title: Relationship between insecticide resistance and kdr mutations in the dengue vector Aedes aegypti in Southern China.
abstract: BACKGROUND
  Aedes aegypti is an important vector for dengue virus and thus has been targeted with pyrethroid insecticides in many areas of the world. As such, resistance has been detected to several of these insecticides, including in China, but the mechanisms of the resistance are not well understood in this country.
  
  
  METHODS
  Using the World Health Organization larval mosquito bioassay, five field populations of Aedes aegypti from Southern China were characterized for their resistance to cypermethrin and cyhalothrin. RNA extraction with PCR amplification, cloning and sequencing of the sodium channel gene was followed by comparisons of susceptible and wild mosquito strains Additionally, genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the sodium channel genes to detect S989P, V1016G and F1534C mutations and allow for correlation analysis of resistance expression for the different mutations.
  
  
  RESULTS
  All wild strains expressed resistance to cypermethrin and cyhalothrin and the resistance expression between the two insecticides was highly correlated suggesting cross-resistance between these two pyrethroids. The AS-PCR technique effectively distinguished individual genotypes for all three mutations. Among the five wild strains tested, two strains carried all three mutations. Although the S989P and V1016G mutations were positively correlated to resistance expression of both pyrethroids, the F1534C mutation was negatively correlated.
  
  
  CONCLUSIONS
  Our methodology proved highly reliable and will aid future detection of kdr mutations. The three sodium channel mutations were common in the Ae. aegypti strains sampled from Southern China. The V1016G mutation appears to be the most important kdr mutation in Ae. aegypti strains in Southern China.
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. vectorlcx@126.com.
authors.forename: Chun-Xiao
authors.initials: CX
authors.lastname: Li
authors.affiliation: Entomology & Nematology Department, University of Florida, Gainesville, FL, 32611, USA. pkaufman@ufl.edu.
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Kaufman
authors.affiliation: Anastasia Mosquito Control District, 500 Old Beach Road, St. Augustine, FL, USA. xueamcd@gmail.com.
authors.forename: Rui-De
authors.initials: RD
authors.lastname: Xue
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. zhaomhmosquito@126.com.
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. wanggang_3314@163.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. tizi401@126.com.
authors.forename: Ting
authors.initials: T
authors.lastname: Yan
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. guoxx99@163.com.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Guo
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. zymmosquito@126.com.
authors.forename: Ying-Mei
authors.initials: YM
authors.lastname: Zhang
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. dongyd99@sina.com.
authors.forename: Yan-De
authors.initials: YD
authors.lastname: Dong
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. xingdan93@163.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Xing
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. 453149452@qq.com.
authors.forename: Heng-Duan
authors.initials: HD
authors.lastname: Zhang
authors.affiliation: Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, China. tongyanzhao@126.com.
authors.forename: Tong-Yan
authors.initials: TY
authors.lastname: Zhao
mesh_terms: D000330:Aedes / Q000187:drug effects / Q000235:genetics* / Q000821:virology; D019943:Amino Acid Substitution; D000818:Animals; D002681:China; D003715:Dengue / Q000635:transmission / Q000821:virology; D005838:Genotype; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007303:Insect Vectors / Q000187:drug effects / Q000235:genetics* / Q000821:virology; D007305:Insecticide Resistance; D020125:Mutation, Missense; D009570:Nitriles / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology; D015222:Sodium Channels / Q000235:genetics* / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D009570:Nitriles; D011722:Pyrethrins; D015222:Sodium Channels; C017160:cypermethrin; C037304:cyhalothrin