Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.465
Filtrar
1.
Sci Rep ; 14(1): 13701, 2024 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871831

RESUMO

Dengue virus (DENV), mainly transmitted by Aedes aegypti mosquitoes, is the most prevalent arbovirus worldwide, representing a public health problem in tropical and subtropical countries. In these areas, antibiotic consumption rises which may impact both mosquito microbiota and dengue transmission. Here, we assessed how the ingestion by Ae. aegypti of therapeutic concentrations of amoxicillin-clavulanic Acid association (Amox/Clav), a broad-spectrum antibiotic used to treat febrile symptoms worldwide, impacted its microbiota. We also evaluated whether simultaneous ingestion of antibiotic and DENV impacted Ae. aegypti ability to transmit this virus. We found that Amox/Clav ingestion impacted microbiota composition in Ae. aegypti and we confirmed such impact in field-collected mosquitoes. Furthermore, we observed that Amox/Clav ingestion enhanced DENV dissemination and transmission by this mosquito at 21 days post-DENV exposure. These findings increase our understanding of factors linked to human hosts that may influence dengue transmission dynamics in regions with mass-drug administration programs.


Assuntos
Aedes , Vírus da Dengue , Dengue , Microbiota , Aedes/microbiologia , Aedes/virologia , Aedes/efeitos dos fármacos , Animais , Vírus da Dengue/efeitos dos fármacos , Dengue/transmissão , Microbiota/efeitos dos fármacos , Mosquitos Vetores/microbiologia , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/virologia , Combinação Amoxicilina e Clavulanato de Potássio/farmacologia , Combinação Amoxicilina e Clavulanato de Potássio/administração & dosagem , Antibacterianos/farmacologia , Humanos , Feminino
2.
Sci Rep ; 14(1): 12959, 2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839934

RESUMO

Temperature is a critical factor shaping physiology, life cycle, and behaviour of ectothermic vector insects, as well as the development and multiplication of pathogens within them. However, the influence of pathogen infections on thermal preferences (behavioural thermoregulation) is not well-understood. The present study examined the thermal preferences of mosquitoes (Aedes aegypti and Ae. japonicus) infected with either Sindbis virus (SINV) or Dirofilaria immitis over 12 days post exposure (p.e.) or injected with a non-pathogenic Sephadex bead over 24 h in a thermal gradient (15-30 °C). SINV-infected Ae. aegypti preferred 5 °C warmer temperatures than non-infected ones at day 6 p.e., probably the time of highest innate immune response. In contrast, D. immitis-infected Ae. japonicus preferred 4 °C cooler temperatures than non-infected ones at day 9 p.e., presumably a stress response during the migration of third instar larvae from their development site to the proboscis. Sephadex bead injection also induced a cold preference in the mosquitoes but to a level that did not differ from control-injections. The cold preference thus might be a strategy to escape the risk of desiccation caused by the wound created by piercing the thorax. Further research is needed to uncover the genetic and physiological mechanisms underlying these behaviours.


Assuntos
Aedes , Temperatura , Animais , Aedes/virologia , Aedes/fisiologia , Aedes/imunologia , Sindbis virus/fisiologia , Dirofilaria immitis/fisiologia , Mosquitos Vetores/virologia , Mosquitos Vetores/parasitologia , Larva/fisiologia , Feminino , Regulação da Temperatura Corporal
3.
PLoS Negl Trop Dis ; 18(6): e0011903, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38829904

RESUMO

BACKGROUND: The first dengue outbreak in Sao Tome and Principe was reported in 2022. Entomological investigations were undertaken to establish the typology of Aedes larval habitats, the distribution of Ae. aegypti and Ae. albopictus, the related entomological risk and the susceptibility profile of Ae. aegypti to insecticides, to provide evidence to inform the outbreak response. METHODOLOGY/PRINCIPAL FINDINGS: Entomological surveys were performed in all seven health districts of Sao Tome and Principe during the dry and rainy seasons in 2022. WHO tube and synergist assays using piperonyl butoxide (PBO) and diethyl maleate (DEM) were carried out, together with genotyping of F1534C/V1016I/V410L mutations in Ae. aegypti. Aedes aegypti and Ae. albopictus were found in all seven health districts of the country with high abundance of Ae. aegypti in the most urbanised district, Agua Grande. Both Aedes species bred mainly in used tyres, discarded tanks and water storage containers. In both survey periods, the Breteau (BI > 50), house (HI > 35%) and container (CI > 20%) indices were higher than the thresholds established by WHO to indicate high potential risk of dengue transmission. The Ae. aegypti sampled were susceptible to all insecticides tested except dichlorodiphenyltrichloroethane (DDT) (9.2% mortality, resistant), bendiocarb (61.4% mortality, resistant) and alpha-cypermethrin (97% mortality, probable resistant). A full recovery was observed in Ae. aegypti resistant to bendiocarb after pre-exposure to synergist PBO. Only one Ae. aegypti specimen was found carrying F1534C mutation. CONCLUSIONS/SIGNIFICANCE: These findings revealed a high potential risk for dengue transmission throughout the year, with the bulk of larval breeding occurring in used tyres, water storage and discarded containers. Most of the insecticides tested remain effective to control Aedes vectors in Sao Tome, except DDT and bendiocarb. These data underline the importance of raising community awareness and implementing routine dengue vector control strategies to prevent further outbreaks in Sao Tome and Principe, and elsewhere in the subregion.


