Distribution of a Knockdown Resistance Mutation (L1014S) in Anopheles gambiae s.s. and Anopheles arabiensis in Western and Southern Kenya
Distribution of a Knockdown Resistance Mutation (L1014S) in Anopheles gambiae s.s. and Anopheles arabiensis in Western and Southern Kenya
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DOI：
10.1371/journal.pone.0024323
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发表时间：
2011-09-09
期刊：
影响因子：
3.7
通讯作者：
Takagi, Masahiro
中科院分区：
文献类型：
--
作者：
Kawada, Hitoshi;Futami, Kyoko;Takagi, Masahiro
在肯尼亚，通过各种方案向孕妇和5岁以下儿童分发经杀虫剂处理的蚊帐，大大减少了疟疾死亡人数。世界卫生组织推荐的所有蚊帐杀虫剂都是拟除虫菊酯，病媒蚊子对这些杀虫剂的抗药性是有效疟疾控制计划的主要障碍之一。冈比亚按蚊和阿拉伯按蚊是广泛分布于肯尼亚的主要疟疾媒介。电压门控钠通道中的两个点突变（L1014 F和L1014 S）与An对DDT和拟除虫菊酯的敲低抗性（kdr）相关。冈比亚有限公司虽然相同的点突变已被报道是罕见的在An。arabiensis，一些代谢抗性的证据已在该物种中报道。为了确定点突变L1014 S在An.冈比亚有限公司和一个.在肯尼亚南部和西部，我们收集了幼虫，并通过DNA测序筛选突变。我们发现高等位基因和纯合子频率的L1014 S突变在AN。冈比亚有限公司L1014 S突变也广泛分布于An. arabiensis的等位基因频率低于An.冈比亚有限公司在两个物种中发现相同的内含子序列（长度：57个碱基），表明突变是通过杂交渐渗。L1014 S等位基因频率在西部地区的两个物种中较高，表明长效驱虫蚊帐（LLITN）/ITN对An施加了强大的选择压力。冈比亚有限公司和一个.这些地区的阿拉伯人。L1014 S突变对拟除虫菊酯抗性的贡献。可以忽略不计。然而，纯合子频率可能会增加持续的选择压力，由于扩大LLITN的覆盖范围在未来。
In Kenya, insecticide-treated mosquito nets (ITNs) distributed to pregnant women and children under 5 years old through various programs have resulted in a significant reduction in malaria deaths. All of the World Health Organization-recommended insecticides for mosquito nets are pyrethroids, and vector mosquito resistance to these insecticides is one of the major obstacles to an effective malaria control program. Anopheles gambiae s.s. and Anopheles arabiensis are major malaria vectors that are widely distributed in Kenya. Two point mutations in the voltage-gated sodium channel (L1014F and L1014S) are associated with knockdown resistance (kdr) to DDT and pyrethroids in An. gambiae s.s. While the same point mutations have been reported to be rare in An. arabiensis, some evidence of metabolic resistance has been reported in this species. In order to determine the distribution of the point mutation L1014S in An. gambiae s.s. and An. arabiensis in southern and western Kenya, we collected larvae and screened for the mutation by DNA sequencing. We found high allelic and homozygous frequencies of the L1014S mutation in An. gambiae s.s. The L1014S mutation was also widely distributed in An. arabiensis, although the allelic frequency was lower than in An. gambiae s.s. The same intron sequence (length: 57 base) found in both species indicated that the mutation was introgressed by hybridization. The allelic frequency of L1014S was higher in both species in western regions, demonstrating the strong selection pressure imposed by long-lasting insecticide-treated nets (LLITN)/ITN on the An. gambiae s.s. and An. arabiensis populations in those areas. The present contribution of the L1014S mutation to pyrethroid resistance in An. arabiensis may be negligible. However, the homozygous frequency could increase with continuing selection pressure due to expanded LLITN coverage in the future.