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1.
Vast viruses are thought to be associated with mosquitoes. Anopheles sinensis, Armigeres subalbatus, Culex quinquefasciatus, and Culex tritaeniorhynchus are very common mosquito species in China, and whether the virome structure in each species is species-specific has not been evaluated. In this study, a total of 2222 mosquitoes were collected from the same geographic location, and RNAs were sequenced using the Illumina Miseq platform. After querying to the Refseq database, a total of 3,435,781, 2,223,509, 5,727,523, and 6,387,867 paired-end reads were classified under viral sequences from An. sinensis, Ar. subalbatus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus, respectively, with the highest prevalence of virus-associated reads being observed in Cx. quinquefasciatus. The metagenomic comparison analysis showed that the virus-related reads were distributed across 26 virus families, together with an unclassified group of viruses. Anelloviridae, Circoviridae, Genomoviridae, Iridoviridae, Mesoniviridae, Microviridae, Myoviridae, Parvoviridae, Phenuiviridae, and Podoviridae were the top ten significantly different viral families among the four species. Further analysis reveals that the virome is species-specific in four mosquito samples, and several viral sequences which maybe belong to novel viruses are discovered for the first time in those mosquitoes. This investigation provides a basis for a comprehensive knowledge on the mosquito virome status in China. 相似文献
2.
Shihong Fu Song Song Hong Liu Yuanyuan Li Xiaolong Li Xiaoyan Gao Ziqian Xu Guoping Liu Dingming Wang Zhenzao Tian Jingzhu Zhou Ying He Wenwen Lei Huanyu Wang Bin Wang Xiaoqing Lu Guodong Liang 《中国科学:生命科学英文版》2017,60(12):1364-1371
A field investigation of arboviruses was conducted in Dejiang, Guizhou Province in the summer of 2016. A total of 8,795 mosquitoes, belonging to four species of three genera, and 1,300 midges were collected. The mosquito samples were identified on site according to their morphology, and the pooled samples were ground and centrifuged in the laboratory. The supernatant was incubated with mosquito tissue culture cells (C6/36) and mammalian cells (BHK-21) for virus isolation. The results indicated that 40% (3,540/8,795) were Anopheles sinensis, 30% (2,700/8,795) were Culex pipiens quinquefasciatus, and 29% (2,530/8,795) were Armigeres subbalbeatus. Furthermore, a total of eight virus isolates were obtained, and genome sequencing revealed two Zika viruses (ZIKVs) isolated from Culex pipiens quinquefasciatus and Armigeres subbalbeatus, respectively; three Japanese encephalitis viruses (JEVs) isolated from Culex pipiens quinquefasciatus; two Banna viruses (BAVs) isolated from Culex pipiens quinquefasciatus and Anopheles sinensis, respectively; and one densovirus (DNV) isolated from Culex pipiens quinquefasciatus. The ZIKVs isolated from the Culex pipiens quinquefasciatus and Armigeres subbalbeatus mosquitoes represent the first ZIKV isolates in mainland China. This discovery presents new challenges for the prevention and control of ZIKV in China, and prompts international cooperation on this global issue. 相似文献
3.
Bridget E Barber Timothy William Matthew J Grigg Tsin W Yeo Nicholas M Anstey 《Malaria journal》2013,12(1):1-6
Background
The question whether Plasmodium falciparum infection affects the fitness of mosquito vectors remains open. A hurdle for resolving this question is the lack of appropriate control, non-infected mosquitoes that can be compared to the infected ones. It was shown recently that heating P. falciparum gametocyte-infected blood before feeding by malaria vectors inhibits the infection. Therefore, the same source of gametocyte-infected blood could be divided in two parts, one heated, serving as the control, the other unheated, allowing the comparison of infected and uninfected mosquitoes which fed on exactly the same blood otherwise. However, before using this method for characterizing the cost of infection to mosquitoes, it is necessary to establish whether feeding on previously heated blood affects the survival and fecundity of mosquito females.Methods
Anopheles gambiae M molecular form females were exposed to heated versus non-heated, parasite-free human blood to mimic blood meal on non-infectious versus infectious gametocyte-containing blood. Life history traits of mosquito females fed on blood that was heat-treated or not were then compared.Results
The results reveal that heat treatment of the blood did not affect the survival and fecundity of mosquito females. Consistently, blood heat treatment did not affect the quantity of blood ingested.Conclusions
The study indicates that heat inactivation of gametocyte-infected blood will only inhibit mosquito infection and that this method is suitable for quantifying the fitness cost incurred by mosquitoes upon infection by P. falciparum. 相似文献4.