Assuntos
Aedes , Dengue , Surtos de Doenças , Resistência a Inseticidas , Inseticidas , Larva , Mosquitos Vetores , Aedes/efeitos dos fármacos , Aedes/genética , Aedes/virologia , Animais , Dengue/transmissão , Dengue/epidemiologia , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , Resistência a Inseticidas/genética , Larva/efeitos dos fármacos , Larva/virologia , Humanos , Butóxido de Piperonila/farmacologia , Feminino , Maleatos/farmacologia , Ecossistema , Vírus da Dengue/efeitos dos fármacos , Vírus da Dengue/genética
4.
PLoS Negl Trop Dis ; 18(6): e0011811, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38829905

RESUMO

BACKGROUND: Dengue, Zika, and chikungunya, whose viruses are transmitted mainly by Aedes aegypti, significantly impact human health worldwide. Despite the recent development of promising vaccines against the dengue virus, controlling these arbovirus diseases still depends on mosquito surveillance and control. Nonetheless, several studies have shown that these measures are not sufficiently effective or ineffective. Identifying higher-risk areas in a municipality and directing control efforts towards them could improve it. One tool for this is the premise condition index (PCI); however, its measure requires visiting all buildings. We propose a novel approach capable of predicting the PCI based on facade street-level images, which we call PCINet. METHODOLOGY: Our study was conducted in Campinas, a one million-inhabitant city in São Paulo, Brazil. We surveyed 200 blocks, visited their buildings, and measured the three traditional PCI components (building and backyard conditions and shading), the facade conditions (taking pictures of them), and other characteristics. We trained a deep neural network with the pictures taken, creating a computational model that can predict buildings' conditions based on the view of their facades. We evaluated PCINet in a scenario emulating a real large-scale situation, where the model could be deployed to automatically monitor four regions of Campinas to identify risk areas. PRINCIPAL FINDINGS: PCINet produced reasonable results in differentiating the facade condition into three levels, and it is a scalable strategy to triage large areas. The entire process can be automated through data collection from facade data sources and inferences through PCINet. The facade conditions correlated highly with the building and backyard conditions and reasonably well with shading and backyard conditions. The use of street-level images and PCINet could help to optimize Ae. aegypti surveillance and control, reducing the number of in-person visits necessary to identify buildings, blocks, and neighborhoods at higher risk from mosquito and arbovirus diseases.


Assuntos
Aedes , Dengue , Mosquitos Vetores , Aedes/virologia , Aedes/fisiologia , Animais , Brasil/epidemiologia , Humanos , Mosquitos Vetores/virologia , Mosquitos Vetores/fisiologia , Dengue/prevenção & controle , Dengue/epidemiologia , Dengue/transmissão , Cidades , Controle de Mosquitos/métodos , Processamento de Imagem Assistida por Computador/métodos , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão
5.
Parasit Vectors ; 17(1): 262, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886805

RESUMO

BACKGROUND: In recent years the Asian bush mosquito Aedes japonicus has invaded Europe, including the Netherlands. This species is a known vector for a range of arboviruses, possibly including West Nile virus (WNV). As WNV emerged in the Netherlands in 2020, it is important to investigate the vectorial capacity of mosquito species present in the Netherlands to estimate the risk of future outbreaks and further spread of the virus. Therefore, this study evaluates the potential role of Ae. japonicus in WNV transmission and spillover from birds to dead-end hosts in the Netherlands. METHODS: We conducted human landing collections in allotment gardens (Lelystad, the Netherlands) in June, August and September 2021 to study the diurnal and seasonal host-seeking behaviour of Ae. japonicus. Furthermore, their host preference in relation to birds using live chicken-baited traps was investigated. Vector competence of field-collected Ae. japonicus mosquitoes for two isolates of WNV at two different temperatures was determined. Based on the data generated from these studies, we developed a Susceptible-Exposed-Infectious-Recovered (SEIR) model to calculate the risk of WNV spillover from birds to humans via Ae. japonicus, under the condition that the virus is introduced and circulates in an enzootic cycle in a given area. RESULTS: Our results show that Ae. japonicus mosquitoes are actively host seeking throughout the day, with peaks in activity in the morning and evening. Their abundance in August was higher than in June and September. For the host-preference experiment, we documented a small number of mosquitoes feeding on birds: only six blood-fed females were caught over 4 full days of sampling. Finally, our vector competence experiments with Ae. japonicus compared to its natural vector Culex pipiens showed a higher infection and transmission rate when infected with a local, Dutch, WNV isolate compared to a Greek isolate of the virus. Interestingly, we also found a small number of infected Cx. pipiens males with virus-positive leg and saliva samples. CONCLUSIONS: Combining the field and laboratory derived data, our model predicts that Ae. japonicus could act as a spillover vector for WNV and could be responsible for a high initial invasion risk of WNV when present in large numbers.


