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1.
Mem. Inst. Oswaldo Cruz ; 116: e200528, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154881

ABSTRACT

Panstrongylus geniculatus (Latreille, 1811) is the triatomine with the largest geographic distribution in Latin America. It has been reported in 18 countries from southern Mexico to northern Argentina, including the Caribbean islands. Although most reports indicate that P. geniculatus has wild habitats, this species has intrusive habits regarding human dwellings mainly located in intermediate deforested areas. It is attracted by artificial light from urban and rural buildings, raising the risk of transmission of Trypanosoma cruzi. Despite the wide body of published information on P. geniculatus, many knowledge gaps exist about its biology and epidemiological potential. For this reason, we analysed the literature for P. geniculatus in Scopus, PubMed, Scielo, Google Scholar and the BibTriv3.0 databases to update existing knowledge and provide better information on its geographic distribution, life cycle, genetic diversity, evidence of intrusion and domiciliation, vector-related circulating discrete taxonomic units, possible role in oral T. cruzi transmission, and the effect of climate change on its biology and epidemiology.


Subject(s)
Humans , Animals , Panstrongylus/genetics , Panstrongylus/parasitology , Triatoma/parasitology , Trypanosoma cruzi/isolation & purification , Chagas Disease/transmission , Insect Vectors/parasitology , Panstrongylus/physiology , Phylogeny , Genetic Variation/genetics , Biology , Genes, Insect , Ecology , Genotype , Geography , Insect Vectors/genetics , Latin America
2.
Rev. Soc. Bras. Med. Trop ; 54: e00282020, 2021. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1143882

ABSTRACT

Abstract INTRODUCTION: We aimed to study intraspecific variation in Triatoma costalimai, a potential vector of Chagas disease present in Brazil and Bolivia. METHODS: We analyzed phenotypic (connexivum color patterns, wing morphometrics) and genetic variation (16S mtDNA) of three Brazilian T. costalimai populations. We compared 16S sequences with those of putative Bolivian T. costalimai and its sister species, T. jatai. RESULTS: Brazilian populations had different connexivum color patterns and forewing shapes. A 16S mtDNA haplotype network showed a clear separation of Brazilian T. costalimai from both T. jatai and Bolivian T. costalimai. CONCLUSIONS: We report considerable variability in T. costalimai populations.


Subject(s)
Animals , Triatoma/genetics , Chagas Disease , Genetic Variation/genetics , Bolivia , Brazil , Insect Vectors/genetics
3.
Mem. Inst. Oswaldo Cruz ; 115: e200313, 2020. tab, graf
Article in English | LILACS | ID: biblio-1154867

ABSTRACT

BACKGROUND Aedes aegypti is the sole vector of urban arboviruses in French Guiana. Overtime, the species has been responsible for the transmission of viruses during yellow fever, dengue, chikungunya and Zika outbreaks. Decades of vector control have produced resistant populations to deltamethrin, the sole molecule available to control adult mosquitoes in this French Territory. OBJECTIVES Our surveillance aimed to provide public health authorities with data on insecticide resistance in Ae. aegypti populations and other species of interest in French Guiana. Monitoring resistance to the insecticide used for vector control and to other molecule is a key component to develop an insecticide resistance management plan. METHODS In 2009, we started to monitor resistance phenotypes to deltamethrin and target-site mechanisms in Ae. aegypti populations across the territory using the WHO impregnated paper test and allelic discrimination assay. FINDINGS Eight years surveillance revealed well-installed resistance and the dramatic increase of alleles on the sodium voltage-gated gene, known to confer resistance to pyrethroids (PY). In addition, we observed that populations were resistant to malathion (organophosphorous, OP) and alpha-cypermethrin (PY). Some resistance was also detected to molecules from the carbamate family. Finally, those populations somehow recovered susceptibility against fenitrothion (OP). In addition, other species distributed in urban areas revealed to be also resistant to pyrethroids. CONCLUSION The resistance level can jeopardize the efficiency of chemical adult control in absence of other alternatives and conducts to strongly rely on larval control measures to reduce mosquito burden. Vector control strategies need to evolve to maintain or regain efficacy during epidemics.


