RESUMO
We describe the immature stages of Migonemyia migonei, which is the vector of Leishmania (Viannia) braziliensis, the etiological agent of cutaneous leishmaniasis in South America, and a putative vector of Leishmania infantum chagasi. Scanning Electron Microscopy (SEM) was used to refine the description of the structures of the egg, all instar larvae, and the pupa. The eggs have polygonal cells on the egg exochorion, and differences between larval and pupal chaetotaxy have been highlighted. Different sensillary subtypes-trichoidea, basiconica, coelonica and campanoformia-were observed in the larval stages. The results presented herein contribute to the taxonomy of Mg. migonei and may contribute to future studies on the phylogeny of this important vector species.
Assuntos
Dípteros/ultraestrutura , Insetos Vetores/ultraestrutura , Animais , Dípteros/crescimento & desenvolvimento , Dípteros/parasitologia , Feminino , Insetos Vetores/crescimento & desenvolvimento , Insetos Vetores/parasitologia , Larva/ultraestrutura , Leishmania infantum/patogenicidade , Masculino , Microscopia Eletrônica de Varredura , Óvulo/ultraestrutura , Pupa/ultraestruturaRESUMO
Whole mitogenome sequences (mtDNA) have been exploited for insect ecology studies, using them as molecular markers to reconstruct phylogenies, or to infer phylogeographic relationships and gene flow. Recent Anopheles phylogenomic studies have provided information regarding the time of deep lineage divergences within the genus. Here we report the complete 15,393 bp mtDNA sequences of Anopheles aquasalis, a Neotropical human malaria vector. When comparing its structure and base composition with other relevant and available anopheline mitogenomes, high similarity and conserved genomic features were observed. Furthermore, 22 mtDNA sequences comprising anopheline and Dipteran sibling species were analyzed to reconstruct phylogenies and estimate dates of divergence between taxa. Phylogenetic analysis using complete mtDNA sequences suggests that A. aquasalis diverged from the Anopheles albitarsis complex ~28 million years ago (MYA), and ~38 MYA from Anopheles darlingi. Bayesian analysis suggests that the most recent ancestor of Nyssorhynchus and Anopheles + Cellia was extant ~83 MYA, corroborating current estimates of ~79-100 MYA. Additional sampling and publication of African, Asian, and North American anopheline mitogenomes would improve the resolution of the Anopheles phylogeny and clarify early continental dispersal routes.
Assuntos
Anopheles/classificação , Anopheles/genética , Genoma Mitocondrial , Genômica , Filogenia , Filogeografia , Animais , Composição de Bases , Biologia Computacional/métodos , Evolução Molecular , Genômica/métodos , Humanos , Anotação de Sequência Molecular , Mosquitos Vetores/classificação , Mosquitos Vetores/genética , Análise de Sequência de DNA , Sequenciamento Completo do GenomaRESUMO
Roads and highways can affect the spread of insect-borne diseases by limiting or amplifying the spatiotemporal distribution of vectors, pathogens, and hosts, which can, in turn, lead to the creation of a nidus of infection. The aim of this study was to compare the diversity (richness and abundance) of phlebotomine sand flies in household and forest edge environments found along two different segments of an Amazonian highway. Sampling was conducted along the northern and southern portions of highway BR-319, in Amazonas State, Brazil. At each sampling point, Hoover Pugedo traps were set in indoor and outdoor habitats, and at forests edges, and captures were made between 06:00 pm and 06:00 am. A total of 1,189 sand flies were captured and 48 species were identified. As expected, a greater number of species and individuals were captured in forest edge environments. Permutational Multivariate Analyses of Variance (PERMANOVA) and Permutational Analyses of Multivariate Dispersions (PERMDISP) analyses showed that sand fly fauna differed significantly among habitats, but no variance in species composition was observed between the two road segments. Some of the captured species were species that have been implicated as vectors of Leishmania spp. Ross, 1903 (Kinetoplastida: Trypanosomatidae).
Assuntos
Biodiversidade , Psychodidae , Animais , Brasil , Florestas , Habitação , Densidade DemográficaRESUMO
Innate immunity is an ancient and conserved defense system that provides an early effective response against invaders. Many immune genes of Anopheles mosquitoes have been implicated in defense against a variety of pathogens, including plasmodia. Nevertheless, only recent work identified some immune genes of Anopheles aquasalis mosquitoes upon P. vivax infection. Among these was a GATA transcription factor gene, which is described here. This is an ortholog of GATA factor Serpent genes described in Drosophila melanogaster and Anopheles gambiae. Gene expression analyses showed an increase of GATA-Serpent mRNA in P. vivax-infected A. aquasalis and functional RNAi experiments identified this transcription factor as an important immune gene of A. aquasalis against both bacteria and P. vivax. Besides, we were able to identify an effect of GATA-Serpent knockdown on A. aquasalis hemocyte proliferation and differentiation. These findings expand our understanding of the poorly studied A. aquasalis-P. vivax interactions and uncover GATA-Serpent as a key player of the mosquito innate immune response.