Assuntos
Aedes , Mosquitos Vetores , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Aedes/virologia , Aedes/fisiologia , Países Baixos/epidemiologia , Mosquitos Vetores/virologia , Mosquitos Vetores/fisiologia , Vírus do Nilo Ocidental/fisiologia , Febre do Nilo Ocidental/transmissão , Febre do Nilo Ocidental/virologia , Humanos , Feminino , Aves/virologia , Galinhas/virologia , Comportamento de Busca por Hospedeiro , Estações do Ano
6.
Trials ; 25(1): 400, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902790

RESUMO

BACKGROUND: This trial is a parallel, two-arm, non-blinded cluster randomised controlled trial that is under way in Singapore, with the aim of measuring the efficacy of male Wolbachia-infected Aedes aegypti deployments in reducing dengue incidence in an endemic setting with all four dengue serotypes in circulation. The trial commenced in July 2022 and is expected to conclude in September 2024. The original study protocol was published in December 2022. Here, we describe amendments that have been made to the study protocol since commencement of the trial. METHODS: The key protocol amendments are (1) addition of an explicit definition of Wolbachia exposure for residents residing in intervention sites based on the duration of Wolbachia exposure at point of testing, (2) incorporation of a high-dimensional set of anthropogenic and environmental characteristics in the analysis plan to adjust for baseline risk factors of dengue transmission, and (3) addition of alternative statistical analyses for endpoints to control for post hoc imbalance in cluster-based environmental and anthropogenic characteristics. DISCUSSION: The findings from this study will provide the first experimental evidence for the efficacy of releasing male-Wolbachia infected mosquitoes to reduce dengue incidence in a cluster-randomised controlled trial. The trial will conclude in 2024 and results will be reported shortly thereafter. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT05505682. Registered on 16 August 2022. Retrospectively registered. Last updated 11 November 2023.


Assuntos
Aedes , Dengue , Mosquitos Vetores , Ensaios Clínicos Controlados Aleatórios como Assunto , Wolbachia , Dengue/prevenção & controle , Dengue/epidemiologia , Dengue/transmissão , Animais , Singapura/epidemiologia , Masculino , Aedes/microbiologia , Aedes/virologia , Humanos , Incidência , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia , Controle de Mosquitos/métodos , Feminino , Controle Biológico de Vetores/métodos
7.
Pan Afr Med J ; 47: 120, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38828420

RESUMO

Introduction: Aedes albopictus, like Aedes aegypti, is a virulent vector of arboviruses especially the well-documented spread of yellow fever around the world. Although yellow fever is prevalent in Nigeria, there is a paucity of information in the Niger Delta region on the distribution of Aedes mosquito vectors and molecular detection of the virus in infected mosquitoes. This study sampled Aedes mosquitoes around houses associated with farms from four communities (Otolokpo, Ute-Okpu, Umunede, and Ute Alohen) in Ika North-East Local Government Area of Delta State, Nigeria. Methods: various sampling methods were used in Aedes mosquito collection to test their efficacy in the survey. Mosquitoes in holding cages were killed by freezing and morphologically identified. A pool of 15 mosquitoes per Eppendorf tube was preserved in RNAi later for yellow fever virus screening. Two samples were molecularly screened for each location. Results: seven hundred and twenty-five (725) mosquitoes were obtained from the various traps. The mean abundance of the mosquitoes was highest in m-HLC (42.9) compared to the mosquitoes sampled using other techniques (p<0.0001). The mean abundance of mosquitoes was lowest in Center for Disease Control (CDC) light traps without attractant (0.29). No yellow fever virus strain was detected in all the mosquitoes sampled at the four locations. Conclusion: this study suggests that Aedes albopictus are the mosquitoes commonly biting around houses associated with farms. More so, yellow fever virus was not detected in the mosquitoes probably due to the mass vaccination exercise that was carried out the previous year in the study area. More studies are required using the m-HLC to determine the infection rate in this endemic area.


