Oberbauer Vera, Mutti Michele, Schwebs Timo, Durica-Mitic Svetlana, Visram Zehra, Kestemont Donaat, Badarau Adriana, Corsini Lorenzo
BioNTech R&D (Austria) GmbH, Vienna, Austria.
Sci Rep. 2025 Aug 11;15(1):29351. doi: 10.1038/s41598-025-14753-y.
Antibiotic resistance is a growing concern, and there is an urgent need for alternative treatments. A proposed solution includes endolysins. Naturally occurring endolysins have limited activity against Gram-negative bacteria due to the presence of an outer membrane. Previous agar-based screening methods did not consider this and screened for activity on autoclaved cell debris. In this study, we used a soft-agar-based screening method to identify endolysins targeting Pseudomonas aeruginosa. This method enabled us to screen for activity of endolysins on live Pseudomonas aeruginosa, taking the outer membrane into account. The application of this randomized forward screening method led to the discovery of three highly bactericidal endolysins, L0779, L0782, and L0799. These endolysins displayed a broad spectrum of activity against other Gram-negative bacterial species. We report minimal inhibitory concentrations (MICs) for endolysins acting on multiple Gram-negative ESKAPE species, with MICs for L0782 on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii ranging from 4 to 16 µg/mL. In summary, our screening method enables rapid identification of endolysins with broad-spectrum activity against Gram-negative bacteria. These show potential for further development as alternative treatments for antibiotic-resistant infections.
抗生素耐药性问题日益严重，迫切需要替代治疗方法。一种提议的解决方案包括内溶素。由于存在外膜，天然存在的内溶素对革兰氏阴性菌的活性有限。以前基于琼脂的筛选方法未考虑到这一点，而是在高压灭菌的细胞碎片上筛选活性。在本研究中，我们使用基于软琼脂的筛选方法来鉴定靶向铜绿假单胞菌的内溶素。该方法使我们能够在考虑外膜的情况下，筛选内溶素对活的铜绿假单胞菌的活性。这种随机正向筛选方法的应用导致发现了三种高度杀菌的内溶素，即L0779、L0782和L0799。这些内溶素对其他革兰氏阴性菌具有广泛的活性。我们报告了作用于多种革兰氏阴性ESKAPE菌属的内溶素的最低抑菌浓度（MIC），L0782对铜绿假单胞菌、大肠杆菌、肺炎克雷伯菌和鲍曼不动杆菌的MIC范围为4至16μg/mL。总之，我们的筛选方法能够快速鉴定对革兰氏阴性菌具有广谱活性的内溶素。这些内溶素显示出作为抗生素耐药感染替代治疗方法进一步开发的潜力。
