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1.
Environ Pollut ; 292(Pt A): 118333, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637829

RESUMO

While interactions with global warming and multigenerational effects are considered crucial to improve risk assessment of pesticides, these have rarely been studied in an integrated way. While heat extremes can magnify pesticide toxicity, no studies tested how their combined effects may transmit to the next generation. We exposed mosquito larvae in a full factorial, two-generation experiment to a heat spike followed by chlorpyrifos exposure. As expected, the heat spike magnified the chlorpyrifos-induced lethal and sublethal effects within both generations. Only when preceded by the heat spike, chlorpyrifos increased mortality and reduced the population growth rate. Moreover, chlorpyrifos-induced reductions in heat tolerance (CTmax), acetylcholinesterase (AChE) activity and development time were further magnified by the heat spike. Notably, when parents were exposed to chlorpyrifos, the chlorpyrifos-induced lethal and sublethal effects in the offspring were smaller, indicating increased tolerance to chlorpyrifos. In contrast, there was no such multigenerational effect for the heat spike. Despite the adaptive multigenerational effect to the pesticide, the synergism with the heat spike was still present in the offspring generation. Generally, our results provide important evidence that short exposure to pulse-like global change stressors can strongly affect organisms within and across generations, and highlight the importance of considering multigenerational effects in risk assessment.


Assuntos
Clorpirifos , Culicidae , Praguicidas , Acetilcolinesterase , Animais , Clorpirifos/toxicidade , Temperatura Alta , Larva
2.
Front Public Health ; 9: 754072, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34778187

RESUMO

Mosquito surveillance is a crucial process for understanding the population dynamics of mosquitoes, as well as implementing interventional programs for controlling and preventing the spread of mosquito-borne diseases. Environmental surveillance agents who performing routine entomological surveys at properties in areas where mosquito-borne diseases are endemic play a critical role in vector surveillance by searching and destroying mosquito hotspots as well as collate information on locations with increased infestation. Currently, the process of recording information on paper-based forms is time-consuming and painstaking due to manual effort. The introduction of mobile surveillance applications will therefore improve the process of data collection, timely reporting, and field worker performance. Digital-based surveillance is critical in reporting real-time data; indeed, the real-time capture of data with phones could be used for predictive analytical models to predict mosquito population dynamics, enabling early warning detection of hotspots and thus alerting fieldworker agents into immediate action. This paper describes the development of a cross-platform digital system for improving mosquito surveillance in Brazil. It comprises of two components: a dashboard for managers and a mobile application for health agents. The former enables managers to assign properties to health workers who then survey them for mosquitoes and to monitor the progress of inspection visits in real-time. The latter, which is primarily designed as a data collection tool, enables the environmental surveillance agents to act on their assigned tasks of recording the details of the properties at inspections by filling out digital forms built into the mobile application, as well as details relating to mosquito infestation. The system presented in this paper was co-developed with significant input with environmental agents in two Brazilian cities where it is currently being piloted.


Assuntos
Culicidae , Aplicativos Móveis , Animais , Brasil , Entomologia , Humanos , Mosquitos Vetores
3.
Zootaxa ; 5016(2): 257-270, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34810451

RESUMO

Culex ekaterinae sp. nov. is described based on an adult male embedded in amber from the Rovno region, northwestern Ukraine. The new species is compared with its presumed closest known relative, i.e. Culex erikae Szadziewski et Szadziewska, 1985 described from adults in Baltic amber. The two species exhibit distinct differences in the size of the main body parts, including the antenna, maxillary palpus and proboscis, as well as in the venation of the wing, the structure of the ungues and male genitaliacharacters crucial in the diagnosis of adult mosquitoes. A redescription of Culiseta gedanica Szadziewski et Gika, 2011, to date known from a single adult male, is presented based on a male in amber from Voronki, Rovno region. A tabulation of fossil Culicidae with their geological ages is provided.


