Interspecies bacterial competition may occur via cell‐associated or secreted determinants and is key to successful niche colonization. We previously evolved Pseudomonas aeruginosa in the presence of Staphylococcus aureus and identified mutations in the Wsp surface‐sensing signalling system. Surprisingly, a ΔwspF mutant, characterized by increased c‐di‐GMP levels and biofilm formation capacity, showed potent killing activity towards S. aureus in its culture supernatant. Here, we used an unbiased metabolomic analysis of culture supernatants to identify rhamnolipids, alkyl quinoline N‐oxides and two siderophores as members of four chemical clusters, which were more abundant in the ΔwspF mutant supernatants. Killing activities were quorum‐sensing controlled but independent of c‐di‐GMP levels. Based on the metabolomic analysis, we formulated a synthetic cocktail of four compounds, showing broad‐spectrum anti‐bacterial killing, including both Gram‐positive and Gram‐negative bacteria. The combination of quorum‐sensing‐controlled killing and Wsp‐system mediated biofilm formation endows P. aeruginosa with capacities essential for niche establishment and host colonization.

中文翻译：

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表面感应在铜绿假单胞菌中触发广谱抗菌反应。

种间细菌竞争可能通过细胞相关或分泌的决定簇发生，这是利基成功定殖的关键。我们以前在金黄色葡萄球菌的存在下进化出了铜绿假单胞菌，并在Wsp表面传感信号系统中鉴定出突变。令人惊讶的是，具有增加的c-di-GMP水平和生物膜形成能力的ΔwspF突变体在其培养上清液中显示出对金黄色葡萄球菌的有效杀伤活性。在这里，我们使用培养物上清液的无偏代谢组学分析来鉴定鼠李糖脂，烷基喹啉N-氧化物和两个铁载体作为四个化学簇的成员，它们在ΔwspF中更为丰富突变体上清液。杀死活动受到群体感应控制，但与c-di-GMP水平无关。基于代谢组学分析，我们配制了四种化合物的合成混合物，显示出广谱的抗菌杀伤力，包括革兰氏阳性菌和革兰氏阴性菌。群体感应控制的杀灭和Wsp系统介导的生物膜形成相结合，使铜绿假单胞菌具有利基建立和寄主定殖的必不可少的能力。