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1.
Acta Trop ; 201: 105207, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31586449

RESUMO

A gynandromorph of Culex sitiens Wiedemann (Diptera: Culicidae) was attracted to a human during a mosquito surveillance programme conducted in Kuala Lipis, Pahang, Malaysia on July 20, 2019. Gynandromorphism was observed in antennae, maxillary palps, legs and wings of the specimen, with distinct male characters on the left and female characters on the right, though the left maxillary palp is slightly shorter than the proboscis of a typical male. The abdomen, however, displays well-developed male genitalia. This study represents the first report of oblique gynandromorphism in Cx. sitiens, one of the vectors of Japanese encephalitis in Asia.


Assuntos
Culex/classificação , Culex/genética , Encefalite Japonesa/transmissão , Mosquitos Vetores/genética , Comportamento Sexual , Animais , Feminino , Genitália Masculina , Genótipo , Humanos , Malásia , Masculino , Fenótipo
2.
Rev Soc Bras Med Trop ; 53: e20190277, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31859951

RESUMO

INTRODUCTION: This study aimed to assess the occurrence of gonotrophic discordance in females of Culex quinquefasciatus in São Paulo, Brazil. METHODS: Resting females were collected monthly for 8 months. Females of Cx. quinquefasciatus were identified, and their midgut and ovaries were dissected. RESULTS: Two hundred females were dissected, out of which, 27.5% were nulliparous and 57% were parous. Most females had no blood in the midgut, but gonotrophic discordance was found in 21% females. CONCLUSIONS: Females of Cx. quinquefasciatus showed a high parity rate and gonotrophic discordance, which could favor the vector capacity of this species.


Assuntos
Culex/fisiologia , Mosquitos Vetores/fisiologia , Animais , Brasil , Culex/classificação , Dirofilariose/transmissão , Filariose Linfática/transmissão , Comportamento Alimentar/fisiologia , Feminino , Longevidade/fisiologia , Masculino , Mosquitos Vetores/classificação , Oviparidade/fisiologia , Reprodução/fisiologia
3.
J Photochem Photobiol B ; 200: 111650, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31698288

RESUMO

The biosynthesis of ZnO nanoparticles was synthesized by biogenic reduction of applied Cucurbita seed extract. The powder X-ray diffraction pattern displayed the high crystalline nature of synthesized ZnO nanoparticles and the crystallite size was calculated at 35 nm range. The Fourier Transform Infra-Red study revealed the functional groups of biogenic reduction and vibrational bands present in the synthesized nanoparticles. The UV-Visible analysis explained the SPR absorption peak at 371 nm. The Photoluminescence study revealed the strong red shoulder emission peak at 665 nm. The particle size analyzer displayed the particle size occupies majorly on 45-65 nm. The SEM analysis pointed the ZnO nanoparticles under rod, rectangular and hexagonal shapes were procured. The EDAX spectrum also mapping exposed the purity of formed ZnO nanoparticles with just Zn and O peaks. The HRTEM analysis exposed the hexagonal shape wurtzite structure ZnO particles formation. The physiochemical analysis revealed general nature of Cucurbita seed powder moreover which explained the phytochemicals involved in biogenic reduction of ZnO nanoparticles. The formed ZnO nanoparticles exhibited good antibacterial activity on E. coli, Bacillus pumilus, and Salmonella typhi bacteria. The cytotoxicity study stated the good toxicity on E. coli AB 1157. The antifungal activity showed a better effect on Aspergillus flavus and Aspergillus niger fungi. The antioxidant activity clarified the good free radical scavenging action. The anti larvicidal activity expressed a better impact on Culex tritaeniorhynchus mosquito larvae.


Assuntos
Cucurbita/química , Culex/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Extratos Vegetais/química , Óxido de Zinco/química , Animais , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Cucurbita/metabolismo , Culex/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Química Verde , Larva/efeitos dos fármacos , Nanopartículas Metálicas/química , Tamanho da Partícula , Sementes/química , Sementes/metabolismo
4.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 510-512, 2019 Aug 16.
Artigo em Chinês | MEDLINE | ID: mdl-31713380

