Study On Insectcides Resistance And Kdr Gene Distribution Of Aedes Albopictus In China

Aedes albopictus,also known as Asian tiger mosquito,is very invasive and diffused.It originated from southeast Asia,but has been reported in all continents except Antarctica,mainly in tropical,subtropical and temperate regions.It has been distributed in 25 provinces(including autonomous regions and municipalities directly under the central government)in China.Ae.albopictus can transmit dengue fever,dengue hemorrhagic fever,chikungunya fever,zika virus disease,yellow fever and other infectious diseases.Ae.albopictus has a significant impact on human life safety and poses a major public health problem worldwide.Due to the lack of vaccines and effective treatment methods,the use of insecticides has become the preferred method of mosquito control.However,due to the long-term and extensive use of insecticides,mosquitoes have developed different levels of resistance to different insecticides,posing challenges to the prevention and control of vector-borne infectious diseases.Pyrethroid insecticides have become the first choice of insecticides in China in the past 30 years due to their low toxicity,high efficiency and other advantages.The purpose and significance of this study are as follows:at present,the research on the drug resistance of Ae.albopictus is mostly limited to biological detection methods and biochemical detection methods,and the research scope is relatively limited.Few studies can summarize the drug resistance nationwide.The purpose of this study was to collect and normalize the resistance data of resistance monitoring sites nationwide,collect Ae.albopictus samples,detect the distribution of knockdown resistance genes,and conduct population genetic studies of different geographic populations.The current situation of drug resistance in China was comprehensively clarified by combining the bioassay test data with the molecular test results,and the guidance for pesticide use was provided.The following achievements have been made:1.To collect the bioassay data of the resistance ofiAe.albopictus in China and analyze the resistance status of three pyrethroids insecticides.It was found that Ae.albopictus in some provinces of China(such as Guangdong,Yunnan,Guizhou,etc.)developed high levels of resistance to the three pyrethroids insecticides in both adult mosquitoes and larvae.Differences in drug resistance levels in different provinces suggest differences in drug use.2.To detect the mutation of VGSC gene of Ae.albopictus in 21 geographical populations in 9 provinces(municipalities,autonomous regions)of China,and to detect 552 Ae.albopictus samples in total.In these populations,mutations of gene locus 1532 and 1534 were found,among which there were two alleles of wild ATC/I and mutant ACC/T,wild homozygous 1532I/I,wild heterozygous 1532I/T and mutant homozygous 1532T/T.At 1534,there are 6 allelic types of wild-type TTC/F,mutant TCC/S,TCG/S,TTG/L,CTC/L and TGC/C,8 genotypes of wild-type homozygous 1534F/F,wild-type heterozygous 1534F/F,1534F/L,1534F/C,mutant homozygous 1534S/S,1534L/L,1534C/C and mutant heterozygous 1534S/C.3.The mutation rate of VGSC gene 1534 in the 3 populations in Zhejiang province was higher than that in other populations,and there were mutations at 1532 and 1534 in the 6 populations in Nanchang,Jining,Shanghai,Jinghong.The allele types and genotypes of Guangzhou and Haikou were more abundant than other populations.4.Combining with the measured data and the testing results of the molecular in most areas,such as Guangzhou,Jinghong,Guizhou Xingyi,Fuzhou and Quanzhou of Fujian,etc.)the results are consistent,parts(e.g.,Hangzhou,Ningbo,Yiwu,Haikou,etc.)down resistance gene mutation rate is higher,but the low level of resistance measurement results and method for prompt strain diversity of insecticide resistance mechanism,should be further explored.5.Jining and Hangzhou have a higher degree of differentiation compared with most other populations,while Guangzhou has a lower degree of differentiation among various groups.Through this study,it can be found that with the continuous spread of Ae.albopictus in China,its drug resistance is also developing in the distribution range of Ae.albopictus in China.Therefore,it is necessary to evaluate the drug resistance monitoring and prevention and control reform plan based on the biological level and molecular level.