Objetivos: Ressaltar a importância da distribuição geográfica e do comportamento dos vetores da doença de Chagas no estado de Pernambuco. Métodos: O material analisado incluiu 100% dos insetos infectados por Trypanosoma sp. e 40% dos insetos negativos, examinados no Laboratório de Endemias para confirmação taxonômica, pesquisa do parasito nas fezes dos triatomíneos e Controle da Qualidade na confirmação do diagnóstico. Resultados: Foram examinados 3.323 triatomíneos. A infecção natural por tripanossomatídeos foi detectada em 21,3% dos exemplares. Triatoma brasiliensis foi a espécie mais frequente no intradomicílio (24,3%), Triatoma pseudomaculata (14,9%) e Panstrongylus megistus apresentaram proporcionalmente taxa de infecção natural superior às demais (40,8%) no peridomicílio. Conclusão: O conhecimento atualizado da distribuição geográfica dos vetores da doença de Chagas é importante para fundamentar ações integradas entre os serviços de saúde, o que contribui para a vigilância entomológica no controle dos triatomíneos. DESCRITORES: Triatomíneos; doença de Chagas; controle de qualidade; Pernambuco.
Background Almost 1000 cases of American cutaneous leishmaniasis have been registered yearly in Rondônia State, Brazil. Little is known about the Leishmania transmission cycle (vectors and reservoirs) in the state. This study aimed to evaluate sand fly fauna from two vertical stratification layers in order to identify potential vectors and their blood-meal sources. Methods The study was conducted in Jamari National Forest. Sand flies were collected in the canopy (15 m) and at ground level (1 m) using HP light traps during four months, February, April, August and October, 2018. Insects were identified to the species level, and females were subjected to DNA extraction and PCR targeting minicircle k DNA and hsp 70 (for Leishmania detection and species identification), and cytb (to identify blood-meal sources). Exploratory data analysis was used to determine mean of abundance and species richness between stratifications. The hsp 70 and cytb sequences were analyzed and compared with sequences from GenBank. Results Overall, 68 species were identified from 15,457 individuals. On the Potosi trail, 7531 individuals of 49 species were collected; canopy captures totaled 6463 individuals of 46 species, while ground captures totaled 1068 individuals of 38 species. On the Santa Maria trail, 7926 individuals of 61 species were collected; canopy captures totaled 6136 individuals of 51 species, while ground captures totaled 1790 individuals of 53 species. A total of 23 pools were positive for k DNA (canopy n = 21, ground n = 2). Only two samples were sequenced for hsp 70 (both in canopy); one sequence exhibited similarity with Leishmania braziliensis ( Lutzomyia davisi pool) and another with L. naiffi ( Lu. antunesi pool). The cytb fragment was amplified in 11 of 86 samples. Sample sequencing identified cytb DNA from 5 blood-meal sources: Micrastur gilvicollis , Psophia viridis , Tamandua tetradactyla , Homo sapiens and Choloepus didactylus . Conclusions Sand fly fauna is more diverse in the canopy than at ground level. Factors such as blood-meal sources, resting sites, and abiotic components probably contribute to high abundance in the canopy. Our results reinforce the possibility that Lu. antunesi and Lu . davisi participate in Leishmania ...
Little is known about the feeding behavior of hematophagous insects that require plant sugar to complete their life cycles. We studied plant feeding of Lutzomyia longipalpis sand flies, known vectors of Leishmania infantum/chagasi parasites, in a Brazilian city endemic with visceral leishmaniasis. The DNA barcode technique was applied to identify plant food source of wild-caught L. longipalpis using specific primers for a locus from the chloroplast genome, ribulose diphosphate carboxylase. DNA from all trees or shrubs within a 100-meter radius from the trap were collected to build a barcode reference library. While plants from the Anacardiaceae and Meliaceae families were the most abundant at the sampling site (25.4% and 12.7% of the local plant population, respectively), DNA from these plant families was found in few flies; in contrast, despite its low abundance (2.9%), DNA from the Fabaceae family was detected in 94.7% of the sand flies. The proportion of sand flies testing positive for DNA from a given plant family was not significantly associated with abundance, distance from the trap, or average crown expansion of plants from that family. The data suggest that there may indeed be a feeding preference of L. longipalpis for plants in the Fabaceae family.
BackgroundIn South America, Lutzomyia umbratilis is the main vector of Leishmania guyanensis, one of the species involved in the transmission of American tegumentary leishmaniasis. In Brazil, L. umbratilis has been recorded in the Amazon region, and in the state of Pernambuco, Northeastern region, where an isolated population has been identified. This study assessed the phylogeographic structure and size and shape differences of the wing of three Brazilian populations.MethodsSamples of L. umbratilis were collected from Rio Preto da Eva (north of the Amazon River, Amazonas), from Manacapuru (south of the Amazon River), and from the isolated population in Recife, Pernambuco state. These samples were processed to obtain sequences of the Cytochrome Oxidase I mitochondrial gene. Geometrics morphometry analysis of the right wing shape of the three populations was made using discriminate canonical analysis.ResultsPhylogenetic analysis revealed the presence of two distinct monophyletic clades: one clade comprised of the Recife and Rio Preto da Eva samples, and the other clade comprised of the Manacapuru samples. Comparing the Manacapuru population with the Recife and Rio Preto da Eva populations generated high indices of interpopulational divergence. Geometric morphometry analysis indicated two distinct groups between the studied populations. Canonical variate analysis of wing shape indicated that Rio Preto da Eva population is significantly closer to Recife population, and both populations were genetically distant from Manacapuru.ConclusionThe polymorphic sites and geometric morphometry analysis indicate that the distance, lack of continuity and environmental differences have not modified the ancestral relationship between Recife and Rio Preto da Eva populations. The genetic and morphological similarities shared by the Recife and Rio Preto da Eva populations suggest that these populations are more closely related evolutionarily. These results confirm the existence of an L. umbratilis species complex in the North and Northeast regions.