RESUMO

OBJECTIVE: To examine the effect of low temperature on trehalose and trehalase levels in Culex pipiens pallens. METHODS: The fourth instar larvae and female adult mosquitoes of Cx. pipiens pallens were exposed at 4 ℃ for 0, 1, 3, 6, 12, 18, 24 h and 0, 1, 3, 6, 12, 18, 24, 36, 48, 72 h, respectively. Then, the trehalose and trehalase contents were detected by enzyme-linked immunosorbent assay (ELISA) in mosquitoes. RESULTS: The contents of trehalose and trehalase significantly increased in the larval and female adult mosquitoes post-exposure to low temperature. The changing trend of trehalose levels was consistent in the larval and female adult mosquitoes, and the highest levels were (2.458 8 ± 0.379 2) mg/g and (2.825 7 ± 0.211 1) mg/g 3 h post-exposure to low temperature, respectively. The trehalose and trehalase levels fluctuated greatly within the first 6 h post-exposure to low temperature. Following adaptation for a period of time, the trehalose and trehalase levels remained at a relatively high level. CONCLUSIONS: Low temperature may induce the production of trehalose and trehalase in Cx. pipiens pallens, and the trehalose and trehalase may play an important role in the improvement of the cold resistance.


Assuntos
Culex , Temperatura Ambiente , Trealase , Trealose , Animais , Culex/enzimologia , Culex/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação Enzimológica da Expressão Gênica/fisiologia , Larva , Trealase/metabolismo , Trealose/metabolismo
5.
Aquat Toxicol ; 216: 105310, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31580997

RESUMO

Pesticide mixtures are increasingly used to fight pest species that developed resistance to pesticides. To assess the pesticide control efficiency and to reduce ecological damage to non-target species, it is important to quantify the effect of these mixtures and compare them with the effect of their single pesticides on pest species, non-target species and their predator-prey interactions. We studied the effects of the chemical pesticide chlorpyrifos (CPF), the biopesticide Bacillus thuringiensis israelensis (Bti) and their mixture both on the direct mortality and on the mortality by predation. We focused on larvae of a CPF-resistant and a non-resistant strain of the vector mosquito Culex quinquefasciatus and its predator, the pygmy backswimmer Plea minutissima. In the CPF-Bti mixture, both pesticides interacted antagonistically for direct mortality. Exposure to the mixture caused equal direct mortality and equal mortality by predation in both strains. As expected, exposure to CPF resulted in less direct mortality and less mortality by predation in the CPF-resistant mosquito strain compared to the non-resistant strain. Notably, Bti caused a higher mortality in the mosquito larvae of the CPF-resistant strain compared to the non-resistant strain. Furthermore, the predator killed more mosquito larvae of the resistant strain compared to the non-resistant strain when exposed before to Bti alone. These observations identify a novel cost of resistance to a chemical pesticide in terms of increased vulnerability to a biopesticide.


Assuntos
Agentes de Controle Biológico/toxicidade , Praguicidas/toxicidade , Comportamento Predatório/efeitos dos fármacos , Animais , Bacillus thuringiensis/efeitos dos fármacos , Clorpirifos/toxicidade , Culex/efeitos dos fármacos , Reação de Congelamento Cataléptica/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Larva/efeitos dos fármacos , Modelos Lineares , Natação , Poluentes Químicos da Água/toxicidade
6.
PLoS Negl Trop Dis ; 13(9): e0007716, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31557156

RESUMO

Japanese Encephalitis virus (JEV) is a zoonotic flavivirus that represents the most significant etiology of childhood viral neurological infections throughout the Asia. During the last 20 years, JEV genotype dominance has shifted from genotype III (GIII) to genotype I (GI). To date, the exact mechanism of this displacement is still not known. Culex (Cx.) mosquitoes are the most common species in China and play an essential role in maintaining JEV enzootic transmission cycle. In this study, we used Cx. pipiens mosquitoes from China as an in vivo mosquito model to explore if mosquitoes played a potential role in JEV genotype shift. We exposed female Cx. pipiens mosquitoes orally to either GI or GIII JEV strains. Midgut, whole mosquitoes, secondary organs, and salivary glands of JEV-infected mosquitoes were collected at 7 and 14 days of post infection (dpi) and subjected to measure the infection rate, replication kinetics, dissemination rate and transmission potential of the infected JEV strains in Cx. pipiens mosquitoes by 50% tissue culture infective dose assay. We found that Cx. pipiens mosquito was competent vector for both GI and GIII JEV infection, with similar infection rates and growth kinetics. After the establishment of infection, Cx. pipiens mosquitoes disseminated both JEV genotypes to secondary organs at similar rates of dissemination. A few GI-infected mosquito salivary glands (16.2%) were positive for GI virus, whereas GIII virus was undetectable in GIII-infected mosquito salivary glands at 7 dpi. However, 29.4% (5/17) and 36.3% (8/22) were positive for GI- and GIII-infected mosquito salivary glands at 14 dpi, respectively, showing an increase in JEV positive rate. No statistical difference in the transmission rate between GI- and GIII-infected mosquitoes was detected. Our experiment data demonstrated that GI and GIII viruses have similar infectivity in Cx. pipiens mosquitoes, suggesting that Cx. pipiens mosquitoes from China may not play a critical role in JEV genotype shift. Although the current data were obtained solely from Cx. pipiens mosquitoes, it is likely that the conclusion drawn could be extrapolated to the role of mosquitoes in JEV genotype shift.


