Background:Arboviral disease transmitted by Aedes albopictus such as dengue fever is an important threat to human health.Pyrethroid resistance raises a great challenge for mosquito control.A systematic assessment of A...Background:Arboviral disease transmitted by Aedes albopictus such as dengue fever is an important threat to human health.Pyrethroid resistance raises a great challenge for mosquito control.A systematic assessment of Ae.albopictus resistance status in China is urgently needed,and the study of correlation between pyrethroid resistance and knockdown resistance(kdr)mutations would provide information to guide the control of the Ae.albopictus vector.Methods:Five field populations of Ae.albopictus were collected from Jinan(JN),Hangzhou(HZ),Baoshan(BS),Yangpu(YP)and Haikou(HK),China in 2017.Insecticide-impregnated papers were prepared with four pyrethroid chemicals,deltamethrin,permethrin,beta-cypermethrin and lambda-cyhalothrin.The susceptibility of Ae.albopictus to pyrethroids was tested by the WHO tube assay.Kdr mutations were identified by PCR and sequencing.Moreover,the correlation analysis between kdr alleles and pyrethroid resistance was performed.Results:All five populations of Ae.albopictus showed resistance to four pyrethroid insecticides.One kdr mutant allele at codon 1532 and three at 1534 were detected with frequency of 5.33%(I1532T),44.20%(F1534S),1.83%(F1534 L)and 0.87%(F1534C),respectively.Both 1532 and 1534 mutation mosquitoes were found in the BS and YP populations.Allele I1532T was negatively correlated with deltamethrin resistance phenotype(OR<1),while F1534S mutation was positively correlated with deltamethrin and permethrin resistance(OR>1).Conclusions:The five field populations of Ae.albopictus adults were all resistant to deltamethrin,permethrin,betacypermethrin and lambda-cyhalothrin.Mutant F1534S was clearly associated with pyrethroid resistance phenotype in Ae.albopictus and this could be developed as a molecular marker to monitor the pyrethroid resistance problem in China.展开更多
The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that in...The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.展开更多
本文首次报道了^(60)Co-γ射线辐射诱导抗药性产生的方法,以2000拉德(rad)的剂量辐射3次,约1年时间培育出尼氏钝绥螨Amblyseius nicholsi Ehara et Lee对拟除虫菊酯农药多虫畏具抗性的两个品系:单抗1(FR1)与双抗(PFR)品系。多虫畏对其...本文首次报道了^(60)Co-γ射线辐射诱导抗药性产生的方法,以2000拉德(rad)的剂量辐射3次,约1年时间培育出尼氏钝绥螨Amblyseius nicholsi Ehara et Lee对拟除虫菊酯农药多虫畏具抗性的两个品系:单抗1(FR1)与双抗(PFR)品系。多虫畏对其致死中浓度LC_(50)由敏感品系的8.22×10^(-5)ppm分别提高到1.3347×10^(-3)和1.4307×10^(-3),抗性水平提高24.16和24.83倍,比直接用农药筛选出的两个品系——单抗1(PR1)与三抗(PDFR)品系的培育时间(27个月)缩短一半以上。FR1,FR2及PFR对常用的几种拟除虫菊酯农药:敌杀死,灭扫利、兴棉宝及来福灵均有一定的交互抗性(3—8倍),其LC_(50)比这些农药田间施用浓度要高3—23倍,为抗性品系的田间利用提供了条件。通过观察辐射的生物学效应再次证实该螨为拟单倍体种(Parahaploid)这一特征。展开更多
基金This work was supported by National Natural Sciences Foundation of China(No.81371848)the Infective Diseases Prevention and Cure Project of China(No.2017ZX10303404–002).
文摘Background:Arboviral disease transmitted by Aedes albopictus such as dengue fever is an important threat to human health.Pyrethroid resistance raises a great challenge for mosquito control.A systematic assessment of Ae.albopictus resistance status in China is urgently needed,and the study of correlation between pyrethroid resistance and knockdown resistance(kdr)mutations would provide information to guide the control of the Ae.albopictus vector.Methods:Five field populations of Ae.albopictus were collected from Jinan(JN),Hangzhou(HZ),Baoshan(BS),Yangpu(YP)and Haikou(HK),China in 2017.Insecticide-impregnated papers were prepared with four pyrethroid chemicals,deltamethrin,permethrin,beta-cypermethrin and lambda-cyhalothrin.The susceptibility of Ae.albopictus to pyrethroids was tested by the WHO tube assay.Kdr mutations were identified by PCR and sequencing.Moreover,the correlation analysis between kdr alleles and pyrethroid resistance was performed.Results:All five populations of Ae.albopictus showed resistance to four pyrethroid insecticides.One kdr mutant allele at codon 1532 and three at 1534 were detected with frequency of 5.33%(I1532T),44.20%(F1534S),1.83%(F1534 L)and 0.87%(F1534C),respectively.Both 1532 and 1534 mutation mosquitoes were found in the BS and YP populations.Allele I1532T was negatively correlated with deltamethrin resistance phenotype(OR<1),while F1534S mutation was positively correlated with deltamethrin and permethrin resistance(OR>1).Conclusions:The five field populations of Ae.albopictus adults were all resistant to deltamethrin,permethrin,betacypermethrin and lambda-cyhalothrin.Mutant F1534S was clearly associated with pyrethroid resistance phenotype in Ae.albopictus and this could be developed as a molecular marker to monitor the pyrethroid resistance problem in China.
文摘The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.
文摘本文首次报道了^(60)Co-γ射线辐射诱导抗药性产生的方法,以2000拉德(rad)的剂量辐射3次,约1年时间培育出尼氏钝绥螨Amblyseius nicholsi Ehara et Lee对拟除虫菊酯农药多虫畏具抗性的两个品系:单抗1(FR1)与双抗(PFR)品系。多虫畏对其致死中浓度LC_(50)由敏感品系的8.22×10^(-5)ppm分别提高到1.3347×10^(-3)和1.4307×10^(-3),抗性水平提高24.16和24.83倍,比直接用农药筛选出的两个品系——单抗1(PR1)与三抗(PDFR)品系的培育时间(27个月)缩短一半以上。FR1,FR2及PFR对常用的几种拟除虫菊酯农药:敌杀死,灭扫利、兴棉宝及来福灵均有一定的交互抗性(3—8倍),其LC_(50)比这些农药田间施用浓度要高3—23倍,为抗性品系的田间利用提供了条件。通过观察辐射的生物学效应再次证实该螨为拟单倍体种(Parahaploid)这一特征。