Assuntos
Âmbar , Culicidae , Animais , Fósseis , Masculino , Ucrânia
4.
Zootaxa ; 4999(6): 534-552, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34811327

RESUMO

A new species of the genus Wyeomyia, Wyeomyia (Decamyia) anthica sp. n., is described based on morphological and molecular analyses and is illustrated in larval, pupal and adult life stages. Among the four valid species of the subgenus Decamyia, the new species is closest to Wy. ulocoma (Theobald, 1903), from which it can be distinguished by morphological characters of the male genitalia, larval and pupal stages, and mitochondrial cytochrome c oxidase 1 gene sequence. Wyeomyia ulocoma is recorded from Brazil for the first time.


Assuntos
Culicidae , Heliconiaceae , Animais , Flores , Pupa
5.
Indian J Med Res ; 154(1): 36-50, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34782529

RESUMO

West Nile virus (WNV) is a mosquito-borne single-stranded RNA neurotropic virus within the family Flaviviridae. The virus was first reported in the West Nile province of Uganda in 1937. Since then, sporadic cases have been reported until the last two decades when it has emerged as a threat to public health. The emergence of WNV with more severity in recent times is intriguing. Considering this phenomenon, the WNV-affected areas of the world were distinguished as old versus new in a depicted world map. The present review showcases the historical and epidemiological perspectives of the virus, genetic diversity of prevailing lineages and clinical spectrum associated with its infection. Emergence of the virus has been discussed in special context to India because of co-circulation of different WNV lineages/strains along with other flaviviruses. Recent laboratory diagnostics, vaccine development and clinical management associated with WNV infection have also been discussed. Further, the research gaps, especially in context to India have been highlighted that may have a pivotal role in combating the spread of WNV.


Assuntos
Culicidae , Flavivirus , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Humanos , Índia/epidemiologia , Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental/genética
6.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(5): 510-512, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34791850

RESUMO

OBJECTIVE: To investigate the distribution and density of Culex mosquito populations and the resistance of Culex pipiens pallens to insecticides in Jiangsu Province in 2018 and 2019. METHODS: During the period from June to October in 2018 and 2019, six counties (districts, cities) were sampled in southern, northern and central Jiangsu Province as surveillance sites. The density of Culex mosquitoes was measured overnight using the light trapping technique. In addition, Culex pipiens pallens mosquitoes were collected from Hai'an of Nantong City and Yandu District of Yancheng City, central Jiangsu Province, and the sensitivity of female first filial generations to dichlorodiphenyltrichloroethane (DDT), malation, proposur, beta cypermethrin and deltamethrin was tested using the standard WHO insecticide susceptibility test assay. RESULTS: A total of 104 423 Culex mosquitoes were captured in six surveillance sites of Jiangsu Province in 2018 and 2019, and Culex quinquefasciatus (49.11%), Culex pipiens pallens (28.38%), and Culex tritaeniorhynchus (21.04%) were predominant species. The density of Culex mosquitoes started to increase since early June, peaked in July and tended to be low in late October. Culex pipiens pallens mosquitoes captured from Hai'an was susceptible to malation, while those from Yandu District were moderately resistant to malation. Culex pipiens pallens mosquitoes from both Yandu and Hai'an were moderately resistant to proposur, and were resistant to DDT, beta cypermethrin and deltamethrin. CONCLUSIONS: Culex quinquefasciatus, Culex pipiens pallens and Culex tritaeniorhynchus are predominant Culex species in Jiangsu Province. Culex pipiens pallens is resistant to DT, beta cypermethrin and deltamethrin in central Jiangsu Province.


Assuntos
Culex , Culicidae , Inseticidas , Piretrinas , Animais , Bioensaio , Feminino , Resistência a Inseticidas , Inseticidas/farmacologia , Piretrinas/farmacologia
7.
BMC Res Notes ; 14(1): 388, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34627362

RESUMO

OBJECTIVE: Due to different concerns in using appropriate mosquito blood feeding techniques, this work focused on evaluating the effectiveness of two artificial mosquito feeding systems (Rutledge and Hemotek) and three different membranes (Parafilm, mouse and chicken skins). Female mosquitoes from an An. coluzzii strain aged between 2 and 5 days were exposed to blood with the two systems at time intervals (5, 10, 15, 20, 25 and 30 min) with blood used on the day of collection, the next day and 2 days after. RESULTS: Our results showed that the Hemotek system gave better blood feeding rates than the Rutledge system. Among the three membranes, the blood feeding rates with chicken and mouse skins were higher than those provided by the Parafilm membrane. Likewise, blood stored 1 day after collection gave higher levels than blood used on the day of collection and 2 days after. Regardless of the system, the lowest blood feeding rates were observed at 5 min compared to the other exposure times.


