Malaria is a main vector-borne public health problem in Iran.The last studies on Iranian mosquitoes show 31 Anopheles species including different sibling species and genotypes,eight of them are reported to play role i...Malaria is a main vector-borne public health problem in Iran.The last studies on Iranian mosquitoes show 31 Anopheles species including different sibling species and genotypes,eight of them are reported to play role in malaria transmission.The objective of this study is to provide a reference for malaria vectors of Iran and to map their spatial and temporal distribution in different climatic zones.Shape files of administrative boundaries and climates of Iran were provided by National Cartographic Center.Data on distribution and seasonal activity of malaria vectors were obtained from different sources and a databank in district level was created in Excel 2003, inserted to the shape files and analyzed by ArcGIS 9.2 to provide the maps.Anopheles culicifacies Giles s.l.,Anopheles dthali Patton,Anopheles fluviatilis James s.L,Anopheles maculipennis Meigen s.L,Anopheles sacharovi Favre,Anopheles stephensi IJston,and Anopheles superpictus Grassi have been introduced as primary and secondary malaria vectors and Anopheles puicherrimus Theobald as a suspected vector in Iran.Temporal distribution of anopheline mosquitoes is restricted to April_December in northern Iran,however mosquitoes can be found during the year in southern region.Spatial distribution of malaria vectors is different based on species,thus six of them(except for Anopheles maculipennis s.l.and Anopheles sacharovi) are reported from endemic malarious area in southern and southeastern areas of Iran.The climate of this part is usually warm and humid,which makes it favorable for mosquito rearing and malaria transmission.Correlation between climate conditions and vector distribution can help to predict the potential range of activity for each species and preparedness for malaria epidemics.展开更多
Objective: To determine abundance, distribution and diversity of potential breeding container habitats of the dengue vectors in public places including schools, restaurants,mosques and parks in southwest areas of Pena...Objective: To determine abundance, distribution and diversity of potential breeding container habitats of the dengue vectors in public places including schools, restaurants,mosques and parks in southwest areas of Penang Island, Malaysia.Methods: Premises at restaurants, schools, parks and mosques were surveyed simultaneously and inspected visually for container habitats and production of immature mosquitoes from March 2015 to March 2016. Abundance(mean ± SE) of breeding containers between sites was compared using One-way ANOVA. Independent sample ttest was used to compare total number of Aedes albopictus(Ae. albopictus) and Aedes aegypti(Ae. aegypti) surveyed.Results: The surveyed locations yielded a total of 3 741 breeding containers and 19 537 immature mosquitoes from four areas. Concurrent artificial and natural containers produced 78.4% immature Ae. albopictus and 6.3% Ae. aegypti mosquitoes in wet season,with 14.2% Ae. albopictus and 1.1% Ae. aegypti mosquitoes in dry season. Artificial containers accounted for 98.1% of the total containers recorded, with restaurants being the most productive locations(8 012) and schools being the least productive(2 234).Conclusions: It was concluded that public places are good sources of potential container habitats of Aedes mosquitoes in Penang Island, Malaysia and Ae. albopictus has exclusively replaced the home-grown Ae. aegypti even in urban areas. Therefore, treatment of artificial containers in such locations is critical in Aedes mosquito control campaigns during dengue outbreaks.展开更多
Objective:To determine spatial distribution of sand flies(Diptera:Psychodidae;Larroussius group),the vectors of visceral leishmaniasis in Ardabil province,Northwest of Iran.Methods:Sand flies were collected using stic...Objective:To determine spatial distribution of sand flies(Diptera:Psychodidae;Larroussius group),the vectors of visceral leishmaniasis in Ardabil province,Northwest of Iran.Methods:Sand flies were collected using sticky traps from the 30 selected points in Ardabil province,during May-November 2017.The MaxEnt model in GIS software was used for modeling.Results:A total of 2794 specimens of sand flies were collected,of which 33%were Larroussius subgenus sand flies.Phlebotomus kandelakii and Phlebotomus wenyoni were the highest and lowest collected species respectively.Based on the modeling,four areas in the province were identified with more than 70%probability of the presence of Larroussius group vectors which were at risk of visceral leishmaniasis disease transmission.Conclusions:The distribution of Larroussius subgenus sand flies was observed in all parts of Ardabil.But the northern parts of the province(Germi and Bilesavar counties)as well as central part(Ardabil and Meshkinshahr counties)were of great importance in terms of the presence of Larroussius subgenus sand flies and the possibility of transmission of the visceral leishmaniasis.展开更多
Objective: To explore the larvicidal activities of different plant parts of Melanochyla fasciculiflora(M. fasciculiflora), Gluta renghas(G. renghas), Anacardium occidentale and Mangifera indica from family Anacardiace...Objective: To explore the larvicidal activities of different plant parts of Melanochyla fasciculiflora(M. fasciculiflora), Gluta renghas(G. renghas), Anacardium occidentale and Mangifera indica from family Anacardiaceae against the laboratory and field strains of dengue vectors Aedes aegypti and Aedes albopictus(Ae. albopictus).Methods: Leaves and bark parts of study plants were collected from Taman Nageri,Bukit Pancor and Teluk Bahang National Park, Penang, Malaysia. Leaves and stem barks were separated, air dried, ground and extracted with methanol by Soxhlet apparatus.Crude extract was obtained by evaporating the extra solvent in rotary evaporator. The 4th instar larvae from laboratory and field strains were exposed to 50–1 300 mg/L concentrations according to World Health Organization standard larval bioassay. Larval mortality was recorded after 24 h of exposure.Results: Highest larvicidal activity was exhibited by G. renghas bark extract against Ae.albopictus laboratory strain at 600 mg/L. G. renghas also showed the highest larvicidal activities for other strains as compared to other plant extracts, followed by Mangifera indica and M. fasciculiflora and Anacardium occidentale.Conclusions: Ae. albopictus has been found to be more susceptible as compare to Aedes aegypti in both laboratory and field strains in this study. G. renghas and M. fasciculiflora were tested for the first time and exhibited prompting larvicidal activities against dengue vectors. These results revealed that all the plants especially G. renghas and M. fasciculiflora have the higher larvicidal activities and can be used for the control of dengue vector as a new environment friendly, target specific and low cost phytochemical.展开更多
Objective:To investigate lethal effect of culture filtrates of Streptomyces citreofluorescens （S.citreofluorescens） against Anopheles stephensi（An.stephensi）,Culex quinquefasciatus（Cx. quinquefasciatus）,and Aede...Objective:To investigate lethal effect of culture filtrates of Streptomyces citreofluorescens （S.citreofluorescens） against Anopheles stephensi（An.stephensi）,Culex quinquefasciatus（Cx. quinquefasciatus）,and Aedes aegypti（Ae.aegypti） larvae vectors for malaria,filarial and dengue. Methods:The culture filtrates obtained from S.cilreofluorescens 2528 was grown in Potato Dextrose Broth（PDB）,filtrated and used for the bioassay after a growth of 15 days.Results:The results demonstrated that the An.stephensi shows mortalities with LC<sub>50</sub>,LG<sub>40</sub> values of first instar 46.8μL/mL,79.5μL/mL,second instar 79.0μL/mL,95.6μL/mL,third instar 79.0μL/mL,136.9μL/mL,and fourth instar 122.6μL/mL,174.5μL/mL Whereas,The Cx.quinquefasciatus were found effective on first instar 40.0μL/mL,138.03μL/mL,second instar 80.0μL/ml,181.97μL/ mL,third instar 100.0μL/mL,309.2μL/mL,and fourth instar 60.0μL/ml,169.82μL/mL.The Ae.aegypti were successfully achieved susceptible with higher concentrations in comparisons of An.stephensi and Cx.quinquefasciatus larvae.These outcomes of the investigations have compared with the Chitinase of Streptomyces griseus（S.griseus） C6137 that shows 90%-95% mortality.Conclusions:These new findings significantly permitted that the culture filtrates of S. citreofluorescens can be used as bacterial larvicides.This is an environmentally safe approach to control the vectors of malaria,dengue and filariasis of tropical areas.展开更多