Assuntos
Culex/virologia , Vírus da Encefalite Japonesa (Espécie)/genética , Animais , China , Vírus da Encefalite Japonesa (Espécie)/crescimento & desenvolvimento , Encefalite Japonesa/transmissão , Encefalite Japonesa/virologia , Feminino , Trato Gastrointestinal/virologia , Genótipo , Mosquitos Vetores/virologia , Glândulas Salivares/virologia
7.
Acta Trop ; 200: 105174, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31525322

RESUMO

Mosquitoes are responsible for transmitting many pathogens to humans and Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are important vectors in the world. The microbiota plays an important role in developmental studies that involve impacts on the biological cycle of mosquitoes and vector control strategies. In this study, the aim was to understand the environment plays in the microbiota culturable diversity of Aedes aegytpi, Aedes albopictus and Culex quinquefasciatus. Midgut of studied mosquitoes (laboratory-reared and wild) were dissected and analyzed by MALDI-TOF MS to identify the microbiota. Most of the bacteria identified in the microbiota of mosquitoes from the laboratory and field belong to the phylum Proteobacteria. We reported on the microbial diversity among the mosquito species studied where Cx. quinquefasciatus and Ae. albopictus show greater bacterial similarity. The genus Rahnella was present in all mosquito species studied, both in those from the laboratory and those from the wild. Bacillus, Ewingella, Microccocus, Klebsiella and Pantoea are genera was predominant among the mosquitoes studied. The difference of microbiota diversity between mosquitoes laboratory-reared and wild shows that the environment plays an important role in the acquisition of bacteria, mainly in Ae. aegypti and Cx. quinquefasciatus.


Assuntos
Bactérias/classificação , Bactérias/genética , Sistema Digestório/microbiologia , Microbioma Gastrointestinal/genética , Mosquitos Vetores/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Aedes/microbiologia , Animais , Culex/microbiologia
8.
Mater Sci Eng C Mater Biol Appl ; 104: 109984, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500006

RESUMO

The present investigation highlights the strong antioxidant, anticancer and larvicidal potential of green synthesized silver nanoparticles (AgNPs) using aqueous leaf extract of Piper longum L. for their diverse therapeutic applications. The optimum conditions for the synthesis of AgNPs were recorded as 1 mM AgNO3, 60 ±â€¯2 °C at pH 6 for 120 min. Synthesized AgNPs proved to be highly stable and monodispersed as characterized through various techniques. UV-Vis spectrum of biosynthesized AgNPs showed a maximum absorption peak at 420 nm. Field emission-Scanning electron microscopy (FE-SEM) and High resolution-Transmission electron microscopy (HR-TEM) micrographs showed the spherical shape of AgNPs with mean diameter size of 28.8 nm. Existence of crystallographic AgNPs was proved by X-ray diffraction (XRD) pattern analysis. Presence of phenolics, terpenoids and flavonoids compounds which act as bioreducing agents were confirmed by Fourier-transform infrared spectroscopy (FTIR) analysis. Furthermore, the AgNPs and leaf extracts prepared individually in different solvents such as methanol, ethyl acetate, chloroform, hexane and aqueous were assessed for their bio-efficacies. AgNPs showed the enhanced antioxidant (IC50 67.56 µg) and radical-scavenging activities (IC50 196.8 µg) as compared to the crude leaf extracts. Anticancer activity revealed the strong and dose-dependent cytotoxic effect of AgNPs against the HeLa cells showing maximum IC50 value being 5.27 µg/mL after 24 h and was also found to be non-toxic to normal cells (HEK). The AgNPs induced the fragmentation of DNA in the cells, indicating the occurrence of apoptosis and necrosis. Subsequently, an efficient larvae mortality was also recorded against Anopheles stephensi having LC50 and LC90 values being 8.969 and 16.102 ppm, followed by Aedes aegypti (LC50;14.791 and LC90;28.526 ppm) and Culex quinquefasciatus (LC50;18.662 and LC90;40.903 ppm) after 72 h of exposure. Besides, they showed no toxicity against Mesocyclops thermocyclopoides (non-target organism). This is the first report showing strong anti-tumorous and larvicidal activity of AgNPs synthesized using P. longum leaf extract against cervical cancer cell line and mosquito vectors causing dengue, malaria and filariasis. Based on our findings, we suggest that AgNPs derived using P. longum leaf extract possessed excellent anti-cancerous and mosquito larvicidal potential and therefore, can be bioprospected further for the management of these hazardous health diseases. This study has given a new insight for the novel drug designing after conducting experiments on the in vivo models.


