RESUMO
A new virus, named Mutum virus, related to members of the family Tymoviridae, was isolated from mosquitoes (Mansonia spp.) in clone C6/36 cells, and its complete genome was sequenced. Its genome is 6494 nt in size with an organization resembling that of tymovirids. The isolated virus is phylogenetically related to two viruses isolated from Culex spp. mosquitoes: Ek Balam virus, reported in Mexico, and Culex-originated Tymoviridae-like virus, isolated in China. The results of this study suggest that this virus is a new member of the family Tymoviridae.
Assuntos
Culex , Culicidae , Malvaceae , Tymoviridae , Animais , Brasil , Genoma Viral , Filogenia , Tymoviridae/genéticaRESUMO
BACKGROUND: Malaria remains a major public health problem in South America, mostly in the Amazon region. Among newly proposed ways of controlling malaria transmission to humans, paratransgenesis is a promising alternative. Paratransgenesis aims to inhibit the development of parasites within the vector through the action of genetically modified bacteria. The first step towards successful paratransgenesis in the Amazon is the identification of Anopheles darlingi symbiotic bacteria, which are transmitted vertically among mosquitoes, and are not pathogenic to humans. METHODS: Culturable bacteria associated with An. darlingi and their breeding sites were isolated by conventional microbiological techniques. Isolated strains were transformed with a GFP expressing plasmid, pSPT-1-GFP, and reintroduced in mosquitoes by feeding. Their survival and persistence in the next generation was assessed by the isolation of fluorescent bacteria from eggs, larvae, pupae and adult homogenates. RESULTS: A total of 179 bacterial strains were isolated from samples from two locations, Coari and Manaus. The predominant genera identified in this study were Acinetobacter, Enterobacter, Klebsiella, Serratia, Bacillus, Elizabethkingia, Stenotrophomonas and Pantoea. Two isolated strains, Serratia-Adu40 and Pantoea-Ovo3, were successfully transformed with the pSPT-1-GFP plasmid and expressed GFP. The fluorescent bacteria fed to adult females were transferred to their eggs, which persisted in larvae and throughout metamorphosis, and were detected in adult mosquitoes of the next generation. CONCLUSION: Serratia-Adu40 and Pantoea-Ovo3 are promising candidates for paratransgenesis in An. darlingi. Further research is needed to determine if these bacteria are vertically transferred in nature.
Assuntos
Anopheles/microbiologia , Bactérias/isolamento & purificação , Técnicas de Transferência de Genes , Simbiose , Animais , Bactérias/classificação , Fenômenos Fisiológicos Bacterianos , Brasil , Malária/transmissão , Mosquitos Vetores/microbiologiaRESUMO
A study was conducted at three sampling regions along the Rio Negro and surrounding Puraquequara Lake, Amazonas, Brazil. The aim was to determine the influence of the local effects of climatic and hydrological variables on new malaria cases. Data was gathered on the river level, precipitation, air temperature, and the number of new cases of autochthonous malaria between January 2003 and December 2013. Monthly averages, time series decompositions, cross-correlations, and multiple regressions revealed different relationships at each location. The sampling region in the upper Rio Negro indicated no statistically significant results. However, monthly averages suggest that precipitation and air temperature correlate positively with the occurrence of new cases of malaria. In the mid Rio Negro and Puraquequara Lake, the river level positively correlated, and temperature negatively correlated with new transmissions, while precipitation correlated negatively in the mid Rio Negro and positively on the lake. Overall, the river level is a key variable affecting the formation of breeding sites, while precipitation may either develop or damage them. A negative temperature correlation is associated with the occurrence of new annual post-peak cases of malaria, when the monthly average exceeds 28.5 °C. This suggests that several factors contribute to the occurrence of new malaria cases as higher temperatures are reached at the same time as precipitation and the river levels are lowest. Differences between signals and correlation lags indicate that local characteristics have an impact on how different variables influence the disease vector's life cycle, pathogens, and consequently, new cases of malaria.
