Bursting out: linking changes in nano-topography and biomechanical properties of biofilm-forming Escherichia coli to T4 lytic cycle

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>Bacteriophage infection cycle has been extensively studied, yet little is known on the structural and mechanical changes that lead to bacterial lysis. Here, bio-atomic force microscopy was used to study in real-time and <jats:italic>in-situ</jats:italic> the impact of the canonical phage T4 on the nano-topography and biomechanics of irreversibly attached, biofilm-forming <jats:italic>E. coli</jats:italic> 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 biofilms undergo gradual lysis, developing distinct sub-micron lesions (∼300 nm in diameter) within the cell envelope. Furthermore, it is shown that the envelope rigidity and cell elasticity decrease (&gt;50% and &gt;40%, respectively) following T4 infection. These new 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 therapeutic.</jats:p><jats:p>There is no conflict of interest and all co-authors have seen and approved the current version for submission.</jats:p>

Scanning probe microscopy investigation of the bacteriophage effect on bacterial biofilms

“…Incubation of A. baumannii biofilms with bacteriophages for 25 minutes at 37°C leads to a complete destruction of some cells (e.g., top left cells in Figure 2b) that is connected with a cell lysis caused by bacteriophage (the lytic cycle of this bacteriophages is 20 minutes). However, the major fraction of the cells remains undistorted due to small multiplicity of infection and peculiarities of lytic cycle in the adsorbed bacterial cells (Abraham et al, 2020).…”