Objective: To determine the spatial distribution and infection rate of sand flies as vectors of Leishmania parasite in Ardabil province, northwest of Iran.Methods: This was a descriptive cross-sectional study. The san...Objective: To determine the spatial distribution and infection rate of sand flies as vectors of Leishmania parasite in Ardabil province, northwest of Iran.Methods: This was a descriptive cross-sectional study. The sand flies were collected from 30 areas in all 10 districts of Ardabil province during 2017. The specimens were caught using the sticky traps. The head and genitalia of sand flies were separated and mounted in Berlese solution for microscopic identification. The Geographical Information System ArcMap10.4.1 software was used to provide the spatial maps. Results: A total of 2 794 sand flies specimens were collected and 22 species of sand flies were identified from the two genera: Phlebotomus and Sergentomyia from Ardabil province. The highest frequency was found in Phlebotomus papatasi(23.7%) followed by Phlebotomus kandelakii(13.0%). The promastigote form of Leishmania infantum parasite has been reported from the three main vectors of visceral leishmaniasis(Phlebotomus kandelakii, Phlebotomus perfiliewi and Phlebotomus tobbi) from Ardabil province, where the spatial distribution map of these visceral leishmaniasis vectors was prepared. Some important species of sand flies such as Phlebotomus kandelakii, Phlebotomus perfiliewi and Phlebotomus tobbi were reported and identified as main and probable vectors of visceral leishmaniasis in Ardabil. Conclusions: According to the Geographic Information System based maps, the frequency of the sand flies as leishmaniasis vectors, the leishmania parasite infection rate and the prevalence of the disease in the central areas of Ardabil province are higher than in other areas in Ardabil province.展开更多
This paper summarises efforts to control Sleeping sickness [Human African Trypanosomiasis (HAT)] by Tsetse flies and Trypanosomiaisis (T & T) control for the 7 consecutive years although started a decade ago in Ta...This paper summarises efforts to control Sleeping sickness [Human African Trypanosomiasis (HAT)] by Tsetse flies and Trypanosomiaisis (T & T) control for the 7 consecutive years although started a decade ago in Tanzania National Parks (TANAPA). These efforts are critical for curbing HAT incidences and HAT epidemics. HAT cases have had profound negative impacts on human health, affecting local residents and international travel as well as tourism industry resulting into human and animal health burden and reduction in tourism income. Understanding the current efforts is essential in the proper planning and decision making on developing effective control strategy against T & T control. In this paper, we summarize the recent efforts in the control of T & T in National Parks and discuss the constraints faced. The information will enable TANAPA and other concerned authorities to make informed decision on optimal ways of controlling HAT in National Parks. The results show that much control efforts have so far concentrated in Serengeti, Ruaha, Tarangire and Katavi National Parks where tsetse fly challenges are high. A total 21,143 (average 3020) Insecticide Treated Targets (ITT) were deployed in different areas in the parks and 82,899 (average 20,725) cars entering these parks were sprayed from 2007/2008 to 2014/2015 and 2007/2008 to 2010/2011 respectively. Deployed ITTs lead to a drastic reduction of FTDs of the two dominant tsetse species to 1.3 and 1.4 of G. swynnertoni and G. pallidipes respectively, and the decline was significant at P = 0.011. The major challenges faced include tsetse re-invasion in controlled areas;resurgence of HAT cases when control efforts are relaxed, ITT maintenance and inadequate health education programs. The control strategy should be continuous and scaled up as failure to implement an effective and sustainable system for HAT control will increase the risk of new epidemic that would impede tourism development.展开更多
Dear Editor,Arthropod-borne viruses are a group of the most important emerging pathogens.They cause a range of diseases in vertebrate hosts and threaten human health(Gan and Leo,2014).The global distribution of arbovi...Dear Editor,Arthropod-borne viruses are a group of the most important emerging pathogens.They cause a range of diseases in vertebrate hosts and threaten human health(Gan and Leo,2014).The global distribution of arboviruses is associated with the vector which is strongly affected by changes in environmental conditions.展开更多
It is important to understand the dynamics of malaria vectors in implementing malaria control strategies.Six villages were selected from different sections in the Three Gorges Reservoir fc,r exploring the relationship...It is important to understand the dynamics of malaria vectors in implementing malaria control strategies.Six villages were selected from different sections in the Three Gorges Reservoir fc,r exploring the relationship between the climatic|:actors and its malaria vector density from 1997 to 2007 using the auto-regressive linear model regressi^n method.The result indicated that both temperature and precipitation were better modeled as quadratic rather than linearly related to the density of Anopheles sinensis.展开更多
A 150 bp epidermal growth factor (EGF) cDNA fragment and a 1024 bp epidermal growth factor receptor (EGFR) cDNA fragment were inserted into 5.05 kb pBabe-puro retroviral vectors between BamH I and EcoR I sites in 3...A 150 bp epidermal growth factor (EGF) cDNA fragment and a 1024 bp epidermal growth factor receptor (EGFR) cDNA fragment were inserted into 5.05 kb pBabe-puro retroviral vectors between BamH I and EcoR I sites in 3'-5' and / or 5'-3' orientation. The vectors were ligated with EGF and EGFR fragments by T-4 Ligase. The recombinant retroviral vectors were then packaged with packaging cell line PA317 through calcium phosphate mediated transfection. The viral supernatant of transfected PA317 cell lines were used to infect the human pancreatic carcinoma cell line PC-7. The resultant transformant cell lines: PC-7 / AS-EGF, PC-7 / S-EGFR, PC-7 / AS-EGFR and PC-7 / pBabe were tested for their endogenous EGF and EGFR mRNA expressions, cell growth rate, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice. The results showed that there were noticeable inhibitions of cell growth, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice in PC-7 / AS-EGF and PC-7 / AS-EGFR transformant cell lines. The endogenous EGF mRNA expression was blocked in PC-7 / AS-EGF cell line and the endogenous EGFR mRNA was significantly down-regulated in PC-7 / AS-EGFR cell line.展开更多
Mosquito-borne diseases pose a significant global health threat,necessitating the development of innovative vector control strategies.In this study,we investigated the potential of harnessing host immunity against mos...Mosquito-borne diseases pose a significant global health threat,necessitating the development of innovative vector control strategies.In this study,we investigated the potential of harnessing host immunity against mosquitoes through vaccination.Using Culex pipiens(C.pipiens)as a model,we demonstrated that polyclonal antibodies against C.pipiens abdominal protein extracts significantly impaired oviposition and increased mosquito mortality,primarily through the classical complement activation pathways.However,repeated exposure led to resistance,indicating potential adaptation.Proteomic analysis identified metabolic proteins as key targets,with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses highlighting their roles in carboxylic acid metabolism,tyrosine degradation,and the proteasome pathways.Notably,cross-species reactivity was revealed by Western blotting,showing strong binding of Culex-specific antibodies to Anopheles and Aedes abdominal proteins.This study provides mechanistic insights into antibody-based mosquito suppression,highlighting its potential as an innovative vector control strategy while underscoring the need for further research on resistance management and ecological impacts.展开更多