Assuntos
Nanopartículas Metálicas/química , Piper/química , Extratos Vegetais/química , Prata/química , Aedes/efeitos dos fármacos , Animais , Anopheles/efeitos dos fármacos , Bioengenharia/métodos , Linhagem Celular , Linhagem Celular Tumoral , Culex/efeitos dos fármacos , Células HEK293 , Células HeLa , Humanos , Inseticidas/química , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Dose Letal Mediana , Extratos Vegetais/farmacologia
9.
Int J Mol Sci ; 20(17)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484301

RESUMO

The G-protein-coupled receptor (GPCR) regulated intracellular signaling pathway is known to be involved in the development of insecticide resistance in the mosquito, Culex quinquefasciatus. To elucidate the specific role of each effector in the GPCR regulating pathway, we initially expressed a GPCR, G-protein alpha subunit (Gαs), adenylate cyclase (AC), and protein kinase A (PKA) in insect Spodoptera frugiperda (Sf9) cells and investigated their regulation function on cyclic AMP (cAMP) production and PKA activity. GPCR, Gαs, and AC individually expressed Sf9 cells showed higher cAMP production as the expression of each effector increased. All the effector-expressed cell lines showed increased PKA activity however. Moreover, Sf9 cytochrome P450 gene expression and cell tolerance to permethrin were examined. The relative expression of CYP9A32gene in Sf9 cells tested was significantly increased in all effector-expressed cell lines compared to a control cell line; these effector-expressed cell lines also showed significantly higher tolerance to permethrin. Inhibitor treatments on each effector-expressed cell line revealed that Bupivacaine HCl and H89 2HCl robustly inhibited cAMP production and PKA activity, respectively, resulting in decreased tolerance to permethrin in all cell lines. The synergistic functions of Bupivacaine HCl and H89 2HCl with permethrin were further examined in Culex mosquito larvae, providing a valuable new information for mosquito control strategies.


Assuntos
Resistência a Inseticidas/fisiologia , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais/fisiologia , Animais , Culex , Feminino , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Permetrina/farmacologia , Receptores Acoplados a Proteínas-G/genética , Células Sf9 , Transdução de Sinais/genética
10.
Parasit Vectors ; 12(1): 407, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429782

RESUMO

BACKGROUND: The study of the mechanisms by which larvae of the Culex quinquefasciatus mosquito survive exposure to the entomopathogen Lysinibacillus sphaericus has benefited substantially from the generation of laboratory-selected colonies resistant to this bacterium. One such colony, RIAB59, was selected after regular long-term exposure of larvae to the L. sphaericus IAB59 strain. This strain is characterized by its ability to produce the well known Binary (Bin) toxin, and the recently characterized Cry48Aa/Cry49Aa toxin, able to kill Bin-resistant larvae. Resistance to Bin is associated with the depletion of its receptor, Cqm1 α-glucosidase, from the larvae midgut. This study aimed to identify novel molecules and pathways associated with survival of the RIAB59 larvae and the resistance phenotype. METHODS: A transcriptomic approach and bioinformatic tools were used to compare the profiles derived from the midguts of larvae resistant and susceptible to L. sphaericus IAB59. RESULTS: The RNA-seq profiles identified 1355 differentially expressed genes (DEGs), with 673 down- and 682 upregulated transcripts. One of the most downregulated DEGs was cqm1, which validates the approach. Other strongly downregulated mRNAs encode the enzyme pantetheinase, apolipoprotein D, lipases, heat-shock proteins and a number of lesser known and hypothetical polypeptides. Among the upregulated DEGs, the top most encodes a peroxisomal enzyme involved in lipid metabolism, while others encode enzymes associated with juvenile hormone synthesis, ion channels, DNA binding proteins and defense polypeptides. Further analyses confirmed a strong downregulation of several enzymes involved in lipid catabolism while the assignment of DEGs into metabolic pathways highlighted the upregulation of those related to DNA synthesis and maintenance, confirmed by their clustering into related protein networks. Several other pathways were also identified with mixed profiles of down- and upregulated transcripts. Quantitative RT-PCR confirmed the changes in levels seen for selected mRNAs. CONCLUSIONS: Our transcriptome-wide dataset revealed that the RIAB59 colony, found to be substantially more resistant to Bin than to the Cry48Aa/Cry49Aa toxin, developed a differential expression profile as well as metabolic features co-selected during the long-term adaptation to IAB59 and that are most likely linked to Bin resistance.