Assuntos
Culicidae , Animais , Galinhas , Comportamento Alimentar , Feminino , Camundongos , Pele
8.
Artigo em Inglês | MEDLINE | ID: mdl-34639855

RESUMO

Arthropod vectors play a crucial role in the transmission of many debilitating infections, causing significant morbidity and mortality globally. Despite the economic significance of arthropods to public health, public knowledge on vector biology, ecology and taxonomic status remains anecdotal and largely unexplored. The present study surveyed knowledge gaps regarding the biology and ecology of arthropod vectors in communities of Botswana, across all districts. Results showed that communities are largely aware of individual arthropod vectors; however, their 'potential contribution' in disease transmission in humans, livestock and wildlife could not be fully attested. As such, their knowledge was largely limited with regards to some aspects of vector biology, ecology and control. Communities were strongly concerned about the burden of mosquitoes, cockroaches, flies and ticks, with the least concerns about fleas, bedbugs and lice, although the same communities did not know of specific diseases potentially vectored by these arthropods. Knowledge on arthropod vector control was mainly limited to synthetic chemical pesticides for most respondents, regardless of their location. The limited knowledge on potentially pathogen-incriminated arthropod vectors reported here has large implications for bridging knowledge gaps on the bio-ecology of these vectors countrywide. This is potentially useful in reducing the local burden of associated diseases and preventing the risk of emerging and re-emerging infectious diseases under global change.


Assuntos
Culicidae , Mosquitos Vetores , Animais , Vetores Artrópodes , Botsuana , Humanos , Inquéritos e Questionários
9.
BMC Ecol Evol ; 21(1): 188, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34635056

RESUMO

BACKGROUND: Industrial wastewater is a human health hazard upon exposure. Aquatic organisms in contaminated wastewater may accumulate the toxic elements with time. Human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms in open drainage channels can be key in metal exposure assessment. Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) were established in samples of wastewater, filamentous green algae (Spirogyra) and mosquitoes obtained from open drainage channels in Nairobi industrial area, Kenya. RESULTS: Pb, Cr, & Ni levels ranged from 3.08 to 15.31 µg/l while Tl, Hg, & Cd ranged from 0.05 to 0.12 µg/l in wastewater. The Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3-2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/kg & 1.8 mg/kg respectively) were higher than in field mosquitoes (0.048 mg/kg & 0.12 mg/kg respectively). The levels of Pb, Cr, & Ni were distinctively higher in field mosquito samples than in wastewater samples from the same site. Pb, Cr, Ni, Cd & Hg levels in green filamentous Spirogyra algae were 110.62, 29.75, 14.45, 0.44, & 0.057 mg/kg respectively. Correlation for Pb & Hg (r (2) = 0.957; P < 0.05); Cd & Cr (r (2) = 0.985; P < 0.05) in algae samples was noted. The metal concentrations in the samples analyzed were highest in filamentous green algae and least in wastewater. CONCLUSION: Wastewater, mosquitoes, and filamentous green algae from open drainage channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Mosquitoes in urban areas and filamentous green algae in open drainage channels can play a role of metal biomonitoring in wastewater. The potential of urban mosquitoes transferring heavy metals to human population from the contaminated wastewater should be investigated.