Subject(s)
Animals , Pyrethrins/pharmacology , Insecticide Resistance/drug effects , Insecticide Resistance/genetics , Aedes/drug effects , Mosquito Vectors/drug effects , Insecticides/pharmacology , Mosquito Control/methods , Aedes/genetics , Spatio-Temporal Analysis , Mosquito Vectors/virology , French Guiana , Insect Vectors/drug effects , Insect Vectors/genetics
4.
Rev. Soc. Bras. Med. Trop ; 53: e20190503, 2020. tab, graf
Article in English | LILACS | ID: biblio-1101448

ABSTRACT

Abstract Introduction: The genus Rhodnius in the subfamily Triatominae comprises 20 species, which can transmit Trypanosoma cruzi and Trypanosoma rangeli. Due to the development of molecular techniques, Triatominae species can now be characterized by mitochondrial and nuclear markers, making it possible to verify and/or correct the existing data on these species. The results achieved in this study provide a more detailed and accurate differentiation of the Rhodnius species, helping the establishment of a more appropriate classification. Methods: Data collection was performed by DNA analysis, morphological and morphometric studies to distinguish four populations of R. neglectus and four of R. prolixus. Phylogenetic data were compared to morphological and morphometric data. Results: The analysis of Cytb fragments suggests that the four colonies designated to Rhodnius neglectus as well as those of R. prolixus were correctly identified. Conclusions: The morphological characters observed in the specimens of the colonies originally identified as R. prolixus and R. neglectus, such as the presence or absence of collar in the eggs, the patterns of the median process of the pygophore, and anterolateral angle, are consistent with the species. Geometric morphometrics also show an intraspecific variability in R. prolixus.


Subject(s)
Animals , Male , Rhodnius/classification , Insect Vectors/anatomy & histology , Phylogeny , Rhodnius/anatomy & histology , Rhodnius/genetics , Species Specificity , Chagas Disease/transmission , Sequence Analysis, DNA , Insect Vectors/classification , Insect Vectors/genetics
5.
Mem. Inst. Oswaldo Cruz ; 115: e200157, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135268

ABSTRACT

BACKGROUND In Acre state, Brazil, the dissemination of cutaneous leishmaniasis has increased in recent years, with limited knowledge of the potential Leishmania spp. vectors involved. OBJECTIVES Here, data concerning the sandfly fauna of Brasiléia municipality, Leishmania DNA-detection rates and the identification of blood meal sources of insects captured in 2013-2015 are presented. METHODS Parasite detection in female sandflies was performed individually by multiplex polymerase chain reaction (PCR) (Leishmania kDNA/sandfly cacophony-gene), with the identification of Leishmania spp. by hsp70-PCR and sequencing. The identification of blood gut-content from fed females was performed by cyt b-PCR and sequencing. FINDINGS A total of 4,473 sandflies were captured. A subgroup of 864 non-blood-fed females evaluated for the presence of Leishmania DNA showed 2.9% positivity for Leishmania (Viannia) braziliensis and L. (V.) guyanensis. The identification of blood meal sources was performed in 96 blood-fed females, allowing the identification of 13 vertebrate species. In nine/96 fed females, DNA from L. (V.) shawi, L. (V.) guyanensis, L. (V.) braziliensis and Endotrypanum sp. was detected. MAIN CONCLUSIONS In Brumptomyia sp. and Evandromyia termitophila, the first report of Leishmania DNA-detection is provided in Acre; Nyssomyia shawi is implicated as potential vector of L. (V.) braziliensis and L. (V.) guyanensis for the first time in Brazil.