Assuntos
Aedes , Mosquitos Vetores , Febre Amarela , Vírus da Febre Amarela , Animais , Aedes/virologia , Nigéria , Vírus da Febre Amarela/isolamento & purificação , Mosquitos Vetores/virologia , Febre Amarela/transmissão , Febre Amarela/epidemiologia , Febre Amarela/virologia , Humanos
9.
mSystems ; 9(6): e0001224, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38742876

RESUMO

In arthropod-associated microbial communities, insect-specific viruses (ISVs) are prevalent yet understudied due to limited infectivity outside their natural hosts. However, ISVs might play a crucial role in regulating mosquito populations and influencing arthropod-borne virus transmission. Some studies have indicated a core virome in mosquitoes consisting of mostly ISVs. Employing single mosquito metagenomics, we comprehensively profiled the virome of native and invasive mosquito species in Belgium. This approach allowed for accurate host species determination, prevalence assessment of viruses and Wolbachia, and the identification of novel viruses. Contrary to our expectations, no abundant core virome was observed in Culex mosquitoes from Belgium. In that regard, we caution against rigidly defining mosquito core viromes and encourage nuanced interpretations of other studies. Nonetheless, our study identified 45 viruses of which 28 were novel, enriching our understanding of the mosquito virome and ISVs. We showed that the mosquito virome in this study is species-specific and less dependent on the location where mosquitoes from the same species reside. In addition, because Wolbachia has previously been observed to influence arbovirus transmission, we report the prevalence of Wolbachia in Belgian mosquitoes and the detection of several Wolbachia mobile genetic elements. The observed prevalence ranged from 83% to 92% in members from the Culex pipiens complex.IMPORTANCECulex pipiens mosquitoes are important vectors for arboviruses like West Nile virus and Usutu virus. Virome studies on individual Culex pipiens, and on individual mosquitoes in general, have been lacking. To mitigate this, we sequenced the virome of 190 individual Culex and 8 individual Aedes japonicus mosquitoes. We report the lack of a core virome in these mosquitoes from Belgium and caution the interpretation of other studies in this light. The discovery of new viruses in this study will aid our comprehension of insect-specific viruses and the mosquito virome in general in relation to mosquito physiology and mosquito population dynamics.


Assuntos
Culex , Viroma , Wolbachia , Animais , Culex/virologia , Culex/microbiologia , Viroma/genética , Wolbachia/genética , Wolbachia/isolamento & purificação , Bélgica , Especificidade da Espécie , Mosquitos Vetores/virologia , Mosquitos Vetores/microbiologia , Metagenômica , Vírus de Insetos/genética , Vírus de Insetos/isolamento & purificação , Clima
10.
Acta Trop ; 256: 107276, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38821146

RESUMO

Culex gelidus (Diptera: Culicidae), an important vector of the Japanese encephalitis virus (JEV), contributes to human viral encephalitis in many Asian countries, including Thailand. This study represents the first investigation of the demographic patterns of Cx. gelidus populations in Thailand using cytochrome c oxidase subunit I (COI) gene analysis and wing geometric morphometrics (GM). Mosquitoes were collected from 10 provinces across six regions of Thailand in 2022. Analysis of the COI sequences (n = 182) indicated high haplotype diversity (0.882) and low nucleotide diversity (0.006), with 72 haplotypes identified. The haplotype network demonstrated no profound splits among the geographic populations. Neutral tests, including Tajima's D and Fu's Fs, displayed negative values, with a significant result observed for Fu's Fs (-33.048, p < 0.05). The mismatch distribution analysis indicated that the population does not statistically deviate from a model of sudden population expansion (SSD = 0.010, p > 0.05; Rg = 0.022, p > 0.05). The estimations suggest that the Cx. gelidus population in Thailand began its expansion approximately between 459,243 and 707,011 years ago. The Mantel test showed no significant relationship between genetic and geographic distances (r = 0.048, p > 0.05). Significant phenotypic differences (based on wing shape) were observed among most populations. Additionally, in this study, we found no significant relationships between phenotypic and genetic distances (r = 0.250, p > 0.05). Understanding the genetic and morphological dynamics of Cx. gelidus is vital for developing targeted surveillance and vector control measures. This knowledge will also help to predict how future environmental changes might affect these populations, thereby informing long-term vector management strategies.