Assuntos
Bacillus/patogenicidade , Culex/genética , Culex/microbiologia , Resistência à Doença/genética , Animais , Toxinas Bacterianas/metabolismo , Biologia Computacional , Sistema Digestório/enzimologia , Feminino , Perfilação da Expressão Gênica , Genes de Insetos , Larva/genética , Larva/microbiologia , Fenótipo , alfa-Glucosidases/metabolismo
11.
J Cosmet Sci ; 70(4): 197-207, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31441773

RESUMO

Studies on topical repellent efficacy conducted with caged mosquitoes in the laboratory are important to both the development and regulation of insect repellents. Guidelines for laboratory studies stipulate specific densities, sex ratios, and biting rates, whereas those for field studies are governmentally required before a promising repellent can be registered for human use. These protocols stipulate minimum biting rates alone. Relatively little is known, however, about the influence of mosquito density and sex ratio on their biting propensity, either in the field or laboratory. Using Environmental Protection Agency guidelines for cage testing, we studied the influence of mosquito density and sex ratio in laboratory repellency tests of the biopesticide Ethyl butylacetylaminopropionate (IR3535™) (20%) against three mosquito species (Aedes aegypti, Anopheles aquasalis, and Culex quinquefasciatus). DEET [3-(N-acetyl-N-butyl) aminopropionic acid ethyl ester] (20%) in a laboratory prepared formulation was used as a comparison article. Studies were conducted by trained investigators at the BioAgri Laboratories in Brazil. We found that higher mosquito density generally decreased protection time, but that the influence of sex ratio was more complex. The presence of male mosquitoes increased protection times against Aedes and Anopheles perhaps because mate-seeking males interfered with female feeding. Interestingly, by contrast, protection times decreased against Culex in the presence of males. Such considerations may potentially assist in improving the match between cage and field testing under a broader range of conditions that permit more accurate labeling of repellents for safe and effective use by consumers.


Assuntos
Aedes , Anopheles , Culex , Repelentes de Insetos/farmacologia , Animais , Feminino , Repelentes de Insetos/química , Masculino , Propionatos , Razão de Masculinidade , Estados Unidos
12.
J Am Mosq Control Assoc ; 35(1): 65-66, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31442177

RESUMO

Mosquitoes can transmit a wide variety of viral and parasitic pathogens. Several species have recently been reported in new locations throughout the Arabian Peninsula as a result of entomological surveillance by the US military. We report a new national record for Culex perexiguus from Kuwait based on morphologic and molecular identification of captured samples. This mosquito might pose a public health threat to local populations and to military personnel as a potential vector of both Sindbis and West Nile viruses.


Assuntos
Distribuição Animal , Culex , Mosquitos Vetores , Animais , Culex/anatomia & histologia , Culex/genética , Kuweit , Mosquitos Vetores/anatomia & histologia , Mosquitos Vetores/genética , Vírus Sindbis , Vírus do Nilo Ocidental
13.
J Am Mosq Control Assoc ; 35(1): 55-64, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31442181

RESUMO

The distribution of Culex coronator Dyar and Knab by county in Texas was updated by combining data from peer-reviewed literature, military and government reports, and university and private collections, and by collecting specimens from counties where data had not been reported. With 254 counties in Texas, the initial collection effort was focused on counties east of US Highway 277, which runs from Val Verde County on the US and Mexico border to Wichita County on the Texas and Oklahoma border. The study resulted in 127 counties with Cx. coronator presence data. The remaining 127 counties need to be surveyed for this species.


Assuntos
Distribuição Animal , Culex , Animais , Texas
14.
J Am Mosq Control Assoc ; 35(1): 1-10, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31442183

RESUMO

Mosquito surveillance and pesticide treatment data can be combined in statistical models to provide insight into drivers of mosquito population dynamics. In cooperation with the county-based public health authority, multiple municipalities in Tarrant County, Texas, supplied surveillance and pesticide treatment data available from the 2014 mosquito season for analysis. With these data, general linear mixed modeling was used to model population dynamics of Culex quinquefasciatus, the primary vector for West Nile virus. Temporally lagged pesticide treatment information, weather data, and habitat variables were used as predictors of log + 1 transformed mosquito count data, and Akaike information criteria corrected for small sample sizes (AICc)-based model selection and multimodel averaging was used to produce a final model of mosquito abundance. The model revealed that mosquito counts were driven mainly by seasonally fluctuating temperature, precipitation, human population density, and treatment. In particular, interactions between temperature and treatment, and precipitation and human population density significantly contributed to the interpretation of the effects of the nonweather variables.


