatoma sordida is the most captured Triatomine species in the Brazilian artifi cial environment. In 2008, the discovery of three Triatomine populations with altered susceptibilities to deltamethrin highlighted the importance of investigating the genetic potential for resistance in triatomines. The purpose of this study was to characterize the susceptibility to deltamethrin of peridomestic T. sordida populations in Minas Gerais, Brazil. Methods: A susceptibility reference lineage derived from Uberaba, Minas Gerais, Brazil was used. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 of the susceptibility reference lineage. Results: Susceptibility profi le characterization of T. sordida populations revealed resistance ratios (RR50s) ranging from 0.42 to 3.94. The percentage mortality in response to the diagnostic dose varied from 70% to 100%. A comparison of the results obtained in the quantitative and qualitative assays demonstrated a lack of correspondence for some populations. Conclusions: We demonstrated that only T. sordida populations that present a RR50>1.0 have altered susceptibility, and the execution of simultaneous fi eld and laboratory tests is required to understand the actual effect of vector control. A possible cause of the observed resistance ratios might be the continuous use of pyrethroids in Brazil since the 1980s

Biological aspects of crosses between Triatoma maculata (Erichson,1848) andTriatoma pseudomaculataCorrêa & Espínola, 1964(Hemiptera: Reduviidae).

Submitted by Nuzia Santos ([email protected]) on 2013-06-19T12:56:04Z No. of bitstreams: 1 18.BELISÁRIO CJ.pdf: 152863 bytes, checksum: 67f8ec379a376c3ac99aa722d09aa631 (MD5)Made available in DSpace on 2013-06-19T12:56:04Z (GMT). No. of bitstreams: 1 18.BELISÁRIO CJ.pdf: 152863 bytes, checksum: 67f8ec379a376c3ac99aa722d09aa631 (MD5) Previous issue date: 2007Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Due to morphological similarities between Triatoma maculataand T. pseudomaculata, which comprise the “maculate complex”, both had been regarded as the same species until 1964. Considering that the studies on triatomine hybridization permit hypotheses formulation concerning origin and divergence of species, enabling a quantitative analysis of taxonomic relationships between species, the present investigation was aimed at broadening further understanding related to the capacity of hybrid production by determining the degree ofreproductive isolation between T. maculataand T. pseudomaculata. Our results have demonstrated that T. maculata and T. pseudomaculatashowed no differences regarding reproduction patterns and they are able to cross, gen-erating infertile hybrid

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

Inheritance and heritability of deltamethrin resistance under laboratory conditions of Triatoma infestans from Bolivia

Submitted by Nuzia Santos ([email protected]) on 2016-04-05T18:53:58Z No. of bitstreams: 1 Inheritance and heritability of deltamethrin resistance under laboratory conditions of Triatoma infestans from Bolivia.pdf: 5217942 bytes, checksum: 285b1b55bc8ff585ef9878da7e69dd2b (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-04-05T18:57:36Z (GMT) No. of bitstreams: 1 Inheritance and heritability of deltamethrin resistance under laboratory conditions of Triatoma infestans from Bolivia.pdf: 5217942 bytes, checksum: 285b1b55bc8ff585ef9878da7e69dd2b (MD5)Made available in DSpace on 2016-04-05T18:57:36Z (GMT). No. of bitstreams: 1 Inheritance and heritability of deltamethrin resistance under laboratory conditions of Triatoma infestans from Bolivia.pdf: 5217942 bytes, checksum: 285b1b55bc8ff585ef9878da7e69dd2b (MD5) Previous issue date: 2015Fundação 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, 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, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilBackground: Over the last few decades, pyrethroid-resistant in Triatoma infestans populations have been reported, mainly on the border between Argentina and Bolivia. Understanding the genetic basis of inheritance mode and heritability of resistance to insecticides under laboratory conditions is crucial for vector management and monitoring of insecticide resistance. Currently, few studies have been performed to characterize the inheritance mode of resistance to pyrethroids in T. infestans; for this reason, the present study aims to characterize the inheritance and heritability of deltamethrin resistance in T. infestans populations from Bolivia with different toxicological profiles. Methods: Experimental crosses were performed between a susceptible (S) colony and resistant (R) and reduced susceptibility (RS) colonies in both directions (♀ x ♂ and ♂ x ♀), and inheritance mode was determined based on degree of dominance (DO) and effective dominance (DML). In addition, realized heritability (h2) was estimated based on a resistant colony, and select pressure was performed for two generations based on the diagnostic dose (10 ng. i. a. /nymph). The F1 progeny of the experimental crosses and the selection were tested by a standard insecticide resistance bioassay. Results: The result for DO and DML (< 1) indicates that resistance is an incompletely dominant character, and inheritance is autosomal, not sex-linked. The LD50 for F1 of ♀S x ♂R and ♂S x ♀R was 0.74 and 3.97, respectively, which is indicative of dilution effect. In the resistant colony, after selection pressure, the value of h2 was 0.37; thus, the LD50 value increased 2.25-fold (F2) and 26.83-fold (F3) compared with the parental colony. Conclusion: The inheritance mode of resistance of T. infestans to deltamethrin, is autosomal and an incompletely dominant character; this is a previously known process, confirmed in the present study on T. infestans populations from Bolivia. The lethal doses (LD50) increase from one generation to another rapidly after selection pressure with deltamethrin. This suggests that resistance is an additive and cumulative factor, mainly in highly structured populations with limited dispersal capacity, such as T. infestans. This phenomenon was demonstrated for the first time for T. infestans in the present study. These results are very important for vector control strategies in problematic areas where high resistance ratios of T. infestans have been reported

Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil

Submitted by Nuzia Santos ([email protected]) on 2016-02-25T18:39:05Z No. of bitstreams: 1 Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil.pdf: 5120034 bytes, checksum: cab9c44109ae839c9982847dfed5bb6b (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-02-25T18:48:00Z (GMT) No. of bitstreams: 1 Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil.pdf: 5120034 bytes, checksum: cab9c44109ae839c9982847dfed5bb6b (MD5)Made available in DSpace on 2016-02-25T18:48:00Z (GMT). No. of bitstreams: 1 Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil.pdf: 5120034 bytes, checksum: cab9c44109ae839c9982847dfed5bb6b (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilUniversidade Federal de Brasília. Laboratório de Entomologia. Brasília, DF, BrasilGerência Regional de Saúde de Montes Claros. Montes Claros, MG, BrasilSecretaria de Saúde do Estado de Minas Gerais. Belo Horizonte, MG, BrasilSecretaria de Saúde do Estado de Minas Gerais. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilBackground: In general, there was a large reduction in the occurrence of cases of Chagas disease in the last decades in Brazil. However, despite all of these efforts, there have been various reports of persistent reinfestations of T. sordida in a large part of the state of Minas Gerais, for reasons still little investigated. Thus, this purpose of this study was to characterize the deltamethrin susceptibility profile of peridomestic T. sordida populations from North of Minas Gerais – Brazil. Methods: Susceptibility to deltamethrin was assessed in seventeen peridomestic populations of T. sordida from North region of Minas Gerais, Brazil. Serial dilutions of deltamethrin in acetone (0.2 μL) were topically applied in first instar nymphs (F1, five days old, fasting, weight 1.2 ± 0.2 mg). Dose response results were analyzed with POLO program, determining the lethal doses, slope and resistance ratios (RR). Results: Susceptibility profile characterization of T. sordida populations revealed resistance ratios (RR50) ranging from 2.50 to 7.08. Conclusions: In fact, we know very little about the real impact of the resistance ratios obtained in the laboratory bioassays on the effectiveness of the vector control activities in the field. Thus, we prefer to refer to the populations with RR > 5 as populations with altered susceptibility. For these populations, the realization of laboratory and field trials, simultaneous and complementary, permitting the evaluation of both, is recommended

Markers for the population genetics studies of Triatoma sordida (Hemiptera: Reduviidae).