Sung Suck Oh Myung Je Hur Gwang Sig Joo Sung Tae Kim Jong Myoung Go Yong Hee Kim Wook Gyo Lee E Hyun Shin 《The Korean journal of parasitology》2010,48(1):35-41
We investigated the seasonality of Anopheles mosquitoes, including its species composition, density, parity, and population densities of mosquitoes infected with the parasite in Ganghwa-do (Island), a vivax malaria endemic area in the Republic of Korea. Mosquitoes were collected periodically with a dry-ice-tent trap and a blacklight trap during the mosquito season (April-October) in 2008. Anopheles sinensis (94.9%) was the most abundant species collected, followed by Anopheles belenrae (3.8%), Anopheles pullus (1.2%), and Anopheles lesteri (0.1%). Hibernating Anopheles mosquitoes were also collected from December 2007 to March 2008. An. pullus (72.1%) was the most frequently collected, followed by An. sinensis (18.4%) and An. belenrae (9.5%). The composition of Anopheles species differed between the mosquito season and hibernation seasons. The parous rate fluctuated from 0% to 92.9%, and the highest rate was recorded on 10 September 2008. Sporozoite infections were detected by PCR in the head and thorax of female Anopheles mosquitoes. The annual sporozoite rate of mosquitoes was 0.11% (2 of 1,845 mosquitoes). The 2 mosquitoes that tested positive for sporozoites were An. sinensis. Malarial infections in anopheline mosquitoes from a population pool were also tried irrespective of the mosquito species. Nine of 2,331 pools of Anopheles mosquitoes were positive. From our study, it can be concluded that An. sinensis, which was the predominant vector species and confirmed as sporozoite-infected, plays an important role in malaria transmission in Ganghwa-do. 相似文献
5.
Zhou Zhiyong Mitchell Rebecca Mans Gutman Julie Wiegand Ryan E Mwandama Dyson A Mathanga Don P Skarbinski Jacek Shi Ya Ping 《Malaria journal》2014,13(1):1-10
Background
Metarhizium anisopliae is a naturally occurring fungal pathogen of mosquitoes. Recently, Metarhizium has been engineered to act against malaria by directly killing the disease agent within mosquito vectors and also effectively blocking onward transmission. It has been proposed that efforts should be made to minimize the virulence of the fungal pathogen, in order to slow the development of resistant mosquitoes following an actual deployment.Results
Two mathematical models were developed and analysed to examine the efficacy of the fungal pathogen. It was found that, in many plausible scenarios, the best effects are achieved with a reduced or minimal pathogen virulence, even if the likelihood of resistance to the fungus is negligible. The results for both models depend on the interplay between two main effects: the ability of the fungus to reduce the mosquito population, and the ability of fungus‐infected mosquitoes to compete for resources with non‐fungus‐infected mosquitoes.Conclusions
The results indicate that there is no obvious choice of virulence for engineered Metarhizium or similar pathogens, and that all available information regarding the population ecology of the combined mosquito‐fungus system should be carefully considered. The models provide a basic framework for examination of anti‐malarial mosquito pathogens that should be extended and improved as new laboratory and field data become available. 相似文献6.