Assuntos
Clima , Hidrologia , Lagos , Malária/etiologia , Chuva , Rios , Temperatura , Animais , Brasil/epidemiologia , Vetores de Doenças , Monitoramento Ambiental , Humanos , Malária/epidemiologia , Áreas AlagadasRESUMO
4-Nerolidylcatechol (1) is an abundant antiplasmodial metabolite that is isolated from Piper peltatum roots. O-Acylation or O-alkylation of compound 1 provides derivatives exhibiting improved stability and significant in vitro antiplasmodial activity. The aim of this work was to study the in vitro inhibition of hemozoin formation, inhibition of isoprenoid biosynthesis in Plasmodium falciparum cultures, and in vivo antimalarial activity of several 4-nerolidylcatechol derivatives. 1,2-O,O-Diacetyl-4-nerolidylcatechol (2) inhibited in vitro hemozoin formation by up to 50%. In metabolic labeling studies using [1-(n)-(3)H]geranylgeranyl pyrophosphate, diester 2: significantly inhibited the biosynthesis of isoprenoid metabolites ubiquinone 8, menaquinone 4, and dolichol 12 in cultures of P. falciparum 3D7. Similarly, 2-O-benzyl-4-nerolidylcatechol (3) significantly inhibited the biosynthesis of dolichol 12. P. falciparum in vitro protein synthesis was not affected by compounds 2 or 3. At oral doses of 50 mg per kg of body weight per day, compound 2 suppressed Plasmodium berghei NK65 in infected BALB/c mice by 44%. This in vivo result for derivative 2 represents marked improvement over that obtained previously for natural product 1. Compound 2 was not detected in mouse blood 1 h after oral ingestion or in mixtures with mouse blood/blood plasma in vitro. However, it was detected after in vitro contact with human blood or blood plasma. Derivatives of 4-nerolidylcatechol exhibit parasite-specific modes of action, such as inhibition of isoprenoid biosynthesis and inhibition of hemozoin formation, and they therefore merit further investigation for their antimalarial potential.
Assuntos
Antimaláricos/farmacocinética , Antimaláricos/uso terapêutico , Catecóis/farmacocinética , Catecóis/uso terapêutico , Malária Falciparum/tratamento farmacológico , Animais , Eletroforese em Gel de Poliacrilamida , Feminino , Malária Falciparum/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/patogenicidade , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/patogenicidade , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
According to the IPCC, by the year 2100, rises in global temperature could reach up to 5 °C above current averages. On a planet-wide scale, this is one of the effects of climate changes that could have repercussions on the biological cycle of Aedes aegypti, the main arbovirus vector in urban environments and a transmitter of the arboviruses that cause dengue, Zika, chikungunya and urban yellow fever. The objective of this study was to evaluate morphological changes in Ae. aegypti eggs and embryos maintained in a climate change simulator. For this, specimens obtained from an insectarium were kept in four chambers that simulated the range of environmental scenarios predicted by the IPCC for the year 2100. The eggs obtained from each room were collected and transported to the laboratory for morphometric and morphological analysis, using confocal and scanning microscopy. Aedes aegypti eggs (n=20) were used to obtain the following variables: total width, total length, length-width ratio and diameter of the micropylar disc. Additionally, 20 embryos were used to obtain the data on head capsule length, width and length-width ratio. The data were subjected to a normality test and the means of each variable were compared using ANOVA and Tukey's post-hoc test, considering (p ≤ 0.05). A significant reduction (p < 0.05) was observed mainly in the mean lengths under the current-extreme scenario (587.5 and 553.6 µm, respectively), as well as in the widths under the current-mild scenario (171 and 158.4 µm, respectively). The length of the cephalic capsule was also affected, showing significant differences in the means under the current-intermediate scenario (189.5 and 208.5 µm, respectively), as well as in the widths between the current-intermediate scenarios (173.7 and 194.9 µm, respectively). The results suggest significant changes in the morphometry of Ae. aegypti eggs and embryos as a result of the climatic influences to which the adults were subjected, which may have an impact on vector population density and, consequently, on arbovirus dynamics in urban environments.