Assuntos
Anopheles/imunologia , Bactérias/imunologia , Fatores de Transcrição GATA/metabolismo , Imunidade Inata , Plasmodium/imunologia , Animais , Anopheles/genética , Diferenciação Celular , Proliferação de Células , Feminino , Fatores de Transcrição GATA/genética , Perfilação da Expressão Gênica , Inativação Gênica , Hemócitos/imunologia , Hemócitos/fisiologiaRESUMO
The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(ß1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly.
Assuntos
Glicoesfingolipídeos/química , Glicoesfingolipídeos/imunologia , Interações Hospedeiro-Parasita , Leishmania mexicana/química , Macrófagos Peritoneais/imunologia , Psychodidae/parasitologia , Receptor 4 Toll-Like/imunologia , Animais , Brasil , Células CHO , Cricetulus , Citocinas/imunologia , Glicoesfingolipídeos/isolamento & purificação , Interações Hospedeiro-Parasita/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/efeitos dos fármacos , Receptor 4 Toll-Like/genéticaRESUMO
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.
Assuntos
Anopheles/genética , Inversão Cromossômica/genética , Insetos Vetores/genética , Cromossomos Politênicos/genética , Glândulas Salivares , Animais , Anopheles/classificação , Brasil , Mapeamento Cromossômico , Insetos Vetores/classificaçãoRESUMO
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.
Assuntos
Animais , Anopheles/genética , Inversão Cromossômica/genética , Insetos Vetores/genética , Cromossomos Politênicos/genética , Glândulas Salivares , Anopheles/classificação , Brasil , Mapeamento Cromossômico , Insetos Vetores/classificaçãoRESUMO
In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Anopheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.
Assuntos
Anopheles/parasitologia , Insetos Vetores/parasitologia , Malária/transmissão , Plasmodium/classificação , Animais , Anopheles/classificação , Anopheles/genética , Anopheles/imunologia , Anopheles/ultraestrutura , Modelos Animais de Doenças , Insetos Vetores/classificação , Insetos Vetores/genética , Insetos Vetores/imunologia , Insetos Vetores/ultraestrutura , Malária/imunologia , Controle de Mosquitos , Carga Parasitária , Floresta ÚmidaRESUMO
In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Amoxicilina/administração & dosagem , Antibacterianos/administração & dosagem , Medicamentos de Ervas Chinesas/administração & dosagem , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Omeprazol/análogos & derivados , Úlcera Péptica/tratamento farmacológico , Antiulcerosos/administração & dosagem , Claritromicina/administração & dosagem , Método Duplo-Cego , Quimioterapia Combinada , Seguimentos , Infecções por Helicobacter/patologia , Lansoprazol , Omeprazol/administração & dosagem , Estudos Prospectivos , Úlcera Péptica/microbiologia , Úlcera Péptica/patologia , Recidiva , Cicatrização/efeitos dos fármacosRESUMO
BACKGROUND: Anopheles darlingi is the major malaria vector in countries located in the Amazon region. Anopheles aquasalis and Anopheles albitarsis s.l. are also proven vectors in this region. Anopheles nuneztovari s.l. and Anopheles triannulatus s.l. were found infected with Plasmodium vivax; however, their status as vectors is not yet well defined. Knowledge of susceptibility of Amazon anopheline populations to Plasmodium infection is necessary to better understand their vector capacity. Laboratory colonization of An. darlingi, the main Amazon vector, has proven to be difficult and presently An. aquasalis is the only available autonomous colony. METHODS: Larvae of An. darlingi, An. albitarsis s.l., An. nuneztovari s.l. and An. triannulatus s.l. were collected in the field and reared until adult stage. Adults of An. aquasalis were obtained from a well-established colony. Mosquitoes were blood-fed using a membrane-feeding device containing infected blood from malarial patients.The infection of the distinct Anopheles species was evaluated by the impact variance of the following parameters: (a) parasitaemia density; (b) blood serum inactivation of the infective bloodmeal; (c) influence of gametocyte number on infection rates and number of oocysts. The goal of this work was to compare the susceptibility to P. vivax of four field-collected Anopheles species with colonized An. aquasalis. RESULTS: All Anopheles species tested were susceptible to P. vivax infection, nevertheless the proportion of infected mosquitoes and the infection intensity measured by oocyst number varied significantly among species. Inactivation of the blood serum prior to mosquito feeding increased infection rates in An. darlingi and An. triannulatus s.l., but was diminished in An. albitarsis s.l. and An. aquasalis. There was a positive correlation between gametocyte density and the infection rate in all tests (Z = -8.37; p < 0.001) but varied among the mosquito species. Anopheles albitarsis s.l., An. aquasalis and An. nuneztovari s.l. had higher infection rates than An. darlingi. CONCLUSION: All field-collected Anopheles species, as well as colonized An. aquasalis are susceptible to experimental P. vivax infections by membrane feeding assays. Anopheles darlingi, An. albitarsis s.l. and An. aquasalis are very susceptible to P. vivax infection. However, colonized An. aquasalis mosquitoes showed the higher infection intensity represented by infection rate and oocyst numbers. This study is the first to characterize experimental development of Plasmodium infections in Amazon Anopheles vectors and also to endorse that P. vivax infection of colonized An. aquasalis is a feasible laboratory model.