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1.
bioRxiv ; 2024 May 03.
Article in English | MEDLINE | ID: mdl-38746412

ABSTRACT

Forest edges, where humans, mosquitoes, and wildlife interact, may serve as a nexus for zoonotic arbovirus exchange. Although often treated as uniform interfaces, the landscape context of edge habitats can greatly impact ecological interactions. Here, we investigated how the landscape context of forest edges shapes mosquito community structure in an Amazon rainforest reserve near the city of Manaus, Brazil, using hand-nets to sample mosquitoes at three distinct forest edge types. Sampling sites were situated at edges bordering urban land cover, rural land cover, and natural treefall gaps, while sites in continuous forest served as controls. Community composition differed substantially among edge types, with rural edges supporting the highest species diversity. Rural edges also provided suitable habitat for forest specialists, including key sylvatic vectors, of which Haemagogus janthinomys was the most abundant species sampled overall. Our findings emphasize the importance of landscape context in assessing pathogen emergence risk at forest edges.

2.
J Med Entomol ; 61(1): 142-151, 2024 01 12.
Article in English | MEDLINE | ID: mdl-37931918

ABSTRACT

Bichromomyia flaviscutellata (Mangabeira, 1942) sensu stricto (Diptera: Psychodidae) has been recognized as the main vector of Leishmania amazonensis in the Brazilian Amazon. For this reason, it is of paramount importance to understand the distribution of genetic diversity of populations of this vector, particularly the genetic structure and gene flow, for its management and control efforts. This study investigated the phylogeographic structure of five B. flaviscutellata s.s. populations from the central Brazilian Amazon region by analyzing 1,141 bp fragment of the 3' region of the COI gene. A total of 85 specimens of B. flaviscutellata s.s. were sequenced from Manaus (14), Rio Preto da Eva (10), Pitinga (14), Novo Airão (21), and Autazes (26); all in the state of Amazonas. The dataset yielded 59 haplotypes, most of them connected to each other in the main network. There were high levels of intrapopulation genetic variability (h = 0.945 ± 0.035 - 0.978 ± 0.054). The genetic distance values among populations varied from moderate (0.0873) to very high (0.3535), and all comparisons were significant, as well as the hierarchical analysis (ΦST = 0.2145). In contrast, these comparisons revealed a high number of shared sites (Ss = 6-34) and no difference in fixed sites (Sf = 0) among populations indicating absence of historical isolation. The Mantel test indicated that 67.92% (r = 0.6792; P = 0.06) of the genetic structure observed in B. flaviscutellata s.s. cannot be explained by the isolation-by-distance (IBD) model. This genetic structure, weakly explained by the IBD, may be due mainly by the forest habitat fragmentation and the low dispersal (flight) capacity of sand flies. Both factors could lead to population fragmentation and isolation, which promote genetic differentiation. Taken together, these findings suggest that the genetic structure observed in the studied populations of B. flaviscutellata s.s. is likely generated by microevolutionary processes acting at the population level at the present time and, therefore, evolutionary lineages were not recognized among the populations analyzed.


Subject(s)
Psychodidae , Animals , Psychodidae/genetics , Brazil , Rainforest , Phylogeography , Ecosystem
3.
Trop Med Infect Dis ; 8(10)2023 Oct 22.
Article in English | MEDLINE | ID: mdl-37888607

ABSTRACT

The objective of this study was to evaluate ecological aspects of Mansonia species before the construction of hydroelectric plants on the Madeira River, and thus enable the assessment of the impact of these projects on mosquitoes. A total of 199 samplings were carried out between November 2003 and August 2004, using the technique of attraction with protection. Temporal distribution was evaluated from monthly incidence values obtained from the bite index per man/hour. Relative abundance was subsequently calculated to evaluate the spatial distribution of species, according to land use and municipal districts; furthermore, the pattern of hematophagous activity was evaluated from 12-h and 4-h samplings. The data were analyzed according to the negative binomial distribution and generalized linear models to estimate the influence of environmental factors on the presence and abundance of Mansonia. A total of 1479 specimens were collected, distributed among four species-Mansonia titillans (87%), Mansonia humeralis (6.3%), Mansonia amazonensis (6%), and Mansonia indubitans (0.5%), and spatial distribution analysis showed Ma. titillans to be dominant. Hematophagous activity had peaks between 6:00 p.m. and 8:00 p.m. and species incidence was higher during the rainy season and in areas where domestic animals are raised. Therefore, the region studied presented characteristics favorable to the reproduction of Mansonia even before the construction of the hydroelectric plants and after construction, these conditions were enhanced, due to the increase in the availability of breeding sites for immatures and blood sources for females, as a consequence of changes in the environment.

