RESUMEN
Rice stripe virus (RSV) transmitted by the small brown planthopper causes severe rice yield losses in Asian countries. Although viral nuclear entry promotes viral replication in host cells, whether this phenomenon occurs in vector cells remains unknown. Therefore, in this study, we systematically evaluated the presence and roles of RSV in the nuclei of vector insect cells. We observed that the nucleocapsid protein (NP) and viral genomic RNAs were partially transported into vector cell nuclei by utilizing the importin α nuclear transport system. When blocking NP nuclear localization, cytoplasmic RSV accumulation significantly increased. In the vector cell nuclei, NP bound the transcription factor YY1 and affected its positive regulation to FAIM. Subsequently, decreased FAIM expression triggered an antiviral caspase-dependent apoptotic reaction. Our results reveal that viral nuclear entry induces completely different immune effects in vector and host cells, providing new insights into the balance between viral load and the immunity pressure in vector insects.
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Animales , Núcleo Celular , Hemípteros/metabolismo , Insectos Vectores/genética , Insectos , Proteínas de la Nucleocápside/metabolismo , Oryza , Enfermedades de las Plantas , Tenuivirus/metabolismo , Replicación ViralRESUMEN
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.
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Humanos , Animales , Panstrongylus/genética , Panstrongylus/parasitología , Triatoma/parasitología , Trypanosoma cruzi/aislamiento & purificación , Enfermedad de Chagas/transmisión , Insectos Vectores/parasitología , Panstrongylus/fisiología , Filogenia , Variación Genética/genética , Biología , Genes de Insecto , Ecología , Genotipo , Geografía , Insectos Vectores/genética , América LatinaRESUMEN
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.
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Animales , Triatoma/genética , Enfermedad de Chagas , Variación Genética/genética , Bolivia , Brasil , Insectos Vectores/genéticaRESUMEN
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.
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Animales , Femenino , Psychodidae/parasitología , ADN/análisis , Insectos Vectores/genética , Leishmania/genética , Psychodidae/clasificación , Brasil , Reacción en Cadena de la Polimerasa , ADN Protozoario/análisis , Leishmaniasis Cutánea/transmisión , Insectos Vectores/clasificación , Insectos Vectores/parasitología , Leishmania/aislamiento & purificaciónRESUMEN
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.
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Animales , Piretrinas/farmacología , Resistencia a los Insecticidas/efectos de los fármacos , Resistencia a los Insecticidas/genética , Aedes/efectos de los fármacos , Mosquitos Vectores/efectos de los fármacos , Insecticidas/farmacología , Control de Mosquitos/métodos , Aedes/genética , Análisis Espacio-Temporal , Mosquitos Vectores/virología , Guyana Francesa , Insectos Vectores/efectos de los fármacos , Insectos Vectores/genéticaRESUMEN
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.
Asunto(s)
Animales , Masculino , Rhodnius/clasificación , Insectos Vectores/anatomía & histología , Filogenia , Rhodnius/anatomía & histología , Rhodnius/genética , Especificidad de la Especie , Enfermedad de Chagas/transmisión , Análisis de Secuencia de ADN , Insectos Vectores/clasificación , Insectos Vectores/genéticaRESUMEN
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.
Asunto(s)
Animales , Masculino , Psychodidae/genética , Variación Genética/genética , Distribución Animal , Insectos Vectores/genética , Argentina , Psychodidae/clasificación , Bolivia , Haplotipos , Brasil , ADN Mitocondrial/genética , Leishmaniasis Cutánea/transmisión , Genes de Insecto/genética , Filogeografía , Insectos Vectores/clasificaciónRESUMEN
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.
Asunto(s)
Animales , Psychodidae/genética , Leishmaniasis Cutánea/transmisión , Insectos Vectores/clasificación , Panamá , Filogenia , Psychodidae/clasificación , Biodiversidad , Insectos Vectores/genéticaRESUMEN
Resumen Introducción. Trypanosoma cruzi se ha dividido en seis unidades taxonómicas discretas (Discreet Typing Units, DTU) denominadas TcI, TcII, TcIII, TcIV, TcV y TcVI. Aún se desconocen los factores determinantes de la dinámica de la transmisión vectorial de los genotipos de T. cruzi en las diferentes regiones geográficas de distribución de la enfermedad de Chagas en Perú. Objetivo. Detectar y tipificar las unidades taxonómicas discretas de T. cruzi en las heces de siete especies de triatominos (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni y T. infestans), capturados en ocho departamentos de diferentes regiones naturales de Perú. Materiales y métodos. Se examinaron 197 insectos para la detección de tripanosomas. Se extrajo el ADN del contenido intestinal de cada insecto y se amplificó mediante reacción en cadena de la polimerasa (PCR) de los genes kDNA, SL-IR, 24Sa rRNA y 18Sa RNA para detectar las DTU de T. cruzi. Resultados. Se detectaron cinco infecciones con T. rangeli y 113 con T. cruzi. De estas últimas, fue posible identificar 95 de TcI (dos en P. chinai, una en P. geniculatus, 68 en P. herreri, cuatro en R. pictipes, siete en R. robustus, una en T. carrioni, y 12 en T. infestans); cinco de TcII (cuatro en P. herreri, una en T. infestans); cuatro de TcIII (tres en P. herreri, una en R. robustus) y cuatro infecciones de TcIV en P. herreri. Conclusión. Este es el primer trabajo de caracterización a gran escala de T. cruzi en el intestino de vectores de importancia epidemiológica en Perú, orientado a generar información básica que permita entender la dinámica de la transmisión vectorial de T. cruzi en esta región del continente.
