Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, California, USA.
Appl Environ Microbiol. 2023 Feb 28;89(2):e0183822. doi: 10.1128/aem.01838-22. Epub 2023 Jan 26.
Symbiotic help fungus-growing ants suppress fungal pathogens through the production of antifungal compounds. ants of the southwest desert of the United States inhabit a unique niche far from the tropical rainforests in which most fungus-growing ant species are found. These ants may not encounter the specialist fungal pathogen known to threaten colonies of other fungus-growing ants. It is unknown whether associated with these ants antagonize contaminant fungi and, if so, what the chemical basis of such antagonism is. We find that and strains isolated from three desert specialist species do antagonize diverse contaminant fungi isolated from field-collected ant colonies. We did not isolate the specialist fungal pathogen in our sampling. We trace strong antifungal activity from isolates to the molecule ECO-0501, an antibiotic that was previously under preclinical development as an antibacterial agent. In addition to suppression of contaminant fungi, we find that this molecule has strong activity against ant-associated and may also play a role in bacterial competition in this niche. By studying interspecies interactions in a previously unexplored niche, we have uncovered novel bioactivity for a structurally unique antibiotic. Animal hosts often benefit from chemical defenses provided by microbes. These molecular defenses are a potential source of novel antibiotics and offer opportunities for understanding how antibiotics are used in ecological contexts with defined interspecies interactions. Here, we recover contaminant fungi from nests of fungus-growing ants of the southwest desert of the United States and find that they are suppressed by isolated from these ants. The antibiotic ECO-0501 is an antifungal agent used by some of these bacterial isolates. This antibiotic was previously investigated in preclinical studies and known only for antibacterial activity.
共生真菌帮助菌食性蚂蚁通过产生抗真菌化合物来抑制真菌病原体。美国西南部沙漠中的蚂蚁栖息在一个独特的小生境中，远离大多数菌食性蚂蚁物种所在的热带雨林。这些蚂蚁可能不会遇到已知威胁其他菌食性蚂蚁种群的专性真菌病原体。目前尚不清楚与这些蚂蚁相关的细菌是否会拮抗污染真菌，如果是，这种拮抗作用的化学基础是什么。我们发现，从三种沙漠专性蚂蚁物种中分离出的 和 菌株会拮抗从野外收集的蚂蚁巢中分离出的多种污染真菌。我们在采样中没有分离出专性真菌病原体 。我们从 分离株中追踪到强烈的抗真菌活性到分子 ECO-0501，这是一种以前作为抗菌剂在临床前开发的抗生素。除了抑制污染真菌外，我们还发现这种分子对与蚂蚁相关的 和 具有很强的活性，并且可能在这个小生境中的细菌竞争中也发挥作用。通过研究以前未探索过的小生境中的种间相互作用，我们发现了一种结构独特的抗生素具有新的生物活性。动物宿主通常受益于微生物提供的化学防御。这些分子防御是新型抗生素的潜在来源，并为理解抗生素在具有明确种间相互作用的生态环境中如何使用提供了机会。在这里，我们从美国西南部沙漠中的菌食性蚂蚁的巢穴中回收污染真菌，并发现它们被从这些蚂蚁中分离出的 所抑制。抗生素 ECO-0501 是一些 细菌分离株中使用的抗真菌剂。这种抗生素以前在临床前研究中进行过研究，仅具有抗菌活性。
