沙蝇是对公众健康非常重要的媒介,因为它们构成了一组食血昆虫,负责人畜共患疾病如内脏利什曼病的病原体传播。面对这些疾病的扩展,需要有效的控制策略,这取决于对沙蝇生态流行病学的理解。在这方面,MALDI-TOF质谱已用于细菌,通过肽/蛋白质谱进行真菌和酵母检测研究。然而,对与媒介生态学相关的生物因素的干扰知之甚少,如血粉偏好,甚至沙蝇年龄对肽/蛋白质谱的影响。因此,本研究旨在评估沙蝇Lutzomialongialpis的肽/蛋白质谱的差异,通过MALDI-TOF,由于沙蝇的年龄,性别,血餐来源和婴儿利什曼原虫感染。进行样品制备,去除头部和最后一个腹部段,保持胸部,它的阑尾和腹部的其余部分。使用每池5个样本来获得肽/蛋白质提取物,将其1μL溶液沉积在干燥的1μLMALDI基质上。使用主坐标分析和指示物种分析对特征光谱进行分析,以区分按性别划分的沙蝇肽/蛋白质谱的差异,年龄,血餐来源和婴儿乳球菌感染。结果表明,评估的变量产生不同的肽/蛋白质谱,通过识别特定的诊断离子来证明。研究发现,在野外研究中使用MALDI-TOF分析沙蝇物种鉴定和生态流行病学应用时,应考虑生物因素的干扰。根据我们的结果,我们认为,有可能在野生沙蝇的集合中识别感染的标本和血粉来源,用于测量传染性并了解矢量传播链的动力学。我们的结果可能对流行病学研究有用,这些研究着眼于沙蝇和利什曼病的生态学,以及提高人们对沙蝇物种鉴定中生物学特性对肽/蛋白质谱的影响的认识。
Sand flies are vectors of great public health importance, since they constitute a group of hematophagous insects responsible for etiological agents transmission of zoonotic diseases such a visceral
leishmaniasis. In face of the expansion of these diseases, efficient control strategies are needed which depend on comprehending the sand fly eco-epidemiology. In this regard, MALDI-TOF mass spectrometry has been used for bacteria, fungi and yeast detection studies through peptide/protein profiles. However, little is known about interference of biological factors associated with vector ecology, such as blood meal preferences and even sand fly age on the peptide/protein profiles. Thus, the present study aimed to evaluate the differences in peptide/protein profiles of the sand fly Lutzomyia longipalpis, by means of MALDI-TOF, due to the sand fly\'s age, sex, blood meal source and Leishmania infantum infection. Sample preparation was made removing both head and last abdomen segments keeping the thorax, its appendices and the rest of the abdomen. Five specimens per pool were used to obtain peptide/protein extract of which 1 μL solution was deposited over 1 μL MALDI matrix dried. Characteristic spectra were analyzed using principal coordinate analysis as well as indicator species analysis to discriminate differences in sand flies\'s peptide/protein profile by sex, age, blood meal source and L. infantum infection. The results show that the evaluated variables produced distinct peptide/protein profiles, demonstrated by the identification of specific diagnostic ions. It was found that the interference of biological factors should be taken into account when using the MALDI-TOF analysis of sand fly species identification and eco-epidemiological applications in field studies. Based on our results, we believe that it is possible to identify infected specimens and the source of blood meal in a collection of wild sand flies, serving to measure infectivity and understand the dynamics of the vector\'s transmission chain. Our results may be useful for epidemiological studies that look at the ecology of sand flies and
leishmaniasis, as well as for raising awareness of biological characteristics\' impact on peptide/protein profiles in sand fly species identification.