Submitted by Nuzia Santos ([email protected]) on 2016-02-04T13:08:07Z No. of bitstreams: 1 Markers for the population genetics studies.pdf: 3604761 bytes, checksum: 7f8913d71b7e2c1494ed8ed71ad3ce1d (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-02-04T13:11:54Z (GMT) No. of bitstreams: 1 Markers for the population genetics studies.pdf: 3604761 bytes, checksum: 7f8913d71b7e2c1494ed8ed71ad3ce1d (MD5)Made available in DSpace on 2016-02-04T13:11:54Z (GMT). No. of bitstreams: 1 Markers for the population genetics studies.pdf: 3604761 bytes, checksum: 7f8913d71b7e2c1494ed8ed71ad3ce1d (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais BrasilBackground: Triatoma sordida, a vector of Trypanosoma cruzi, is native of Brazil, Bolivia, Paraguay, Argentina, and Uruguay, and occurs primarily in peridomiciles. Currently, it is the species most frequently captured by the Chagas Disease Control Program in Brazil. For this reason, population genetic studies attract great interest, as they can provide further information about the dispersal and household invasion processes of this species. In the absence of suitable markers, the objective of this study was to test the cross amplification of microsatellite primers. Findings: 23 primers were tested for microsatellite loci already described for other species of the genus Triatoma sp. Forty four specimens of T. sordida captured in the north of Minas Gerais were used to validate the use of standardized loci for population genetic analyses. It was possible to amplify 10 of the 23 loci tested for T. sordida. Conclusions: This is the first study that provides 10 microsatellite markers for population analysis of this triatomine species. Cross-amplification of primers can be used among other phylogenetically related species whose loci are already available for stud

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae) in State of Ceará; Northeastern Brazil

Submitted by Nuzia Santos ([email protected]) on 2016-06-16T16:55:51Z No. of bitstreams: 1 ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf: 202511 bytes, checksum: 80336ab7c4611a95956db4264270a2b6 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-06-16T16:59:14Z (GMT) No. of bitstreams: 1 ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf: 202511 bytes, checksum: 80336ab7c4611a95956db4264270a2b6 (MD5)Made available in DSpace on 2016-06-16T16:59:14Z (GMT). No. of bitstreams: 1 ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf: 202511 bytes, checksum: 80336ab7c4611a95956db4264270a2b6 (MD5) Previous issue date: 2015Item withdrawn by Nuzia Santos ([email protected]) on 2016-07-01T18:51:37Z Item was in collections: CPqRR - Artigos de Periódicos (ID: 80) No. of bitstreams: 2 ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf.txt: 23745 bytes, checksum: 8786b1015f4fce0542398a8a6fddb8aa (MD5) ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf: 202511 bytes, checksum: 80336ab7c4611a95956db4264270a2b6 (MD5)Made available in DSpace on 2016-07-08T02:09:53Z (GMT). No. of bitstreams: 3 ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf.txt: 23745 bytes, checksum: 8786b1015f4fce0542398a8a6fddb8aa (MD5) ve_Grasielle_Pessoa_etal_Toxicological_CPqRR_2015.pdf: 202511 bytes, checksum: 80336ab7c4611a95956db4264270a2b6 (MD5) license.txt: 2991 bytes, checksum: 5a560609d32a3863062d77ff32785d58 (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Secretaria de Saúde do Estado do Ceará. Fortaleza, CE, Brasil.Secretaria de Saúde do Estado de Minas Gerais. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.INTRODUCTION: Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD) to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. METHODS: The susceptibility reference lineage (SRL) was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph) of the SRL. RESULTS: The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50) that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. CONCLUSIONS: We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive

Baseline susceptibility to alpha-cypermethrin in Lutzomyia longipalpis (Lutz & Neiva, 1912) from Lapinha Cave (Brazil).