Assuntos
Culex/fisiologia , Meio Ambiente , Controle de Mosquitos , Animais , Modelos Biológicos , Dinâmica Populacional , Estações do Ano , Texas
15.
J Am Mosq Control Assoc ; 35(1): 32-39, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31442187

RESUMO

A series of field experiments was conducted in Florida, California, and Louisiana in order to investigate whether adding the Biogents® (BG)-Sweetscent lure to several commercially available mosquito traps increases their Aedes albopictus catch rates and to evaluate the BG-Mosquitaire trap with and without CO2. Adding the BG-Sweetscent to the SkeeterVac Bite-Guard SVE6211, MosClean UV LED (ultraviolet light-emitting diode), Flowtron® Galaxie PV 75, Dynatrap® DT2000XL, Bite Shield Protector, and Black Flag® BZ-40 increased their Ae. albopictus catch rates up to 4.2-fold. The catch rates of the BG-Mosquitaire and the BG-Sentinel did not differ significantly for Ae. aegypti and Culex quinquefasciatus. The BG-Mosquitaire without CO2 and only with BG-Sweetscent caught 1.2 times more Ae. albopictus than the CO2- and Lurex3-baited Mosquito Magnet® Patriot and 2.6 times more than the CO2- and Sweetscent-baited SkeeterVac, respectively. The BG-Mosquitaire baited with Sweetscent and CO2 collected 6.8 times more Ae. albopictus than the Mosquito Magnet Patriot and 11.9 times more than the SkeeterVac. We conclude that BG-Sweetscent increases the tiger mosquito catch rates of many commercially available mosquito traps. We proved that the BG-Mosquitaire is as efficient as the well-known BG-Sentinel and that it can outperform mosquito traps that are baited with propane-generated CO2.


Assuntos
Aedes , Dióxido de Carbono , Culex , Controle de Mosquitos , Mosquitos Vetores , Animais , California , Feminino , Florida , Louisiana , Masculino , Controle de Mosquitos/instrumentação , Controle de Mosquitos/métodos , Especificidade da Espécie
16.
Insect Biochem Mol Biol ; 113: 103213, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31442487

RESUMO

Mosquitoes rely heavily on the olfactory system to find a host for a bloodmeal, plants for a source of energy and suitable sites for oviposition. Here, we examined a cluster of eight odorant receptors (ORs), which includes one OR, CquiOR1, previously identified to be sensitive to plant-derived compounds. We cloned 5 ORs from Culex quinquefasciatus and two ORs from Aedes aegypti, ie, CquiOR2, CquiOR4, CquiOR5, CquiOR84, CquiOR85, AaegOR14, and AaegOR15 and then deorphanized these receptors using the Xenopus oocyte recording system and a large panel of odorants. 2-Phenylethanol, phenethyl formate, and phenethyl propionate were the best ligands for CquiOR4 somewhat resembling the profile of AaegOR15, which gave the strongest responses to phenethyl propionate, phenethyl formate, and acetophenone. In contrast, the best ligands for CquiOR5 were linalool, PMD, and linalool oxide. CquiOR4 was predominantly expressed in antennae of nonblood fed female mosquitoes, with transcript levels significantly reduced after a blood meal. 2-Phenylethanol showed repellency activity comparable to that of DEET at 1%. RNAi experiments suggest that at least in part 2-phenylethanol-elicited repellency is mediated by CquiOR4 activation.


Assuntos
Aedes/fisiologia , Culex/fisiologia , Flores/química , Proteínas de Insetos/genética , Odorantes/análise , Receptores Odorantes/genética , Aedes/genética , Animais , Quimiotaxia , Culex/genética , Feminino , Proteínas de Insetos/metabolismo , Repelentes de Insetos/farmacologia , Receptores Odorantes/metabolismo , Especificidade da Espécie
17.
PLoS Negl Trop Dis ; 13(8): e0007702, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31465453