Subject(s)
Animals , Female , Psychodidae/parasitology , DNA/analysis , Insect Vectors/genetics , Leishmania/genetics , Psychodidae/classification , Brazil , Polymerase Chain Reaction , DNA, Protozoan/analysis , Leishmaniasis, Cutaneous/transmission , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania/isolation & purification
6.
Mem. Inst. Oswaldo Cruz ; 114: e190184, 2019. graf
Article in English | LILACS | ID: biblio-1040604

ABSTRACT

American visceral leishmaniasis (AVL) has two main scenarios of transmission as follows: scattered cases in rural areas and urban outbreaks. Urban AVL is in active dispersion from the northeastern border of Argentina-Paraguay-Brazil to the South. The presence of Lutzomyia longipalpis was initially reported in urban environments in the northwestern border of the country. The presence of Lu. longipalpis, environmental variables associated with its distribution, and its genetic diversity were assessed in Salvador Mazza, Argentina, on the border with Bolivia. The genetic analysis showed high haplotype diversity, low nucleotide diversity, and low nucleotide polymorphism index. We discuss the hypothesis of an expanding urban population with introgressive hybridisation of older haplogroups found in their path in natural forest or rural environments, acquiring a new adaptability to urban environments, and the possibility of changes in vector capacity.


Subject(s)
Animals , Male , Psychodidae/genetics , Genetic Variation/genetics , Animal Distribution , Insect Vectors/genetics , Argentina , Psychodidae/classification , Bolivia , Haplotypes , Brazil , DNA, Mitochondrial/genetics , Leishmaniasis, Cutaneous/transmission , Genes, Insect/genetics , Phylogeography , Insect Vectors/classification
7.
Mem. Inst. Oswaldo Cruz ; 114: e190034, 2019. tab, graf
Article in English | LILACS | ID: biblio-1040606

ABSTRACT

Six Phlebotominae sand fly species are incriminated as biological vectors of human pathogens in Panama, but molecular corroboration is still needed. We aim at confirming the identity of Phlebotominae species documented as anthropophilic in Panama. Adult sandflies were collected from August 2010 to February 2012 in Central Panama using CDC light traps. Species confirmation was accomplished through molecular barcodes and allied sequences from GenBank. A total of 53,366 sand fly specimens representing 18 species were collected. Five species were validated molecularly as single phylogenetic clusters, but Psychodopygus thula depicted two genetically divergent lineages, which may be indicative of cryptic speciation.


Subject(s)
Animals , Psychodidae/genetics , Leishmaniasis, Cutaneous/transmission , Insect Vectors/classification , Panama , Phylogeny , Psychodidae/classification , Biodiversity , Insect Vectors/genetics
9.
Mem. Inst. Oswaldo Cruz ; 112(3): 161-174, Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-841774

ABSTRACT

Lutzomyia longipalpis s.l. is a complex of sibling species and is the principal vector of American visceral leishmaniasis. The present review summarises the diversity of efforts that have been undertaken to elucidate the number of unnamed species in this species complex and the phylogenetic relationships among them. A wide variety of evidence, including chemical, behavioral and molecular traits, suggests very recent speciation events and complex population structure in this group. Although significant advances have been achieved to date, differential vector capacity and the correlation between structure of parasite and vector populations have yet to be elucidated. Furthermore, increased knowledge about recent epidemiological changes, such as urbanisation, is essential for pursuing effective strategies for sandfly control in the New World.


Subject(s)
Animals , Psychodidae/classification , Psychodidae/genetics , Species Specificity , Genes, Insect , Biodiversity , Insect Vectors/classification , Insect Vectors/genetics , Leishmaniasis, Visceral/transmission , Phylogeny , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length , Brazil
10.
Rev. Inst. Med. Trop. Säo Paulo ; 59: e10, 2017. tab, graf
Article in English | LILACS | ID: biblio-842769

