title: Status of organophosphate and carbamate resistance in Anopheles gambiae sensu lato from the south and north Benin, West Africa.
abstract: BACKGROUND
  With the rapid spread of pyrethroid resistance in the main malaria vectors from Benin and the various resistance mechanisms involved (metabolic resistance and knock-down resistance (kdr), it is important to foresee effective resistance management strategies. Thus, the knowledge of the insensitive acetylcholinesterase (ace-1R) effects on phenotypes of An. gambiae will help us to strengthen basic and operational research on the development of strategies that will use organophosphates or carbamates as alternatives against pyrethroids-resistant malaria vectors in the field.
  
  
  METHODS
  Larvae and pupae of Anopheles gambiae s.l. mosquitoes were collected from the breeding sites in Ouemé , Atacora, and Alibori departments. CDC susceptibility tests were conducted on unfed female mosquitoes aged 2-5 days old. CDC bioassays were performed with stock solutions of fenitrothion (50 μg per bottle) and bendiocarb (12.5 μg per bottle). PCR techniques were used to detect species and Ace-1 mutations.
  
  
  RESULTS
  Anopheles gambiae Seme and Kandi populations were susceptible to fenitrothion whereas Anopheles gambiae Tanguieta and Malanville populations were resistant. An. gambiae populations from Seme, Kandi and Malanville were fully susceptible to bendiocarb whereas those from Tanguieta have developed a strong resistance to the same insecticide. A slight decrease in mortality rate was observed with 97.91% in populations of mosquitoes from Malanville. PCR revealed that all specimens tested were Anopheles gambiae s.s..
  
  
  CONCLUSIONS
  This study demonstrated the need to monitor organophosphate (OPs) and Carbamates resistance among populations of the An. gambiae s.l. in Benin, to determine its spread and anticipate vector control failure where these insecticides are used. However, further studies are needed to understand the current distribution of the Ace-1R mutation in other localities in the south-north transect Benin.
authors: Nazaire
authors: N
authors: Aïzoun
authors: Rock
authors: R
authors: Aïkpon
authors: Virgile
authors: V
authors: Gnanguenon
authors: Olivier
authors: O
authors: Oussou
authors: Fiacre
authors: F
authors: Agossa
authors: Gil
authors: G
authors: Padonou
authors: Martin
authors: M
authors: Akogbéto
mesh_terms: D000818:Animals; D000852:Anopheles / Q000145:classification / Q000187:drug effects*; D001541:Benin; D005260:Female; D005278:Fenitrothion / Q000494:pharmacology*; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D048448:Phenylcarbamates / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D048448:Phenylcarbamates; C007725:bendiocarb; D005278:Fenitrothion