title: Identification of putative kdr mutations in the tropical bed bug, Cimex hemipterus (Hemiptera: Cimicidae).
abstract: BACKGROUND
  Bed bugs [both Cimex hemipterus (F.) and Cimex lectularius L.] are highly resistant to pyrethroids worldwide. An important resistance mechanism known as 'knockdown resistance' (kdr) is caused by genetic point mutations on the voltage-gated sodium channel (VGSC) gene. Previous studies have identified two point mutations (V419L and L925I) on the VGSC gene in C. lectularius that are responsible for kdr-type resistance. However, the kdr mutations in C. hemipterus have not been investigated.
  
  
  RESULTS
  Four novel mutations, L899V (leucine to valine), M918I (methionine to isoleucine), D953G (aspartic acid to glycine) and L1014F (leucine to phenylalanine), were identified in the domain II region of the C. hemipterus VGSC gene. This region has been widely investigated for the study of kdr-type resistance to pyrethroids in other insect pests. The V419L and L925I kdr mutations as previously identified in C. lectularius were not detected in C. hemipterus.
  
  
  CONCLUSIONS
  M918I and L1014F are considered to be probable kdr mutations and may play essential roles in kdr-type resistance to pyrethroids in C. hemipterus. Further studies are under way in the authors' laboratory to determine the non-kdr-type resistance mechanisms in C. hemipterus.
authors.affiliation: Department of Medical Entomology, Institute for Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia.|Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Dang
authors.affiliation: Department of Medical Entomology, Institute for Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia.
authors.forename: Cheryl S
authors.initials: CS
authors.lastname: Toi
authors.affiliation: Department of Medical Entomology, Institute for Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Lilly
authors.affiliation: Urban Entomology Laboratory, Vector Control Research Unit, School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia.
authors.forename: Chow-Yang
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Prior's Loft, Coleford Road, Tidenham, Monmouthshire, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Naylor
authors.affiliation: Department of Medical Sciences, National Institute of Health, Nonthaburi, Thailand.
authors.forename: Apiwat
authors.initials: A
authors.lastname: Tawatsin
authors.affiliation: Department of Medical Sciences, National Institute of Health, Nonthaburi, Thailand.
authors.forename: Usavadee
authors.initials: U
authors.lastname: Thavara
authors.affiliation: Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Wenun
authors.initials: W
authors.lastname: Bu
authors.affiliation: Department of Medical Entomology, Institute for Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Doggett
mesh_terms: D000487:Allethrins / Q000494:pharmacology*; D000818:Animals; D001511:Bedbugs / Q000187:drug effects / Q000235:genetics*; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology*; D017354:Point Mutation; D011722:Pyrethrins / Q000494:pharmacology*; D061566:Voltage-Gated Sodium Channels / Q000235:genetics
chemical_list: D000487:Allethrins; D007306:Insecticides; D011722:Pyrethrins; D061566:Voltage-Gated Sodium Channels
keywords: Cimex; insecticide resistance; knockdown resistance; sodium channel