Assuntos
Culex , Complexo IV da Cadeia de Transporte de Elétrons , Mosquitos Vetores , Asas de Animais , Animais , Tailândia , Culex/genética , Culex/virologia , Culex/anatomia & histologia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mosquitos Vetores/genética , Mosquitos Vetores/anatomia & histologia , Mosquitos Vetores/virologia , Asas de Animais/anatomia & histologia , DNA Mitocondrial/genética , Variação Genética , Haplótipos , Feminino , Encefalite Japonesa/virologia , Vírus da Encefalite Japonesa (Espécie)/genética , Masculino , Filogenia
11.
Sci Rep ; 14(1): 12479, 2024 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816487

RESUMO

Insects often exhibit irruptive population dynamics determined by environmental conditions. We examine if populations of the Culex tarsalis mosquito, a West Nile virus (WNV) vector, fluctuate synchronously over broad spatial extents and multiple timescales and whether climate drives synchrony in Cx. tarsalis, especially at annual timescales, due to the synchronous influence of temperature, precipitation, and/or humidity. We leveraged mosquito collections across 9 National Ecological Observatory Network (NEON) sites distributed in the interior West and Great Plains region USA over a 45-month period, and associated gridMET climate data. We utilized wavelet phasor mean fields and wavelet linear models to quantify spatial synchrony for mosquitoes and climate and to calculate the importance of climate in explaining Cx. tarsalis synchrony. We also tested whether the strength of spatial synchrony may vary directionally across years. We found significant annual synchrony in Cx. tarsalis, and short-term synchrony during a single period in 2018. Mean minimum temperature was a significant predictor of annual Cx. tarsalis spatial synchrony, and we found a marginally significant decrease in annual Cx. tarsalis synchrony. Significant Cx. tarsalis synchrony during 2018 coincided with an anomalous increase in precipitation. This work provides a valuable step toward understanding broadscale synchrony in a WNV vector.


Assuntos
Culex , Mosquitos Vetores , Vírus do Nilo Ocidental , Animais , Mosquitos Vetores/virologia , Mosquitos Vetores/fisiologia , Vírus do Nilo Ocidental/fisiologia , Culex/virologia , Culex/fisiologia , Temperatura , Febre do Nilo Ocidental/transmissão , Dinâmica Populacional , Clima , Estações do Ano
12.
Commun Biol ; 7(1): 667, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816486

RESUMO

The Anopheles gambiae 1000 Genomes (Ag1000G) Consortium previously utilized deep sequencing methods to catalogue genetic diversity across African An. gambiae populations. We analyzed the complete datasets of 1142 individually sequenced mosquitoes through Microsoft Premonition's Bayesian mixture model based (BMM) metagenomics pipeline. All specimens were confirmed as either An. gambiae sensu stricto (s.s.) or An. coluzzii with a high degree of confidence ( > 98% identity to reference). Homo sapiens DNA was identified in all specimens indicating contamination may have occurred either at the time of specimen collection, preparation and/or sequencing. We found evidence of vertebrate hosts in 162 specimens. 59 specimens contained validated Plasmodium falciparum reads. Human hepatitis B and primate erythroparvovirus-1 viral sequences were identified in fifteen and three mosquito specimens, respectively. 478 of the 1,142 specimens were found to contain bacterial reads and bacteriophage-related contigs were detected in 27 specimens. This analysis demonstrates the capacity of metagenomic approaches to elucidate important vector-host-pathogen interactions of epidemiological significance.


Assuntos
Anopheles , Metagenômica , Animais , Anopheles/virologia , Anopheles/genética , Metagenômica/métodos , Genoma de Inseto , Mosquitos Vetores/virologia , Mosquitos Vetores/genética , Humanos , Variação Genética , Plasmodium falciparum/genética , Metagenoma
13.
Parasit Vectors ; 17(1): 222, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38745242

