Induction of Attachment-Independent Biofilm Formation and Repression ofhfqExpression by Low-Fluid-Shear Culture of Staphylococcus aureus
Open Access
- 15 September 2011
- journal article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 77 (18), 6368-6378
- https://doi.org/10.1128/aem.00175-11
Abstract
The opportunistic pathogen Staphylococcus aureus encounters a wide variety of fluid shear levels within the human host, and they may play a key role in dictating whether this organism adopts a commensal interaction with the host or transitions to cause disease. By using rotating-wall vessel bioreactors to create a physiologically relevant, low-fluid-shear environment, S. aureus was evaluated for cellular responses that could impact its colonization and virulence. S. aureus cells grown in a low-fluid-shear environment initiated a novel attachment-independent biofilm phenotype and were completely encased in extracellular polymeric substances. Compared to controls, low-shear-cultured cells displayed slower growth and repressed virulence characteristics, including decreased carotenoid production, increased susceptibility to oxidative stress, and reduced survival in whole blood. Transcriptional whole-genome microarray profiling suggested alterations in metabolic pathways. Further genetic expression analysis revealed downregulation of the RNA chaperone Hfq, which parallels low-fluid-shear responses of certain Gram-negative organisms. This is the first study to report an Hfq association with fluid shear in a Gram-positive organism, suggesting an evolutionarily conserved response to fluid shear among structurally diverse prokaryotes. Collectively, our results suggest S. aureus responds to a low-fluid-shear environment by initiating a biofilm/colonization phenotype with diminished virulence characteristics, which could lead to insight into key factors influencing the divergence between infection and colonization during the initial host-pathogen interaction.This publication has 88 references indexed in Scilit:
- Analysis of Interactions of Salmonella Type Three Secretion Mutants with 3-D Intestinal Epithelial CellsPLOS ONE, 2010
- Hfq Is a Global Regulator That Controls the Pathogenicity of Staphylococcus aureusPLOS ONE, 2010
- Vaccine development inStaphylococcus aureus: taking the biofilm phenotype into considerationFEMS Immunology & Medical Microbiology, 2010
- Redox sensing by a Rex‐family repressor is involved in the regulation of anaerobic gene expression in Staphylococcus aureusMolecular Microbiology, 2010
- The Mevalonate Pathway ofStaphylococcus aureusJournal of Bacteriology, 2009
- Space flight alters bacterial gene expression and virulence and reveals a role for global regulator HfqProceedings of the National Academy of Sciences of the United States of America, 2007
- Staphylococcus aureus intestinal colonization is associated with increased frequency of S. aureuson skin of hospitalized patientsBMC Infectious Diseases, 2007
- Novel Quantitative Biosystem for Modeling Physiological Fluid Shear Stress on CellsApplied and Environmental Microbiology, 2007
- Escherichia coli Biofilms Formed under Low-Shear Modeled Microgravity in a Ground-Based SystemApplied and Environmental Microbiology, 2006
- Getting a grip on things: how do communities of bacterial symbionts become established in our intestine?Nature Immunology, 2004