Institut Pasteur de Madagascar, G4 Malaria Group, Ambatofotsikely, Antananarivo 101, Madagascar.
Ecole Doctorale Génie du Vivant et Modélisation, Université de Mahajanga, Mahajanga 401, Madagascar.
Biomed Res Int. 2018 Oct 8;2018:5806179. doi: 10.1155/2018/5806179. eCollection 2018.
In Madagascar, malaria control relies on the countrywide use of long lasting insecticide treated bed nets (LLINs) and on indoor residual spraying (IRS) in the central highland area as well as a small area on the eastern coast. We tested insecticide resistance mechanisms of from Tsararano, a malaria endemic village in the coastal health district of Marovoay.
Insecticide susceptibility bioassays were done in July 2017 on first-generation (F1) to assess (i) the susceptibility to permethrin (0.05%), deltamethrin (0.05%), DDT (4%), malathion (5%), fenitrothion (1%), and bendiocarb (0.1%); (ii) the effect of preexposure to the piperonyl butoxide (PBO) synergist; and (iii) the enzymatic activities of cytochrome P450, esterases, and glutathione S-transferases (GST).
Our results demonstrated that . was phenotypically resistant to pyrethroids and bendiocarb, with a mortality rate (MR) of 33.6% (95%CI: 24.5-43.7%) and 86% (95%CI: 77.6-92.1%), respectively. In contrast, . were 100% susceptible to DDT and organophosphates (malathion and fenitrothion). Preexposure of . to PBO synergist significantly restored the susceptibility to bendiocarb (MR=100%) and increased the MR in the pyrethroid group, from 96% (95%CI: 90.0-98.9%) to 100% for deltamethrin and permethrin, respectively ( = 43, = 3, ). Enzymatic activities of cytochrome P450 and -esterases were significantly elevated among . compared with the IPM strain (Mann-Whitney = 30; = , respectively). No significant differences of -esterases activities compared to the IPM reference strain were observed (Mann-Whitney ).
In Tsararano, despite the absence of an IRS programme, there is evidence of high levels of insecticide resistance to pyrethroids and bendiocarb in .
马达加斯加的疟疾控制依赖于全国范围内使用长效驱虫蚊帐（LLINs）和在中央高地地区以及东海岸的一个小区域进行室内残留喷洒（IRS）。我们测试了来自马尔沃埃伊沿海卫生区 Tsararano 疟疾流行村的 对杀虫剂的抗药性机制。
2017 年 7 月，对第一代 （F1）进行了杀虫剂敏感性生物测定，以评估（i）对氯菊酯（0.05%）、溴氰菊酯（0.05%）、滴滴涕（4%）、马拉硫磷（5%）、杀螟硫磷（1%）和丁醚脲（0.1%）的敏感性；（ii）预先接触增效剂胡椒基丁醚（PBO）的效果；以及（iii）细胞色素 P450、酯酶和谷胱甘肽 S-转移酶（GST）的酶活性。
我们的结果表明， 对拟除虫菊酯和丁醚脲呈表型抗性，死亡率（MR）分别为 33.6%（95%CI：24.5-43.7%）和 86%（95%CI：77.6-92.1%）。相比之下， 对滴滴涕和有机磷（马拉硫磷和杀螟硫磷）完全敏感。 预先接触 PBO 增效剂可显著恢复对丁醚脲的敏感性（MR=100%），并使拟除虫菊酯组的 MR 从 96%（95%CI：90.0-98.9%）分别增加到 100%（对溴氰菊酯和氯菊酯）（ = 43， = 3， ）。与 IPM 品系相比， 中细胞色素 P450 和 -酯酶的活性显著升高（Mann-Whitney = 30； = ，分别）。与 IPM 参考菌株相比，-酯酶的活性没有显著差异（Mann-Whitney ）。
在 Tsararano，尽管没有 IRS 计划，但 对拟除虫菊酯和丁醚脲具有高水平的杀虫剂抗性。
