Evaluation of a novel mosquito repellent isolated from bacteria

 描述(申请人提供)：最近在北美爆发的西尼罗热和基孔肯雅热给美国的公共卫生系统带来了新的挑战。缺乏针对这些疾病的疫苗和治疗选择，提高了针对蚊子媒介的个人保护的重要性。N，N-二乙基间甲苯胺(DEET)是目前市场上最有效的驱蚊剂。然而，消费者对DEET接受度的下降导致了对新型驱虫剂的研究。偶然的是，我们对几个昆虫病原细菌的成虫活性进行了筛选，发现从致病杆菌中提取的一种提取物具有很强的驱蚊活性。雌性埃及伊蚊死于干燥，而不是接受糖水和细菌提取物的混合。初步数据表明，该活性化合物是一种小肽，纯化的多肽是水溶性的，具有至少几周的驱避活性。为了加深我们对该分子的理解，我们提出了三个具体目标。目的1将使用核磁共振波谱方法来解析纯化的驱避肽的结构。目的2鉴定伊氏X.innexi中参与驱避肽生产的生物合成基因簇，这将使在其他细菌物种中寻找类似的基因簇以及用于结构/功能分析的突变方法成为可能。目标3将进一步表征这种新型的驱避剂化合物。在这里，将量化驱蚊活性对几种关键媒介蚊子的有效性和寿命。此外，还将对几种哺乳动物细胞株进行细胞存活试验，以检查该驱避肽的毒性分布。这项研究产生的信息将有助于我们了解一种新的驱蚊剂类别，并最终可能导致新的产品来保护蚊子媒介。

 DESCRIPTION (provided by applicant): The recent outbreaks of West Nile fever and Chikungunya fever in North America created a new challenge for the public health system in the United States. The lack of vaccines and treatment options for these diseases raises the importance of personal protection against the mosquito vectors. N,N-diethyl-meta-toluamide (DEET) is the most effective mosquito repellent currently on the market. However, decreasing consumer acceptance of DEET has led to a search for new types of repellents. Serendipitously, we screened several isolates of entomopathogenic bacteria for adulticidal activity and found potent mosquito repellent activity in an extract from Xenorhabdus innexi. Female Aedes aegypti died of desiccation rather than accept sugar water mixed with the bacterial extract. Preliminary data indicate that the active compound is a small peptide and the purified peptide is water soluble and retains repellent activity for at least several weeks. Three specific aims are proposed to further our understanding of the molecule. Aim 1 will use nuclear magnetic resonance (NMR) spectroscopy methods to resolve the structure of the purified repellent peptide. Aim 2 will identify the biosynthetic gene cluster involved in the repellent peptide production in X. innexi, which will enable searches for similar gene clusters in other bacterial species as well as mutagenic approaches for structure/function analyses. Aim 3 will further characterize the novel repellent compound. Here, the efficacy and longevity of the repellent activity will be quantified against several key vector mosquito species. In addition, cell viabilit assays will be performed against several mammalian cell lines to examine the toxicity profile of the repellent peptide. The information generated in this study will contribute to our understanding of a new category of mosquito repellents and may ultimately result in new products for protection against mosquito vectors.