Biofilm dispersion is a physiological behavior of cells escaping from biofilms during biofilm development. The dispersion response is important because cells in the planktonic state are more susceptible to antibiotics than biofilm cells. Prior to the work described in current study, it had not been established whether dispersed cells are physiologically distinct from free-living planktonic cells, or whether they are more similar to biofilm cells, or represent a distinct third physiology. The main goal of this research was to understand the physiology involved in the transition from a biofilm to a planktonic state in Pseudomonas aeruginosa. Investigation of the biofilm dispersion response in relation to its protein synthesis demonstrated protein synthesis was required for the dispersion response. Protein analysis demonstrated global changes in protein expression, including an increase, decrease, or no change in the concentration of proteins detected in dispersed biofilms. The proteins that were de novo synthesized during dispersion were identified. Characterization of the virulence of P. aeruginosa following biofilm dispersion confirmed that biofilm dispersion was associated with altered virulence in P. aeruginosa. Several virulence factors that have been known to be associated with acute infection showed higher abundance upon dispersion, indicating that dispersion might be involved in transition between chronic and acute infection. In vivo studies using two host eukaryotic organisms (Arabidopsis thaliana and Caenorhabditis elegans) confirmed that there were changes in pathogenicity of P. aeruginosa following induction of biofilm dispersion. This study will contribute to our understanding of the biofilm dispersion response and may provide important insight into maintenance of the chronic infection process demonstrated by pathogenic bacteria.
|Advisor:||Davies, David G.|
|School:||State University of New York at Binghamton|
|School Location:||United States -- New York|
|Source:||DAI-B 72/10, Dissertation Abstracts International|
|Keywords:||Biofilms, Dispersed cells, Pseudomonas aeruginosa|
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