Assuntos
Clorófitas , Culicidae , Metais Pesados , Animais , Monitoramento Biológico , Drenagem , Humanos , Quênia , Metais Pesados/análise
10.
PLoS One ; 16(10): e0256868, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34624026

RESUMO

Ecological Niche Modeling is a process by which spatiotemporal, climatic, and environmental data are analyzed to predict the distribution of an organism. Using this process, an ensemble ecological niche model for West Nile virus habitat prediction in the state of Florida was developed. This model was created through the weighted averaging of three separate machine learning models-boosted regression tree, random forest, and maximum entropy-developed for this study using sentinel chicken surveillance and remote sensing data. Variable importance differed among the models. The highest variable permutation value included mean dewpoint temperature for the boosted regression tree model, mean temperature for the random forest model, and wetlands focal statistics for the maximum entropy mode. Model validation resulted in area under the receiver curve predictive values ranging from good [0.8728 (95% CI 0.8422-0.8986)] for the maximum entropy model to excellent [0.9996 (95% CI 0.9988-1.0000)] for random forest model, with the ensemble model predictive value also in the excellent range [0.9939 (95% CI 0.9800-0.9979]. This model should allow mosquito control districts to optimize West Nile virus surveillance, improving detection and allowing for a faster, targeted response to reduce West Nile virus transmission potential.


Assuntos
Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Clima , Culicidae/virologia , Ecossistema , Florida/epidemiologia , Humanos , Aprendizado de Máquina , Probabilidade , Fatores de Risco , Vigilância de Evento Sentinela , Áreas Alagadas
11.
J Gen Virol ; 102(10)2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34609940

RESUMO

Mosquito-transmitted arboviruses constitute a large proportion of emerging infectious diseases that are both a public health problem and a threat to animal populations. Many such viruses were identified in East Africa, a region where they remain important and from where new arboviruses may emerge. We set out to describe and review the relevant mosquito-borne viruses that have been identified specifically in Uganda. We focused on the discovery, burden, mode of transmission, animal hosts and clinical manifestation of those previously involved in disease outbreaks. A search for mosquito-borne arboviruses detected in Uganda was conducted using search terms 'Arboviruses in Uganda' and 'Mosquitoes and Viruses in Uganda' in PubMed and Google Scholar in 2020. Twenty-four mosquito-borne viruses from different animal hosts, humans and mosquitoes were documented. The majority of these were from family Peribunyaviridae, followed by Flaviviridae, Togaviridae, Phenuiviridae and only one each from family Rhabdoviridae and Reoviridae. Sixteen (66.7%) of the viruses were associated with febrile illnesses. Ten (41.7%) of them were first described locally in Uganda. Six of these are a public threat as they have been previously associated with disease outbreaks either within or outside Uganda. Historically, there is a high burden and endemicity of arboviruses in Uganda. Given the many diverse mosquito species known in the country, there is also a likelihood of many undescribed mosquito-borne viruses. Next generation diagnostic platforms have great potential to identify new viruses. Indeed, four novel viruses, two of which were from humans (Ntwetwe and Nyangole viruses) and two from mosquitoes (Kibale and Mburo viruses) were identified in the last decade using next generation sequencing. Given the unbiased approach of detection of viruses by this technology, its use will undoubtedly be critically important in the characterization of mosquito viromes which in turn will inform other diagnostic efforts.


Assuntos
Infecções por Arbovirus , Arbovírus , Culicidae/virologia , Mosquitos Vetores/virologia , Animais , Infecções por Arbovirus/epidemiologia , Infecções por Arbovirus/transmissão , Infecções por Arbovirus/veterinária , Infecções por Arbovirus/virologia , Arbovírus/classificação , Arbovírus/genética , Arbovírus/isolamento & purificação , Arbovírus/fisiologia , Doenças Transmissíveis Emergentes/epidemiologia , Surtos de Doenças , Doenças Endêmicas , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Prevalência , Uganda/epidemiologia
12.
Molecules ; 26(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34641433