RESUMO

Polyarthritis and rash caused by Sindbis virus (SINV), was first recognised in northern Europe about 50 years ago and is known as Ockelbo disease in Sweden and Pogosta disease in Finland. This mosquito-borne virus occurs mainly in tropical and sub-tropical countries, and in northern Europe it is suggested to cause regularly reoccurring outbreaks. Here a seven-year cycle of SINV outbreaks has been referred to in scientific papers, although the hypothesis is based solely on reported human cases. In the search for a more objective outbreak signal, we evaluated mosquito abundance and SINV prevalence in vector mosquitoes from an endemic area in central Sweden. Vector mosquitoes collected in the River Dalälven floodplains during the years before, during, and after the hypothesised 2002 outbreak year were assayed for virus on cell culture. Obtained isolates were partially sequenced, and the nucleotide sequences analysed using Bayesian maximum clade credibility and median joining network analysis. Only one SINV strain was recovered in 2001, and 4 strains in 2003, while 15 strains were recovered in 2002 with significantly increased infection rates in both the enzootic and the bridge-vectors. In 2002, the Maximum Likelihood Estimated infection rates were 10.0/1000 in the enzootic vectors Culex torrentium/pipiens, and 0.62/1000 in the bridge-vector Aedes cinereus, compared to 4.9/1000 and 0.0/1000 in 2001 and 0.0/1000 and 0.32/1000 in 2003 Sequence analysis showed that all isolates belonged to the SINV genotype I (SINV-I). The genetic analysis revealed local maintenance of four SINV-I clades in the River Dalälven floodplains over the years. Our findings suggest that increased SINV-I prevalence in vector mosquitoes constitutes the most valuable outbreak marker for further scrutinising the hypothesized seven-year cycle of SINV-I outbreaks and the mechanisms behind.


Assuntos
Aedes/virologia , Infecções por Alphavirus/epidemiologia , Artrite/epidemiologia , Culex/virologia , Surtos de Doenças , Mosquitos Vetores/virologia , Vírus Sindbis/isolamento & purificação , Aedes/crescimento & desenvolvimento , Infecções por Alphavirus/virologia , Animais , Artrite/virologia , Culex/crescimento & desenvolvimento , Feminino , Genótipo , Humanos , Mosquitos Vetores/crescimento & desenvolvimento , Prevalência , Vírus Sindbis/classificação , Vírus Sindbis/genética , Suécia/epidemiologia
18.
Acta Trop ; 199: 105121, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31400299

RESUMO

Lymphatic filariasis (LF) has been known in Egypt since ancient times. By 1930s it was recognized to be a major public health problem in the Nile Delta, and to be caused by Wuchereria bancrofti and transmitted by Culex pipiens. Remarkably, as a result of widespread DEC treatment and intensive vector control by the Ministry of Health and Population (MoHP), the infection rate of LF declined in the 1960s. However, relaxation of these efforts resulted in resurgence of filariasis in the 1980s and 1990s. In 2000, Egypt was among the first countries to join the WHO global efforts to eliminate LF as a public health problem by initiating a national LF elimination programme (NLFEP). This article reviews the history of LF control activities and summarizes the NLFEP extensive interventions to eliminate LF in Egypt. Based on MoHP data, mass drug administration (MDA) with DEC and ALB was started in 2000 in 161 implementation units (IUs). Additional IUs were included in subsequent MDA rounds, with the last IU included in 2007. MDA stopping surveys were conducted based on WHO guidelines (2005; 2011). Information about the presence of those suffering from lymphoedema/elephantiasis and hydrocele patients was collected, and care provided to those needing care in five rural health units (RHU) by primary health care system providers who were given training on LF morbidity management and disability prevention (MMDP). The NLFEP made excellent progress due to strong collaboration between different ministries, through intensive training and supervision, and the use of advocacy for mobilization of endemic communities. The epidemiological coverage for all MDA rounds was effectively ≥80%. Antigenemia levels found in schoolchildren during transmission assessment surveys (TAS) in 166 IUs approximately 10 years after stopping MDA was 0%. In 2017, TAS conducted in additional 29 IUs indicated 0.1% antigenemia and 0% microfilaremia. In 2015, the registration of chronic LF patients was updated to 1472 lymphoedema and 18 hydrocele patients. Lymphoedema patients were trained on self-management, and hydrocele patients were referred to local General Hospitals for surgery. Thus, after over a decade of sustained effort, Egypt met the WHO criteria for successful elimination of LF as a public health problem. In December 2017, WHO validated Egypt as the first country in the Eastern Mediterranean Region to successfully achieve elimination.