4.
PLoS One ; 18(8): e0288983, 2023.
Article in English | MEDLINE | ID: mdl-37624846

ABSTRACT

BACKGROUND: In Brazilian Amazon, deforestation and other anthropogenic activities as a consequence of human occupation have created new and artificial larval habitats for anopheline mosquitoes, providing conditions for oviposition, development and expansion of malaria vector populations. OBJECTIVES: This study aimed to structurally characterize and describe the entomological and limnological parameters of Anopheles larval habitats from a malaria region in northern Brazilian Amazon. METHODS: Fifty-two larval habitats were investigated in the District of Ilha de Santana, in the Brazilian state of Amapá, comprising fish farming tanks, ponds, and streams. For entomological parameters, the immature larvae were collected monthly from July 2019 to June 2020. For limnological parameters, the water samples were collected from 20 larval habitats during the sampling period. The data were analyzed using Generalized Linear Models, Multivariate analyses, and Kruskal-Wallis tests. RESULTS: Fifty habitats were positive for Anopheles larvae and a total of nine species were collected. The fish farming tanks had the highest abundance of larvae compared with ponds and streams. Anopheles darlingi, Anopheles nuneztovari s.l. and Anopheles triannulatus were collected in 94% of the larval habitats and showed the highest positivity index. The degree of shade and the type of water of the breeding sites were important factors for the presence of the main malaria vector, A. darlingi. This species was the most affected by pH, total dissolved solids, electrical conductivity, and nitrate. CONCLUSIONS: Our findings indicate that fish farming tanks are major contributors to vector anopheline abundance and malaria transmission. Vector control strategies focused on these habitats are urgently needed.


Subject(s)
Anopheles , Malaria , Animals , Humans , Female , Brazil , Mosquito Vectors , Ecology , Population Dynamics , Fisheries , Larva
5.
Viruses ; 15(6)2023 06 12.
Article in English | MEDLINE | ID: mdl-37376655

ABSTRACT

Zika virus (ZIKV) is an RNA flavivirus (Flaviviridae family) endemic in tropical and subtropical regions that is transmitted to humans by Aedes (Stegomyia) species mosquitoes. The two main urban vectors of ZIKV are Aedes aegypti and Aedes albopictus, which can be found throughout Brazil. This study investigated ZIKV infection in mosquito species sampled from urban forest fragments in Manaus (Brazilian Amazon). A total of 905 non-engorged female Ae. aegypti (22 specimens) and Ae. albopictus (883 specimens) were collected using BG-Sentinel traps, entomological hand nets, and Prokopack aspirators during the rainy and dry seasons between 2018 and 2021. All pools were macerated and used to inoculate C6/36 culture cells. Overall, 3/20 (15%) Ae. aegypti and 5/241 (2%) Ae. albopictus pools screened using RT-qPCR were positive for ZIKV. No supernatants from Ae. aegypti were positive for ZIKV (0%), and 15 out of 241 (6.2%) Ae. albopictus pools were positive. In this study, we provide the first-ever evidence of Ae. albopictus naturally infected with ZIKV in the Amazon region.


