1. Cytoplasmic condensation induced by membrane damage is associated with antibiotic lethality.
- Author
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Wong F, Stokes JM, Cervantes B, Penkov S, Friedrichs J, Renner LD, and Collins JJ
- Subjects
- Aminoglycosides pharmacology, Cell Membrane Permeability drug effects, Cytoplasm metabolism, Escherichia coli cytology, Escherichia coli metabolism, Fluoroquinolones pharmacology, Microbial Sensitivity Tests methods, Microbial Viability drug effects, Microscopy, Atomic Force methods, Microscopy, Fluorescence methods, Single-Cell Analysis methods, Anti-Bacterial Agents pharmacology, Cell Membrane drug effects, Cytoplasm drug effects, Escherichia coli drug effects
- Abstract
Bactericidal antibiotics kill bacteria by perturbing various cellular targets and processes. Disruption of the primary antibiotic-binding partner induces a cascade of molecular events, leading to overproduction of reactive metabolic by-products. It remains unclear, however, how these molecular events contribute to bacterial cell death. Here, we take a single-cell physical biology approach to probe antibiotic function. We show that aminoglycosides and fluoroquinolones induce cytoplasmic condensation through membrane damage and subsequent outflow of cytoplasmic contents as part of their lethality. A quantitative model of membrane damage and cytoplasmic leakage indicates that a small number of nanometer-scale membrane defects in a single bacterium can give rise to the cellular-scale phenotype of cytoplasmic condensation. Furthermore, cytoplasmic condensation is associated with the accumulation of reactive metabolic by-products and lipid peroxidation, and pretreatment of cells with the antioxidant glutathione attenuates cytoplasmic condensation and cell death. Our work expands our understanding of the downstream molecular events that are associated with antibiotic lethality, revealing cytoplasmic condensation as a phenotypic feature of antibiotic-induced bacterial cell death.
- Published
- 2021
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