研究実績の概要 |
Pseudomonas aeruginosa is an opportunistic human pathogen and is often used as a model to understand biofilms. This ubiquitous bacterium was recently listed by the World Health Organization as a bacterial species for which new antibiotics are desperately needed. The goal and purpose of this fundamental work is to clarify surface motility and the biofilm forming properties of the PA mucoid mutant, which produces copious amounts of the polysaccharide alginate. This mutant is often found in cystic fibrosis patients and leads to a worsening of their condition. Understanding the primary factors that influence their behavior may lead to methods to control and disrupt their biofilms. Through our experiments we discovered that the mucoid strain acquires spontaneous mutations, which leads to a loss of the alginate overexpression phenotype and a “reversion” to the wild-type (WT) phenotype. We have generated a reporter strain of the mucoid mutant that reports its phenotype through expression of fluorescent proteins. We are beginning to clarify the factors that influence the timing and location of the appearance of the reversion mutant from within mucoid colonies. We have used flow cytometry and confocal microscopy to begin to quantify the frequency and location of appearance of the reversion mutant. We are still working to understand and clarify these points by looking into the major factors that induce spontaneous mutations. We have reported our results in domestic and international conferences (ASM Biofilms) and intend to summarize these results in a publication.
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