Assuntos
Aedes , Mudança Climática , Óvulo , Animais , Aedes/anatomia & histologia , Aedes/crescimento & desenvolvimento , Aedes/virologia , Aedes/fisiologia , Brasil , Mosquitos Vetores/anatomia & histologia , Mosquitos Vetores/crescimento & desenvolvimento , Mosquitos Vetores/virologia , Mosquitos Vetores/fisiologia , Embrião não MamíferoRESUMO
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.
RESUMO
BACKGROUND: Mansonia mosquitoes transmit arboviruses to humans. This study describes the karyotypes and C-banding of Mansonia humeralis, Mansonia titillans, Mansonia pseudotitillans, and Mansonia indubitans. METHODS: From the 202 larvae, the brain ganglia were dissected (n=120) for the preparation of slides. Twenty slides with well-distended chromosomes for each species (10 for karyotyping and 10 for C-banding) were selected for further study. RESULTS: The haploid genome and the average lengths of the chromosomal arms differed in relation to the centromere between species, and intraspecific differences also occurred in the distribution of the C-bands. CONCLUSIONS: These results are useful for better understanding of the chromosomal variability of Mansonia mosquitoes.
Assuntos
Culicidae , Humanos , Animais , Culicidae/genética , Heterocromatina/genética , Brasil , Cariótipo , CariotipagemRESUMO
The canine filarial parasite Dirofilaria immitis has not been reported in Brazil´s Amazonas state capital, Manaus, for over a century. Here, we report one imported and 27 autochthonous D. immitis infections from a microfilarial survey of 766 domestic dog blood samples collected between 2017 and 2021 in Manaus. An Overall prevalence estimate of 15.44% (23/149) was calculated from our two rural collection sites; a prevalence of 1.22% (4/328) was estimated at our periurban collection site, and an overall prevalence of 0.35% (1/289) was calculated from our two urban clinic collections. Our data suggest that in the urban areas of Manaus, where the parasites are very likely vectored by the same species of mosquito that historically vectored Wuchereria bancrofti (Culex quinquefasciatus), prevalence levels are very low and possibly maintained by an influx from rural areas where sylvatic reservoirs and/or more favorable vector transmission dynamics maintain high prevalences.
Assuntos
Dirofilaria immitis , Dirofilariose , Doenças do Cão , Animais , Cães , Dirofilariose/diagnóstico , Dirofilariose/epidemiologia , Dirofilariose/parasitologia , Brasil/epidemiologia , Mosquitos Vetores/parasitologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , PrevalênciaRESUMO
4-nerolidylcatechol (4-NC) is an unstable natural product that exhibits important antioxidant, anti-inflammatory and other properties. It is readily obtainable on a multi-gram scale through straightforward solvent extraction of the roots of cultivated Piper peltatum or P. umbellatum, followed by column chromatography on the resulting extract. Semi-synthetic derivatives of 4-NC with one or two substituent groups (methyl, acetyl, benzyl, benzoyl) on the O atoms have been introduced that have increased stability compared to 4-NC and significant in vitro inhibitory activity against the human malaria parasite Plasmodium falciparum. Antioxidant and anti-inflammatory properties may be important for the antiplasmodial mode of action of 4-NC derivatives. Thus, we decided to investigate the antioxidant properties, cytotoxicity and stability of 4-NC derivatives as a means to explore the potential utility of these compounds. 4-NC showed high antioxidant activity in the DPPH and ABTS assays and in 3T3-L1 cells (mouse embryonic fibroblast), however 4-NC was more cytotoxic (IC50 = 31.4 µM) and more unstable than its derivatives and lost more than 80% of its antioxidant activity upon storage in solution at -20 °C for 30 days. DMSO solutions of mono-O-substituted derivatives of 4-NC exhibited antioxidant activity and radical scavenging activity in the DPPH and ABTS assays that was comparable to that of BHA and BHT. In the cell-based antioxidant model, most DMSO solutions of derivatives of 4-NC were less active on day 1 than 4-NC, quercetin and BHA and more active antioxidants than BHT. After storage for 30 days at -20 °C, DMSO solutions of most of the derivatives of 4-NC were more stable and exhibited more antioxidant activity than 4-NC, quercetin and BHA and exhibited comparable antioxidant activity to BHT. These findings point to the potential of derivatives of 4-NC as antioxidant compounds.