RESUMO

Poly(lactic acid) (PLA) is an attractive candidate for replacing petrochemical polymers because it is fully biodegradable. This study investigated the potential of PLA as a sustainable and environmentally friendly alternative material that can be developed into commercially viable wearable mosquito repellent devices with desirable characteristics. PLA strands containing DEET and IR3535 were prepared by twin screw extrusion compounding and simultaneously functioned as plasticizers for the polymer. The plasticizing effect was investigated by thermal and rheological studies. DSC studies showed that the addition of DEET and IR3535 into PLA strands reduced the glass transition temperature consistent with predictions of the Fox equation, thus proving their efficiency as plasticizers. The rheology of molten samples of neat PLA and PLA/repellents blends, evaluated at 200 °C, was consistent with shear-thinning pseudoplastic behaviour. Raman studies revealed a nonlinear concentration gradient for DEET in the PLA strand, indicating non-Fickian Type II transport controlling the desorption process. Release data obtained at 50 °C showed initial rapid release followed by a slower, near constant rate at longer times. The release rate data were fitted to a novel modification of the Peppas-Sahlin desorption model.


Assuntos
Culicidae/crescimento & desenvolvimento , Repelentes de Insetos/química , Plastificantes/química , Poliésteres/química , Polímeros/química , Animais , Culicidae/efeitos dos fármacos , Reologia , Temperatura
13.
Nat Commun ; 12(1): 6018, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34650045

RESUMO

Mosquito bites transmit a number of pathogens via salivary droplets deposited during blood-feeding, resulting in potentially fatal diseases. Little is known about the genomic content of these nanodroplets, including the transmission dynamics of live pathogens. Here we introduce Vectorchip, a low-cost, scalable microfluidic platform enabling high-throughput molecular interrogation of individual mosquito bites. We introduce an ultra-thin PDMS membrane which acts as a biting interface to arrays of micro-wells. Freely-behaving mosquitoes deposit saliva droplets by biting into these micro-wells. By modulating membrane thickness, we observe species-dependent differences in mosquito biting capacity, utilizable for selective sample collection. We demonstrate RT-PCR and focus-forming assays on-chip to detect mosquito DNA, Zika virus RNA, as well as quantify infectious Mayaro virus particles transmitted from single mosquito bites. The Vectorchip presents a promising approach for single-bite-resolution laboratory and field characterization of vector-pathogen communities, and could serve as a powerful early warning sentinel for mosquito-borne diseases.


Assuntos
Culicidae/fisiologia , Mordeduras e Picadas de Insetos , Microfluídica/métodos , Mosquitos Vetores/fisiologia , Aedes/fisiologia , Animais , Feminino , Ensaios de Triagem em Larga Escala , Mosquitos Vetores/virologia , Saliva/virologia , Zika virus , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão
14.
Trials ; 22(1): 613, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507602

RESUMO

BACKGROUND: In cluster randomized trials (CRTs) of interventions against malaria, mosquito movement between households ultimately leads to contamination between intervention and control arms, unless they are separated by wide buffer zones. METHODS: This paper proposes a method for adjusting estimates of intervention effectiveness for contamination and for estimating a contamination range between intervention arms, the distance over which contamination measurably biases the estimate of effectiveness. A sigmoid function is fitted to malaria prevalence or incidence data as a function of the distance of households to the intervention boundary, stratified by intervention status and including a random effect for the clustering. The method is evaluated in a simulation study, corresponding to a range of rural settings with varying intervention effectiveness and contamination range, and applied to a CRT of insecticide treated nets in Ghana. RESULTS: The simulations indicate that the method leads to approximately unbiased estimates of effectiveness. Precision decreases with increasing mosquito movement, but the contamination range is much smaller than the maximum distance traveled by mosquitoes. For the method to provide precise and approximately unbiased estimates, at least 50% of the households should be at distances greater than the estimated contamination range from the discordant intervention arm. CONCLUSIONS: A sigmoid approach provides an appropriate analysis for a CRT in the presence of contamination. Outcome data from boundary zones should not be discarded but used to provide estimates of the contamination range. This gives an alternative to "fried egg" designs, which use large clusters (increasing costs) and exclude buffer zones to avoid bias.


