Vancomycin Reduces Cell Wall Stiffness and Slows Swim Speed of the Lyme Disease Bacterium

Title data

Harman, Michael W. ; Hamby, Alex E. ; Boltyanskiy, Ross ; Belperron, Alexia A. ; Bockenstedt, Linda K. ; Kress, Holger ; Dufresne, Eric R. ; Wolgemuth, Charles W.:
Vancomycin Reduces Cell Wall Stiffness and Slows Swim Speed of the Lyme Disease Bacterium.
In: Biophysical Journal. Vol. 112 (2017) Issue 4 . - pp. 746-754.
ISSN 1542-0086
DOI: https://doi.org/10.1016/j.bpj.2016.12.039

Official URL:

Abstract in another language

Borrelia burgdorferi, the spirochete that causes Lyme disease, is a tick-transmitted pathogen that requires motility to invade and colonize mammalian and tick hosts. These bacteria use a unique undulating flat-wave shape to penetrate and propel themselves through host tissues. Previous mathematical modeling has suggested that the morphology and motility of these spirochetes depends crucially on the flagellar/cell wall stiffness ratio. Here, we test this prediction using the antibiotic vancomycin to weaken the cell wall. We found that low to moderate doses of vancomycin (≤2.0 μg/mL for 24 h) produced small alterations in cell shape and that as the dose was increased, cell speed decreased. Vancomycin concentrations >1.0 μg/mL also inhibited cell growth and led to bleb formation on a fraction of the cells. To quantitatively assess how vancomycin affects cell stiffness, we used optical traps to bend unflagellated mutants of B. burgdorferi. We found that in the presence of vancomycin, cell wall stiffness gradually decreased over time, with a 40 reduction in the bending stiffness after 36 h. Under the same conditions, the swimming speed of wild-type B. burgdorferi slowed by ∼15, with only marginal changes to cell morphology. Interestingly, our biophysical model for the swimming dynamics of B. burgdorferi suggested that cell speed should increase with decreasing cell stiffness. We show that this discrepancy can be resolved if the periplasmic volume decreases as the cell wall becomes softer. These results provide a testable hypothesis for how alterations of cell wall stiffness affect periplasmic volume regulation. Furthermore, since motility is crucial to the virulence of B. burgdorferi, the results suggest that sublethal doses of antibiotics could negatively impact spirochete survival by impeding their swim speed, thereby enabling their capture and elimination by phagocytes.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Professor Experimental Physics VI - Biologial Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Professor Experimental Physics VI - Biologial Physics > Professor Experimental Physics VI - Biologial Physics - Univ.-Prof. Dr. Holger Kreß Profile Fields > Advanced Fields > Molecular Biosciences Profile Fields Profile Fields > Advanced Fields
Result of work at the UBT:	No
DDC Subjects:	500 Science > 530 Physics 500 Science > 570 Life sciences, biology
Date Deposited:	26 Feb 2021 10:09
Last Modified:	25 Apr 2022 13:15
URI:	https://eref.uni-bayreuth.de/id/eprint/63462