Assuntos
Antimaláricos/farmacologia , Antioxidantes/farmacologia , Catecóis/química , Catecóis/farmacologia , Piper/química , Células 3T3-L1 , Animais , Antimaláricos/química , Antioxidantes/química , Hidroxianisol Butilado/química , Hidroxianisol Butilado/farmacologia , Hidroxitolueno Butilado/química , Hidroxitolueno Butilado/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Concentração Inibidora 50 , Malária/tratamento farmacológico , Camundongos , Dinâmica não Linear , Raízes de Plantas/química , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimentoRESUMO
BACKGROUND: Aedes aegypti is currently controlled with synthetic larvicides; however, mosquitoes have become highly resistant to these larvicides and difficult to eradicate. Studies have shown that insecticides derived from fungal extracts have various mechanisms of action that reduce the risk of resistance in these mosquitoes. One possible mechanism is uncontrolled production of reactive oxygen species (ROS) in the larvae, which can cause changes at the cellular level. Thus, the crude extract of Xylaria sp. was evaluated to investigate the oxidative effect of this extract in A. aegypti larvae by quantifying the oxidative damage to proteins and lipids. METHODS: The larvicidal potential of the crude extract of Xylaria sp. Was evaluated, and the extract was subsequently tested in human lung fibroblasts for cytotoxicity and ROS production. ROS level was quantified in the larvae that were killed following exposure to the extract in the larvicide test. RESULTS: The crude extract of Xylaria sp. Caused cytotoxicity and induced ROS production in human lung fibroblasts and A. aegypti larvae, respectively. In the larvicide trial, the extract showed an LC50 of 264.456 ppm and an LC90 of 364.307 ppm, and was thus considered active. The extract showed greater oxidative damage to lipids and proteins, with LC90 values of 24.7 µmol MDA/L and 14.6278 ×10-3 nmol carbonyl/ mg protein, respectively. CONCLUSIONS: Crude extracts of Xylaria sp. induced oxidative stress that may have caused the mortality of A. aegypti larvae.
Assuntos
Aedes , Anopheles , Culex , Inseticidas , Animais , Humanos , Inseticidas/toxicidade , Larva , Lipídeos , Estresse Oxidativo , Extratos Vegetais/farmacologia , Folhas de Planta , Espécies Reativas de Oxigênio/farmacologiaRESUMO
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.
Assuntos
Culicidae , Malvaceae , Animais , Teorema de Bayes , Brasil , DNA , Código de Barras de DNA TaxonômicoRESUMO
BACKGROUND: Aedes aegypti is the primary vector of viruses, such as Zika, chikungunya, yellow fever, and dengue. In this context, a biomonitored chemical study was conducted to evaluate the activity of the crude extract of the endophytic fungus Phomopsis sp. against the larvae of Aedes aegypti. METHODS: Crude extract, fractions, and isolated substances were evaluated in in-vitro assays against third-stage larvae of Aedes aegypti. RESULTS: We isolated 3-nitropropionic acid with an LC50 of 15.172 ppm and LC90 of 18.178 ppm after 24 hours of larval exposure. CONCLUSIONS: The results indicated that 3-nitropropionic acid exerted larvicidal activity.
