Extracellular Polymeric Matrix Production and Relaxation under Fluid Shear and Mechanical Pressure in Staphylococcus aureus Biofilms.

Extracellular Polymeric Matrix Production and Relaxation under Fluid Shear and Mechanical Pressure in Staphylococcus aureus Biofilms. Appl Environ Microbiol. 2017 Oct 20;: Authors: Hou J, Veeregowda DH, van de Belt-Gritter B, Busscher HJ, van der Mei HC Abstract The viscoelasticity of a biofilm's EPS (extracellular-polymeric-substance) matrix conveys protection against mechanical challenges, but adaptive responses of biofilm inhabitants to produce EPS are not well known. Here, we compare the response of a biofilm of an EPS producing (ATCC 12600) and non-EPS producing (5298) Staphylococcus aureus strain to fluid shear and mechanical challenge. Confocal-Laser-Scanning-Microscopy confirmed absence of calcofluorwhite-stainable EPS in biofilms of S. aureus 5298. ATR-FTIR spectroscopy combined with tribometry indicated that the polysaccharide production per bacterium in the initial adhering layer was higher during growth at high shear than at low shear and this increased EPS production extended to entire biofilms, as indicated by tribometrically measured coefficients of friction (CoF). CoFs of biofilms grown under high fluid shear were higher than when grown under low shear, likely due to wash-off of polysaccharides. Measurement of a biofilm's CoF implies application of mechanical pressure that yielded an immediate increase in polysaccharide band area of S. aureus ATCC 12600 biofilms due to their compression that decreased after relieving ...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research