Hai-Lin Zhang Yu-Zhen Zhang Wei-Hong Yang Yun Feng Roger S. Nasci Jie Yang Yong-Hua Liu Chao-Liang Dong Shi Li Bao-Sen Zhang Zheng-Liu Yin Pi-Yu Wang Shi-Hong Fu Ming-Hua Li Fen Liu Juan Zhang Jie Sun Can-Wei Li Xiao-Yan Gao Hong Liu Huan-Yu Wang Lyle R. Petersen Guo-Dong Liang 《PloS one》2013,8(10)
Objective
The western borderland between Yunnan Province, China, and Myanmar is characterized by a climate that facilitates year-round production of mosquitoes. Numerous mosquito-transmitted viruses, including Japanese encephalitis virus circulate in this area. This project was to describe seasonal patterns in mosquito species abundance and arbovirus activity in the mosquito populations.Methods
Mosquitoes were collected in Mangshi and Ruili cities of Dehong Prefecture near the border of China and Burma in Yunnan Province, the Peoples Republic of China in 2010. We monitored mosquito species abundance for a 12-month period using ultraviolet light, carbon dioxide baited CDC light and gravid traps; and tested the captured mosquitoes for the presence of virus to evaluate mosquito-virus associations in rural/agricultural settings in the area.Results
A total of 43 species of mosquitoes from seven genera were collected, including 15 Culex species, 15 Anopheles spp., four Aedes spp., three Armigeres spp., one Mimomyia spp., two Uranotaenia spp. and three Mansonia spp.. Species richness and diversity varied between Mangshi and Ruili. Culex tritaeniorhynchus, Culex quinquefasciatus, Anopheles sinensis and Anopheles peditaeniatus were the most abundant species in both sampling sites. Ultraviolet light traps collected more specimens than CDC light traps baited with dry ice, though both collected the same variety of mosquito species. The CDC gravid trap was the most effective trap for capture of Culex quinquefasciatus, a species underrepresented in light trap collections. A total of 26 virus strains were isolated, which included 13 strains of Japanese encephalitis virus, four strains of Getah virus, one strain of Oya virus, one strain from the orbivirus genus, and seven strains of Culex pipien pallens densovirus.Conclusions
The present study illustrates the value of monitoring mosquito populations and mosquito-transmitted viruses year-round in areas where the climate supports year-round adult mosquito activity. 相似文献7.
Katja Kalan Tatjana Avšič-Županc Katarina Resman Rus Elena Bužan Darja Duh 《Biologia》2018,73(12):1277-1282
Autochthonous transmissions of mosquito-borne diseases were described in close proximity to Slovenia where the knowledge of mosquito species and the viruses they transmit remains very scarce. Therefore we aimed to assess the burden mosquitoes bring to the local community and to test mosquitoes for the presence of the selected zoonotic arboviruses, i. e. Dengue (DENV), West Nile (WNV) and Chikungunya (CHIKV). A pilot mosquito monitoring was conducted in 2012 within two municipalities based on adult mosquito trapping. Altogether 2007 adult mosquitoes were caught. Females of Aedes albopictus and Culex pipiens represented the majority of the total mosquito catch. In sites with more households and nearby greenery, catches of Ae. albopictus were more abundant. Highest numbers of Cx. pipiens females were caught close to a nature reserve, where many bird species stop during their migrations. Trapping results are consistent with both species’ feeding behaviour. Female mosquitoes were grouped into 58 pools according to species, location and date of catch. Real time RT-PCRs for WNV, DENV and CHIKV were performed, but no arboviral genomes were detected in any of the tested mosquito pools. However, amplicons were obtained in three pools when using generic RT-PCR markers for flaviviruses. The viruses detected were propagated and isolated in mosquito cell line C3/36 and identified with sequencing as mosquito-only flaviviruses (MOFs). The important contributions of this study are a successful first isolation of MOFs and confirmation of the presence of the invasive mosquito Ae. albopictus in Slovenia. 相似文献
8.