Arthropod melanization is a crucial defense mechanism mediated by a complex cascade of CLIP domain serine proteases(CLIPs).In this study,it was confirmed that microRNA-11903a(miR-11903a)targets Aedes-CLIPB9(AeCLIPB9)b...Arthropod melanization is a crucial defense mechanism mediated by a complex cascade of CLIP domain serine proteases(CLIPs).In this study,it was confirmed that microRNA-11903a(miR-11903a)targets Aedes-CLIPB9(AeCLIPB9)by bioinformatics prediction and dual-luciferase reporter assays.Following intrathoracic injection of miR-11903a agomir and antagomir,Real-time quantitative polymerase chain reaction confirmed that AeCLIPB9 is negatively regulated by miR-11903a.Spatiotemporal expression analysis revealed that miR-11903a is most abundant in 4th instar larvae,followed by pupae and adults,and highly expressed in the wings,head,and midgut of female adults.Following pathogen infection,AeCLIPB9 and miR-11903a exhibited opposite expression trends,indicating their potential roles in mosquito innate immunity.To further investigate the relationship between AeCLIPB9 and miR-11903a,double-strand CLIPB9 was synthesized and RNA interference was performed.Seven-d survival assays revealed that both AeCLIPB9 and miR-11903a were crucial immune factors in fighting pathogens.Finally,longevity assays demonstrated that miR-11903a influenced mosquito lifespan.展开更多
The seasonality of Haemaphysalis longicornis in the United States comprises overlapping life stages in the spring and summer.This is partially attributed to the ability of all stages to survive the winter.Physiologica...The seasonality of Haemaphysalis longicornis in the United States comprises overlapping life stages in the spring and summer.This is partially attributed to the ability of all stages to survive the winter.Physiological condition in ticks refers to nutritional reserve levels and is often used to characterize tick populations.To determine if lipids were suitable for estimating the physiological condition in H.longicornis,lipid content was measured in unfed laboratory-reared ticks for up to 480 d.The results showed that lipids decrease significantly over time in adults(36%at 183 d),nymphs(33%at 63 d)and larvae(28%at 102 d)and could be used to study the population structure of field-collected H.longicornis.Lipids extracted from field-collected ticks(March to October)were measured to determine if different groups or cohorts could be identified during the season.The spring nymph population included high-and low-lipid groups that partially overlapped in April and May.In larvae,the lipid content of ticks in the spring was significantly higher than in the fall,suggesting that active larvae in the early fall do not overwinter.The analysis of lipids in adults showed that high-and low-lipid adults were present throughout the season,suggesting a continuous influx of recently molted adults until the end of the adult season,where only low-lipid ticks are found.The analysis of physiological condition in the Asian longhorned tick demonstrated a complex univoltine structure with some overlap in adults from different years.展开更多
Aedes albopictus(Ae.albopictus)is widely distributed and can transmit many infectious diseases,and insecticide-based interventions play an important role in vector control.However,increased insecticide resistance has ...Aedes albopictus(Ae.albopictus)is widely distributed and can transmit many infectious diseases,and insecticide-based interventions play an important role in vector control.However,increased insecticide resistance has become a severe public health problem,and the clarification of its detailed mechanism is a matter of urgence.This study found that target-site resistance and metabolic resistance could not fully explain insecticide resistance in field Ae.albopictus,and there were likely other resistance mechanisms involved.The 16S and internal transcribed spacer sequencing revealed significant differences in the species compositions of the cuticle surface symbiotic bacteria and fungi between deltamethrin(DM)-resistant(DR)and DM-susceptible(DS)Ae.albopictus.Additionally,the abundances of Serratia spp.and Candida spp.significantly increased after DM treatment.Furthermore,2 fungi(Rhodotorula mucilaginosa and Candida melibiosica)and 3 bacteria(Serratia marcescens,Klebsiella aerogenes,and Serratia sp.)isolated from DR Ae.albopictus can use DM as their sole carbon source.After reinoculation onto the cuticle surface of DS Ae.albopictus,R.mucilaginosa and C.melibiosica significantly enhanced the DM resistance of Ae.albopictus.Moreover,transcriptome sequencing of the surviving Ae.albopictus after DM exposure revealed that the gene expression of cytochrome P450 enzymes and glutathione-S-transferases increased,suggesting that besides the direct degradation,the candidate degrading microbes could also cause insecticide resistance via indirect enhancement of mosquito gene expression.In conclusion,we demonstrated that the cuticle surface symbiotic microbes were involved in the development of insecticide resistance in Ae.albopictus,providing novel and supplementary insights into insecticide resistance mechanisms.展开更多
While conventional FISH and IHC methods struggle to decode complex tissue heterogeneity and comprehensive molecular diagnosis due to low-throughput spatial information,spatial omics technologies enable high-throughput...While conventional FISH and IHC methods struggle to decode complex tissue heterogeneity and comprehensive molecular diagnosis due to low-throughput spatial information,spatial omics technologies enable high-throughput molecular mapping across tissue microenvironments.These technologies are emerging as transformative tools in molecular diagnostics and medical research.By integrating histopathological morphology with spatial multi-omics profiling(genome,transcriptome,epigenome,and proteome),spatial omics technologies open an avenue for understanding disease progression,therapeutic resistance mechanisms,and precise diagnosis.It particularly enhances tumor microenvironment analysis by mapping immune cell distributions and functional states,which may greatly facilitate tumor molecular subtyping,prognostic assessment,and prediction of the radiotherapy and chemotherapy efficacy.Despite the substantial advancements in spatial omics,the translation of spatial omics into clinical applications remains challenging due to robustness,efficacy,clinical validation,and cost constraints.In this review,we summarize the current progress and prospects of spatial omics technologies,particularly in medical research and diagnostic applications.展开更多
Summary What is already known on this topic?Malaria is an infectious parasitic disease transmitted by the bite of Anopheles mosquitoes and is a serious threat to human health.Surveillance of malaria vectors is part of...Summary What is already known on this topic?Malaria is an infectious parasitic disease transmitted by the bite of Anopheles mosquitoes and is a serious threat to human health.Surveillance of malaria vectors is part of the integrated strategy for malaria elimination in China.What is added by this report?This research supplements the population distribution,density,and seasonal fluctuation of malaria vectors in the Anopheles surveillance sites from 2018 to 2020 in China.展开更多
Background:Mass drug administration(MDA)programmes for the control of lymphatic filariasis in Ghana,have been ongoing in some endemic districts for 16 years.The current study aimed to assess factors that govern the su...Background:Mass drug administration(MDA)programmes for the control of lymphatic filariasis in Ghana,have been ongoing in some endemic districts for 16 years.The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana.Methods:The study was undertaken in two"hotspot"districts(Ahanta West and Kassena Nankana West)and two control districts(Mpohor and Bongo)in Ghana.Mosquitoes were collected and identified using morphological and molecular tools.A proportion of the cibarial armatures of each species was examined.Dissections were performed onAnopheles gambiae for filarial worm detection.A questionnaire was administered to obtain information on MDA compliance and vector control activities.Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis.Results:High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district(F=16.09,P=0.002).There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts(F=2.16,P=0.185).Mansonia species were predominant in Ahanta West district.An.coluzzii mosquitoes were prevalent in all districts.An.melas with infected and infective filarial worms was found only in Ahanta West district.No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts.Reported MDA coverage was high in all districts.The average use of bednet and indoor residual spraying was 82.4 and 66.2%,respectively.There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts,both considered hotspots of lymphatic filariasis transmission.Conclusions:The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis.Unlike Kassena Nankana West district where transmission dynamics could be explained by initial infection prevalence and low vector densities,ongoing lymphatic filariasis transmission in Ahanta West district might be explained by high biting rates ofAn.gambiae and initial infection prevalence,coupled with high densities ofAn.melas andMansonia vector species that have low or no teeth and exhibiting limitation.展开更多