RESUMO

BACKGROUND: Culex pipiens pallens is a well-known mosquito vector for several diseases. Deltamethrin, a commonly used pyrethroid insecticide, has been frequently applied to manage adult Cx. pipiens pallens. However, mosquitoes can develop resistance to these insecticides as a result of insecticide misuse and, therefore, it is crucial to identify novel methods to control insecticide resistance. The relationship between commensal bacteria and vector resistance has been recently recognized. Bacteriophages (= phages) are effective tools by which to control insect commensal bacteria, but there have as yet been no studies using phages on adult mosquitoes. In this study, we isolated an Aeromonas phage vB AhM-LH that specifically targets resistance-associated symbiotic bacteria in mosquitoes. We investigated the impact of Aeromonas phage vB AhM-LH in an abundance of Aeromonas hydrophila in the gut of Cx. pipiens pallens and its effect on the status of deltamethrin resistance. METHODS: Phages were isolated on double-layer agar plates and their biological properties analyzed. Phage morphology was observed by transmission electron microscopy (TEM) after negative staining. The phage was then introduced into the mosquito intestines via oral feeding. The inhibitory effect of Aeromonas phage vB AhM-LH on Aeromonas hydrophila in mosquito intestines was assessed through quantitative real-time PCR analysis. Deltamethrin resistance of mosquitoes was assessed using WHO bottle bioassays. RESULTS: An Aeromonas phage vB AhM-LH was isolated from sewage and identified as belonging to the Myoviridae family in the order Caudovirales using TEM. Based on biological characteristics analysis and in vitro antibacterial experiments, Aeromonas phage vB AhM-LH was observed to exhibit excellent stability and effective bactericidal activity. Sequencing revealed that the Aeromonas phage vB AhM-LH genome comprises 43,663 bp (51.6% CG content) with 81 predicted open reading frames. No integrase-related gene was detected in the vB AH-LH genome, which marked it as a potential biological antibacterial. Finally, we found that Aeromonas phage vB AhM-LH could significantly reduce deltamethrin resistance in Cx. pipiens pallens, in both the laboratory and field settings, by decreasing the abundance of Aeromonas hydrophila in their midgut. CONCLUSIONS: Our findings demonstrate that Aeromonas phage vB AhM-LH could effectively modulate commensal bacteria Aeromonas hydrophila in adult mosquitoes, thus representing a promising strategy to mitigate mosquito vector resistance.


Assuntos
Aeromonas hydrophila , Bacteriófagos , Culex , Resistência a Inseticidas , Nitrilas , Piretrinas , Animais , Aeromonas hydrophila/virologia , Aeromonas hydrophila/efeitos dos fármacos , Culex/virologia , Culex/microbiologia , Bacteriófagos/fisiologia , Bacteriófagos/isolamento & purificação , Bacteriófagos/genética , Piretrinas/farmacologia , Nitrilas/farmacologia , Inseticidas/farmacologia , Mosquitos Vetores/virologia , Mosquitos Vetores/microbiologia , Feminino
14.
Artigo em Inglês | MEDLINE | ID: mdl-38791823

RESUMO

In the Americas, wild yellow fever (WYF) is an infectious disease that is highly lethal for some non-human primate species and non-vaccinated people. Specifically, in the Brazilian Atlantic Forest, Haemagogus leucocelaenus and Haemagogus janthinomys mosquitoes act as the major vectors. Despite transmission risk being related to vector densities, little is known about how landscape structure affects vector abundance and movement. To fill these gaps, we used vector abundance data and a model-selection approach to assess how landscape structure affects vector abundance, aiming to identify connecting elements for virus dispersion in the state of São Paulo, Brazil. Our findings show that Hg. leucocelaenus and Hg. janthinomys abundances, in highly degraded and fragmented landscapes, are mainly affected by increases in forest cover at scales of 2.0 and 2.5 km, respectively. Fragmented landscapes provide ecological corridors for vector dispersion, which, along with high vector abundance, promotes the creation of risk areas for WYF virus spread, especially along the border with Minas Gerais state, the upper edges of the Serra do Mar, in the Serra da Cantareira, and in areas of the metropolitan regions of São Paulo and Campinas.


Assuntos
Mosquitos Vetores , Febre Amarela , Brasil , Animais , Febre Amarela/transmissão , Mosquitos Vetores/virologia , Ecossistema , Clima Tropical , Vírus da Febre Amarela , Densidade Demográfica , Culicidae/virologia , Culicidae/fisiologia
15.
Front Immunol ; 15: 1368066, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38751433

RESUMO

Introduction: Aedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes. Methods: We tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG. Results: We found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue. Discussion: The IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion.


Assuntos
Aedes , Dengue , Proteínas de Insetos , Mosquitos Vetores , Proteínas e Peptídeos Salivares , Humanos , Aedes/imunologia , Aedes/virologia , Animais , Proteínas e Peptídeos Salivares/imunologia , Criança , Mosquitos Vetores/imunologia , Mosquitos Vetores/virologia , Dengue/imunologia , Dengue/transmissão , Proteínas de Insetos/imunologia , Feminino , Pré-Escolar , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , Masculino , Camboja , Estudos Longitudinais , Vírus da Dengue/imunologia , Adolescente , Mordeduras e Picadas de Insetos/imunologia
16.
BMC Infect Dis ; 24(1): 523, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789932