Rebecca Hood-Nowotny Bettina Schwarzinger Clemens Schwarzinger Sharon Soliban Odessa Madakacherry Martina Aigner Margarete Watzka Jeremie Gilles 《PloS one》2012,7(10)
Background
Knowing the underlying mechanisms of mosquito ecology will ensure effective vector management and contribute to the overall goal of malaria control. Mosquito populations show a high degree of population plasticity in response to environmental variability. However, the principle factors controlling population size and fecundity are for the most part unknown. Larval habitat and diet play a crucial role in subsequent mosquito fitness. Developing the most competitive insects for sterile insect technique programmes requires a “production” orientated perspective, to deduce the most effective larval diet formulation; the information gained from this process offers us some insight into the mechanisms and processes taking place in natural native mosquito habitats.Methodology/Principal Findings
Fatty acid profiles and de-novo or direct assimilation pathways, of whole-individual mosquitoes reared on a range of larval diets were determined using pyrolysis gas chromatograph/mass spectrometry. We used elemental analysis and isotope ratio mass spectrometry to measure individual-whole-body carbon, nitrogen and phosphorous values and to assess the impact of dietary quality on subsequent population stoichiometry, size, quality and isotopic signature. Diet had the greatest impact on fatty acid (FA) profiles of the mosquitoes, which exhibited a high degree of dietary routing, characteristic of generalist feeders. De-novo synthesis of a number of important FAs was observed. Mosquito C:N stoichiometry was fixed in the teneral stage. Dietary N content had significant influence on mosquito size, and P was shown to be a flexible pool which limited overall population size.Conclusions/Significance
Direct routing of FAs was evident but there was ubiquitous de-novo synthesis suggesting mosquito larvae are competent generalist feeders capable of survival on diet with varying characteristics. It was concluded that nitrogen availability in the larval diet controlled teneral mosquito size and that teneral CN ratio is a sex- and species-specific fixed parameter. This finding has significant implications for overall mosquito competitiveness and environmental management. 相似文献9.
Luciano A. Moreira Emad Saig Andrew P. Turley José M. C. Ribeiro Scott L. O'Neill Elizabeth A. McGraw 《PLoS neglected tropical diseases》2009,3(12)
Background
Mosquitoes are vectors of many serious pathogens in tropical and sub-tropical countries. Current control strategies almost entirely rely upon insecticides, which increasingly face the problems of high cost, increasing mosquito resistance and negative effects on non-target organisms. Alternative strategies include the proposed use of inherited life-shortening agents, such as the Wolbachia bacterium. By shortening mosquito vector lifespan, Wolbachia could potentially reduce the vectorial capacity of mosquito populations. We have recently been able to stably transinfect Aedes aegypti mosquitoes with the life-shortening Wolbachia strain wMelPop, and are assessing various aspects of its interaction with the mosquito host to determine its likely impact on pathogen transmission as well as its potential ability to invade A. aegypti populations.Methodology/Principal Findings
Here we have examined the probing behavior of Wolbachia-infected mosquitoes in an attempt to understand both the broader impact of Wolbachia infection on mosquito biology and, in particular, vectorial capacity. The probing behavior of wMelPop-infected mosquitoes at four adult ages was examined and compared to uninfected controls during video-recorded feeding trials on a human hand. Wolbachia-positive insects, from 15 days of age, showed a drastic increase in the time spent pre-probing and probing relative to uninfected controls. Two other important features for blood feeding, saliva volume and apyrase content of saliva, were also studied.Conclusions/Significance
As A. aegypti infected with wMelPop age, they show increasing difficulty in completing the process of blood feeding effectively and efficiently. Wolbachia-infected mosquitoes on average produced smaller volumes of saliva that still contained the same amount of apyrase activity as uninfected mosquitoes. These effects on blood feeding behavior may reduce vectorial capacity and point to underlying physiological changes in Wolbachia-infected mosquitoes. 相似文献10.