Many devastating plant viruses are transmitted by insect vectors among plant hosts in a persistent-propagative manner.Pelota(Pelo)is an evolutionarily conserved protein involved in the mRNA surveillance system.In this...Many devastating plant viruses are transmitted by insect vectors among plant hosts in a persistent-propagative manner.Pelota(Pelo)is an evolutionarily conserved protein involved in the mRNA surveillance system.In this study,it was found that the accumulation of Pelo proteins are slightly decreased during the propagation of the fijivirus southern rice black-streaked dwarf virus(SRBSDV)in rice and transmission vector planthopper(Sogatella furcifera).The tubular protein P7-1 encoded by SRBSDV interacted with Pelo of rice or planthopper vector.Overexpression or knockdown of Pelo expression inhibits the formation of P7-1 tubules in insect cells,further exerting antiviral activity.Furthermore,overexpression or knockout of Pelo expression in transgenic rice plants also inhibits the effective propagation of SRBSDV as well as two other rice viruses of different families.The slight reduction of Pelo accumulation during SRBSDV propagation in rice and insect vectors would avoid Pelo-mediated excessive inhibition of P7-1 tubule formation,ensuring effective virus propagation.Our findings provide insights into how the up-or down-regulated expression of Pelo in rice hosts and insect vectors elevate their resistance to rice viruses.展开更多
Background The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools.H...Background The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools.Here,we investigated the performance of piperonyl-butoxide(PBO)-pyrethroid[Permanet 3.0(P3.0)]and dual active ingredients(AI)nets[Interceptor G2(IG2):containing pyrethroids and chlorfenapyr and Royal Guard(RG):containing pyrethroids and pyriproxyfen]compared to pyrethroid-only net Royal Sentry(RS)against pyrethroid-resistant malaria vectors in Cameroon.Methods The efficacy of these tools was firstly evaluated onAnopheles gambiae s.l.andAnopheles funestus s.l.from Gounougou,Mibellon,Mangoum,Nkolondom,and Elende using cone/tunnel assays.In addition,experimental hut trials(EHT)were performed to evaluate the performance of unwashed and 20 times washed nets in semi-field conditions.Furthermore,pyrethroid-resistant markers were genotyped in dead vs alive,blood-fed vs unfed mosquitoes after exposure to the nets to evaluate the impact of these markers on net performance.The XLSTAT software was used to calculate the various entomological outcomes and the Chi-square test was used to compare the efficacy of various nets.The odds ratio and Fisher exact test were then used to establish the statistical significance of any association between insecticide resistance markers and bed net efficacy.Results Interceptor G2 was the most effective net against wild pyrethroid-resistantAn.funestus followed by Permanet 3.0.In EHT,this net induced up to 87.8%mortality[95%confidence interval(CI):83.5-92.1%)and 55.6%(95%CI:48.5-62.7%)after 20 washes whilst unwashed pyrethroid-only net(Royal Sentry)killed just 18.2%(95%CI:13.4-22.9%)of host-seekingAn.funestus.The unwashed Permanet 3.0 killed up to 53.8%(95%CI:44.3-63.4%)of field-resistant mosquitoes and 47.2%(95%CI:37.7-56.7%)when washed 20 times,and the Royal Guard 13.2%(95%CI:9.0-17.3%)for unwashed net and 8.5%(95%CI:5.7-11.4%)for the 20 washed net.Interceptor G2,Permanet 3.0,and Royal Guard provided better personal protection(blood-feeding inhibition 66.2%,77.8%,and 92.8%,respectively)compared to pyrethroid-only net Royal Sentry(8.4%).Interestingly,a negative association was found betweenkdrw and the chlorfenapyr-based net Interceptor G2(χ^(2)=138;P<0.0001)with homozygote-resistant mosquitoes predominantly found in the dead ones.Conclusions The high mortality recorded with Interceptor G2 against pyrethroid-resistant malaria vectors in this study provides first semi-field evidence of high efficacy against these major malaria vectors in Cameroon encouraging the implementation of this novel net for malaria control in the country.However,the performance of this net should be established in other locations and on other major malaria vectors before implementation at a large scale.展开更多
PBQ[1-(4-chlorophenyl)-3-(pyridin-3-yl)urea],an enormous potent molluscicide,showed excellent Pomacea canaliculata(P.canaliculata)control activity and low toxicity for other aquatic organisms,but its snail-killing mec...PBQ[1-(4-chlorophenyl)-3-(pyridin-3-yl)urea],an enormous potent molluscicide,showed excellent Pomacea canaliculata(P.canaliculata)control activity and low toxicity for other aquatic organisms,but its snail-killing mechanisms are still not fully understood.We employed an optical method to elucidate PBQ action via a novel fluorescent viscosity probe,NCV.As the viscosity in the test solutions increased,compared with that in pure ethanol,a 54-fold fluorescence intensity enhancement of NCV was observed in 310 cP of 90%glycerol.Furthermore,NCV successfully exhibited a selective fluorescence response towards monensin-induced cellular viscosity changes in HepG2 cells.The liver,stomach,and foot plantar of the tested snails were frozen and sectioned for fluorescent imaging experiments after the treatment with different PBQ concentrations over various times.A significant fluorescent increase in the snail's liver was observed upon exposure to 0.75 mg/L PBQ for 72 h,which highlighted an increase in viscosity.Hematoxylin and eosin(HE)staining further supported PBQ-induced liver damage with a viscosity increase in P.canaliculata.Our study provides a new rapid optical visualization method to study the killing mechanisms of PBQ and may help discover new chemicals that control snail populations.展开更多
文摘Malaria is a main vector-borne public health problem in Iran.The last studies on Iranian mosquitoes show 31 Anopheles species including different sibling species and genotypes,eight of them are reported to play role in malaria transmission.The objective of this study is to provide a reference for malaria vectors of Iran and to map their spatial and temporal distribution in different climatic zones.Shape files of administrative boundaries and climates of Iran were provided by National Cartographic Center.Data on distribution and seasonal activity of malaria vectors were obtained from different sources and a databank in district level was created in Excel 2003, inserted to the shape files and analyzed by ArcGIS 9.2 to provide the maps.Anopheles culicifacies Giles s.l.,Anopheles dthali Patton,Anopheles fluviatilis James s.L,Anopheles maculipennis Meigen s.L,Anopheles sacharovi Favre,Anopheles stephensi IJston,and Anopheles superpictus Grassi have been introduced as primary and secondary malaria vectors and Anopheles puicherrimus Theobald as a suspected vector in Iran.Temporal distribution of anopheline mosquitoes is restricted to April_December in northern Iran,however mosquitoes can be found during the year in southern region.Spatial distribution of malaria vectors is different based on species,thus six of them(except for Anopheles maculipennis s.l.and Anopheles sacharovi) are reported from endemic malarious area in southern and southeastern areas of Iran.The climate of this part is usually warm and humid,which makes it favorable for mosquito rearing and malaria transmission.Correlation between climate conditions and vector distribution can help to predict the potential range of activity for each species and preparedness for malaria epidemics.
