Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boqer Campus, Midreshet Ben-Gurion, Israel.
School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
NPJ Biofilms Microbiomes. 2021 Mar 17;7(1):26. doi: 10.1038/s41522-021-00195-7.
The bacteriophage infection cycle has been extensively studied, yet little is known about the nanostructure and mechanical changes that lead to bacterial lysis. Here, atomic force microscopy was used to study in real time and in situ the impact of the canonical phage T4 on the nanotopography and biomechanics of irreversibly attached, biofilm-forming E. coli cells. The results show that in contrast to the lytic cycle in planktonic cells, which ends explosively, anchored cells that are in the process of forming a biofilm undergo a more gradual lysis, developing distinct nanoscale lesions (~300 nm in diameter) within the cell envelope. Furthermore, it is shown that the envelope rigidity and cell elasticity decrease (>50% and >40%, respectively) following T4 infection, a process likely linked to changes in the nanostructure of infected cells. These insights show that the well-established lytic pathway of planktonic cells may be significantly different from that of biofilm-forming cells. Elucidating the lysis paradigm of these cells may advance biofilm removal and phage therapeutics.
噬菌体感染周期已经得到了广泛的研究，但对于导致细菌裂解的纳米结构和力学变化知之甚少。在这里，原子力显微镜被用于实时原位研究经典噬菌体 T4 对不可逆附着的、形成生物膜的大肠杆菌细胞的纳米形貌和生物力学的影响。结果表明，与在浮游细胞中以爆炸方式结束的裂解周期相比，正在形成生物膜的锚定细胞经历了更为渐进的裂解，在细胞包膜内形成明显的纳米级损伤（直径约 300nm）。此外，研究表明，T4 感染后，包膜刚性和细胞弹性分别下降（分别超过 50%和 40%），这一过程可能与感染细胞的纳米结构变化有关。这些发现表明，浮游细胞中成熟的裂解途径可能与形成生物膜的细胞显著不同。阐明这些细胞的裂解范例可能有助于生物膜去除和噬菌体治疗。
