title: Investigation of mechanisms of bendiocarb resistance in Anopheles gambiae populations from the city of Yaoundé, Cameroon.
abstract: Resistance to the carbamate insecticide bendiocarb is emerging in Anopheles gambiae populations from the city of Yaoundé in Cameroon. However, the molecular basis of this resistance remains uncharacterized. The present study objective is to investigate mechanisms promoting resistance to bendiocarb in An. gambiae populations from Yaoundé.
  
  
  
  The level of susceptibility of An. gambiae s.l. to bendiocarb 0.1 % was assessed from 2010 to 2013 using bioassays. Mosquitoes resistant to bendiocarb, unexposed and susceptible mosquitoes were screened for the presence of the Ace-1(R) mutation using TaqMan assays. Microarray analyses were performed to assess the pattern of genes differentially expressed between resistant, unexposed and susceptible.
  
  
  
  Bendiocarb resistance was more prevalent in mosquitoes originating from cultivated sites compared to those from polluted and unpolluted sites. Both An. gambiae and Anopheles coluzzii were found to display resistance to bendiocarb. No G119S mutation was detected suggesting that resistance was mainly metabolic. Microarray analysis revealed the over-expression of several cytochrome P450 s genes including cyp6z3, cyp6z1, cyp12f2, cyp6m3 and cyp6p4. Gene ontology (GO) enrichment analysis supported the detoxification role of cytochrome P450 s with several GO terms associated with P450 activity significantly enriched in resistant samples. Other detoxification genes included UDP-glucosyl transferases, glutathione-S transferases and ABC transporters.
  
  
  
  The study highlights the probable implication of metabolic mechanisms in bendiocarb resistance in An. gambiae populations from Yaoundé and stresses the need for further studies leading to functional validation of detoxification genes involved in this resistance.
authors.affiliation: Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon. antonio_nk@yahoo.fr.|Vector Group Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK. antonio_nk@yahoo.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Antonio-Nkondjio
authors.affiliation: Vector Group Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Poupardin
authors.affiliation: Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.|Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon.
authors.forename: Billy Fossog
authors.initials: BF
authors.lastname: Tene
authors.affiliation: Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.|Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon.
authors.forename: Edmond
authors.initials: E
authors.lastname: Kopya
authors.affiliation: Institut de Recherche pour le Développement (IRD), UR 016, 911, Avenue Agropolis, P.O. Box 64501, 34394, Montpellier Cedex 5, France.
authors.forename: Carlo
authors.initials: C
authors.lastname: Costantini
authors.affiliation: Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.
authors.forename: Parfait
authors.initials: P
authors.lastname: Awono-Ambene
authors.affiliation: Vector Group Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Wondji
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects*; D001681:Biological Assay; D002163:Cameroon; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D008658:Inactivation, Metabolic; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D046228:Microarray Analysis; D048448:Phenylcarbamates / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D048448:Phenylcarbamates; D003577:Cytochrome P-450 Enzyme System; C007725:bendiocarb
keywords: Anopheles gambiae; Bendiocarb resistance; Cameroon; P450 monooxygenase; Yaoundé; metabolic resistance