Assuntos
Aedes , Anopheles , Culex , Inseticidas , Infecção por Zika virus , Zika virus , Animais , Phomopsis , Inseticidas/farmacologia , Extratos Vegetais , Mosquitos Vetores , LarvaRESUMO
Bites Bites of mosquitoes belonging to the genera Anopheles Meigen, Aedes Meigen, Culex L. and Haemagogus L. are a general nuisance and are responsible for the transmission of important tropical diseases such as malaria, hemorrhagic dengue and yellow fevers and filariasis (elephantiasis). Plants are traditional sources of mosquito repelling essential oils (EOs), glyceridic oils and repellent and synergistic chemicals. A Chemical Abstracts search on mosquito repellent inventions containing plant-derived EOs revealed 144 active patents mostly from Asia. Chinese, Japanese and Korean language patents and those of India (in English) accounted for roughly 3/4 of all patents. Since 1998 patents on EO-containing mosquito repellent inventions have almost doubled about every 4 years. In general, these patents describe repellent compositions for use in topical agents, cosmetic products, incense, fumigants, indoor and outdoor sprays, fibers, textiles among other applications. 67 EOs and 9 glyceridic oils were individually cited in at least 2 patents. Over 1/2 of all patents named just one EO. Citronella [Cymbopogon nardus (L.) Rendle, C.winterianus Jowitt ex Bor] and eucalyptus (Eucalyptus LʼHér. spp.) EOs were each cited in approximately 1/3 of all patents. Camphor [Cinnamomum camphora (L.) J. Presl], cinnamon (Cinnamomum zeylanicum Blume), clove [Syzygium aromaticum (L.) Merr. & L.M. Perry], geranium (Pelargonium graveolens LʼHér.), lavender (Lavandula angustifolia Mill.), lemon [Citrus × limon (L.) Osbeck], lemongrass [Cymbopogon citratus (DC.) Stapf] and peppermint (Mentha × piperita L.) EOs were each cited in > 10% of patents. Repellent chemicals present in EO compositions or added as pure "natural" ingredients such as geraniol, limonene, p-menthane-3,8-diol, nepetalactone and vanillin were described in approximately 40% of all patents. About 25% of EO-containing inventions included or were made to be used with synthetic insect control agents having mosquito repellent properties such as pyrethroids, N,N-diethyl-m-toluamide (DEET), (±)-p-menthane-3,8-diol (PMD) and dialkyl phthalates. Synergistic effects involving one or more EOs and synthetic and/or natural components were claimed in about 10% of all patents. Scientific literature sources provide evidence for the mosquito repellency of many of the EOs and individual chemical components found in EOs used in patented repellent inventions.
Assuntos
Produtos Biológicos/farmacologia , Culicidae/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Óleos Voláteis/farmacologia , Plantas/química , Animais , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Sinergismo Farmacológico , Repelentes de Insetos/química , Óleos Voláteis/síntese química , Óleos Voláteis/química , Patentes como Assunto/estatística & dados numéricos , Controle de Pragas/métodosRESUMO
4-Nerolidylcatechol (4-NC) isolated from Piper peltatum L. (Piperaceae) was evaluated for in vitro antiplasmodial activity against Plasmodium falciparum (cultures of both standard CQR (K1) and CQS (3D7) strains and two Amazonian field isolates) and for in vivo antimalarial activity using the Plasmodium berghei-murine model. 4-NC exhibits significant in vitro and moderate in vivo antiplasmodial activity. 4-NC administered orally and subcutaneously at doses of 200, 400 and 600 mg/kg/day suppressed the growth of P. berghei by up to 63% after four daily treatments (days 1-4). Also, 4-NC exhibited important in vitro antiplasmodial activity against both standard and field P. falciparum strains in which 50% inhibition of parasite growth (IC(50) ) was produced at concentrations of 0.05-2.11 µg/mL and depended upon the parasite strain. Interestingly, healthy (non-infected) mice that received 4-NC orally presented (denatured) blood plasma which exhibited significant in vitro activity against P. falciparum. This is evidence that mouse metabolism allows 4-NC or active metabolites to enter the blood. Further chemical and pharmacological studies are necessary to confirm the potential of 4-NC as a new antimalarial prototype.