基金Funded by a grant from Universiti Sains Malaysia(Grant No.1001/PBIOLOGI/811277)
文摘Objective: To determine abundance, distribution and diversity of potential breeding container habitats of the dengue vectors in public places including schools, restaurants,mosques and parks in southwest areas of Penang Island, Malaysia.Methods: Premises at restaurants, schools, parks and mosques were surveyed simultaneously and inspected visually for container habitats and production of immature mosquitoes from March 2015 to March 2016. Abundance(mean ± SE) of breeding containers between sites was compared using One-way ANOVA. Independent sample ttest was used to compare total number of Aedes albopictus(Ae. albopictus) and Aedes aegypti(Ae. aegypti) surveyed.Results: The surveyed locations yielded a total of 3 741 breeding containers and 19 537 immature mosquitoes from four areas. Concurrent artificial and natural containers produced 78.4% immature Ae. albopictus and 6.3% Ae. aegypti mosquitoes in wet season,with 14.2% Ae. albopictus and 1.1% Ae. aegypti mosquitoes in dry season. Artificial containers accounted for 98.1% of the total containers recorded, with restaurants being the most productive locations(8 012) and schools being the least productive(2 234).Conclusions: It was concluded that public places are good sources of potential container habitats of Aedes mosquitoes in Penang Island, Malaysia and Ae. albopictus has exclusively replaced the home-grown Ae. aegypti even in urban areas. Therefore, treatment of artificial containers in such locations is critical in Aedes mosquito control campaigns during dengue outbreaks.
基金funded and supported by the Tehran University of Medical Sciences(Project Number:31437)
文摘Objective:To determine spatial distribution of sand flies(Diptera:Psychodidae;Larroussius group),the vectors of visceral leishmaniasis in Ardabil province,Northwest of Iran.Methods:Sand flies were collected using sticky traps from the 30 selected points in Ardabil province,during May-November 2017.The MaxEnt model in GIS software was used for modeling.Results:A total of 2794 specimens of sand flies were collected,of which 33%were Larroussius subgenus sand flies.Phlebotomus kandelakii and Phlebotomus wenyoni were the highest and lowest collected species respectively.Based on the modeling,four areas in the province were identified with more than 70%probability of the presence of Larroussius group vectors which were at risk of visceral leishmaniasis disease transmission.Conclusions:The distribution of Larroussius subgenus sand flies was observed in all parts of Ardabil.But the northern parts of the province(Germi and Bilesavar counties)as well as central part(Ardabil and Meshkinshahr counties)were of great importance in terms of the presence of Larroussius subgenus sand flies and the possibility of transmission of the visceral leishmaniasis.
基金Supported by USM Research University Grant(1001/PBIOLOGI/815079)Ministry of Higher Education Commission,Malaysia(MOHE)
文摘Objective: To explore the larvicidal activities of different plant parts of Melanochyla fasciculiflora(M. fasciculiflora), Gluta renghas(G. renghas), Anacardium occidentale and Mangifera indica from family Anacardiaceae against the laboratory and field strains of dengue vectors Aedes aegypti and Aedes albopictus(Ae. albopictus).Methods: Leaves and bark parts of study plants were collected from Taman Nageri,Bukit Pancor and Teluk Bahang National Park, Penang, Malaysia. Leaves and stem barks were separated, air dried, ground and extracted with methanol by Soxhlet apparatus.Crude extract was obtained by evaporating the extra solvent in rotary evaporator. The 4th instar larvae from laboratory and field strains were exposed to 50–1 300 mg/L concentrations according to World Health Organization standard larval bioassay. Larval mortality was recorded after 24 h of exposure.Results: Highest larvicidal activity was exhibited by G. renghas bark extract against Ae.albopictus laboratory strain at 600 mg/L. G. renghas also showed the highest larvicidal activities for other strains as compared to other plant extracts, followed by Mangifera indica and M. fasciculiflora and Anacardium occidentale.Conclusions: Ae. albopictus has been found to be more susceptible as compare to Aedes aegypti in both laboratory and field strains in this study. G. renghas and M. fasciculiflora were tested for the first time and exhibited prompting larvicidal activities against dengue vectors. These results revealed that all the plants especially G. renghas and M. fasciculiflora have the higher larvicidal activities and can be used for the control of dengue vector as a new environment friendly, target specific and low cost phytochemical.
