Lepori Irene, Jackson Kiserian, Liu Zichen, Chordia Mahendra D, Wong Mitchell, Rivera Sylvia L, Roncetti Marta, Poliseno Laura, Pires Marcos M, Siegrist M Sloan
bioRxiv. 2025 Jan 2:2024.12.31.630956. doi: 10.1101/2024.12.31.630956.
The recalcitrance of to antibiotic treatment has been broadly attributed to the impermeability of the organism's outer mycomembrane. However, the studies that support this inference have been indirect and/or reliant on bulk population measurements. We previously developed the P eptidoglycan A ccessibility C lick- M ediated A ssessme N t (PAC-MAN) method to covalently trap azide-modified small molecules in the peptidoglycan cell wall of live mycobacteria, after they have traversed the mycomembrane. Using PAC-MAN we now show that the mycomembrane differentially restricts access of fluorophores and antibiotic derivatives. Mycomembranes of both and the model organism discriminate between divergent classes of antibiotics as well as between antibiotics within a single family, the fluoroquinolones. By analyzing sub-populations of and , we also found that some fluorophores and vancomycin are heterogeneously restricted by the mycomembrane. Our data indicate that the mycomembrane is a molecule- and cell-specific barrier to antibiotic permeation.
结核分枝杆菌对抗生素治疗的顽固性普遍归因于该生物体外部分枝菌膜的不可渗透性。然而，支持这一推断的研究一直是间接的和/或依赖于总体群体测量。我们之前开发了肽聚糖可及性点击介导评估（PAC-MAN）方法，用于在叠氮化物修饰的小分子穿过分枝菌膜后，将其共价捕获在活分枝杆菌的肽聚糖细胞壁中。现在，我们使用PAC-MAN表明，分枝菌膜以不同方式限制荧光团和抗生素衍生物的进入。结核分枝杆菌和模式生物耻垢分枝杆菌的分枝菌膜能够区分不同类别的抗生素以及单一氟喹诺酮类抗生素家族中的不同抗生素。通过分析结核分枝杆菌和耻垢分枝杆菌的亚群体，我们还发现一些荧光团和万古霉素受到分枝菌膜的异质性限制。我们的数据表明，分枝菌膜是抗生素渗透的分子和细胞特异性屏障。
