Yadouleton Anges William M, Asidi Alex, Djouaka Rousseau F, Braïma James, Agossou Christian D, Akogbeto Martin C
Centre de Recherche Entomologique de Cotonou, Benin.
Malar J. 2009 May 14;8:103. doi: 10.1186/1475-2875-8-103.
A fast development of urban agriculture has recently taken place in many areas in the Republic of Benin. This study aims to assess the rapid expansion of urban agriculture especially, its contribution to the emergence of insecticide resistance in populations of Anopheles gambiae.
The protocol was based on the collection of sociological data by interviewing vegetable farmers regarding various agricultural practices and the types of pesticides used. Bioassay tests were performed to assess the susceptibility of malaria vectors to various agricultural insecticides and biochemical analysis were done to characterize molecular status of population of An. gambiae.
This research showed that:(1) The rapid development of urban agriculture is related to unemployment observed in cities, rural exodus and the search for a balanced diet by urban populations;(2) Urban agriculture increases the farmers' household income and their living standard;(3) At a molecular level, PCR revealed the presence of three sub-species of An. gambiae (An. gambiae s.s., Anopheles melas and Anopheles arabiensis) and two molecular forms (M and S). The kdr west mutation recorded in samples from the three sites and more specifically on the M forms seems to be one of the major resistance mechanisms found in An. gambiae from agricultural areas. Insecticide susceptibility tests conducted during this research revealed a clear pattern of resistance to permethrin (76% mortality rate at Parakou; 23.5% at Porto-Novo and 17% at Cotonou).
This study confirmed an increase activity of the vegetable farming in urban areas of Benin. This has led to the use of insecticide in an improper manner to control vegetable pests, thus exerting a huge selection pressure on mosquito larval population, which resulted to the emergence of insecticide resistance in malaria vectors.
近年来，贝宁共和国许多地区的都市农业发展迅速。本研究旨在评估都市农业的快速扩张，尤其是其对冈比亚按蚊种群中杀虫剂抗性出现的影响。
该方案基于通过采访菜农收集社会学数据，了解各种农业实践和所使用的农药类型。进行生物测定试验以评估疟蚊媒介对各种农用杀虫剂的敏感性，并进行生化分析以表征冈比亚按蚊种群的分子状态。
本研究表明：（1）都市农业的快速发展与城市中观察到的失业、农村人口外流以及城市居民对均衡饮食的追求有关；（2）都市农业增加了农民家庭收入和生活水平；（3）在分子水平上，聚合酶链反应显示存在三种冈比亚按蚊亚种（冈比亚按蚊指名亚种、梅拉斯按蚊和阿拉伯按蚊）和两种分子型（M型和S型）。在三个地点的样本中记录到的kdr西突变，更具体地说是在M型上，似乎是在农业地区的冈比亚按蚊中发现的主要抗性机制之一。本研究期间进行的杀虫剂敏感性试验显示出对氯菊酯的明显抗性模式（帕拉库的死亡率为76%；波多诺伏为23.5%；科托努为17%）。
本研究证实了贝宁城市地区蔬菜种植活动的增加。这导致了以不当方式使用杀虫剂来控制蔬菜害虫，从而对蚊虫幼虫种群施加了巨大的选择压力，导致疟蚊媒介中出现杀虫剂抗性。