ABSTRACT

ABSTRACT The genetic study of sandfly populations needs to be further explored given the importance of these insects for public health. Were sequenced the NDH4 mitochondrial gene from populations of Nyssomyia neivai from Doutor Camargo, Lobato, Japira, and Porto Rico, municipalities in the State of Paraná, Brazil, to understand the genetic structure and gene flow. Eighty specimens of Ny. Neivai were sequenced, 20 from each municipality, and 269 base pairs were obtained. A total of 27 haplotypes and 28 polymorphic sites were found, along with a haplotypic diversity of 0.80696 and a nucleotide diversity of 0.00567. Haplotype H5, with 33 specimens, was the most common among the four populations. Only haplotypes H5 and H7 were present in all four populations. The population from Doutor Camargo showed the highest genetic diversity, and only this population shared haplotypes with those from the other municipalities. The highest number of haplotypes was sheared with Lobato which also had the highest number of unique haplotypes. This probably occurred because of constant anthropic changes that happened in the environment during the first half of the twentieth century, mainly after 1998. There was no significant correlation between genetic and geographical distances regarding these populations. However, the highest genetic and geographical distances, and the lowest gene flow were observed between Japira and Porto Rico. Geographical distance is a possible barrier between these municipalities through the blocking of haplotype sharing.


Subject(s)
Animals , Female , Genetic Variation/genetics , Insect Vectors/genetics , Psychodidae/genetics , Brazil , DNA, Mitochondrial/analysis , DNA, Protozoan/analysis , Insect Vectors/classification , Leishmaniasis, Cutaneous/transmission , Polymerase Chain Reaction , Psychodidae/classification
11.
Mem. Inst. Oswaldo Cruz ; 111(10): 614-624, Oct. 2016. tab, graf
Article in English | LILACS | ID: lil-796906

ABSTRACT

The subfamily Triatominae (Hemiptera, Reduviidae) includes 150 species of blood-sucking insects, vectors of Chagas disease or American trypanosomiasis. Karyotypic information reveals a striking stability in the number of autosomes. However, this group shows substantial variability in genome size, the amount and distribution of C-heterochromatin, and the chromosome positions of 45S rDNA clusters. Here, we analysed the karyotypes of 41 species from six different genera with C-fluorescence banding in order to evaluate the base-pair richness of heterochromatic regions. Our results show a high heterogeneity in the fluorescent staining of the heterochromatin in both autosomes and sex chromosomes, never reported before within an insect subfamily with holocentric chromosomes. This technique allows a clear discrimination of the heterochromatic regions classified as similar by C-banding, constituting a new chromosome marker with taxonomic and evolutionary significance. The diverse fluorescent patterns are likely due to the amplification of different repeated sequences, reflecting an unusual dynamic rearrangement in the genomes of this subfamily. Further, we discuss the evolution of these repeated sequences in both autosomes and sex chromosomes in species of Triatominae.


Subject(s)
Animals , Chromosomes, Insect/genetics , Heterochromatin/genetics , Insect Vectors/genetics , Triatominae/genetics , Biological Evolution , Chagas Disease/transmission , DNA, Ribosomal/genetics , Karyotyping , RNA, Ribosomal/genetics , Triatominae/classification
12.
Mem. Inst. Oswaldo Cruz ; 111(7): 423-432, tab, graf
Article in English | LILACS | ID: lil-787560

ABSTRACT

In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality.


Subject(s)
Humans , Animals , Female , DNA/analysis , Insect Vectors/genetics , Leishmania/genetics , Psychodidae/genetics , Biodiversity , Bolivia , Brazil , DNA, Kinetoplast , Genotype , Insect Vectors/classification , Insect Vectors/parasitology , Leishmaniasis, Cutaneous/transmission , Peru , Polymerase Chain Reaction , Population Density , Psychodidae/classification , Psychodidae/parasitology
13.
Mem. Inst. Oswaldo Cruz ; 111(5): 322-329, May 2016. tab, graf
Article in English | LILACS | ID: lil-782046

ABSTRACT

Triatoma 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.


Subject(s)
Animals , Cytochromes b/genetics , DNA, Mitochondrial/genetics , Genetic Variation/genetics , Insect Vectors/genetics , Triatoma/genetics , Brazil , Chagas Disease/transmission , Insect Vectors/classification , Triatoma/classification
14.
Mem. Inst. Oswaldo Cruz ; 111(5): 335-346, May 2016. tab, graf
Article in English | LILACS | ID: lil-782048

ABSTRACT

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies.