Abstract Introduction: Trypanosoma cruzi has been divided by international consensus into six discrete typing units (DTU): TcI, TcII, TcIII, TcIV, TcV y TcVI. The factors determining the dynamics of T. cruzi genotypes vector transmission of Chagas' disease in the different geographical regions of Perú are still unknown. Objective: To detect and type T. cruzi DTUs from the faeces of seven species of triatomines (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni and T. infestans) captured in eight departments from different natural regions of Perú. Materials and methods: We examined 197 insects for detecting trypanosomes. DNA was extracted from each insect intestinal contents and PCR amplification of kDNA, SL-IR, 24Sa rRNA and 18Sa RNAwas performed for detecting T. cruzi DTUs. Results: Five T. rangeli and 113 T. cruzi infections were detected; 95 of the latter were identified as TcI (two in P. chinai, one in P. geniculatus, 68 in P. herreri, four in R. pictipes, seven in R. robustus, one in T. carrioni, 12 in T. infestans), five as TcII (four in P. herreri, one in T. infestans), four as TcIII (three in P. herreri, one in R. robustus) and four TcIV infections in P. herreri. Conclusions: This is the first study which has attempted a large-scale characterization of T. cruzi found in the intestine of epidemiologically important vectors in Perú, thus providing basic information that will facilitate a better understanding of the dynamics of T. cruzi vector transmission in Perú.
Asunto(s)
Animales , Preescolar , Humanos , Trypanosoma cruzi/clasificación , ADN Protozoario/genética , Triatominae/parasitología , Insectos Vectores/clasificación , Perú , Especificidad de la Especie , Trypanosoma cruzi/genética , ADN Protozoario/análisis , Triatominae/crecimiento & desarrollo , Enfermedad de Chagas/transmisión , Enfermedad de Chagas/epidemiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribotipificación , Heces/parasitología , Distribución Animal , Geografía Médica , Genotipo , Vivienda , Insectos Vectores/genéticaRESUMEN
Resumen Introducción. Los departamentos de Chocó y Antioquia en Colombia presentan condiciones climáticas y de vegetación que favorecen el establecimiento de especies de vectores del género Lutzomyia y la transmisión de Leishmania spp. a poblaciones humanas que ingresan a ambientes selváticos conservados. Objetivo. Reportar las especies de flebotomíneos presentes en tres reservas naturales de las regiones del Darién y del Pacífico en Colombia. Materiales y métodos. Los flebotomíneos se recolectaron en las reservas naturales El Aguacate (Acandí, Chocó), Nabugá (Bahía Solano, Chocó) y Tulenapa (Carepa, Antioquia). La recolección se hizo con trampas de luz CDC, mediante búsqueda activa en sitios de reposo y con trampas Shannon. La determinación taxonómica de especies se basó en las claves taxonómicas. En algunas especies de interés taxonómico, se evaluó el uso de secuencias parciales de la región 5' del gen COI. Resultados. Se recolectaron 611 flebotomíneos adultos: 531 en Acandí, 45 en Carepa y 35 en Bahía Solano. Se identificaron 17 especies del género Lutzomyia, tres del género Brumptomyia y una del género Warileya. Las distancias genéticas (K2P) y los soportes de agrupación (>99 %) en el dendrograma de neighbor joining correspondieron a la mayoría de unidades taxonómicas operacionales moleculares (Molecular Operational Taxonomic Units, MOTU) establecidas para el grupo Aragaoi y confirmaron claramente la identidad de Lu. coutinhoi. Conclusión. Se identificaron especies que tienen importancia en la transmisión de la leishmaniasis en Acandí, Bahía Solano y Carepa. Se confirmó la presencia de Lu. coutinhoi en Colombia.
Abstract Introduction: The departments of Chocó and Antioquia in Colombia show climatic and vegetation conditions favoring the establishment of vector species of the genus Lutzomyia and the transmission of Leishmania spp. to human populations entering conserved forest environments. Objective: To report the species of Phlebotomine sandflies present in three natural reserves in the Darien and Pacific regions of Colombia. Materials and methods: Sand flies were collected specifically in the natural reserves El Aguacate (Acandí, Chocó), Nabugá (Bahía Solano, Chocó) and Tulenapa (Carepa, Antioquia). Sand flies were collected with CDC light traps, active search in resting places and Shannon traps. The taxonomic determination of species was based on taxonomic keys. For some species of taxonomic interest, we evaluated the partial sequences of the 5' region of COI gene. Results: A total of 611 adult sand flies were collected: 531 in Acandí, 45 in Carepa and 35 in Bahía Solano. Seventeen species of the genus Lutzomyia, three of the genus Brumptomyia and one of the genus Warileya were identified. The genetic distances (K2P) and grouping supported (>99%) in the neighbor joining dendrogram were consistent for most established molecular operational taxonomic units (MOTU) of the Aragaoi group and clearly confirmed the identity of Lu. coutinhoi. Conclusion: Species that have importance in the transmission of leishmaniasis in Acandí, Bahía Solano and Carepa were identified. The presence of Lu. coutinhoi was confirmed and consolidated in Colombia.
