Pseudomonas aeruginosa rhamnolipid micelles deliver toxic metabolites and antibiotics into Staphylococcus aureus

Efficient delivery of toxic compounds to bacterial competitors is essential during interspecies microbial warfare. Rhamnolipids (RLPs) are glycolipids produced by Pseudomonas and Burkholderia species involved in solubilization and uptake of environmental aliphatic hydrocarbons, and perform as biosurfactants for swarming motility. Here we show that RLPs produced by Pseudomonas aeruginosaassociate to form micelles. Using high resolution microscopy, we found that RLPs micelles serve as carriers for self-produced toxic compounds, which they deliver to Staphylococcus aureuscells, thereby enhancing and accelerating S. aureus killing. RLPs also potentiated the activity of lincosamide antibiotics, suggesting that RLPs micelles may transport not only self-produced, but also heterologous compounds to target competing bacterial species在种间微生物对抗过程中，将有毒化合物高效递送至细菌竞争者至关重要。鼠李糖脂（Rhamnolipids，RLPs）是由假单胞菌属（Pseudomonas）和伯克霍尔德菌属（Burkholderia）物种产生的糖脂类物质，参与环境脂肪族烃类的溶解与摄取，并作为参与群集运动的生物表面活性剂发挥功能。本研究显示，铜绿假单胞菌（Pseudomonas aeruginosa）产生的鼠李糖脂可组装形成胶束。通过高分辨率显微镜观察，我们发现鼠李糖脂胶束可作为自身产生的有毒化合物的载体，将其递送至金黄色葡萄球菌（Staphylococcus aureus）细胞，从而增强并加速对金黄色葡萄球菌的杀灭效果。此外，鼠李糖脂还可增强林可酰胺类抗生素的活性，这表明鼠李糖脂胶束不仅能够转运自身产生的化合物，还可将异源化合物递送至目标竞争细菌物种。