Lyke KE Laurens M Adams M Billingsley PF Richman A Loyevsky M Chakravarty S Plowe CV Sim BK Edelman R Hoffman SL 《PloS one》2010,5(10):e13490
Background
Experimental infection of malaria-naïve volunteers by the bite of Plasmodium falciparum-infected mosquitoes is a preferred means to test the protective effect of malaria vaccines and drugs. The standard model relies on the bite of five infected mosquitoes to induce malaria. We examined the efficacy of malaria transmission using mosquitoes raised aseptically in compliance with current Good Manufacturing Practices (cGMPs).Methods and Findings
Eighteen adults aged 18–40 years were randomized to receive 1, 3 or 5 bites of Anopheles stephensi mosquitoes infected with the chloroquine-sensitive NF54 strain of P. falciparum.Seventeen participants developed malaria; fourteen occurring on Day 11. The mean prepatent period was 10.9 days (9–12 days). The geometric mean parasitemia was 15.7 parasites/µL (range: 4–70) by microscopy. Polymerase chain reaction (PCR) detected parasites 3.1 (range: 0–4) days prior to microscopy. The geometric mean sporozoite load was 16,753 sporozoites per infected mosquito (range: 1,000–57,500). A 1-bite participant withdrew from the study on Day 13 post-challenge and was PCR and smear negative.Conclusions
The use of aseptic, cGMP-compliant P. falciparum-infected mosquitoes is safe, is associated with a precise prepatent period compared to the standard model and appears more efficient than the standard approach, as it led to infection in 100% (6/6) of volunteers exposed to three mosquito bites and 83% (5/6) of volunteers exposed to one mosquito bite.Trial Registration
ClinicalTrials.gov NCT00744133相似文献11.
12.
Background
In Malaysia, researchers and medical practitioners are unfamiliar with Naegleria infections. Thus little is known about the existence of pathogenic Naegleria fowleri, and the resultant primary amoebic meningoencephalitis (PAM) is seldom included in the differential diagnosis of central nervous system infections. This study was conducted to detect the presence of Naegleria species in various environmental samples.Methods/Findings
A total of 41 Naegleria-like isolates were isolated from water and dust samples. All these isolates were subjected to PCR using two primer sets designed from the ITS1-ITS2 regions. The N. fowleri species-specific primer set failed to produce the expected amplicon. The Naegleria genus-specific primers produced amplicons of 408 bp (35), 450 bp (2), 457 bp (2) or 381 bp (2) from all 41 isolates isolated from aquatic (33) and dust (8) samples. Analysis of the sequences from 10 representative isolates revealed that amplicons with fragments 408, 450 and 457 bp showed homology with non-pathogenic Naegleria species, and 381 bp showed homology with Vahlkampfia species. These results concurred with the morphological observation that all 39 isolates which exhibited flagella were Naegleria, while 2 isolates (AC7, and AC8, JN034055) that did not exhibit flagella were Vahlkampfia species. JN034056Conclusion
To date, pathogenic species of N. fowleri have not been isolated from Malaysia. All 39 isolates that produced amplicons (408, 450 and 457 bp) from the genus-specific primers were identified as being similar to nonpathogenic Naegleria. Amplicon 408 bp from 5 representative isolates showed 100% and 99.7% identity to Naegleria philippinensis isolate RJTM () and is thus believed to be the most common species in our environment. Amplicons 450 bp and 457 bp were respectively believed to be from 2 new species of Naegleria, since representative isolates showed lower homology and had a longer base pair length when compared to the reference species in the Genbank, Naegleria schusteri ( AM167890) and Naegleria laresi ( AJ566626), respectively. AJ566630相似文献13.
Rabbia Pervaiz Mohsin Ahmad Khan Nadeem Ahmed Hafsa Naeem Ahmad Usman Zafar 《Biologia》2018,73(10):1015-1023
Mosquitoes spread deadly infections around the world. Since decades Bacillus thuringiensis (Bt) δ-endotoxins have been used successfully as a biopesticide for controlling mosquito larvae. However, over a few years, mosquito larvae have evolved tolerance against Bt δ-endotoxins, rendering them ineffective for mosquito control. Such a problem entails the development of improved toxins with enhanced toxicity, affinity towards a wide range of mosquito receptors and ability to overcome or delay the resistance buildup. In this study, using in silico tools, we aimed to design a fusion protein by fusing active region of Bt subsp. jegathesan Cry11Ba protein with Aedes aegypti TMOF (trypsin modulating oostatic factor). Using computational study, the fusion protein was validated and its mosquitocidal potential was determined through molecular docking against cadherin and aminopeptidase N midgut receptors of Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Molecular docking revealed that from Cry11Ba-TMOF fusion protein, domain II amino acids of Cry11Ba protein showed hydrogen bond interactions with cadherin and aminopeptidase N receptors of the targeted mosquitoes. These results conclude that Cry11Ba-TMOF fusion protein has a strong affinity for the receptors of Ae.aegypti, An.gambiae and Cx.quinquefasciatus. Thus the designed fusion protein can be used as a potent mosquitocidal agent for the control of targeted mosquitoes. 相似文献
14.