Assuntos
Culicidae , Inseticidas , Malária , Animais , Humanos , Malária/prevenção & controle , Controle de Mosquitos , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
Environ Sci Pollut Res Int ; 28(40): 55952-55966, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34495471

RESUMO

This paper explores the main factors for mosquito-borne transmission of the Zika virus by focusing on environmental, anthropogenic, and social risks. A literature review was conducted bringing together related information from this genre of research from peer-reviewed publications. It was observed that environmental conditions, especially precipitation, humidity, and temperature, played a role in the transmission. Furthermore, anthropogenic factors including sanitation, urbanization, and environmental pollution promote the transmission by affecting the mosquito density. In addition, socioeconomic factors such as poverty as well as social inequality and low-quality housing have also an impact since these are social factors that limit access to certain facilities or infrastructure which, in turn, promote transmission when absent (e.g., piped water and screened windows). Finally, the paper presents short-, mid-, and long-term preventative solutions together with future perspectives. This is the first review exploring the effects of anthropogenic aspects on Zika transmission with a special emphasis in Brazil.


Assuntos
Aedes , Culicidae , Infecção por Zika virus , Zika virus , Animais , Brasil/epidemiologia , Mosquitos Vetores , Infecção por Zika virus/epidemiologia
16.
Appl Microbiol Biotechnol ; 105(19): 7505-7515, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34524470

RESUMO

The diseases transmitted by mosquito vectors are a great public health issue. Thus, effective vector control becomes the main strategy to reduce their prevalence. However, insecticide resistance has become a huge concern for the mitigation of mosquitoes; here, we propose the use of rhamnolipids in emulsion with clove oil against Aedes aegypti and Culex quinquefasciatus. The toxicity of rhamnolipids and clove oil to two species of mosquitoes transmitting tropical diseases was investigated. After 24 h, the LC50 was 140 mg/L when rhamnolipids were used and 154 mg/L when clove oil was used against Aedes aegypti larvae. In the case of Culex quinquefasciatus, the LC50 was 130 mg/L for rhamnolipids and 19 mg/L for clove oil. When the concentrations of the upper limits of one of the solutions (rhamnolipid or clove oil) were mixed, 100% mortality was obtained after 24 h. The bioassay of insecticidal action for solutions of rhamnolipids and clove oil in the lower limit, upper limit, and lethal concentration 50 to determine the effect on 50% of the population (KD50) achieved low results from KD50 to the upper limit compared to the other concentrations for both Aedes aegypti and Culex quinquefasciatus. The rhamnolipids and clove oil at the upper limit concentration had the greatest repellent activity against the two mosquito species. Bioassays using different concentrations of rhamnolipids revealed variations in the morphology of the intestinal epithelium (800 mg/L). A concentration of 900 mg/L led to the most severe morphological changes in the organization of the epithelium and the cells lining the intestines of these larvae. When larvae were exposed to a concentration of 1000 mg/L, the marginalization of chromatin in the nucleus of epithelial cells was very severe, indicating the onset of cell death.Key points• The toxicity of rhamnolipids and clove oil has a larvicidal, insecticidal, and repellent effect.• The combination of concentrations of these compounds enhances their action.• Different concentrations of rhamnolipids led to severe morphological changes in the organization of the epithelium and the cells and the intestines of larvae.


Assuntos
Culicidae , Óleos Voláteis , Animais , Morte Celular , Glicolipídeos , Óleos Voláteis/farmacologia
17.
Microb Pathog ; 160: 105203, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34547408

RESUMO

Malaria, a mosquito-borne infection, is the most widespread parasitic disease. Despite numerous efforts to eradicate malaria, this disease is still a health concern worldwide. Owing to insecticide-resistant vectors and drug-resistant parasites, available controlling measures are insufficient to achieve a malaria-free world. Thus, there is an urgent need for new intervention tools such as efficient malaria vaccines. Subunit vaccines are the most promising malaria vaccines under development. However, one of the major drawbacks of subunit vaccines is the lack of efficient and durable immune responses including antigen-specific antibody, CD4+, and CD8+ T-cell responses, long-lived plasma cells, memory cells, and functional antibodies for parasite neutralization or inhibition of parasite invasion. These types of responses could be induced by whole organism vaccines, but eliciting these responses with subunit vaccines has been proven to be more challenging. Consequently, subunit vaccines require several policies to overcome these challenges. In this review, we address common approaches that can improve the efficacy of subunit vaccines against malaria.


