Proteomic analysis of Staphylococcus aureus biofilm cells grown under physiologically relevant fluid shear stress conditions.

Nazrul Islam,Yonghyun Kim,Julia M Ross,Mark R Marten

doi:10.1186/1477-5956-12-21

Abstract

BackgroundThe biofilm forming bacterium Staphylococcus aureus is responsible for maladies ranging from severe skin infection to major diseases such as bacteremia, endocarditis and osteomyelitis. A flow displacement system was used to grow S. aureus biofilms in four physiologically relevant fluid shear rates (50, 100, 500 and 1000 s-1) to identify proteins that are associated with biofilm.ResultsGlobal protein expressions from the membrane and cytosolic fractions of S. aureus biofilm cells grown under the above shear rate conditions are reported. Sixteen proteins in the membrane-enriched fraction and eight proteins in the cytosolic fraction showed significantly altered expression (p < 0.05) under increasing fluid shear. These 24 proteins were identified using nano-LC-ESI-MS/MS. They were found to be associated with various metabolic functions such as glycolysis / TCA pathways, protein synthesis and stress tolerance. Increased fluid shear stress did not influence the expression of two important surface binding proteins: fibronectin-binding and collagen-binding proteins.ConclusionsThe reported data suggest that while the general metabolic function of the sessile bacteria is minimal under high fluid shear stress conditions, they seem to retain the binding capacity to initiate new infections.

Highlights

The biofilm forming bacterium Staphylococcus aureus is responsible for maladies ranging from severe skin infection to major diseases such as bacteremia, endocarditis and osteomyelitis
A biofilm is an aggregate of bacterial microcolonies adherent to each other and to biotic or abiotic surfaces, embedded in an extracellular matrix produced by the sessile bacteria composing the microcolonies
Among the biofilm forming bacteria, Staphylococcus aureus is responsible for severe skin infections to such major diseases as bacteremia, endocarditis and osteomyelitis

Summary

Introduction

The biofilm forming bacterium Staphylococcus aureus is responsible for maladies ranging from severe skin infection to major diseases such as bacteremia, endocarditis and osteomyelitis. Among the biofilm forming bacteria, Staphylococcus aureus is responsible for severe skin infections to such major diseases as bacteremia, endocarditis and osteomyelitis. S. aureus causes serious complications in devices like implants and catheters by producing biofilms on them [2,3]. Treatment of such infections becomes even more challenging given that several S. aureus strains show resistance to multiple antibiotics (e.g., methicilin and vancomycin). Growth rate and physiological changes are considered the major causes of resistance to antibiotics. Characterizing bacterial biofilm architecture and stability in their favorable growth conditions would help elucidate how these bacteria survive during their processes of biofilm formation

Methods

Results

Conclusion