Subject(s)
Animals , Anopheles/genetics , Chromosome Inversion/genetics , Insect Vectors/genetics , Polytene Chromosomes/genetics , Salivary Glands , Anopheles/classification , Brazil , Chromosome Mapping , Insect Vectors/classification
15.
Mem. Inst. Oswaldo Cruz ; 110(3): 353-362, 05/2015. tab, graf
Article in English | LILACS | ID: lil-745984

ABSTRACT

A pseudogene, designated as "ps(5.8S+ITS-2)", paralogous to the 5.8S gene and internal transcribed spacer (ITS)-2 of the nuclear ribosomal DNA (rDNA), has been recently found in many triatomine species distributed throughout North America, Central America and northern South America. Among characteristics used as criteria for pseudogene verification, secondary structures and free energy are highlighted, showing a lower fit between minimum free energy, partition function and centroid structures, although in given cases the fit only appeared to be slightly lower. The unique characteristics of "ps(5.8S+ITS-2)" as a processed or retrotransposed pseudogenic unit of the ghost type are reviewed, with emphasis on its potential functionality compared to the functionality of genes and spacers of the normal rDNA operon. Besides the technical problem of the risk for erroneous sequence results, the usefulness of "ps(5.8S+ITS-2)" for specimen classification, phylogenetic analyses and systematic/taxonomic studies should be highlighted, based on consistence and retention index values, which in pseudogenic sequence trees were higher than in functional sequence trees. Additionally, intraindividual, interpopulational and interspecific differences in pseudogene amount and the fact that it is a pseudogene in the nuclear rDNA suggests a potential relationships with fitness, behaviour and adaptability of triatomine vectors and consequently its potential utility in Chagas disease epidemiology and control.


Subject(s)
Animals , DNA, Ribosomal Spacer/genetics , Insect Vectors/genetics , Pseudogenes , Triatominae/genetics , Chagas Disease/transmission , Genes, Insect/genetics , Insect Vectors/classification , Phylogeny , Sequence Alignment , Sequence Analysis, DNA , Triatominae/classification
16.
Arq. bras. cardiol ; 104(2): 112-119, 02/2015. tab
Article in English | LILACS | ID: lil-741142

ABSTRACT

Background: Neutrophil-to-lymphocyte ratio (NLR) has been found to be a good predictor of future adverse cardiovascular outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Changes in the QRS terminal portion have also been associated with adverse outcomes following STEMI. Objective: To investigate the relationship between ECG ischemia grade and NLR in patients presenting with STEMI, in order to determine additional conventional risk factors for early risk stratification. Methods: Patients with STEMI were investigated. The grade of ischemia was analyzed from the ECG performed on admission. White blood cells and subtypes were measured as part of the automated complete blood count (CBC) analysis. Patients were classified into two groups according to the ischemia grade presented on the admission ECG, as grade 2 ischemia (G2I) and grade 3 ischemia (G3I). Results: Patients with G3I had significantly lower mean left ventricular ejection fraction than those in G2I (44.58 ± 7.23 vs. 48.44 ± 7.61, p = 0.001). As expected, in-hospital mortality rate increased proportionally with the increase in ischemia grade (p = 0.036). There were significant differences in percentage of lymphocytes (p = 0.010) and percentage of neutrophils (p = 0.004), and therefore, NLR was significantly different between G2I and G3I patients (p < 0.001). Multivariate logistic regression analysis revealed that only NLR was the independent variable with a significant effect on ECG ischemia grade (odds ratio = 1.254, 95% confidence interval 1.120–1.403, p < 0.001). Conclusion: We found an association between G3I and elevated NLR in patients with STEMI. We believe that such an association might provide an additional prognostic value for risk stratification in patients with STEMI when combined with standardized risk scores. .


