Dabiré K R, Diabaté A, Agostinho F, Alves F, Manga L, Faye O, Baldet T
Laboratoire de parasitologie et d'entomologie médicale, IRSS/Centre Muraz BP 390 Bobo-Dioulasso, Burkina Faso.
Bull Soc Pathol Exot. 2008 Apr;101(2):119-23.
An entomological survey conducted in 2002 in Guinea Bissau aimed i) to study the distribution of the members of Anopheles gambiae Giles complex (Diptera: Culicidae) throughout four ecological areas extended from mangrove to savannah ii) to evaluate the insecticide susceptibility status of these malaria vectors exposed to permethrin 0.75% and DDT4%, and finally iii) to investigate the occurrence and the spread of the Leu-Phe knock down resistance (kdr) gene associated with pyrethroid and DDT resistance within these vector populations. Adult female mosquitoes issued from indoor morning collections were tested using WHO procedures, test kits and impregnated papers to assess their insecticide susceptibility status. Tested specimens were identified by PCR assays and characterized for the kdr gene. Malaria vectors were mainly dominated elsewhere by An. gambiae s.s. (both S and M molecular forms) living in sympatry with low proportion of An. melas in the littoral. An. gambiae s.s. tested populations were fully susceptible both to permethrin 0.75% and to DDT 4% irrespective to their location and ecotypes. The Leu-Phe kdr mutation was detected at low frequency only in two sites respectively urban (Bissau) and Guinea-savannah (Gabu) areas. It occurred only in the S molecular form in Gabu (at the frequency of 0.14) and both in the S and M molecular forms in Bissau at the frequency of 0.06 and 0.02 respectively. These results suggested that the populations of An. gambiae s.s., the most frequent malaria vector in Guinea Bissau, still remain cross-susceptible to pyrethroids and DDT This susceptibility status and the frequency of resistance mechanism such as the kdr mutation must be monitored in the future particularly in the urban and savannah areas with continuous and intensive use of insecticides.
2002年在几内亚比绍进行了一项昆虫学调查，目的如下：i）研究冈比亚按蚊吉尔斯复合体（双翅目：蚊科）成员在从红树林到稀树草原的四个生态区域的分布情况；ii）评估这些疟疾媒介对0.75%氯菊酯和4%滴滴涕的杀虫剂敏感性状况；最后iii）调查这些媒介种群中与拟除虫菊酯和滴滴涕抗性相关的亮氨酸-苯丙氨酸击倒抗性（kdr）基因的发生和传播情况。使用世卫组织的程序、测试试剂盒和浸渍纸对室内清晨采集的成年雌性蚊子进行测试，以评估它们的杀虫剂敏感性状况。通过聚合酶链反应（PCR）分析鉴定测试样本，并对kdr基因进行特征分析。在其他地方，疟疾媒介主要由冈比亚按蚊指名亚种（S和M两种分子型）主导，它们与沿海地区少量的梅拉斯按蚊共存。无论其位置和生态型如何，冈比亚按蚊指名亚种测试种群对0.75%氯菊酯和4%滴滴涕均完全敏感。仅在城市（比绍）和几内亚稀树草原（加布）地区的两个地点分别以低频率检测到亮氨酸-苯丙氨酸kdr突变。该突变仅在加布地区的S分子型中出现（频率为0.14），在比绍地区的S和M分子型中均有出现，频率分别为0.06和0.02。这些结果表明，冈比亚按蚊指名亚种作为几内亚比绍最常见的疟疾媒介种群，对拟除虫菊酯和滴滴涕仍具有交叉敏感性。这种敏感性状况以及诸如kdr突变等抗性机制的频率在未来必须进行监测，特别是在持续大量使用杀虫剂的城市和稀树草原地区。