RESUMO

BACKGROUND: In Thailand, the Department of Disease Control (DDC) regularly performs visual larval surveys throughout the country to monitor dengue fever outbreaks. Since 2016, the DDC switched from a paper-based to a digital-based larval survey process. The significant amount of larval survey data collected digitally presents a valuable opportunity to precisely identify the villages and breeding habitats that are vulnerable to dengue transmission. METHODS: The study used digitally collected larval survey data from 2017 to 2019. It employed larval indices to evaluate the risk of dengue transmission in villages based on seasonal, regional, and categorical perspectives. Furthermore, the study comprehensively scrutinized each container category by employing different measures to determine its breeding preference ratio. RESULTS: The result showed that villages with a very high-risk of dengue transmission were present year-round in all regions, with the highest proportion during the rainy season. The Southern region had more high-risk villages during the winter season due to rainfall. Slums and residential communities were more vulnerable to dengue than commercial areas. All container categories could potentially serve as breeding habitats for dengue-carrying mosquitoes, with abandoned containers being the most significant breeding sites. CONCLUSIONS: The risk of dengue transmission was present year-round throughout Thailand. This underscores the importance of community and government initiatives, along with sustained public awareness campaigns and active community engagement, to efficiently and permanently eradicate mosquito breeding habitats. It should be noted that larval indices may not strongly correlate with dengue cases, as indicated by the preliminary analysis. However, they offer valuable insights into potential breeding sites for targeted preventive measures.


Assuntos
Aedes , Dengue , Ecossistema , Larva , Mosquitos Vetores , Dengue/transmissão , Dengue/epidemiologia , Tailândia/epidemiologia , Animais , Larva/virologia , Mosquitos Vetores/virologia , Mosquitos Vetores/fisiologia , Humanos , Aedes/virologia , Aedes/fisiologia , Estações do Ano , Vírus da Dengue/fisiologia , Surtos de Doenças
17.
Sci Rep ; 14(1): 10814, 2024 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734695

RESUMO

Chikungunya virus (CHIKV) poses a significant global health threat, re-emerging as a mosquito-transmitted pathogen that caused high fever, rash, and severe arthralgia. In Thailand, a notable CHIKV outbreak in 2019-2020 affected approximately 20,000 cases across 60 provinces, underscoring the need for effective mosquito control protocols. Previous studies have highlighted the role of midgut bacteria in the interaction between mosquito vectors and pathogen infections, demonstrating their ability to protect the insect from invading pathogens. However, research on the midgut bacteria of Aedes (Ae.) aegypti, the primary vector for CHIKV in Thailand remains limited. This study aims to characterize the bacterial communities in laboratory strains of Ae. aegypti, both infected and non-infected with CHIKV. Female mosquitoes from a laboratory strain of Ae. aegypti were exposed to a CHIKV-infected blood meal through membrane feeding, while the control group received a non-infected blood meal. At 7 days post-infection (dpi), mosquito midguts were dissected for 16S rRNA gene sequencing to identify midgut bacteria, and CHIKV presence was confirmed by E1-nested RT-PCR using mosquito carcasses. The study aimed to compare the bacterial communities between CHIKV-infected and non-infected groups. The analysis included 12 midgut bacterial samples, divided into three groups: CHIKV-infected (exposed and infected), non-infected (exposed but not infected), and non-exposed (negative control). Alpha diversity indices and Bray-Curtis dissimilarity matrix revealed significant differences in bacterial profiles among the three groups. The infected group exhibited an increased abundance of bacteria genus Gluconobacter, while Asaia was prevalent in both non-infected and negative control groups. Chryseobacterium was prominent in the negative control group. These findings highlight potential alterations in the distribution and abundance of gut microbiomes in response to CHIKV infection status. This study provides valuable insights into the dynamic relationship between midgut bacteria and CHIKV, underscoring the potential for alterations in bacterial composition depending on infection status. Understanding the relationships between mosquitoes and their microbiota holds promise for developing new methods and tools to enhance existing strategies for disease prevention and control. This research advances our understanding of the circulating bacterial composition, opening possibilities for new approaches in combating mosquito-borne diseases.


Assuntos
Aedes , Vírus Chikungunya , Microbioma Gastrointestinal , Mosquitos Vetores , Animais , Feminino , Aedes/microbiologia , Aedes/virologia , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Febre de Chikungunya/transmissão , Febre de Chikungunya/virologia , Vírus Chikungunya/genética , Vírus Chikungunya/isolamento & purificação , Vírus Chikungunya/fisiologia , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia , RNA Ribossômico 16S/genética , Tailândia
18.
PLoS One ; 19(5): e0303137, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38722911

RESUMO

The Asian tiger mosquito, Aedes albopictus, is a significant public health concern owing to its expanding habitat and vector competence. Disease outbreaks attributed to this species have been reported in areas under its invasion, and its northward expansion in Japan has caused concern because of the potential for dengue virus infection in newly populated areas. Accurate prediction of Ae. albopictus distribution is crucial to prevent the spread of the disease. However, limited studies have focused on the prediction of Ae. albopictus distribution in Japan. Herein, we used the random forest model, a machine learning approach, to predict the current and potential future habitat ranges of Ae. albopictus in Japan. The model revealed that these mosquitoes prefer urban areas over forests in Japan on the current map. Under predictions for the future, the species will expand its range to the surrounding areas and eventually reach many areas of northeastern Kanto, Tohoku District, and Hokkaido, with a few variations in different scenarios. However, the affected human population is predicted to decrease owing to the declining birth rate. Anthropogenic and climatic factors contribute to range expansion, and urban size and population have profound impacts. This prediction map can guide responses to the introduction of this species in new areas, advance the spatial knowledge of diseases vectored by it, and mitigate the possible disease burden. To our knowledge, this is the first distribution-modelling prediction for Ae. albopictus with a focus on Japan.


Assuntos
Aedes , Mosquitos Vetores , Animais , Aedes/virologia , Aedes/fisiologia , Japão , Mosquitos Vetores/virologia , Ecossistema , Humanos , Distribuição Animal , Dengue/transmissão , Dengue/epidemiologia , Aprendizado de Máquina , Modelos Biológicos
19.
Bull Math Biol ; 86(7): 81, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38805120

RESUMO

The mosquito-borne dengue virus remains a major public health concern in Malaysia. Despite various control efforts and measures introduced by the Malaysian Government to combat dengue, the increasing trend of dengue cases persists and shows no sign of decreasing. Currently, early detection and vector control are the main methods employed to curb dengue outbreaks. In this study, a coupled model consisting of the statistical ARIMAX model and the deterministic SI-SIR model was developed and validated using the weekly reported dengue data from year 2014 to 2019 for Selangor, Malaysia. Previous studies have shown that climate variables, especially temperature, humidity, and precipitation, were able to influence dengue incidence and transmission dynamics through their effect on the vector. In this coupled model, climate is linked to dengue disease through mosquito biting rate, allowing real-time forecast of dengue cases using climate variables, namely temperature, rainfall and humidity. For the period chosen for model validation, the coupled model can forecast 1-2 weeks in advance with an average error of less than 6%, three weeks in advance with an average error of 7.06% and four weeks in advance with an average error of 8.01%. Further model simulation analysis suggests that the coupled model generally provides better forecast than the stand-alone ARIMAX model, especially at the onset of the outbreak. Moreover, the coupled model is more robust in the sense that it can be further adapted for investigating the effectiveness of various dengue mitigation measures subject to the changing climate.


Assuntos
Aedes , Clima , Dengue , Surtos de Doenças , Previsões , Conceitos Matemáticos , Modelos Estatísticos , Mosquitos Vetores , Dengue/epidemiologia , Dengue/transmissão , Malásia/epidemiologia , Humanos , Incidência , Mosquitos Vetores/virologia , Previsões/métodos , Animais , Aedes/virologia , Surtos de Doenças/estatística & dados numéricos , Modelos Epidemiológicos , Simulação por Computador , Temperatura , Chuva , Umidade , Mudança Climática/estatística & dados numéricos , Modelos Biológicos
20.
Parasit Vectors ; 17(1): 220, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741172

RESUMO

BACKGROUND: Japanese encephalitis virus (JEV) is an emerging mosquito-borne Orthoflavivirus that poses a significant public health risk in many temperate and tropical regions in Asia. Since the climate in some endemic countries is similar to temperate climates observed in Europe, understanding the role of specific mosquito species in the transmission of JEV is essential for predicting and effectively controlling the potential for the introduction and establishment of JEV in Europe. METHODS: This study aimed to investigate the vector competence of colonized Culex pipiens biotype molestus mosquitoes for JEV. The mosquitoes were initially collected from the field in southern Sweden. The mosquitoes were offered a blood meal containing the Nakayama strain of JEV (genotype III), and infection rates, dissemination rates, and transmission rates were evaluated at 14, 21, and 28 days post-feeding. RESULTS: The study revealed that colonized Swedish Cx. pipiens are susceptible to JEV infection, with a stable infection rate of around 10% at all timepoints. However, the virus was only detected in the legs of one mosquito at 21 days post-feeding, and no mosquito saliva contained JEV. CONCLUSIONS: Overall, this research shows that Swedish Cx. pipiens can become infected with JEV, and emphasizes the importance of further understanding of the thresholds and barriers for JEV dissemination in mosquitoes.


Assuntos
Culex , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Mosquitos Vetores , Animais , Culex/virologia , Culex/fisiologia , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Suécia , Mosquitos Vetores/virologia , Encefalite Japonesa/transmissão , Encefalite Japonesa/virologia , Feminino , Saliva/virologia , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...