Subject(s)
Aedes , Zika Virus Infection , Zika Virus , Humans , Animals , Female , Zika Virus/genetics , Brazil/epidemiology , Mosquito Vectors
6.
PLoS Negl Trop Dis ; 17(4): e0011296, 2023 04.
Article in English | MEDLINE | ID: mdl-37099599

ABSTRACT

Risk of spillover and spillback of mosquito-borne viruses in the neotropics, including yellow fever, dengue, Zika (Flaviviridae: Flavivirus), chikungunya, and Mayaro (Togaviridae: Alphavirus) viruses, is highest at ecotones where humans, monkeys, and mosquitoes coexist. With a view to identifying potential bridge vectors, we investigated changes in mosquito community composition and environmental variables at ground level at distances of 0, 500, 1000, and 2000 m from the edge of a rainforest reserve bordering the city of Manaus in the central Brazilian Amazon. During two rainy seasons in 2019 and 2020, we sampled 9,467 mosquitoes at 244 unique sites using BG-Sentinel traps, hand-nets, and Prokopack aspirators. Species richness and diversity were generally higher at 0 m and 500 m than at 1000 m and 2000 m, while mosquito community composition changed considerably between the forest edge and 500 m before stabilizing by 1000 m. Shifts in environmental variables mainly occurred between the edge and 500 m, and the occurrence of key taxa (Aedes albopictus, Ae. scapularis, Limatus durhamii, Psorophora amazonica, Haemagogus, and Sabethes) was associated with one or more of these variables. Sites where Ae. aegypti and Ae. albopictus were detected had significantly higher surrounding mean NDBI (Normalized Difference Built-up Index) values than sites where they were not detected, while the opposite was true for Sabethes mosquitoes. Our findings suggest that major changes in mosquito communities and environmental variables occur within 500 m of the forest edge, where there is high risk for contact with both urban and sylvatic vectors. By 1000 m, conditions stabilize, species diversity decreases, and forest mosquitoes predominate. Environmental variables associated with the occurrence of key taxa may be leveraged to characterize suitable habitat and refine risk models for pathogen spillover and spillback.


Subject(s)
Aedes , Flavivirus , Zika Virus Infection , Zika Virus , Humans , Animals , Brazil , Mosquito Vectors , Forests , Ecosystem
7.
Acta Trop ; 233: 106574, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35768041

ABSTRACT

Previous studies have linked the construction of hydroelectric dams with increases in the density of mosquitoes, especially Mansonia. In Brazil, Mansonia mosquitoes are still poorly studied at the taxonomic, biological, ecological and epidemiological levels, and nothing is known about the genetic diversity and the cryptic speciation of the group. The current study analyzed the molecular taxonomy of Mansonia species captured in the area surrounding the Jirau hydroelectric dam, Rondônia state, Brazil. Samples were collected from fifteen locations between 2018 and 2019. Genomic DNA of the specimens was extracted, and the DNA barcode region of the Cytochrome Oxidase, subunit I gene was amplified with PCR and both DNA strands were sequenced. The dataset was analyzed using MEGA, Mr. Bayes and DnaSP software. The results provided COI sequences for 100 specimens collected in the area surrounding from Jirau hydroelectric dam. These belonged to five species of the Mansonia subgenus, identified morphologically as Mansonia humeralis, Mansonia amazonensis, Mansonia titillans, Mansonia dyari and Mansonia indubitans. Findings showed that the COI gene is an effective and accessible DNA barcode that provides a high-resolution tool for delimiting species within the subgenus Mansonia, with the tree construction (Bayesian Inference) well supported and non-overlapping intraspecific and interspecific (K2-P) genetic distance values. These findings also indicate the occurrence of cryptic speciation within M. dyari and near of M. titillans. This is the first study to apply molecular tools to the taxonomy of Mansonia species from Brazil.


Subject(s)
Culicidae , Malvaceae , Animals , Bayes Theorem , Brazil , DNA , DNA Barcoding, Taxonomic
8.
Viruses ; 15(1)2022 12 23.
Article in English | MEDLINE | ID: mdl-36680085