Asunto(s)
Animales , Psychodidae , Insectos Vectores , Filogenia , Psychodidae/clasificación , Psychodidae/genética , Especificidad de la Especie , Secuencia de Bases , Homología de Secuencia de Ácido Nucleico , Bosques , Alineación de Secuencia , Leishmaniasis Cutánea/transmisión , Leishmaniasis Cutánea/epidemiología , Colombia/epidemiología , Complejo IV de Transporte de Electrones/genética , Proteínas de Insectos/genética , Ecología , Distribución Animal , Parques Recreativos , Insectos Vectores/clasificación , Insectos Vectores/genéticaRESUMEN
ABSTRACT Triatoma infestans is an insect of subfamily Triatominae (Hemiptera: Reduviidae) and an important vector of Trypanosoma cruzi, the etiologic agent of human Chagas disease. In this work we reported a transcriptome assembly and annotation of T. infestans heads obtained by Next Generation Sequencing (NGS) technologies.
Asunto(s)
Animales , Triatoma/genética , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Insectos Vectores/genéticaRESUMEN
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.
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Animales , Psychodidae/clasificación , Psychodidae/genética , Especificidad de la Especie , Genes de Insecto , Biodiversidad , Insectos Vectores/clasificación , Insectos Vectores/genética , Leishmaniasis Visceral/transmisión , Filogenia , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de Restricción , BrasilRESUMEN
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.
Asunto(s)
Animales , Femenino , Variación Genética/genética , Insectos Vectores/genética , Psychodidae/genética , Brasil , ADN Mitocondrial/análisis , ADN Protozoario/análisis , Insectos Vectores/clasificación , Leishmaniasis Cutánea/transmisión , Reacción en Cadena de la Polimerasa , Psychodidae/clasificaciónRESUMEN
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.
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Animales , Cromosomas de Insectos/genética , Heterocromatina/genética , Insectos Vectores/genética , Triatominae/genética , Evolución Biológica , Enfermedad de Chagas/transmisión , ADN Ribosómico/genética , Cariotipificación , ARN Ribosómico/genética , Triatominae/clasificaciónRESUMEN
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.
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Humanos , Animales , Femenino , ADN/análisis , Insectos Vectores/genética , Leishmania/genética , Psychodidae/genética , Biodiversidad , Bolivia , Brasil , ADN de Cinetoplasto , Genotipo , Insectos Vectores/clasificación , Insectos Vectores/parasitología , Leishmaniasis Cutánea/transmisión , Perú , Reacción en Cadena de la Polimerasa , Densidad de Población , Psychodidae/clasificación , Psychodidae/parasitologíaRESUMEN
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.
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Animales , Citocromos b/genética , ADN Mitocondrial/genética , Variación Genética/genética , Insectos Vectores/genética , Triatoma/genética , Brasil , Enfermedad de Chagas/transmisión , Insectos Vectores/clasificación , Triatoma/clasificaciónRESUMEN
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.
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Animales , Anopheles/genética , Inversión Cromosómica/genética , Insectos Vectores/genética , Cromosomas Politénicos/genética , Glándulas Salivales , Anopheles/clasificación , Brasil , Mapeo Cromosómico , Insectos Vectores/clasificaciónRESUMEN
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.
Asunto(s)
Animales , ADN Espaciador Ribosómico/genética , Insectos Vectores/genética , Seudogenes , Triatominae/genética , Enfermedad de Chagas/transmisión , Genes de Insecto/genética , Insectos Vectores/clasificación , Filogenia , Alineación de Secuencia , Análisis de Secuencia de ADN , Triatominae/clasificaciónRESUMEN
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. .
Asunto(s)
Animales , Femenino , Genoma de los Insectos , Proteínas de Insectos/genética , Moscas Tse-Tse/genética , Sangre , Conducta Alimentaria , Genes de Insecto , Proteínas de Insectos/fisiología , Insectos Vectores/genética , Insectos Vectores/microbiología , Insectos Vectores/parasitología , Insectos Vectores/fisiología , Microbiota , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Reproducción/genética , Análisis de Secuencia de ADN , Simbiosis , Glándulas Salivales/parasitología , Glándulas Salivales/fisiología , Sensación/genética , Trypanosoma/fisiología , Tripanosomiasis Africana/transmisión , Moscas Tse-Tse/microbiología , Moscas Tse-Tse/parasitología , Moscas Tse-Tse/fisiología , Wolbachia/genética , Wolbachia/fisiologíaRESUMEN
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.