Larry J Dishaw M Gail Mueller Natasha Gwatney John P Cannon Robert N Haire Ronda T Litman Chris T Amemiya Tatsuya Ota Lee Rowen Gustavo Glusman Gary W Litman 《BMC genetics》2008,9(1):1-16
Background
Genetic isolates such as the Ashkenazi Jews (AJ) potentially offer advantages in mapping novel loci in whole genome disease association studies. To analyze patterns of genetic variation in AJ, genotypes of 101 healthy individuals were determined using the Affymetrix EAv3 500 K SNP array and compared to 60 CEPH-derived HapMap (CEU) individuals. 435,632 SNPs overlapped and met annotation criteria in the two groups.Results
A small but significant global difference in allele frequencies between AJ and CEU was demonstrated by a mean F ST of 0.009 (P < 0.001); large regions that differed were found on chromosomes 2 and 6. Haplotype blocks inferred from pairwise linkage disequilibrium (LD) statistics (Haploview) as well as by expectation-maximization haplotype phase inference (HAP) showed a greater number of haplotype blocks in AJ compared to CEU by Haploview (50,397 vs. 44,169) or by HAP (59,269 vs. 54,457). Average haplotype blocks were smaller in AJ compared to CEU (e.g., 36.8 kb vs. 40.5 kb HAP). Analysis of global patterns of local LD decay for closely-spaced SNPs in CEU demonstrated more LD, while for SNPs further apart, LD was slightly greater in the AJ. A likelihood ratio approach showed that runs of homozygous SNPs were approximately 20% longer in AJ. A principal components analysis was sufficient to completely resolve the CEU from the AJ.Conclusion
LD in the AJ versus was lower than expected by some measures and higher by others. Any putative advantage in whole genome association mapping using the AJ population will be highly dependent on regional LD structure. 相似文献15.
Xiaozhou He Qikai Yin Liwei Zhou Lei Meng Weijun Hu Fan Li Yang Li Kun Han Shaobai Zhang Shihong Fu Xiaoshu Zhang Ji Wang Songtao Xu Yi Zhang Ying He Maoxing Dong Xinxin Shen Zheng Zhang Kai Nie Guodong Liang Xuejun Ma Huanyu Wang 《PLoS neglected tropical diseases》2021,15(4)
BackgroundMosquitoes host and transmit numerous arthropod-borne viruses (arboviruses) that cause disease in both humans and animals. Effective surveillance of virome profiles in mosquitoes is vital to the prevention and control of mosquito-borne diseases in northwestern China, where epidemics occur frequently.MethodsMosquitoes were collected in the Shaanxi-Gansu-Ningxia region (Shaanxi Province, Gansu Province, and Ningxia Hui Autonomous Region) of China from June to August 2019. Morphological methods were used for taxonomic identification of mosquito species. High-throughput sequencing and metagenomic analysis were used to characterize mosquito viromes.ResultsA total of 22,959 mosquitoes were collected, including Culex pipiens (45.7%), Culex tritaeniorhynchus (40.6%), Anopheles sinensis (8.4%), Aedes (5.2%), and Armigeres subalbatus (0.1%). In total, 3,014,183 (0.95% of clean reads) viral sequences were identified and assigned to 116 viral species (including pathogens such as Japanese encephalitis virus and Getah virus) in 31 viral families, including Flaviviridae, Togaviridae, Phasmaviridae, Phenuiviridae, and some unclassified viruses. Mosquitoes collected in July (86 species in 26 families) showed greater viral diversity than those from June and August. Culex pipiens (69 species in 25 families) and Culex tritaeniorhynchus (73 species in 24 families) carried more viral species than Anopheles sinensis (50 species in 19 families) or Aedes (38 species in 20 families) mosquitoes.ConclusionViral diversity and abundance were affected by mosquito species and collection time. The present study elucidates the virome compositions of various mosquito species in northwestern China, improving the understanding of virus transmission dynamics for comparison with those of disease outbreaks. 相似文献
16.