ABSTRACT

Haemagogus (Haemagogus) janthinomys (Dyar, 1921), the major neotropical vector of sylvatic yellow fever virus, is notoriously difficult to maintain in captivity. It has never been reared beyond an F1 generation, and almost no experimental transmission studies have been performed with this species since the 1940s. Herein we describe installment hatching, artificial blood feeding, and forced-mating techniques that enabled us to produce small numbers of F3 generation Hg. janthinomys eggs for the first time. A total of 62.8% (1562/2486) F1 generation eggs hatched during ≤10 four-day cycles of immersion in a bamboo leaf infusion followed by partial drying. Hatching decreased to 20.1% (190/944) in the F2 generation for eggs laid by mosquitoes copulated by forced mating. More than 85% (79/92) female F2 mosquitoes fed on an artificial blood feeding system. While we were unable to maintain a laboratory colony of Hg. janthinomys past the F3 generation, our methods provide a foundation for experimental transmission studies with this species in a laboratory setting, a critical capacity in a region with hyper-endemic transmission of dengue, Zika, and chikungunya viruses, all posing a risk of spillback into a sylvatic cycle.


Subject(s)
Blood Substitutes , Culicidae , Yellow Fever , Zika Virus Infection , Zika Virus , Animals , Female , Mosquito Vectors , Yellow fever virus , Brazil
9.
Sci Rep ; 11(1): 21129, 2021 10 26.
Article in English | MEDLINE | ID: mdl-34702887

ABSTRACT

In the Americas, some mosquito-borne viruses such as Zika, chikungunya, and dengue circulate among humans in urban transmission cycles, while others, including yellow fever and Mayaro, circulate among monkeys in sylvatic cycles. The intersection of humans and wildlife at forest edges creates risk for zoonotic virus exchange. We built a scaffold tower at the edge of a treefall gap in rainforest bordering Manaus, Brazil, to identify vectors that may bridge transmission between humans and monkeys. We vertically sampled diurnally active, anthropophilic mosquitoes using handheld nets at 0, 5, and 9 m and container-breeding mosquitoes in ovitraps at 0, 5, 10, and 15 m. Haemagogus janthinomys and Psorophora amazonica were present in high relative abundance in nets at each height sampled, while anthropophilic species were uncommon in ovitraps. Hg. janthinomys was more abundant at elevated heights than at ground level, while Ps. amazonica abundance was not significantly stratified across heights. The presence of each species increased with increasing 7-day rainfall lagged at 1 week, and at 1 and 4 weeks prior to collection, respectively. In addition, Hg. janthinomys was most frequently collected at 29.9 °C, irrespective of height. These data provide insight into the potential role of each species as bridge vectors.


Subject(s)
Arboviruses , Culicidae/virology , Forests , Microclimate , Models, Biological , Mosquito Vectors/virology , Animals , Arboviruses/classification , Arboviruses/isolation & purification , Arboviruses/metabolism , Brazil , Culicidae/physiology , Haplorhini , Mosquito Vectors/physiology
11.
Sci Rep ; 11(1): 15323, 2021 07 28.
Article in English | MEDLINE | ID: mdl-34321495

ABSTRACT

Lutzomyia umbratilis is the main vector of Leishmania guyanensis in the Brazilian Amazon and in neighboring countries. Previous biological and molecular investigations have revealed significant differences between L. umbratilis populations from the central Brazilian Amazon region. Here, a phylogeographic survey of L. umbratilis populations collected from nine localities in the Brazilian Amazon was conducted using two mitochondrial genes. Statistical analyses focused on population genetics, phylogenetic relationships and species delimitations. COI genetic diversity was very high, whereas Cytb diversity was moderate. COI genealogical haplotypes, population structure and phylogenetic analyses identified a deep genetic differentiation and three main genetic groups. Cytb showed a shallower genetic structure, two main haplogroups and poorly resolved phylogenetic trees. These findings, allied to absence of isolation by distance, support the hypothesis that the Amazon and Negro Rivers and interfluves are the main evolutionary forces driving L. umbratilis diversification. The main three genetic groups observed represent three evolutionary lineages, possibly species. The first lineage occurs north of the Amazon River and east of Negro River, where Le. guyanensis transmission is intense, implying that L. umbratilis is an important vector there. The second lineage is in the interfluve between north of Amazon River and west of Negro River, an area reported to be free of Le. guyanensis transmission. The third lineage, first recorded in this study, is in the interfluve between south of Amazonas River and west of Madeira River, and its involvement in the transmission of this parasite remains to be elucidated.


