title: Effect of Shear Stress on Pseudomonas aeruginosa Isolated from the Cystic Fibrosis Lung.
abstract: Chronic colonization of the lungs by Pseudomonas aeruginosa is one of the major causes of morbidity and mortality in cystic fibrosis (CF) patients. To gain insights into the characteristic biofilm phenotype of P. aeruginosa in the CF lungs, mimicking the CF lung environment is critical. We previously showed that growth of the non-CF-adapted P. aeruginosa PAO1 strain in a rotating wall vessel, a device that simulates the low fluid shear (LS) conditions present in the CF lung, leads to the formation of in-suspension, self-aggregating biofilms. In the present study, we determined the phenotypic and transcriptomic changes associated with the growth of a highly adapted, transmissible P. aeruginosa CF strain in artificial sputum medium under LS conditions. Robust self-aggregating biofilms were observed only under LS conditions. Growth under LS conditions resulted in the upregulation of genes involved in stress response, alginate biosynthesis, denitrification, glycine betaine biosynthesis, glycerol metabolism, and cell shape maintenance, while genes involved in phenazine biosynthesis, type VI secretion, and multidrug efflux were downregulated. In addition, a number of small RNAs appeared to be involved in the response to shear stress. Finally, quorum sensing was found to be slightly but significantly affected by shear stress, resulting in higher production of autoinducer molecules during growth under high fluid shear (HS) conditions. In summary, our study revealed a way to modulate the behavior of a highly adapted P. aeruginosa CF strain by means of introducing shear stress, driving it from a biofilm lifestyle to a more planktonic lifestyle.
  
  
  
  Biofilm formation by Pseudomonas aeruginosa is one of the hallmarks of chronic cystic fibrosis (CF) lung infections. The biofilm matrix protects this bacterium from antibiotics as well as from the immune system. Hence, the prevention or reversion of biofilm formation is believed to have a great impact on treatment of chronic P. aeruginosa CF lung infections. In the present study, we showed that it is possible to modulate the behavior of a highly adapted transmissible P. aeruginosa CF isolate at both the transcriptomic and phenotypic levels by introducing shear stress in a CF-like environment, driving it from a biofilm to a planktonic lifestyle. Consequently, the results obtained in this study are of great importance with regard to therapeutic applications that introduce shear stress in the lungs of CF patients.
authors.affiliation: Department of Bioengineering Sciences, Research Group Microbiology, Vrije Universiteit Brussel, and VIB Structural Biology, Brussels, Belgium Unit of Microbiology, Expert Group Molecular and Cellular Biology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Dingemans
authors.affiliation: Unit of Microbiology, Expert Group Molecular and Cellular Biology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Monsieurs
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Sung-Huan
authors.initials: SH
authors.lastname: Yu
authors.affiliation: Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Crabbé
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Konrad U
authors.initials: KU
authors.lastname: Förstner
authors.affiliation: Cystic Fibrosis Clinic and Pediatric Infectious Diseases, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (UZB), Brussels, Belgium.
authors.forename: Anne
authors.initials: A
authors.lastname: Malfroot
authors.affiliation: Department of Bioengineering Sciences, Research Group Microbiology, Vrije Universiteit Brussel, and VIB Structural Biology, Brussels, Belgium pcornel@vub.ac.be.
authors.forename: Pierre
authors.initials: P
authors.lastname: Cornelis
authors.affiliation: Unit of Microbiology, Expert Group Molecular and Cellular Biology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Belgium.
authors.forename: Rob
authors.identifier: 0000-0002-7459-496X
authors.initials: R
authors.lastname: Van Houdt
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D003470:Culture Media / Q000737:chemistry; D003550:Cystic Fibrosis / Q000150:complications*; D020869:Gene Expression Profiling; D006801:Humans; D008168:Lung / Q000382:microbiology*; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D013183:Sputum / Q000382:microbiology; D013314:Stress, Mechanical; D013312:Stress, Physiological
chemical_list: D003470:Culture Media