Non-mucoid reversion of mucoid pseudomonas aeruginosa induced by sulfate-stimulated growth
Other Titles
황산염 매개 성장에 의한 점액성 녹농균의 비점액성화
Authors
민경배
Issue Date
2014
Description
Dept. of Medical Science/석사
Abstract
Alginate overproducing mucoid Pseudomonas aeruginosa, responsible for chronic airway infections in cystic fibrosis (CF) patients, is resistant to antibiotic treatments and host immune clearance. In this study, we performed a Phenotype Microarray screen and identified sulfate ion as a molecule that can suppress alginate production. When a mucoid P. aeruginosa strain CM21 and additional mucoid isolates were grown with 5% sodium sulfate, significantly decreased levels of alginate were produced. Suppression of alginate production was also induced by other sulfate salts. Expression of a reporter gene fused to algD promoter was considerably decreased when grown with sulfate. Furthermore, bacterial cell shape was abnormally altered in CM21, but not in PAO1, a prototype non-mucoid strain suggesting that sulfate-stimulated cell shape change is associated with transcriptional suppression of the alginate operon. Finally, a CM21 lpxC mutant defective in lipid A biosynthesis continued to produce alginate and maintained the correct cell shape when grown with sulfate. These results suggest a potential involvement of LPS biosynthesis in the sulfate-induced reversion to non-mucoid phenotype. Together, this study proposes a novel strategy that can be potentially applied to treat persistent infection by recalcitrant mucoid P. aeruginosa.