Evaluation of a novel mosquito repellent isolated from bacteria

 描述（由申请人提供）：最近在北美爆发的西尼罗河热和基孔肯雅热给美国的公共卫生系统带来了新的挑战。由于缺乏针对这些疾病的疫苗和治疗方案，因此必须采取个人保护措施，防止蚊子传播。N，N-二乙基间甲苯酰胺（DEET）是目前市场上最有效的驱蚊剂。然而，消费者对避蚊胺的接受度下降导致了对新型驱虫剂的研究。偶然地，我们筛选了几个分离的昆虫病原细菌的杀成虫活性，并发现有效的驱蚊活性的提取物中的Xellichabdus innexi。雌性埃及伊蚊死于脱水，而不是接受与细菌提取物混合的糖水。初步数据表明，活性化合物是一种小肽，纯化的肽是水溶性的，并保留驱避活性至少几周。提出了三个具体的目标，以进一步了解分子。目的1：利用核磁共振（NMR）方法对纯化的驱避肽进行结构解析。目的二是鉴定出与黄毛鼠驱避肽产生有关的生物合成基因簇。innexi，这将使搜索类似的基因簇在其他细菌物种以及诱变方法的结构/功能分析。目的3将进一步表征新的驱避化合物。在此，将针对几种关键病媒蚊子物种量化驱避活性的效力和寿命。此外，将针对几种哺乳动物细胞系进行细胞活力测定，以检查驱避肽的毒性特征。这项研究中产生的信息将有助于我们了解一种新的驱蚊剂，并可能最终导致新的产品，以防止蚊子传播媒介。

 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.