title: First report on co-occurrence knockdown resistance mutations and susceptibility to beta-cypermethrin in Anopheles sinensis from Jiangsu Province, China.
abstract: The increasing prevalence of insecticide resistance in Anopheles sinensis, a major vector of malaria in Jiangsu province in eastern China, threatens to compromise the successful use of insecticides in malaria control strategies. It is therefore vital to understand the insecticide resistance status of An. sinensis in the region. This study examined the nucleotide diversity of the para-sodium channel and knockdown resistance (kdr) in five field populations of adult An. sinensis mosquitoes collected in Jiangsu province, identifying the L1014F and L1014C substitutions for the first time. Competitive polymerase chain reaction (PCR) amplification of specific allele (cPASA) and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) for resistance diagnosis were developed and validated. Comparing the results with direct sequencing revealed that the PCR-RFLP method was more sensitive and specific whereas the cPASA method was more convenient and suitable. The significant positive correlation between kdr allele frequency and bioassay-based resistance phenotype demonstrates that the frequency of L1014F and L1014C substitutions in the kdr gene provides a useful molecular marker for monitoring beta-cypermethrin resistance in natural populations of An. sinensis. Our results point to the L1014F substitution as the key mutation associated with beta-cypermethrin resistance. The high resistance and mutation frequency detected in the five populations also suggest cross-resistance with other pyrethroids may occur in An. sinensis, highlighting the need for further surveys to map insecticide resistance in China and the adoption of a rational management of insecticide application for resistance management and mosquito vector control.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People's Republic of China.
authors.forename: Wei-Long
authors.initials: WL
authors.lastname: Tan
authors.forename: Zhong-Ming
authors.initials: ZM
authors.lastname: Wang
authors.forename: Chun-Xiao
authors.initials: CX
authors.lastname: Li
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Chu
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Yan-De
authors.initials: YD
authors.lastname: Dong
authors.forename: Zhong-can
authors.initials: ZC
authors.lastname: Wang
authors.forename: Dong-Ya
authors.initials: DY
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Da-Peng
authors.initials: DP
authors.lastname: Liu
authors.forename: Nannan
authors.initials: N
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Sun
authors.forename: Tongyan
authors.initials: T
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D000852:Anopheles / Q000145:classification / Q000235:genetics*; D001483:Base Sequence; D002681:China; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D019476:Insect Proteins / Q000235:genetics*; D007303:Insect Vectors / Q000187:drug effects / Q000235:genetics; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology; D008288:Malaria / Q000469:parasitology / Q000517:prevention & control; D008969:Molecular Sequence Data; D009032:Mosquito Control / Q000379:methods; D009154:Mutation; D059645:Mutation Rate; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011722:Pyrethrins / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015222:Sodium Channels / Q000235:genetics*; D013045:Species Specificity
chemical_list: D019476:Insect Proteins; D007306:Insecticides; D011722:Pyrethrins; D015222:Sodium Channels; C017160:cypermethrin