Fundamento: A relação neutrófilos/linfócitos (N/L) tem sido descrita como boa preditora de eventos cardiovasculares adversos futuros em pacientes com infarto agudo do miocárdio com elevação do segmento ST (IAMEST). Mudanças na porção terminal do complexo QRS também têm sido associadas a eventos adversos após IAMEST. Objetivo: Investigar a associação entre o grau de isquemia no ECG e a relação N/L em pacientes com IAMEST para determinar fatores de risco convencionais adicionais na estratificação precoce de risco. Métodos: Pacientes com IAMEST foram investigados. O grau de isquemia foi analisado a partir do ECG obtido à admissão. A contagem de leucócitos e seus subtipos foi realizada a partir de hemograma automatizado. De acordo com o grau de isquemia presente no ECG de admissão, os pacientes foram classificados em dois grupos, isquemia grau 2 (IG2) e isquemia grau 3 (IG3). Resultados: Pacientes com IG3 apresentaram valores médios significativamente menores de fração de ejeção do ventrículo esquerdo do que os pacientes com IG2 (44,58 ± 7,23 versus 48,44 ± 7,61; p = 0,001). Como esperado, a taxa de mortalidade intra-hospitalar aumentou proporcionalmente com o aumento no grau de isquemia (p = 0,036). Houve diferenças significativas nas porcentagens de linfócitos (p = 0,010) e de neutrófilos (p = 0,004) e, portanto, a relação N/L diferiu significativamente entre pacientes com IG2 e IG3 (p < 0,001). À análise de regressão logística multivariada, apenas a relação N/L emergiu como variável independente com efeito significativo sobre o grau de isquemia no ECG (odds ratio = 1,254; intervalo de confiança de 95% 1,120-1,403; p < 0,001). Conclusão: Nós encontramos uma associação entre IG3 e relação N/L aumentada em pacientes com IAMEST. Acreditamos que esta associação possa oferecer um valor prognóstico adicional para estratificação de risco em pacientes com IAMEST quando usado em combinação com escores de risco padronizados. .


Subject(s)
Animals , Female , Genome, Insect , Insect Proteins/genetics , Tsetse Flies/genetics , Blood , Feeding Behavior , Genes, Insect , Insect Proteins/physiology , Insect Vectors/genetics , Insect Vectors/microbiology , Insect Vectors/parasitology , Insect Vectors/physiology , Microbiota , Molecular Sequence Annotation , Molecular Sequence Data , Reproduction/genetics , Sequence Analysis, DNA , Symbiosis , Salivary Glands/parasitology , Salivary Glands/physiology , Sensation/genetics , Trypanosoma/physiology , Trypanosomiasis, African/transmission , Tsetse Flies/microbiology , Tsetse Flies/parasitology , Tsetse Flies/physiology , Wolbachia/genetics , Wolbachia/physiology
17.
Mem. Inst. Oswaldo Cruz ; 109(5): 672-684, 19/08/2014. tab, graf
Article in English | LILACS | ID: lil-720419

ABSTRACT

Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current “omics” era and the available data are mostly scattered or in “tables” that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.


Subject(s)
Animals , Anopheles/genetics , Anopheles/microbiology , Insect Vectors/genetics , Metagenomics , Microbiota , Geography, Medical , Microbiota/genetics , Phylogeny
18.
Biomédica (Bogotá) ; 33(supl.1): 89-98, set. 2013. ilus, graf, mapas, tab
Article in Spanish | LILACS | ID: lil-695800

ABSTRACT

Introducción. Aedes aegypti es el principal vector del dengue en zonas urbanas. A pesar de su importancia epidemiológica, se desconoce la variabilidad genética de las poblaciones del vector en Colombia. Objetivo. Determinar la variabilidad genética del gen mitocondrial ND4 , que codifica para la subunidad 4 de la enzima NADH-deshidrogenasa, entre poblaciones de Ae. aegypti de los municipios de Sincelejo y Guaranda, donde se registra alta y baja incidencia de dengue, respectivamente. Materiales y métodos. A partir del material genético extraído de 36 hembras de Ae. aegypti , se determinó la secuencia parcial del gen mitocondrial ND4 y se estimaron los parámetros de diversidad de nucleótidos, diversidad haplotípica, estructura genética y flujo de genes entre las poblaciones de Sincelejo y Guaranda. También, se analizó la varianza molecular y se construyó una red haplotípica. Resultados. Se obtuvieron 36 secuencias de nucleótidos de 282 pb; éstas presentaron doce sitios polimórficos y se agruparon en diez haplotipos, dos presentes en ambas poblaciones, tres exclusivos de la población de Sincelejo y cinco de la población de Guaranda. Los estimadores de estructura genética ( F ST =0,15) y de flujo de genes ( Nm =1,40) evidencian diferenciación genética y un limitado intercambio de genes entre las poblaciones. Conclusión. Las poblaciones de Ae. aegypti de Sincelejo y Guaranda son genéticamente divergentes.