基金financially supported by Univeresiry Grants Commission. New Post Doctoral Fellowship(2009-2011)the University Grants Conuuission, New Delhi of Major Research Projcct for the financial support 2010-2012 to DST-FIST program (2003-2008)for providing laboratory facilities. G.Singh is indebted to UGC, New Delhi, for an award of Post Doctoral Fellowship (2009-2011)
文摘Objective:To investigate lethal effect of culture filtrates of Streptomyces citreofluorescens （S.citreofluorescens） against Anopheles stephensi（An.stephensi）,Culex quinquefasciatus（Cx. quinquefasciatus）,and Aedes aegypti（Ae.aegypti） larvae vectors for malaria,filarial and dengue. Methods:The culture filtrates obtained from S.cilreofluorescens 2528 was grown in Potato Dextrose Broth（PDB）,filtrated and used for the bioassay after a growth of 15 days.Results:The results demonstrated that the An.stephensi shows mortalities with LC<sub>50</sub>,LG<sub>40</sub> values of first instar 46.8μL/mL,79.5μL/mL,second instar 79.0μL/mL,95.6μL/mL,third instar 79.0μL/mL,136.9μL/mL,and fourth instar 122.6μL/mL,174.5μL/mL Whereas,The Cx.quinquefasciatus were found effective on first instar 40.0μL/mL,138.03μL/mL,second instar 80.0μL/ml,181.97μL/ mL,third instar 100.0μL/mL,309.2μL/mL,and fourth instar 60.0μL/ml,169.82μL/mL.The Ae.aegypti were successfully achieved susceptible with higher concentrations in comparisons of An.stephensi and Cx.quinquefasciatus larvae.These outcomes of the investigations have compared with the Chitinase of Streptomyces griseus（S.griseus） C6137 that shows 90%-95% mortality.Conclusions:These new findings significantly permitted that the culture filtrates of S. citreofluorescens can be used as bacterial larvicides.This is an environmentally safe approach to control the vectors of malaria,dengue and filariasis of tropical areas.
基金sponsored financially by Ardabil University of Medical Sciences at No.92218
文摘Objective: To determine the spatial distribution and infection rate of sand flies as vectors of Leishmania parasite in Ardabil province, northwest of Iran.Methods: This was a descriptive cross-sectional study. The sand flies were collected from 30 areas in all 10 districts of Ardabil province during 2017. The specimens were caught using the sticky traps. The head and genitalia of sand flies were separated and mounted in Berlese solution for microscopic identification. The Geographical Information System ArcMap10.4.1 software was used to provide the spatial maps. Results: A total of 2 794 sand flies specimens were collected and 22 species of sand flies were identified from the two genera: Phlebotomus and Sergentomyia from Ardabil province. The highest frequency was found in Phlebotomus papatasi(23.7%) followed by Phlebotomus kandelakii(13.0%). The promastigote form of Leishmania infantum parasite has been reported from the three main vectors of visceral leishmaniasis(Phlebotomus kandelakii, Phlebotomus perfiliewi and Phlebotomus tobbi) from Ardabil province, where the spatial distribution map of these visceral leishmaniasis vectors was prepared. Some important species of sand flies such as Phlebotomus kandelakii, Phlebotomus perfiliewi and Phlebotomus tobbi were reported and identified as main and probable vectors of visceral leishmaniasis in Ardabil. Conclusions: According to the Geographic Information System based maps, the frequency of the sand flies as leishmaniasis vectors, the leishmania parasite infection rate and the prevalence of the disease in the central areas of Ardabil province are higher than in other areas in Ardabil province.
文摘This paper summarises efforts to control Sleeping sickness [Human African Trypanosomiasis (HAT)] by Tsetse flies and Trypanosomiaisis (T & T) control for the 7 consecutive years although started a decade ago in Tanzania National Parks (TANAPA). These efforts are critical for curbing HAT incidences and HAT epidemics. HAT cases have had profound negative impacts on human health, affecting local residents and international travel as well as tourism industry resulting into human and animal health burden and reduction in tourism income. Understanding the current efforts is essential in the proper planning and decision making on developing effective control strategy against T & T control. In this paper, we summarize the recent efforts in the control of T & T in National Parks and discuss the constraints faced. The information will enable TANAPA and other concerned authorities to make informed decision on optimal ways of controlling HAT in National Parks. The results show that much control efforts have so far concentrated in Serengeti, Ruaha, Tarangire and Katavi National Parks where tsetse fly challenges are high. A total 21,143 (average 3020) Insecticide Treated Targets (ITT) were deployed in different areas in the parks and 82,899 (average 20,725) cars entering these parks were sprayed from 2007/2008 to 2014/2015 and 2007/2008 to 2010/2011 respectively. Deployed ITTs lead to a drastic reduction of FTDs of the two dominant tsetse species to 1.3 and 1.4 of G. swynnertoni and G. pallidipes respectively, and the decline was significant at P = 0.011. The major challenges faced include tsetse re-invasion in controlled areas;resurgence of HAT cases when control efforts are relaxed, ITT maintenance and inadequate health education programs. The control strategy should be continuous and scaled up as failure to implement an effective and sustainable system for HAT control will increase the risk of new epidemic that would impede tourism development.
基金a specific grant from National Institute for Medical Research Development,Iran(Grand No.940947)the National Institute for Medical Research Development ethics committee(IR.NIMAD.REC.1394.940947)
文摘Dear Editor,Arthropod-borne viruses are a group of the most important emerging pathogens.They cause a range of diseases in vertebrate hosts and threaten human health(Gan and Leo,2014).The global distribution of arboviruses is associated with the vector which is strongly affected by changes in environmental conditions.
基金funded by the Public Project(20080219)of the Ministry of Science and Technology,PRC
文摘It is important to understand the dynamics of malaria vectors in implementing malaria control strategies.Six villages were selected from different sections in the Three Gorges Reservoir fc,r exploring the relationship between the climatic|:actors and its malaria vector density from 1997 to 2007 using the auto-regressive linear model regressi^n method.The result indicated that both temperature and precipitation were better modeled as quadratic rather than linearly related to the density of Anopheles sinensis.
文摘A 150 bp epidermal growth factor (EGF) cDNA fragment and a 1024 bp epidermal growth factor receptor (EGFR) cDNA fragment were inserted into 5.05 kb pBabe-puro retroviral vectors between BamH I and EcoR I sites in 3'-5' and / or 5'-3' orientation. The vectors were ligated with EGF and EGFR fragments by T-4 Ligase. The recombinant retroviral vectors were then packaged with packaging cell line PA317 through calcium phosphate mediated transfection. The viral supernatant of transfected PA317 cell lines were used to infect the human pancreatic carcinoma cell line PC-7. The resultant transformant cell lines: PC-7 / AS-EGF, PC-7 / S-EGFR, PC-7 / AS-EGFR and PC-7 / pBabe were tested for their endogenous EGF and EGFR mRNA expressions, cell growth rate, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice. The results showed that there were noticeable inhibitions of cell growth, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice in PC-7 / AS-EGF and PC-7 / AS-EGFR transformant cell lines. The endogenous EGF mRNA expression was blocked in PC-7 / AS-EGF cell line and the endogenous EGFR mRNA was significantly down-regulated in PC-7 / AS-EGFR cell line.
基金supported by the National Natural Science Foundation of China(Grant No.82472312).
文摘Mosquito-borne diseases pose a significant global health threat,necessitating the development of innovative vector control strategies.In this study,we investigated the potential of harnessing host immunity against mosquitoes through vaccination.Using Culex pipiens(C.pipiens)as a model,we demonstrated that polyclonal antibodies against C.pipiens abdominal protein extracts significantly impaired oviposition and increased mosquito mortality,primarily through the classical complement activation pathways.However,repeated exposure led to resistance,indicating potential adaptation.Proteomic analysis identified metabolic proteins as key targets,with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses highlighting their roles in carboxylic acid metabolism,tyrosine degradation,and the proteasome pathways.Notably,cross-species reactivity was revealed by Western blotting,showing strong binding of Culex-specific antibodies to Anopheles and Aedes abdominal proteins.This study provides mechanistic insights into antibody-based mosquito suppression,highlighting its potential as an innovative vector control strategy while underscoring the need for further research on resistance management and ecological impacts.