Subject(s)
Biological Evolution , Insect Vectors/genetics , Leishmania guyanensis/pathogenicity , Leishmaniasis, Mucocutaneous/transmission , Phylogeny , Psychodidae/genetics , Animals , Brazil/epidemiology , Cytochromes b/genetics , Electron Transport Complex IV/genetics , Female , Gene Expression , Genetic Variation , Haplotypes , Humans , Insect Proteins/genetics , Insect Vectors/classification , Leishmania guyanensis/growth & development , Leishmaniasis, Mucocutaneous/epidemiology , Leishmaniasis, Mucocutaneous/parasitology , Mitochondria/enzymology , Mitochondria/genetics , Phylogeography , Psychodidae/classification , Rivers/parasitology
12.
Acta Trop ; 221: 106004, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34119461

ABSTRACT

The Oswaldoi-konderi Complex (Anopheles, Nyssorhynchus) is composed of five species that have been distinguished and delimited using DNA sequences of mitochondrial and nuclear genes. At least two species of the complex have been formally described, namely Anopheles oswaldoi s.s. and An. konderi; however, the identity of An. konderi s.s. is unclear because two morphologically similar species co-exist in the type-locality in the municipality of Coari, Amazonas state, Brazil. Moreover, the study of resurrection and designation of the neotype of An. konderi s.s. included a mixture of both forms. In the present study, mosquitoes were collected in Coari to establish the molecular identity of An. konderi s.s. and describe a new species based on morphological and molecular data. Six females were collected and separated individually for oviposition. The parental progenies were obtained from field collected females, fourth-instar larva, pupa, and female and male were employed for morphological characterization. Genomic DNA from one fourth-instar larva of each progeny was extracted and sequenced for the mtDNA COI barcode region, CAD gene, and the ITS2 rDNA nuclear region to establish the molecular identity of the two morphological forms of An. konderi s.l. The An. konderi neotype was re-examined. The morphological and molecular analyses revealed two distinct groups: the first group was identical to the neotype of An. konderi s.s., whereas the second was found to belong to the group informally referred to as An. sp. near konderi or An. konderi B, herein described as Anopheles tadei n. sp.


Subject(s)
Anopheles , Animals , Anopheles/genetics , DNA, Mitochondrial/genetics , DNA, Ribosomal/genetics , Female , Larva/genetics , Male , Pupa
13.
Rev. bras. entomol ; 65(4): e20200048, 2021. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1351730

ABSTRACT

ABSTRACT The present study aimed identifying the behavioral patterns of Anopheles species as well as to estimate the parity rate and natural infection analysis for Plasmodium species in the district of Ilha de Santana, state of Amapá, Brazil. The samples were obtained in four and 12-hours collections. In the intradomiciliary and peridomiciliary conditions and also in environments with the presence of animals from January/2017 to December/2018. The entomological parameters evaluated were human biting rate (HBR); Indexes of Anthropophily (IA) and Zoophily (IZ); Parity Rate (PR); Natural Infection Rate (NIR); Monthly and annual entomological inoculation rate (EIR). A total of 1,330 Anopheles specimens were collected, distributed in nine species. All captured species showed preference biting in outdoor enviroment. Anopheles darlingi was the most frequent species collected in indoor environment and the most anthropophilic (IA = 0.39) compared with the remaining species captured. It was also the unique species positive for Plasmodium vivax, had the highest anthropophily degree, highest biting activity and HBR in the first hours with a hight rate of parous females. Anopheles nuneztovari s.l. was the most zoophilic species (IZ = 0.65). These findings suggest that A. darlingi is the main malaria vector in the studied area. Anopheles albitarsis s.l. was the second species more anthropophilic (IA = 0.31) and revealed a stable pattern with a biting activity peak after sunset, consequently this species may contribute with malaria transmission in area.

