Evidence of multiple pyrethroid resistance mechanisms in the malaria vector Anopheles gambiae sensu stricto from Nigeria.
Trans R Soc Trop Med Hyg
; 103(11): 1139-45, 2009 Nov.
Article
en En
| MEDLINE
| ID: mdl-18829056
Pyrethroid insecticide resistance in Anopheles gambiae sensu stricto is a major concern to malaria vector control programmes. Resistance is mainly due to target-site insensitivity arising from a single point mutation, often referred to as knockdown resistance (kdr). Metabolic-based resistance mechanisms have also been implicated in pyrethroid resistance in East Africa and are currently being investigated in West Africa. Here we report the co-occurrence of both resistance mechanisms in a population of An. gambiae s.s. from Nigeria. Bioassay, synergist and biochemical analysis carried out on resistant and susceptible strains of An. gambiae s.s. from the same geographical area revealed >50% of the West African kdr mutation in the resistant mosquitoes but <3% in the susceptible mosquitoes. Resistant mosquitoes synergized using pyperonyl butoxide before permethrin exposure showed a significant increase in mortality compared with the non-synergized. Biochemical assays showed an increased level of monooxygenase but not glutathione-S-transferase or esterase activities in the resistant mosquitoes. Microarray analysis using the An. gambiae detox-chip for expression of detoxifying genes showed five over-expressed genes in the resistant strain when compared with the susceptible one. Two of these, CPLC8 and CPLC#, are cuticular genes not implicated in pyrethroid metabolism in An. gambiae s.s, and could constitute a novel set of candidate genes that warrant further investigation.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Resistencia a los Insecticidas
/
Mutación Puntual
/
Larva
/
Anopheles
Límite:
Animals
País/Región como asunto:
Africa
Idioma:
En
Revista:
Trans R Soc Trop Med Hyg
Año:
2009
Tipo del documento:
Article
País de afiliación:
Nigeria
Pais de publicación:
Reino Unido