基金supported by the Major Science and Technology Plan of Hainan Province(ZDKJ2021035)the National Natural Science Foundation of China(U22A20363)the Innovative Research Projects for Postgraduates in Hainan Province(Qhyb2022-41).
文摘Arthropod melanization is a crucial defense mechanism mediated by a complex cascade of CLIP domain serine proteases(CLIPs).In this study,it was confirmed that microRNA-11903a(miR-11903a)targets Aedes-CLIPB9(AeCLIPB9)by bioinformatics prediction and dual-luciferase reporter assays.Following intrathoracic injection of miR-11903a agomir and antagomir,Real-time quantitative polymerase chain reaction confirmed that AeCLIPB9 is negatively regulated by miR-11903a.Spatiotemporal expression analysis revealed that miR-11903a is most abundant in 4th instar larvae,followed by pupae and adults,and highly expressed in the wings,head,and midgut of female adults.Following pathogen infection,AeCLIPB9 and miR-11903a exhibited opposite expression trends,indicating their potential roles in mosquito innate immunity.To further investigate the relationship between AeCLIPB9 and miR-11903a,double-strand CLIPB9 was synthesized and RNA interference was performed.Seven-d survival assays revealed that both AeCLIPB9 and miR-11903a were crucial immune factors in fighting pathogens.Finally,longevity assays demonstrated that miR-11903a influenced mosquito lifespan.
基金supported by the United States Department of Agriculture National Institute of Food and Agriculture,Multi-State project NE1943(NJ08510)to ATthe State of New Jersey FY22 Tick Research and Control-Special Purpose Funding to NJAES/CVBsupported in part by Cooperative Agreement Number 1U01CK000509 between the Centers for Disease Control and Prevention(CDC)and the Northeast Center of Excellence in Vector-Borne Diseases.
文摘The seasonality of Haemaphysalis longicornis in the United States comprises overlapping life stages in the spring and summer.This is partially attributed to the ability of all stages to survive the winter.Physiological condition in ticks refers to nutritional reserve levels and is often used to characterize tick populations.To determine if lipids were suitable for estimating the physiological condition in H.longicornis,lipid content was measured in unfed laboratory-reared ticks for up to 480 d.The results showed that lipids decrease significantly over time in adults(36%at 183 d),nymphs(33%at 63 d)and larvae(28%at 102 d)and could be used to study the population structure of field-collected H.longicornis.Lipids extracted from field-collected ticks(March to October)were measured to determine if different groups or cohorts could be identified during the season.The spring nymph population included high-and low-lipid groups that partially overlapped in April and May.In larvae,the lipid content of ticks in the spring was significantly higher than in the fall,suggesting that active larvae in the early fall do not overwinter.The analysis of lipids in adults showed that high-and low-lipid adults were present throughout the season,suggesting a continuous influx of recently molted adults until the end of the adult season,where only low-lipid ticks are found.The analysis of physiological condition in the Asian longhorned tick demonstrated a complex univoltine structure with some overlap in adults from different years.
基金supported by the Key Research and Development Program sponsored by the Ministry of Science and Technology(MOST)(2023YFA1801004)National Natural Science Foundation of China and the Bill and Melinda Gates Foundation joint program(82261128002,2022YFML1003).
文摘Aedes albopictus(Ae.albopictus)is widely distributed and can transmit many infectious diseases,and insecticide-based interventions play an important role in vector control.However,increased insecticide resistance has become a severe public health problem,and the clarification of its detailed mechanism is a matter of urgence.This study found that target-site resistance and metabolic resistance could not fully explain insecticide resistance in field Ae.albopictus,and there were likely other resistance mechanisms involved.The 16S and internal transcribed spacer sequencing revealed significant differences in the species compositions of the cuticle surface symbiotic bacteria and fungi between deltamethrin(DM)-resistant(DR)and DM-susceptible(DS)Ae.albopictus.Additionally,the abundances of Serratia spp.and Candida spp.significantly increased after DM treatment.Furthermore,2 fungi(Rhodotorula mucilaginosa and Candida melibiosica)and 3 bacteria(Serratia marcescens,Klebsiella aerogenes,and Serratia sp.)isolated from DR Ae.albopictus can use DM as their sole carbon source.After reinoculation onto the cuticle surface of DS Ae.albopictus,R.mucilaginosa and C.melibiosica significantly enhanced the DM resistance of Ae.albopictus.Moreover,transcriptome sequencing of the surviving Ae.albopictus after DM exposure revealed that the gene expression of cytochrome P450 enzymes and glutathione-S-transferases increased,suggesting that besides the direct degradation,the candidate degrading microbes could also cause insecticide resistance via indirect enhancement of mosquito gene expression.In conclusion,we demonstrated that the cuticle surface symbiotic microbes were involved in the development of insecticide resistance in Ae.albopictus,providing novel and supplementary insights into insecticide resistance mechanisms.
基金supported by the National Natural Science Foundation of China(32171022,32221005,and 32401246).
文摘While conventional FISH and IHC methods struggle to decode complex tissue heterogeneity and comprehensive molecular diagnosis due to low-throughput spatial information,spatial omics technologies enable high-throughput molecular mapping across tissue microenvironments.These technologies are emerging as transformative tools in molecular diagnostics and medical research.By integrating histopathological morphology with spatial multi-omics profiling(genome,transcriptome,epigenome,and proteome),spatial omics technologies open an avenue for understanding disease progression,therapeutic resistance mechanisms,and precise diagnosis.It particularly enhances tumor microenvironment analysis by mapping immune cell distributions and functional states,which may greatly facilitate tumor molecular subtyping,prognostic assessment,and prediction of the radiotherapy and chemotherapy efficacy.Despite the substantial advancements in spatial omics,the translation of spatial omics into clinical applications remains challenging due to robustness,efficacy,clinical validation,and cost constraints.In this review,we summarize the current progress and prospects of spatial omics technologies,particularly in medical research and diagnostic applications.
文摘Summary What is already known on this topic?Malaria is an infectious parasitic disease transmitted by the bite of Anopheles mosquitoes and is a serious threat to human health.Surveillance of malaria vectors is part of the integrated strategy for malaria elimination in China.What is added by this report?This research supplements the population distribution,density,and seasonal fluctuation of malaria vectors in the Anopheles surveillance sites from 2018 to 2020 in China.
基金This study was supported by SightSavers International,Ghana and the Centre for Neglected Tropical Diseases,Liverpool School of Tropical MedicineSPB is grateful to the "Amt fur Ausbildungsbeitrage"of the canton of Basel-Stadt for a PhD fellowship.