Assuntos
Antimaláricos/farmacologia , Catecóis/farmacologia , Malária/tratamento farmacológico , Piper/química , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Animais , Brasil , Modelos Animais de Doenças , Feminino , Malária/sangue , Malária/parasitologia , Malária Falciparum/sangue , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , CamundongosRESUMO
The global increase in diseases transmitted by the vector Aedes aegypti, new and re-emerging, underscores the need for alternative and more effective methods of controlling mosquitoes. Our aim was to identify fungal strains from the Amazon rain forest that produce metabolites with larvicidal activity against Aedes aegypti. Thirty-six fungal strains belonging to 23 different genera of fungi, isolated from water samples collected in the state of Amazonas, Brazil were cultivated. The liquid medium was separated from the mycelium by filtration. Medium fractions were extracted with ethyl acetate and isopropanol 9:1 volume:volume, and the mycelia with ethyl acetate and methanol 1:1. The extracts were vacuum dried and the larvicidal activity was evaluated in selective bioassays containing 500 µg/ml of the dried fungal extracts. Larval mortality was evaluated up to 72 h. None of the mycelium extracts showed larvicidal activity greater than 50% at 72 h. In contrast, 15 culture medium extracts had larvicidal activity equal to or greater than 50% and eight killed more than 90% of the larvae within 72 h. These eight extracts from fungi belonging to seven different genera (Aspergillus, Cladosporium, Trichoderma, Diaporthe, Albifimbria, Emmia, and Sarocladium) were selected for the determination of LC50 and LC90. Albifimbria lateralis (1160) medium extracts presented the lowest LC50 value (0.268 µg/ml) after 24 h exposure. Diaporthe ueckerae (1203) medium extracts presented the lowest value of LC90 (2.928 µg/ml) at 24 h, the lowest values of LC50 (0.108 µg/ml) and LC90 (0.894 µg/ml) at 48 h and also at 72 h (LC50 = 0.062 µg/ml and LC90 = 0.476 µg/ml). Extracts from Al. lateralis (1160) and D. ueckerae (1203) showed potential for developing new, naturally derived products, to be applied in integrated vector management programs against Ae. aegypti.
RESUMO
The genome assembly of Anopheles darlingi consists of 2221 scaffolds (N50 = 115,072 bp) and has a size spanning 136.94 Mbp. This assembly represents one of the smallest genomes among Anopheles species. Anopheles darlingi genomic DNA fragments of ~37 Kb were cloned, end-sequenced, and used as probes for fluorescence in situ hybridization (FISH) with salivary gland polytene chromosomes. In total, we mapped nine DNA probes to scaffolds and autosomal arms. Comparative analysis of the An. darlingi scaffolds with homologous sequences of the Anopheles albimanus and Anopheles gambiae genomes identified chromosomal rearrangements among these species. Our results confirmed that physical mapping is a useful tool for anchoring genome assemblies to mosquito chromosomes.
RESUMO
Serious concerns have arisen regarding urbanization processes in western Amazônia, which result in the creation of artificial habitats, promoting the colonization of malaria vectors. We used structural equation modelling to investigate direct and indirect effects of forest cover on larval habitats and anopheline assemblages in different seasons. We found 3474 larvae in the dry season and 6603 in the rainy season, totalling ten species and confirming the presence of malaria vectors across all sites. Forest cover had direct and indirect (through limnological variables) effects on the composition of larval anopheline assemblages in the rainy season. However, during the dry season, forest cover directly affected larval distribution and habitat variables (with no indirect affects). Additionally, artificial larval habitats promote ideal conditions for malaria vectors in Amazonia, mainly during the rainy season, with positive consequences for anopheline assemblages. Therefore, the application of integrated management can be carried out during both seasons. However, we suggest that the dry season is the optimal time because larval habitats are more limited, smaller in volume and more accessible for applying vector control techniques.