Assuntos
Culex/parasitologia , Filariose Linfática/prevenção & controle , Filaricidas/administração & dosagem , Mosquitos Vetores/parasitologia , Wuchereria bancrofti , Animais , Criança , Egito/epidemiologia , Filariose Linfática/epidemiologia , Filariose Linfática/transmissão , Filaricidas/farmacologia , Filaricidas/uso terapêutico , Humanos , Masculino , Administração Massiva de Medicamentos , Saúde Pública , Saúde da População Rural , Inquéritos e Questionários , Wuchereria bancrofti/efeitos dos fármacos
19.
Parasit Vectors ; 12(1): 413, 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31443737

RESUMO

BACKGROUND: Culex mosquitoes cause considerable biting nuisance and sporadic transmission of arboviral and filarial diseases. METHODS: Using standard World Health Organization procedures, insecticide resistance profiles and underlying mechanisms were investigated during dry and wet seasons of 2015 and 2016 in Culex pipiens complex from three neighbouring administrative wards in Ulanga District, Tanzania. Synergist tests with piperonyl butoxide, diethyl maleate, and triphenyl phosphate, were employed to investigate mechanisms of the observed resistance phenotypes. Proportional biting densities of Culex species, relative to other taxa, were determined from indoor surveillance data collected in 2012, 2013, and 2015. RESULTS: Insecticide resistance varied significantly between wards and seasons. For example, female mosquitoes in one ward were susceptible to bendiocarb and fenitrothion in the wet season, but resistant during the dry season, while in neighbouring ward, the mosquitoes were fully susceptible to these pesticides in both seasons. Similar variations occurred against bendiocarb, DDT, deltamethrin, and lambda-cyhalothrin. Surprisingly, with the exception of one ward in the wet season, the Culex populations were susceptible to permethrin, commonly used on bednets in the area. No insecticide resistance was observed against the organophosphates, pirimiphos-methyl and malathion, except for one incident of reduced susceptibility in the dry season. Synergist assays revealed possible involvement of monooxygenases, esterases, and glutathione S-transferase in pyrethroid and DDT resistance. Morphology-based identification and molecular assays of adult Culex revealed that 94% were Cx. pipiens complex, of which 81% were Cx. quinquefasciatus, 2% Cx. pipiens, and 3% hybrids. About 14% of the specimens were non-amplified during molecular identifications. Female adults collected indoors were 100% Cx. pipiens complex, and constituted 79% of the overall biting risk. CONCLUSIONS: The Cx. pipiens complex constituted the greatest biting nuisance inside people's houses, and showed resistance to most public health insecticides possible. Resistance varied at a fine geographical scale, between adjacent wards, and seasons, which warrants some modifications to current insecticide resistance monitoring strategies. Resistance phenotypes are partly mediated by metabolic mechanisms, but require further evaluation through biochemical and molecular techniques. The high densities and resistance in Culex could negatively influence the acceptability of other interventions such as those used against malaria mosquitoes.


Assuntos
Anopheles/genética , Culex/genética , Resistência a Inseticidas/genética , Inseticidas , Análise Espaço-Temporal , Animais , Feminino , Geografia , Malária/prevenção & controle , Masculino , Controle de Mosquitos/métodos , Fenótipo , Estações do Ano , Tanzânia
20.
Insect Biochem Mol Biol ; 113: 103224, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31446031

RESUMO

In addition to its primary function as an insect repellent, DEET has many "off-label" properties, including a deterrent effect on the attraction of gravid female mosquitoes. DEET negatively affects oviposition sites. While deorphanizing odorant receptors (ORs) using the Xenopus oocyte recording system, we have previously observed that DEET generated outward (inhibitory) currents on ORs sensitive to oviposition attractants. Here, we systematically investigated these inhibitory currents. We recorded dose-dependent outward currents elicited by DEET and other repellents on ORs from Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae. Similar responses were observed with other plant-derived and plant-inspired compounds, including methyl jasmonate and methyl dihydrojasmolate. Inward (regular) currents elicited by skatole upon activation of CquiOR21 were modulated when this oviposition attractant was coapplied with a repellent. Compounds that generate outward currents in ORs sensitive to oviposition attractants elicited inward currents in a DEET-sensitive receptor, CquiOR136. The best ligand for this receptor, methyl dihydrojasmolate, showed repellency activity but was not as strong as DEET in our test protocol.


Assuntos
Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Culex/efeitos dos fármacos , Proteínas de Insetos/antagonistas & inibidores , Repelentes de Insetos/farmacologia , Oviposição/efeitos dos fármacos , Receptores Odorantes/antagonistas & inibidores , Aedes/fisiologia , Animais , Anopheles/fisiologia , Quimiotaxia/efeitos dos fármacos , Culex/fisiologia , DEET/farmacologia , Mentol/análogos & derivados , Mentol/farmacologia , Piperidinas/farmacologia , Propionatos/farmacologia
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