Evaluating preservation methods for identifying Anopheles gambiae s.s. and Anopheles arabiensis complex mosquitoes species using near infra-red spectroscopy
Evaluating preservation methods for identifying Anopheles gambiae s.s. and Anopheles arabiensis complex mosquitoes species using near infra-red spectroscopy
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DOI：
10.1186/s13071-015-0661-4
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发表时间：
2015-01-27
影响因子：
3.2
通讯作者：
Maia, Marta Ferreira
中科院分区：
文献类型：
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作者：
Mayagaya, Valeriana Simon;Ntamatungiro, Alex John;Maia, Marta Ferreira
背景资料：近红外光谱法已成功地用于冈比亚按蚊复合体的新鲜和RNAlater（R）保存的成员，以确定同胞物种和年龄。除了使用RNAlater（R）之外，没有测试过其他保存方法来保存蚊子，以便使用NIRS进行物种鉴定。然而，RNAlater（R）并不是最实用的田间防腐剂，因为它价格昂贵，需要基本的实验室储存条件，而且在撒哈拉以南非洲地区并不普遍。本研究的目的是测试几种更便宜，更友好的现场保存方法，以确定兄弟物种的An。方法：在这项研究中，我们描述了使用近红外光谱技术来鉴定保存的冈比亚按蚊的兄弟种。冈比亚公司和一个.阿拉伯的。将每种蚊子置于样品管中，并使用以下保存方法之一进行保存：（i）在4 ℃下冷藏，（ii）在-20 ℃下冷冻，（iii）在硅胶干燥剂上干燥，（iv）在室温下浸没在RNAlater中，（v）在4 ℃下浸没在RNAlater中，和（vi）在-20 ℃下浸入RNAlater中。蚊子被保存1，4，10，32或50周前，他们被scanned.Results：存储在4摄氏度是唯一的保存方法，长达32周，没有导致显着低于预测值比那些从新鲜的昆虫。然而，50周后，冷藏样品没有给出有意义的结果。在保存50周时，硅胶干燥法保存效果最好，偏最小二乘回归交叉验证率> 80%。结论：近红外光谱技术可用于干冈比亚按蚊种属鉴定。和阿拉伯按蚊长达50周的储存，准确率超过80%。
Background: Near-infrared spectroscopy (NIRS) has been successfully used on fresh and RNAlater (R)-preserved members of the Anopheles gambiae complex to identify sibling species and age. No preservation methods other than using RNAlater (R) have been tested to preserve mosquitoes for species identification using NIRS. However, RNAlater (R) is not the most practical preservative for field settings because it is expensive, requires basic laboratory conditions for storage and is not widely available in sub-Saharan Africa. The aim of this study was to test several cheaper and more field-friendly preservation methods for identifying sibling species of the An. gambiae complex using NIRS.Methods: In this study we describe the use of NIRS to identify sibling species of preserved An. gambiae s.s. and An. arabiensis. Mosquitoes of each species were placed in sample tubes and preserved using one of the following preservation methods: (i) refrigeration at 4 degrees C, (ii) freezing at -20 degrees C, (iii) drying over a silica-gel desiccant, (iv) submersion in RNAlater (R) at room temperature, (v) submersion in RNAlater (R) at 4 degrees C, and (vi) submersion in RNAlater (R) at -20 degrees C. Mosquitoes were preserved for 1, 4, 10, 32 or 50 weeks before they were scanned.Results: Storage at 4 degrees C was the only preservation method that, up to 32 weeks, did not result in significantly lower predicted values than those obtained from fresh insects. After 50 weeks, however, refrigerated samples did not give meaningful results. When storing for 50 weeks, desiccating samples over silica gel was the best preservation method, with a partial least squares regression cross-validation of >80%. Predictive data values were analyzed using a generalized linear model.Conclusion: NIRS can be used to identify species of desiccated Anopheles gambiae s.s. and Anopheles arabiensis for up to 50 weeks of storage with more than 80% accuracy.