Exploring the endophytic parvome for the discovery of novel biologically active molecular scaffolds

越来越多对目前使用的抗生素具有耐药性的微生物菌株的出现是对人类健康的重大威胁，因为已经观察到对目前临床使用的所有主要类别的抗生素具有耐药性。越来越多的泛耐药病原体被发现，目前的预测表明，抗菌剂的大范围失效迫在眉睫。新的天然产物的发现为前所未有的分子支架和独特的分子结构提供了前所未有的途径，这些分子结构具有理想的生物活性和效力，这是通过合理和组合合成策略无法获得的。我的研究项目侧重于分离具有生物活性的天然产物，这些天然产物具有抗病原微生物的活性，因此具有开发感染性疾病新疗法的先导化合物的巨大潜力。我们专注于陆地、海洋和淡水植物内生真菌产生的天然产物，目前正在研究大约500个真菌内生培养物，其中许多可能代表新的真菌物种。更多的内生菌株正在不断被分离出来，以增加我们的收集，我们也将真菌与其他真菌和细菌共同培养，并在各种生物和化学条件下发酵，以触发隐藏的生物合成基因，最大限度地提高我们收集的化学多样性。我的团队已经开发出简单、稳健、有效的生物活性和代谢组学分析程序，我们将应用于寻找新的分子支架。真菌提取物将在一套生物测定中进行评估，以评估其对病原微生物的抑制作用及其调节这些病原体内外排泵的能力。这将使我们能够编制与其抗生素成分作用方式相关的提取物的生物活性概况，以努力发现新的抗生素类别，并确定可用于通过纠正耐药性影响来提高我们现有抗生素有效性的天然产物。结合生物活性谱的编制，基于NMR和LC-MS的代谢组学方法将用于重复含有已知抗生素的提取物，并优先考虑进一步研究的项目。具有生物活性特征和独特代谢组学特征的提取物将进行生物测定指导分离，以分离和鉴定活性成分。分离出来的新型天然产物的作用模式将通过基因组学、蛋白质组学和化学遗传学进行探测。我的研究最终将导致从真菌内生菌提供的广泛生物多样性中发现先导化合物，用于开发对抗传染病的新疗法。

The growing emergence of microbial strains that are resistant to currently used antibiotic agents is a major threat to human health as resistance to all of the major classes of antibiotics currently in clinical use has already been observed. Pan-resistant pathogens are increasingly being discovered and current forecasts predict that broad-scale ineffectiveness of antimicrobial agents is imminent. The discovery of novel natural products provides unparalleled access to unprecedented molecular scaffolds and unique molecular structures with desirable bioactivities and potencies that are unavailable through rational and combinatorial synthetic strategies. My research program focuses on the isolation of biologically active natural products that exhibit activity against pathogenic microbes, and consequently have significant potential as lead compounds for the development of new therapeutics for infectious disease. We focus on natural products produced by endophytic fungi of terrestrial, marine and freshwater plants, and a library of about 500 fungal endophyte cultures, many of which could represent new fungal species, is currently under investigation. Additional endophytic strains are continuously being isolated to increase our collection and we will also ferment fungi in co-culture with other fungi and bacteria and under various biological and chemical conditions to trigger cryptic biosynthetic genes and maximise the chemical diversity of our collection. My group has developed simple, robust and effective bioactivity and metabolomic profiling procedures that we will be applying in our search for novel molecular scaffolds. Fungal extracts will be evaluated in a suite of bioassays to assess their inhibitory effects against pathogenic microorganisms and their ability to modulate efflux pumps within these pathogens. This will allow us to compile bioactivity profiles for the extracts that can be related to the modes-of-action of their antibiotic constituents in an effort to discover new antibiotic classes and also identify natural products that can be used to increase the effectiveness of our current antibiotics by remediating for the effects of drug resistance. In conjunction with the compilation of the bioactivity profiles, NMR and LC-MS based metabolomics approaches will be used to dereplicate extracts that contain known antibiotics and prioritise projects for further investigation. Extracts that exhibit promising bioactivity profiles and unique metabolomic signatures will be subjected to bioassay-guided fractionation to isolate and identify the active components. The modes-of-action of the novel natural products that are isolated will then be probed by genomics, proteomics and chemical genetics. My research will ultimately lead to the discovery of lead compounds from the extensive biodiversity provided by fungal endophytes for the development of new therapeutics to fight infectious disease.