Assuntos
Anopheles , Ecossistema , Florestas , Mosquitos Vetores , Estações do Ano , Animais , Anopheles/crescimento & desenvolvimento , Brasil , Geografia , Larva/crescimento & desenvolvimento , Malária/transmissão , Mosquitos Vetores/crescimento & desenvolvimento , ChuvaRESUMO
The control of arboviruses carried by Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) can be performed with tools that monitor and reduce the circulation of these vectors. Therefore, the efficiency of four types of traps in capturing A. aegypti and A. albopictus eggs and adults, with the biological product Vectobac WG, was evaluated in the field. For this, 20 traps were installed in two locations, which were in the South (Londrina, Paraná) and North (Manaus, Amazonas) Regions of Brazil, from March to April 2017 and January to February 2018, respectively. The UELtrap-E (standard trap) and UELtrap-EA traps captured A. aegypti and A. albopictus eggs: 1703/1866 eggs in Londrina, and 10268/2149 eggs in Manaus, respectively, and presented high ovitraps positivity index (OPI) values (averages: 100%/100% in Londrina, and 100%/96% in Manaus, respectively); and high egg density index (EDI) values (averages: 68/75 in Londrina, and 411/89 in Manaus, respectively), so they had statistically superior efficiency to that of the CRtrap-E and CRtrap-EA traps in both regions, that captured less eggs and adults: 96/69 eggs in Londrina, and 1091/510 eggs in Manaus, respectively. Also presented lower OPI values (averages: 28%/4% in Londrina, and 88%/60% in Manaus, respectively); and lower EDI values (averages: 10.5/9 in Londrina, and 47/30 in Manaus, respectively). The capture ratios of Aedes adults in the UELtrap-EA and CRtrap-EA traps in Londrina and Manaus were 53.3%/29.5% and 0%/9.8%, respectively. UELtrap-EA can be adopted as efficient tool for Aedes monitoring due to their high sensitivity, low cost and ease of use.
Assuntos
Aedes/fisiologia , Controle de Mosquitos/instrumentação , Óvulo , Animais , Brasil , Controle de Mosquitos/métodos , Densidade DemográficaRESUMO
Piper peltatum L. is used for the treatment of inflammation, malaria, and other ailments. 4-Nerolidylcatechol (4-NC) is a valuable natural product that has important anti-inflammatory, antimalarial, and antioxidant properties. 4-NC is a component of P. peltatum and P. umbellatum extracts, which are used in cosmetics. The aim of this work was to evaluate the production of plant biomass and the production of 4-NC in roots of cultivated P. peltatum over a full life cycle. Seedlings were produced in a greenhouse and then transplanted. The weight of dry plant parts (leaves, stems, roots, and inflorescences); numbers of stems, leaves, and inflorescences; and the leaf-to-stem ratio were evaluated at intervals of 60 days after transplanting (DAT). Extracts were prepared using 1:1 ethanol-chloroform and an ultrasound bath. Roots, leaves, and inflorescences contained 4-NC according to TLC photodensitometry analysis. Quantification of 4-NC in root extracts was performed using HPLC-DAD analysis. Per-hectare production of 4-NC by roots was estimated based on quantitative HPLC analysis and biomass data. Optimal per-hectare yields of 4-NC were obtained by harvesting roots between 350 and 400 DAT. In this period, the average yield was 27 kg 4-NC per hectare. Importantly, at the time of maximal overall production of root biomass (470 DAT), there was a decrease in the production of 4-NC (23.8 kg/ha), probably due to the onset of senescence.