14.
Sci Rep ; 10(1): 18254, 2020 10 26.
Article in English | MEDLINE | ID: mdl-33106507

ABSTRACT

The emergence of Zika virus (ZIKV) in Latin America brought to the fore longstanding concerns that forests bordering urban areas may provide a gateway for arbovirus spillback from humans to wildlife. To bridge urban and sylvatic transmission cycles, mosquitoes must co-occur with both humans and potential wildlife hosts, such as monkeys, in space and time. We deployed BG-Sentinel traps at heights of 0, 5, 10, and 15 m in trees in a rainforest reserve bordering Manaus, Brazil, to characterize the vertical stratification of mosquitoes and their associations with microclimate and to identify potential bridge vectors. Haemagogus janthinomys and Sabethes chloropterus, two known flavivirus vectors, showed significant stratification, occurring most frequently above the ground. Psorophora amazonica, a poorly studied anthropophilic species of unknown vector status, showed no stratification and was the most abundant species at all heights sampled. High temperatures and low humidity are common features of forest edges and microclimate analyses revealed negative associations between minimum relative humidity, which was inversely correlated with maximum temperature, and the occurrence of Haemagogus and Sabethes mosquitoes. In this reserve, human habitations border the forest while tamarin and capuchin monkeys are also common to edge habitats, creating opportunities for the spillback of mosquito-borne viruses.


Subject(s)
Animals, Wild/virology , Arbovirus Infections/transmission , Culicidae/virology , Mosquito Vectors/virology , Yellow Fever/transmission , Zika Virus Infection/transmission , Animals , Arbovirus Infections/virology , Arboviruses/isolation & purification , Arboviruses/pathogenicity , Brazil , Ecosystem , Flavivirus/isolation & purification , Flavivirus/pathogenicity , Forests , Haplorhini , Humans , Trees , Yellow Fever/virology , Zika Virus/isolation & purification , Zika Virus/pathogenicity , Zika Virus Infection/virology
15.
Infect Genet Evol ; 81: 104256, 2020 07.
Article in English | MEDLINE | ID: mdl-32084625

ABSTRACT

Leishmaniasis is considered one of the six most important infectious diseases in the world. In spite of its importance, the leishmaniasis is one of the world's most neglected tropical diseases. Bichromomyia flaviscutellata sensu lato is a complex composed of at least three species: B. flaviscutellata sensu stricto, B. reducta and B. olmeca. The latter is composed of three subspecies: B. olmeca olmeca, B. olmeca bicolor and B. olmeca nociva, which are distributed from Central America to South America. Of these, B. flaviscutellata s.s. is recognized as the main vector of Leishmania amazonensis in Brazil. The present study aimed to identify molecularly the species and subspecies of the B. flaviscutellata complex using the 5' region of the COI gene (Barcode region). A total of 44 specimens, comprising 22 B. flaviscutellata s.s. and 22 B. olmeca nociva, were analyzed from six localities in the Brazilian Amazon: five in the State of Amazonas (Autazes, Manaus, Pitinga, Novo Airão, and Rio Preto da Eva), and one in the State of Pará (Serra do Cachorro). Three sequences from B. olmeca olmeca and one of B. olmeca bicolor from GenBank were also added to the dataset, totaling 48 sequences with a length of 549 base pairs (bp). The total dataset generated 28 haplotypes and four disconnected networks. Phylogenetic analyses using three algorithms (Neighbor-Joining [NJ], Maximum Likelihood [ML] and Bayesian Inference [BI]) generated similar topologies and most clades were from moderately to highly supported. The phylogenetic relationship, together with genetic distance values (1%) and haplotypes networks, confirm the position of B. olmeca bicolor as a subspecies of B. olmeca olmeca. However, B. olmeca nociva was closer phylogenetically to B. flaviscutellata s.s. than to B. olmeca olmeca and B. olmeca bicolor. Additionally, the haplotype network separated B. olmeca nociva from B. olmeca olmeca and B. olmeca bicolor. These findings, combined with previous morphological data, suggest that the B. olmeca nociva should be elevated to full-species status. The findings of this study also found that B. flaviscutellata s.s. populations may be in process of forming lineages.