Introduction: Aedes aegypti is the principal vector of dengue in urban areas. Despite its epidemiological importance, the genetic variability of Colombian populations of this species is unknown. Objetive: To determine the genetic variability of mitocondrial gene ND4, which codes for subunit 4 of the enzyme NADH deshydrogenase, between populations of Ae. aegypti from municipalities of Sincelejo and Guaranda. The incidences of dengue reported from these two localities are high and low, respectively. Materials and methods: Genetic material extracted from 36 females of Ae. aegypti was used to determine the partial sequence of the mitocondrial gene ND4 as well as to estimate the parameters of nucleotidic and haplotypic diversities, genetic structure and gene flow between the Sincelejo and Guaranda populations. The molecular variance was also analysed and a haplotypic network constructed. Results: In all 36 nucleotide sequences of 282pb were obtained. These presented 12 polymorphic sites and could grouped into 10 haplotypes, two of them present in both populations, three exclusive to the Sincelejo population and five to that of Guaranda. The estimators of genetic structure ( F ST = 0.15) and gene flow ( Nm = 1.40) are both indicative of genetic differentiation and a limited exchange of genes between the populations. Conclusions: The Sincelejo and Guaranda populations of Ae. aegypti are genetically divergent.


Subject(s)
Animals , Female , Aedes/genetics , Dengue/epidemiology , Insect Vectors/genetics , Aedes/classification , Colombia/epidemiology , DNA, Mitochondrial/genetics , Dengue/transmission , Ecosystem , Gene Transfer, Horizontal , Genes, Insect , Genetic Variation , Haplotypes , Incidence , Insect Proteins/genetics , NADH Dehydrogenase/genetics , Polymorphism, Genetic , Sequence Analysis, DNA , Species Specificity , Urban Health
19.
Mem. Inst. Oswaldo Cruz ; 108(5): 605-615, ago. 2013. tab, graf
Article in English | LILACS | ID: lil-680764

ABSTRACT

To evaluate whether environmental heterogeneity contributes to the genetic heterogeneity in Anopheles triannulatus, larval habitat characteristics across the Brazilian states of Roraima and Pará and genetic sequences were examined. A comparison with Anopheles goeldii was utilised to determine whether high genetic diversity was unique to An. triannulatus. Student t test and analysis of variance found no differences in habitat characteristics between the species. Analysis of population structure of An. triannulatus and An. goeldii revealed distinct demographic histories in a largely overlapping geographic range. Cytochrome oxidase I sequence parsimony networks found geographic clustering for both species; however nuclear marker networks depicted An. triannulatus with a more complex history of fragmentation, secondary contact and recent divergence. Evidence of Pleistocene expansions suggests both species are more likely to be genetically structured by geographic and ecological barriers than demography. We hypothesise that niche partitioning is a driving force for diversity, particularly in An. triannulatus.


Subject(s)
Animals , Anopheles/genetics , Genetic Variation/genetics , Insect Vectors/genetics , Anopheles/classification , Brazil , Gene-Environment Interaction , Geography , Insect Vectors/classification , Population Density
20.
Mem. Inst. Oswaldo Cruz ; 108(4): 529-531, jun. 2013. graf
Article in English | LILACS | ID: lil-678292

ABSTRACT

Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemolymph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.


Subject(s)
Animals , Culex/genetics , Gene Expression/genetics , Insect Vectors/genetics , Luminescent Proteins/genetics , Transformation, Genetic/genetics
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