V Soti A Tran P Degenne V Chevalier D Lo Seen Y Thiongane M Diallo JF Guégan D Fontenille 《PLoS neglected tropical diseases》2012,6(8):e1795
Background
Rift Valley fever (RVF) is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV) is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated.Methodology/Principal Findings
A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes) involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites.The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961–2003). We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species.Conclusion/Significance
Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends the identification of rainfall patterns favourable for RVFV amplification. 相似文献17.
Pei-Sze Jeslyn Wong Mei-zhi Irene Li Chee-Seng Chong Lee-Ching Ng Cheong-Huat Tan 《PLoS neglected tropical diseases》2013,7(8)
Background
Zika virus (ZIKV) is a little known arbovirus until it caused a major outbreak in the Pacific Island of Yap in 2007. Although the virus has a wide geographic distribution, most of the known vectors are sylvatic Aedes mosquitoes from Africa where the virus was first isolated. Presently, Ae. aegypti is the only known vector to transmit the virus outside the African continent, though Ae. albopictus has long been a suspected vector. Currently, Ae. albopictus has been shown capable of transmitting more than 20 arboviruses and its notoriety as an important vector came to light during the recent chikungunya pandemic. The vulnerability of Singapore to emerging infectious arboviruses has stimulated our interest to determine the competence of local Ae. albopictus to transmit ZIKV.Methodology/Principal Findings
To determine the competence of Ae. albopictus to ZIKV, we orally infected local mosquito strains to a Ugandan strain virus. Fully engorged mosquitoes were maintained in an environmental chamber set at 29°C and 80–85%RH. Twelve mosquitoes were then sampled daily from day one to seven and on day 10 and 14 post infection (pi). Zika virus titre in the midgut and salivary glands of each mosquito were determined using tissue culture infectious dose50 assay, while transmissibility of the virus was determined by detecting viral antigen in the mosquito saliva by qRT-PCR. High dissemination and transmission rate of ZIKV were observed. By day 7-pi, all mosquitoes have disseminated infection and 73% of these mosquitoes have ZIKV in their saliva. By day 10-pi, all mosquitoes were potentially infectious.Conclusions/Significance
The study highlighted the potential of Ae. albopictus to transmit ZIKV and the possibility that the virus could be established locally. Nonetheless, the threat of ZIKV can be mitigated by existing dengue and chikungunya control program being implemented in Singapore. 相似文献18.
19.
Silas W. Avicor Mustafa F. F. Wajidi Fatma M. A. El-garj Zairi Jaal Zary S. Yahaya 《The protein journal》2014,33(5):457-464
Mosquito coils are insecticides commonly used for protection against mosquitoes due to their toxic effects on mosquito populations. These effects on mosquitoes could induce the expression of metabolic enzymes in exposed populations as a counteractive measure. Cytochrome P450 family 4 (CYP4) are metabolic enzymes associated with a wide range of biological activities including insecticide resistance. In this study, the efficacies of three commercial mosquito coils with different pyrethroid active ingredients were assessed and their potential to induce the expression of CYP4 genes in Aedes albopictus analyzed by real-time quantitative PCR. Coils containing 0.3 % d-allethrin and 0.005 % metofluthrin exacted profound toxic effects on Ae. albopictus, inducing high mortalities (≥90 %) compared to the 0.2 % d-allethrin reference coil. CYP4H42 and CYP4H43 expressions were significantly higher in 0.3 % d-allethrin treated mosquitoes compared to the other treated populations. Short-term (KT50) exposure to mosquito coils induced significantly higher expression of both genes in 0.005 % metofluthrin exposed mosquitoes. These results suggest the evaluated products provided better protection than the reference coil; however, they also induced the expression of metabolic genes which could impact negatively on personal protection against mosquito. 相似文献
20.
Su Hyun Lee Kwang Woo Nam Ji Yeon Jeong Seung Jin Yoo Young-Sang Koh Seogjae Lee Sang Taek Heo Seung-Yong Seong Keun Hwa Lee 《PloS one》2013,8(7)