Berlin 2024 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 22: Bacterial Biophysics II
BP 22.2: Vortrag
Mittwoch, 20. März 2024, 15:15–15:30, H 0112
Local decrease in cell wall mechanical stress as a possible trigger for cell splitting in Staphylococcus aureus — •Sheila Hoshyaripour1,2,3, Marco Mauri1,2, Abimbola F. Adedeji Olulana4, David Owen4, Jamie K. Hobbs4, Simon J. Foster4, and Rosalind J. Allen1,2 — 1Friedrich Schiller university, Jena, Germany — 2Cluster of Excellence Balance of the Microverse, Jena, Germany — 3Jena School of Microbial Communication, Jena, Germany — 4University of Sheffield, Sheffield, UK
Staphylococcus aureus is a clinically important Gram-positive bacterium able to generate antibiotic-resistant strains. Cell division happens in few milliseconds without cell wall constriction and how the cell controls the initiation of division is not clear. Our observations using atomic force microscopy and fluorescence microscopy show that the mechanical and geometrical properties of the cell and the cell cycle timing change with genetic mutations and in the presence of antibiotics. In addition, it is observed that peptidoglycan hydrolase activity, which plays a key role in cell division, may be negatively stress dependent. Here, we created a theoretical model to show how mechanics and hydrolysis work together to regulate the cell cycle. Our modelling shows that, during the cell cycle, mechanical stress decreases around the division site. With the hypothesis of stress-dependent triggering of the enzymes, the model predicts the timing of the later phases of the cell cycle which is supported by microscopy data. The model provides new insights into the combined effects of mechanical forces and enzyme activity in cell cycle regulation and initiation of division in S. aureus.
Keywords: bacterial cell wall; mechanical stress; cell division; hydrolases; antibiotics