Subject(s)
Genes, Insect/genetics , Insect Vectors/classification , Insect Vectors/genetics , Insecta/classification , Insecta/genetics , Animals , Bayes Theorem , Brazil , DNA Barcoding, Taxonomic/methods , Haplotypes/genetics , Leishmania/pathogenicity , Leishmaniasis/parasitology , Phylogeny
16.
J Med Entomol ; 57(3): 745-754, 2020 05 04.
Article in English | MEDLINE | ID: mdl-31819960

ABSTRACT

The eggs of three Amazonian species of the genus Mansonia (Diptera: Culicidae) were analyzed using morphological and morphometric characters. Eggs of Mansonia humeralis Dyar & Knab, 1916 were morphologically different from those of Mansonia titillans (Walker, 1848) and Mansonia amazonensis (Theobald, 1901), which were more similar to each other according to linear and geometric morphometry. A principal component analysis generated from elliptic Fourier contour data (PC1-92.6% and PC2-2.61%) indicated that Ma. amazonensis and Ma. titillans are more similar to each other than either is to Ma. humeralis. Discriminant multivariate analysis was highly accurate with only four classification errors and a 90% accuracy rate. The results indicate that the three Amazonian species can be precisely distinguished in the egg stage and that geometric morphometry based on elliptic Fourier contours is a promising method for distinguishing eggs of species of Mansonia. An identification key based on egg morphology is provided to distinguish the four Neotropical species.


Subject(s)
Culicidae/ultrastructure , Ovum/ultrastructure , Animals , Culicidae/classification , Female , Microscopy, Electron, Scanning
17.
Acta Trop ; 195: 68-77, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31034798

ABSTRACT

Aedes aegypti, being the principal vector of dengue (DENV1 to 4), chikungunya and Zika viruses, is considered as one of the most important mosquito vectors. In Brazil, despite regular vector control programs, Ae. aegypti still persists with high urban density in all the states. This study aimed to estimate the intra and inter population genetic diversity and genetic structure among 15 Brazilian populations of Ae. aegypti based on 12 microsatellite loci. A total of 510 specimens were analyzed comprising eight locations from northern (Itacoatiara, Manaus, Novo Airão, Boa Vista, Rio Branco, Porto Velho, Guajará-Mirim and Macapá), three from southeastern (Araçatuba, São José de Rio Preto and Taubaté), one from southern (Foz do Iguaçu), one from central west (Cuiabá) and two from northeastern (Campina Grande and Teresina) regions of Brazil. Genetic distances (pairwise values of FST and Nm) and the analysis of molecular variance (AMOVA) were statistically significant, independent of geographic distances among the sites analyzed, indicating that them are under a complex dynamic process that influence the levels of gene flow within and among regions of the country. Bayesian analysis in STRUCTURE revealed the existence of two major genetic clusters, as well as there was genetic substructure within them; these results were confirmed by AMOVA, BAPS and DAPC analyses. This differentiation is the cumulative result of several factors combined as events of multiple introduction, passive dispersal, environmental and climatic conditions, use of insecticides, cycles of extinction and re-colonization followed by microevolutionary processes throughout the country. Isolation by distance also contributed to this differentiation, especially among geographically closer localities. These genetic differences may affect its vector competence to transmit dengue, chikungunya, Zika and the response to vector control programs.


Subject(s)
Aedes/genetics , Genetic Variation , Geography , Mosquito Vectors/genetics , Animals , Bayes Theorem , Brazil , Gene Flow , Genetics, Population , Microsatellite Repeats
18.
BMC Genomics ; 20(1): 166, 2019 Mar 04.
Article in English | MEDLINE | ID: mdl-30832587

