Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Más filtros

Banco de datos
País como asunto
Tipo del documento
Publication year range
1.
Parasit Vectors ; 13(1): 407, 2020 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-32778147

RESUMEN

BACKGROUND: Drastic increases of dengue fever (DF) over the past few years have prompted studies on the development of resistance to insecticides in the mosquito vector, Aedes aegypti (Linnaeus). In Sri Lanka control of the vector population is essentially achieved using larvicides (temephos) and adulticides (principally pyrethroids). The present study investigates resistance to commonly used insecticides and underlying mechanisms of Ae. aegypti in selected sites in Sri Lanka. METHODS: In this study, susceptibility to three commonly used adulticides (malathion, permethrin and deltamethrin) and the larvicide temephos were tested for Ae. aegypti sampled from five localities in Sri Lanka using WHO dose diagnostics tests. In addition, we performed dose-response tests for permethrin to determine lethal concentrations (LCs) with CDC bottle bioassays. An assessment of the activity of metabolic detoxifying enzymes (multifunction oxidases (MFOs), glutathione S-transferases (GSTs) and esterases) and determination of frequency of the kdr mutations (F1534C, V1016G and S989P) were also carried out to ascertain the associated resistance mechanisms. Kdr genotype frequencies were compared with samples collected from the same sites in 2015 to determine the change of allele frequencies over the years. RESULTS: The present study revealed resistance in all Ae. aegypti populations studied, with low mortality percentages for both permethrin (10-89%) and deltamethrin (40-92%). Dose response tests revealed highest resistance ratios (RR) for permethrin and temephos from Colombo district whereas Puttalum district exhibited the lowest. High frequencies of the 1534C allele (0.052-0.802) were found in the study sites in 2017. Comparison with samples collected in 2015 revealed a substantial increase in this allele. The activity of MFOs and p-nitro phenyl-acetate esterase was significantly greater in most Sri Lankan populations in comparison to that of the New Orleans (NO) susceptible strain. In contrast, the activity of α-esterase and ß-esterase was similar or lower than that in the NO strain. CONCLUSIONS: Aedes aegypti from Sri Lanka is resistant to pyrethroid insecticides showing rapid selection for kdr mutations and varying metabolic mechanisms. Continued monitoring of vector populations is crucial to mitigate the development of resistance to commonly used insecticides and in turn, controlling the vector population.


Asunto(s)
Aedes/efectos de los fármacos , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Aedes/genética , Aedes/metabolismo , Animales , Dengue/prevención & control , Dengue/transmisión , Vectores de Enfermedades , Esterasas/efectos de los fármacos , Esterasas/metabolismo , Genes de Insecto , Glutatión Transferasa/efectos de los fármacos , Glutatión Transferasa/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Insecticidas/metabolismo , Larva/efectos de los fármacos , Larva/genética , Larva/metabolismo , Control de Mosquitos , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/genética , Mosquitos Vectores/metabolismo , Oxidorreductasas/efectos de los fármacos , Oxidorreductasas/metabolismo , Sri Lanka/epidemiología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda