Aix Marseille University, IRD, SSA, AP-HM, VITROME, Marseille, France.
Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques (CRAPC), Zone Industrielle, BP 384 Bou-Ismail, Tipaza, Algérie.
Parasit Vectors. 2020 Apr 1;13(1):161. doi: 10.1186/s13071-020-04029-x.
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) biotyping is an innovative strategy, applied successfully for the identification of numerous arthropod families including mosquitoes. The effective mosquito identification using this emerging tool was demonstrated possible at different steps of their life-cycle, including eggs, immature and adult stages. Unfortunately, for species identification by MS, the euthanasia of the mosquito specimen is required.
To avoid mosquito euthanasia, the present study assessed whether aedine mosquitoes could be identified by MALDI-TOF MS biotyping, using their respective exuviae. In this way, exuviae from the fourth-instar and pupal stages of Aedes albopictus and Aedes aegypti were submitted to MALDI-TOF MS analysis.
Reproducible and specific MS spectra according to aedine species and stage of exuviae were observed which were objectified by cluster analyses, composite correlation index (CCI) tool and principal components analysis (PCA). The query of our reference MS spectra database (DB) upgraded with MS spectra of exuviae from fourth-instar larvae and pupae of both Aedes species revealed that 100% of the samples were correctly classified at the species and stage levels. Among them, 93.8% (135/144) of the MS profiles reached the threshold log score value (LSV > 1.8) for reliable identification.
The extension of reference MS spectra DB to exuviae from fourth-instar and pupal stages made now possible the identification of mosquitoes throughout their life-cycle at aquatic and aerial stages. The exuviae presenting the advantage to avoid specimen euthanasia, allowing to perform complementary analysis on alive mosquitoes.
基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）生物分型是一种创新策略，已成功应用于包括蚊子在内的许多节肢动物科目的鉴定。这种新兴工具在蚊子生命周期的不同阶段，包括卵、幼虫和成虫阶段，都被证明可以有效地进行识别。不幸的是，为了通过 MS 进行物种鉴定，需要对蚊子标本进行安乐死。
为了避免蚊子安乐死，本研究评估了是否可以使用拟蚊科的蜕壳来通过 MALDI-TOF MS 生物分型进行鉴定。为此，将白纹伊蚊和埃及伊蚊的第四龄幼虫和蛹蜕壳提交给 MALDI-TOF MS 分析。
观察到根据拟蚊科物种和蜕壳阶段的可重复和特异性 MS 谱，通过聚类分析、综合相关指数（CCI）工具和主成分分析（PCA）进行了客观化。我们的参考 MS 图谱数据库（DB）的查询得到了升级，其中包含了来自两种白纹伊蚊和埃及伊蚊第四龄幼虫和蛹的蜕壳 MS 图谱，结果表明，在物种和阶段水平上，100%的样本都得到了正确的分类。其中，93.8%（135/144）的 MS 图谱达到了可靠鉴定的阈值对数得分值（LSV>1.8）。
将参考 MS 图谱数据库扩展到第四龄幼虫和蛹的蜕壳，现在可以在水生和空气生阶段通过整个生命周期来识别蚊子。蜕壳具有避免标本安乐死的优势，允许对活体蚊子进行补充分析。