文摘Background:Mass drug administration(MDA)programmes for the control of lymphatic filariasis in Ghana,have been ongoing in some endemic districts for 16 years.The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana.Methods:The study was undertaken in two"hotspot"districts(Ahanta West and Kassena Nankana West)and two control districts(Mpohor and Bongo)in Ghana.Mosquitoes were collected and identified using morphological and molecular tools.A proportion of the cibarial armatures of each species was examined.Dissections were performed onAnopheles gambiae for filarial worm detection.A questionnaire was administered to obtain information on MDA compliance and vector control activities.Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis.Results:High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district(F=16.09,P=0.002).There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts(F=2.16,P=0.185).Mansonia species were predominant in Ahanta West district.An.coluzzii mosquitoes were prevalent in all districts.An.melas with infected and infective filarial worms was found only in Ahanta West district.No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts.Reported MDA coverage was high in all districts.The average use of bednet and indoor residual spraying was 82.4 and 66.2%,respectively.There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts,both considered hotspots of lymphatic filariasis transmission.Conclusions:The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis.Unlike Kassena Nankana West district where transmission dynamics could be explained by initial infection prevalence and low vector densities,ongoing lymphatic filariasis transmission in Ahanta West district might be explained by high biting rates ofAn.gambiae and initial infection prevalence,coupled with high densities ofAn.melas andMansonia vector species that have low or no teeth and exhibiting limitation.
基金supported by funds from the National Natural Science Foundation of China(31920103014 and U23A20197).
文摘Many devastating plant viruses are transmitted by insect vectors among plant hosts in a persistent-propagative manner.Pelota(Pelo)is an evolutionarily conserved protein involved in the mRNA surveillance system.In this study,it was found that the accumulation of Pelo proteins are slightly decreased during the propagation of the fijivirus southern rice black-streaked dwarf virus(SRBSDV)in rice and transmission vector planthopper(Sogatella furcifera).The tubular protein P7-1 encoded by SRBSDV interacted with Pelo of rice or planthopper vector.Overexpression or knockdown of Pelo expression inhibits the formation of P7-1 tubules in insect cells,further exerting antiviral activity.Furthermore,overexpression or knockout of Pelo expression in transgenic rice plants also inhibits the effective propagation of SRBSDV as well as two other rice viruses of different families.The slight reduction of Pelo accumulation during SRBSDV propagation in rice and insect vectors would avoid Pelo-mediated excessive inhibition of P7-1 tubule formation,ensuring effective virus propagation.Our findings provide insights into how the up-or down-regulated expression of Pelo in rice hosts and insect vectors elevate their resistance to rice viruses.
基金This work was supported by the PIIVEC operational research project(PV/OP2-03/TW to MT under the MRC grant MR/PO27873/1),the Renewal Wellcome Trust Senior Research Fellowship in Biomedical Sciences(217188/Z/19/Z),and the BMGF Grant(INV-006003)awarded to CSW.
文摘Background The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools.Here,we investigated the performance of piperonyl-butoxide(PBO)-pyrethroid[Permanet 3.0(P3.0)]and dual active ingredients(AI)nets[Interceptor G2(IG2):containing pyrethroids and chlorfenapyr and Royal Guard(RG):containing pyrethroids and pyriproxyfen]compared to pyrethroid-only net Royal Sentry(RS)against pyrethroid-resistant malaria vectors in Cameroon.Methods The efficacy of these tools was firstly evaluated onAnopheles gambiae s.l.andAnopheles funestus s.l.from Gounougou,Mibellon,Mangoum,Nkolondom,and Elende using cone/tunnel assays.In addition,experimental hut trials(EHT)were performed to evaluate the performance of unwashed and 20 times washed nets in semi-field conditions.Furthermore,pyrethroid-resistant markers were genotyped in dead vs alive,blood-fed vs unfed mosquitoes after exposure to the nets to evaluate the impact of these markers on net performance.The XLSTAT software was used to calculate the various entomological outcomes and the Chi-square test was used to compare the efficacy of various nets.The odds ratio and Fisher exact test were then used to establish the statistical significance of any association between insecticide resistance markers and bed net efficacy.Results Interceptor G2 was the most effective net against wild pyrethroid-resistantAn.funestus followed by Permanet 3.0.In EHT,this net induced up to 87.8%mortality[95%confidence interval(CI):83.5-92.1%)and 55.6%(95%CI:48.5-62.7%)after 20 washes whilst unwashed pyrethroid-only net(Royal Sentry)killed just 18.2%(95%CI:13.4-22.9%)of host-seekingAn.funestus.The unwashed Permanet 3.0 killed up to 53.8%(95%CI:44.3-63.4%)of field-resistant mosquitoes and 47.2%(95%CI:37.7-56.7%)when washed 20 times,and the Royal Guard 13.2%(95%CI:9.0-17.3%)for unwashed net and 8.5%(95%CI:5.7-11.4%)for the 20 washed net.Interceptor G2,Permanet 3.0,and Royal Guard provided better personal protection(blood-feeding inhibition 66.2%,77.8%,and 92.8%,respectively)compared to pyrethroid-only net Royal Sentry(8.4%).Interestingly,a negative association was found betweenkdrw and the chlorfenapyr-based net Interceptor G2(χ^(2)=138;P<0.0001)with homozygote-resistant mosquitoes predominantly found in the dead ones.Conclusions The high mortality recorded with Interceptor G2 against pyrethroid-resistant malaria vectors in this study provides first semi-field evidence of high efficacy against these major malaria vectors in Cameroon encouraging the implementation of this novel net for malaria control in the country.However,the performance of this net should be established in other locations and on other major malaria vectors before implementation at a large scale.
基金the financial support of this work by the National Natural Science Foundation of China(Nos.82072309,22067019 and 22367023)the Major Science and Technology Projects in Yunnan Province(No.202402AE090006)+3 种基金the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(No.2022YKZY001)Yunnan Provincial Science and Technology Department Yunnan University Joint Special Project(No.202201BF070001-001)the Postgraduate Research Innovation Foundation of Yunnan University(No.KC-23234403)the Scientific Research Foundation Project of Yunnan Provincial Department of Education(No.2023Y0240)。
文摘PBQ[1-(4-chlorophenyl)-3-(pyridin-3-yl)urea],an enormous potent molluscicide,showed excellent Pomacea canaliculata(P.canaliculata)control activity and low toxicity for other aquatic organisms,but its snail-killing mechanisms are still not fully understood.We employed an optical method to elucidate PBQ action via a novel fluorescent viscosity probe,NCV.As the viscosity in the test solutions increased,compared with that in pure ethanol,a 54-fold fluorescence intensity enhancement of NCV was observed in 310 cP of 90%glycerol.Furthermore,NCV successfully exhibited a selective fluorescence response towards monensin-induced cellular viscosity changes in HepG2 cells.The liver,stomach,and foot plantar of the tested snails were frozen and sectioned for fluorescent imaging experiments after the treatment with different PBQ concentrations over various times.A significant fluorescent increase in the snail's liver was observed upon exposure to 0.75 mg/L PBQ for 72 h,which highlighted an increase in viscosity.Hematoxylin and eosin(HE)staining further supported PBQ-induced liver damage with a viscosity increase in P.canaliculata.Our study provides a new rapid optical visualization method to study the killing mechanisms of PBQ and may help discover new chemicals that control snail populations.