Assuntos
Culicidae , Vacinas Antimaláricas , Malária , Animais , Malária/prevenção & controle , Mosquitos Vetores , Vacinas de Subunidades
18.
Front Cell Infect Microbiol ; 11: 694020, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34527601

RESUMO

Mosquitoes not only transmit human and veterinary pathogens called arboviruses (arthropod-borne viruses) but also harbor mosquito-associated insect-specific viruses (mosquito viruses) that cannot infect vertebrates. In the past, studies investigating mosquito viruses mainly focused on highly pathogenic interactions that were easier to detect than those without visible symptoms. However, the recent advances in viral metagenomics have highlighted the abundance and diversity of viruses which do not generate mass mortality in host populations. Over the last decade, this has facilitated the rapid growth of virus discovery in mosquitoes. The circumstances around the discovery of mosquito viruses greatly affected how they have been studied so far. While earlier research mainly focused on the pathogenesis caused by DNA and some double-stranded RNA viruses during larval stages, more recently discovered single-stranded RNA mosquito viruses were heavily studied for their putative interference with arboviruses in female adults. Thus, many aspects of mosquito virus interactions with their hosts and host-microbiota are still unknown. In this context, considering mosquito viruses as endosymbionts can help to identify novel research areas, in particular in relation to their long-term interactions with their hosts (e.g. relationships during all life stages, the stability of the associations at evolutionary scales, transmission routes and virulence evolution) and the possible context-dependent range of interactions (i.e. beneficial to antagonistic). Here, we review the symbiotic interactions of mosquito viruses considering different aspects of their ecology, such as transmission, host specificity, host immune system and interactions with other symbionts within the host cellular arena. Finally, we highlight related research gaps in mosquito virus research.


Assuntos
Arbovírus , Culicidae , Vírus de Insetos , Vírus , Animais , Feminino , Humanos , Metagenômica
20.
J Gen Virol ; 102(9)2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34554079

RESUMO

The genus Orbivirus includes a variety of pathogenic viruses that are transmitted by biting midges, mosquitoes and ticks. Some of the economically most relevant orbiviruses are endemic to Namibia, like the livestock-pathogenic Bluetongue and African horse sickness viruses. Here, we assessed the diversity of orbiviruses circulating in the Zambezi region of north-eastern Namibia. A total of 10 250 biting midges and 10 206 mosquitoes were collected and screened for orbivirus infections. We identified Palyam virus (PALV) in a pool of biting midges (Culicoides sp.) sampled in the Wuparo Conservancy and three strains of Corriparta virus (CORV) in Culex sp. mosquitoes sampled in Mudumu National Park and the Mashi Conservancy. This is, to our knowledge, the first detection of PALV and CORV in Namibia. Both viruses infect vertebrates but only PALV has been reported to cause disease. PALV can cause foetal malformations and abortions in ruminants. Furthermore, a novel orbivirus, related to Kammavanpettai virus from India and Umatilla virus from North America, was discovered in biting midges (Culicoides sp.) originating from Mudumu National Park and tentatively named Mudumu virus (MUMUV). Complete genomes of PALV, CORV and MUMUV were sequenced and genetically characterized. The Namibian CORV strain showed 24.3 % nucleotide divergence in its subcore shell gene to CORV strains from Australia, indicating that African CORV variants vary widely from their Australian relatives. CORV was isolated in cell culture and replicated to high titres in mosquito and duck cells. No growth was found in rodent and primate cells. The data presented here show that diverse orbiviruses are endemic to the Zambezi region. Further studies are needed to assess their effects on wildlife and livestock.


Assuntos
Ceratopogonidae/virologia , Culicidae/virologia , Orbivirus/isolamento & purificação , Animais , Linhagem Celular , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Insetos Vetores/virologia , Mosquitos Vetores/virologia , Namíbia , Orbivirus/classificação , Orbivirus/genética , Orbivirus/fisiologia , Filogenia , Replicação Viral , Sequenciamento Completo do Genoma
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