BackgroundEven one hundred years after being originally identified, aspects of the taxonomy of the sand fly Lutzomyia longipalpis, the principal vector of Leishmania infantum in the Americas, remain unresolved for Brazilian populations of this vector. The diversity of morphological, behavioral, biochemical, and ethological characters, as well as the genetic variability detected by molecular markers are indicative of the presence of a complex of species.MethodsIn this study, a 525 bp fragment of the period gene was used to evaluate sympatric populations of L. longipalpis. A combination of probabilistic methods such as maximum likelihood and genetic assignment approach to investigate sympatric species of L. longipalpis were applied in three populations of Northeast Brazil.ResultsFixed polymorphisms in geographically isolated populations of L. longipalpis from two localities in the state of Ceará and one in the state of Pernambuco, Brazil, was identified in a 525 bp fragment of the gene period (per). Our results suggest a direct relationship between the number of spots found in males’ tergites and the genetic variation in cryptic species of L. longipalpis. The fragment used in this study revealed the nature of the ancestral morphotype 1S.ConclusionNew polymorphisms were identified in the gene per which can be used as a genetic barcode to sympatric taxonomy of L. longipalpis. The per gene fragment confirmed the presence of two siblings species of L. longipalpis in Sobral and showed that these same species are present in two other localities, representing an expansion within the L. longipalpis species complex with regards to the states of Ceará and Pernambuco.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0785-6) contains supplementary material, which is available to authorized users.
In South America, Lutzomyia umbratilis is the main vector of Leishmania guyanensis, one of the species involved in the transmission of American tegumentary leishmaniasis. In Brazil, L. umbratilis has been recorded in the Amazon region, and an isolated population has been identified in the state of Pernambuco, Northeastern region. This study assessed the phylogeographic structure of three allopatric Brazilian populations of L. umbratilis. Samples of L. umbratilis were collected from Rio Preto da Eva (north of the Amazon River, Amazonas), from Manacapuru (south of the Amazon River), and from the isolated population in Recife, Pernambuco state. These samples were processed to obtain sequences of the period gene. Phylogenetic analysis revealed the presence of two distinct monophyletic clades: one clade comprised of the Recife and Rio Preto da Eva samples, and one clade comprised of the Manacapuru samples. Comparing the Manacapuru population with the Recife and Rio Preto da Eva populations revealed high indices of interpopulational divergence. Phylogenetic analysis indicated that geographical distance and environmental differences have not modified the ancestral relationship shared by the Recife and Rio Preto da Eva populations. Genetic similarities suggest that, in evolutionary terms, these populations are more closely related to each other than to the Manacapuru population. These results confirm the existence of an L. umbratilis species complex composed of at least two incipient species.
-In Brazil, species of the genus Liriomyza are widely distributed and have economic importance as they cause damage to at least 14 plant families, especially Solanaceae, Cucurbitaceae, Asteraceae, and Fabaceae. Studies suggest existence of a species complex within this genus, based on the presence of morphological similarities among the species Liriomyza trifolii (Burgess), L. sativae Blanchard and L. huidobrensis (Blanchard). The present study aimed to use DNA barcoding to establish new distribution records of L. sativae in distinct regions in Brazil, determine intra-and inter-population genetic diversity, and reconstruct the phylogeny of Liriomyza species using the DNA barcode sequences. Identity values were between 97% and 99%, confirming that all the examined Brazilian populations belonged to the species L. sativae. Phylogenetic analyses indicated the presence of a single clade of L. sativae, composed of seven populations. Intra-population analysis on individuals of these populations indicated low levels of nucleotide and haplotype diversity. The haplotype network indicated presence of only 14 haplotypes distributed among the Brazilian populations. The genetic similarities shared by the Brazilian populations of L. sativae suggest that these populations are closely related. Genetic patterns observed among populations of L. sativae might be associated with bottleneck events or founder effect during establishment of this leafminer in Brazil.Keywords: Cryptic species. DNA barcoding. Population genetics. IDENTIFICAÇÃO MOLECULAR DE Liriomyza sp. NAS REGIÕES NORDESTE E SUDESTE DO BRASILRESUMO -No Brasil, as espécies do gênero Liriomyza têm importância econômica e são amplamente distribuídos no país, causando danos a pelo menos 14 famílias de plantas, especialmente Solanaceae, Cucurbitaceae, Asteraceae e Fabaceae. Estudos sugerem a existência de um complexo de espécies dentro deste gênero com base na presença de semelhança morfológica nas espécies Liriomyza trifolii (Burgess), L. sativae (Blanchard) e L. huidobrensis (Blanchard). Este estudo teve como objetivo empregar o DNA Barcode em novas áreas para estabelecer novos registros de Liriomyza sativae no Brasil e também a determinação da diversidade genética intra e interpopulacional, e reconstruir a filogenia das espécies Liriomyza utilizando sequências do DNA barcode. Os valores de identidade foram entre 97% a 99%, confirmando que as todas as populações brasileiras avaliadas pertencem à espécie L. sativae. A análise filogenética indicou a presença de um único clado de L. sativae composto pelas sete populações. A análise intrapopulacional indicou níveis baixos de diversidade nucleotidica e haplótipica de indivíduos dessas populações. A rede de haplótipos indicou a presença de apenas 14 haplótipos distribuídos entre populações brasileiras. As semelhanças genéticas compartilhadas pelas populações brasileiras de L. sativae sugere que essas populações estão intimamente relacionados. Os padrões genéticos observados em populações de L. sativae pode estar associad...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.