Submitted by Nuzia Santos ([email protected]) on 2016-03-09T17:20:31Z No. of bitstreams: 1 Baseline susceptibility to alpha-cypermethrin in Lutzomyia longipalpis.pdf: 4698596 bytes, checksum: 43af4b1ddc46d98530c8bb6e3131a826 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-03-10T12:07:19Z (GMT) No. of bitstreams: 1 Baseline susceptibility to alpha-cypermethrin in Lutzomyia longipalpis.pdf: 4698596 bytes, checksum: 43af4b1ddc46d98530c8bb6e3131a826 (MD5)Made available in DSpace on 2016-03-10T12:07:19Z (GMT). No. of bitstreams: 1 Baseline susceptibility to alpha-cypermethrin in Lutzomyia longipalpis.pdf: 4698596 bytes, checksum: 43af4b1ddc46d98530c8bb6e3131a826 (MD5) Previous issue date: 2015Fundação 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 Leishmanioses. Belo Horizonte, MG, BrasilPrefeitura de Montes Claros. Centro de Controle de Zoonoses. Montes Claros, 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, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Leishmanioses. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Leishmanioses. Belo Horizonte, MG, BrasilBackground: Given the increase in cases of visceral leishmaniasis in recent years, associated with the socio-economic impact of this disease, as well as the wide distribution of Lutzomyia longipalpis in Brazil and the likelihood that this vector may develop resistance to insecticides used for control, the Ministry of Health considers as crucial the creation of a network in order to study and monitor the resistance of this vector to insecticides used for control. In this sense, this study aimed: 1) to characterize the susceptibility of L. longipalpis from Lapinha Cave (Lagoa Santa, MG - Brazil) to Alfateck SC200 in field bioassays, and 2) to define the susceptibility baseline to alpha-cypermethrin in laboratory bioassays, checking the possibility of using it as susceptibility reference lineage (SRL). Findings: The field bioassays revealed that the tested population was highly susceptible to alpha-cypermethrin in all time periods with high mortality (~100 %) in all treated surfaces before six months after spraying. In the laboratory bioassays, the studied population presented LD 50 ,LD 95 and LD 99 to 0.78013, 10.5580 and 31.067 mg/m2, respectively. The slope was 1.454121. Conclusions: The studied population of L. longipalpis was considered as adequate for SRL according criterion recommended by Pan-American Health Organization and has proven susceptibility to tested insecticide in the field. One cannot rule out the possibility of finding populations of L. longipalpis more susceptible to alpha-cypermethrin; therefore, further research is necessary on other populations with potential use as a SR

Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil

Submitted by Nuzia Santos ([email protected]) on 2016-03-01T17:24:53Z No. of bitstreams: 1 Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil..pdf: 4776994 bytes, checksum: 86de1fc66048148a559d28e72a04ca30 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-03-01T17:30:00Z (GMT) No. of bitstreams: 1 Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil..pdf: 4776994 bytes, checksum: 86de1fc66048148a559d28e72a04ca30 (MD5)Made available in DSpace on 2016-03-01T17:30:00Z (GMT). No. of bitstreams: 1 Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil..pdf: 4776994 bytes, checksum: 86de1fc66048148a559d28e72a04ca30 (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, Brasil.Governo do Estado de Minas Gerais. Secretaria de Saúde do Estado de Minas Gerais. Belo Horizonte, MG, BrasilGoverno do Estado de Minas Gerais. Secretaria de Saúde do Estado de Minas Gerais. 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, Brasil.Despite chemical and physical vector control strategies, persistent infestations of Triatoma sórdida have been reported in a large part of Minas Gerais, Brazil, and the cause for this is little investigated. We aimed to characterize the deltamethrin toxicological profi le in peridomestic T. sordid populations from Triângulo Mineiro area of Minas Gerais. Methods: Susceptibility to deltamethrin was assessed in seventeen peridomestic T. sordida populations. Serial dilutions of deltamethrin in acetone (0.2μL) were topically applied on the fi rst instar nymphs (F1; fi ve days old; fasting weight, 1.2 ± 0.2mg). Dose response results were analyzed using Probit software, and the lethal doses, slope and resistance ratios were determined. Qualitative tests were also performed. Results: The deltamethrin susceptibility profi le of T. sordida populations revealed resistance ratios ranging from 0.84 to 2.8. The percentage mortality in response to a diagnostic dose was 100.0% in all populations. Conclusions: From our results, the lack of resistance to insecticides but persistent T. sordida infestations in the Triângulo Mineiro area may be because of: 1) environmental degradation facilitating dispersion of T. sordida, allowing colonization in artificial ecotopes; 2) operational failures; and 3) complexity of the peridomicile in the study area.These variables are being investigate