ABSTRACT

BACKGROUND: Saliva of mosquitoes contains anti-platelet, anti-clotting, vasodilatory, anti-complement and anti-inflammatory substances that help the blood feeding process. The salivary polypeptides are at a fast pace of evolution possibly due to their relative lack of structural constraint and possibly also by positive selection on their genes leading to evasion of host immune pressure. RESULTS: In this study, we used deep mRNA sequence to uncover for the first time the sialomes of four Amazonian anophelines species (Anopheles braziliensis, A. marajorara, A. nuneztovari and A. triannulatus) and extend the knowledge of the A. darlingi sialome. Two libraries were generated from A. darlingi mosquitoes, sampled from two localities separated ~ 1100 km apart. A total of 60,016 sequences were submitted to GenBank, which will help discovery of novel pharmacologically active polypeptides and the design of specific immunological markers of mosquito exposure. Additionally, in these analyses we identified and characterized novel phasmaviruses and anpheviruses associated to the sialomes of A. triannulatus, A. marajorara and A. darlingi species. CONCLUSIONS: Besides their pharmacological properties, which may be exploited for the development of new drugs (e.g. anti-thrombotics), salivary proteins of blood feeding arthropods may be turned into tools to prevent and/or better control vector borne diseases; for example, through the development of vaccines or biomarkers to evaluate human exposure to vector bites. The sialotranscriptome study reported here provided novel data on four New World anopheline species and allowed to extend our knowledge on the salivary repertoire of A. darlingi. Additionally, we discovered novel viruses following analysis of the transcriptomes, a procedure that should become standard within future RNAseq studies.


Subject(s)
Anopheles/genetics , Peptides/genetics , Saliva/chemistry , Salivary Proteins and Peptides/genetics , Amino Acid Sequence/genetics , Animals , Anopheles/chemistry , Brazil , Humans , Insect Vectors/chemistry , Insect Vectors/genetics , Mosquito Vectors/genetics , N-Acetylneuraminic Acid/chemistry , Peptides/chemistry , RNA, Messenger/genetics , Salivary Proteins and Peptides/chemistry , Selection, Genetic/genetics
19.
Acta amaz ; 49(1): 71-74, jan. - mar. 2019. mapas, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1119229

ABSTRACT

We report the first record of Aedes albopictus (Diptera: Culicidae) in the state of Amapá, northern Brazil. Two female specimens were collected from a Shannon trap in the locality of Ilha de Santana, municipality of Santana, Amapá. The occurrence of the species was confirmed with the installation of ten ovitraps. Aedes albopictus is a species of epidemiological importance for the transmission of arboviruses. Amapá was one of two Brazilian states without any record of this species. (AU)


Relatamos o primeiro registro de Aedes albopictus (Diptera: Culicidae) no Estado do Amapá, no norte do Brasil. Dois espécimes foram coletados em uma armadilha de Shannon na localidade de "Ilha de Santana", município de Santana, no Amapá. O registro foi confirmado com a instalação de dez ovitrampas. Aedes albopictus é uma espécie com importância epidemiológica na transmissão de arboviroses. O Amapá era um de dois estados brasileiros sem registro dessa espécie.(AU)


Subject(s)
Animals , Arboviruses , Aedes/classification , Arbovirus Infections/epidemiology , Species Specificity , Brazil
20.
Acta Trop ; 187: 182-189, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30055173

ABSTRACT

The chorionic sculpturing of ten Brazilian sandfly species, Nyssomyia antunesi (Coutinho), N. whitmani (Antunes and Coutinho), Bichromomyia flaviscutellata (Mangabeira), B. olmeca nociva (Young and Arias), Evandromyia walkeri (Newstead), E. williamsi (Antunes and Coutinho), Deanemyia maruaga (Alves, Freitas and Barrett), D. samueli (Deane), Viannamyia furcata (Mangabeira) and Lutzomyia dispar (Martins and Silva), was examined using scanning electron microscopy. Eggs of the last seven species, as well as the genera Deanemyia and Viannamyia, are described for the first time. In total, five patterns of chorionic sculpturing were found: polygonal, connected parallel ridges, unconnected parallel ridges, volcano-like and placoid. The last one is a new chorionic sculpture pattern, which was observed in D. samueli. These structures are illustrated and discussed. These results show that egg morphology can be used in phlebotomine taxonomy, both at generic and specific levels.


Subject(s)
Insect Vectors , Ovum/ultrastructure , Phlebotomus , Animals , Brazil , Female , Leishmaniasis/transmission , Microscopy, Electron, Scanning , Psychodidae
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