# Different Cell Wall Compositions of ESKAPE Isolates on Glass Surfaces Impact Adhesion Adaptability to Dynamic Shear Stress

## TL;DR

This study shows how different bacteria adapt to changing physical conditions on surfaces, which could help explain how they survive in challenging environments.

## Contribution

The study reveals distinct adhesion adaptation strategies in ESKAPE bacteria under dynamic shear stress.

## Key findings

- Coccoid bacteria adapt to shear changes by altering adhesion density or strength.
- A. baumannii and E. faecalis maintain constant adhesion strength despite shear changes.
- Bacillus bacteria show changes in both adhesion density and strength with shear direction.

## Abstract

Although many studies have focused on the initial adhesion of bacteria, there have been few that looked at responses to changing environmental conditions. To more closely examine the viscoelastic nature of initial adhesion, surface-associated bacteria were quantified and monitored for their Brownian motion vibrations. This study used a flow chamber to observe the surface association of Enterobacter cloacae BS 1037, Staphylococcus aureus ATCC 12600, Klebsiella pneumoniae–1, Acinetobacter baumannii–1, Pseudomonas aeruginosa PA O1, and Enterococcus faecalis 1396 to glass under dynamic shear rates of 7–15–30 s−1, 15–30–60 s−1, and 30–15–7 s−1. Comparing increasing and decreasing shear rates, information about retention and recovery became apparent. Coccoid bacteria primarily reacted to directional changes in shear rates with changes in either surface-associated bacterial densities or surface-associated strength independently. A. baumannii and E. faecalis did not change their associated strength, whereas S. aureus did not change its associated density. Bacillus bacteria demonstrated differences in both associations with directional changes in shear rates. We demonstrate that retention and recovery are different methods of adaptation to environmental conditions utilised by different bacterial species. These adaptations may form the basis of upregulation and downregulation responses used for survival.