title: Nonmucoid conversion of mucoid Pseudomonas aeruginosa induced by sulfate-stimulated growth.
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 the algD promoter was considerably decreased when grown with sulfate. Furthermore, bacterial cell shape was abnormally altered in CM21, but not in PAO1, a prototype nonmucoid 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 lipoploysaccharide biosynthesis in the sulfate-induced reversion to nonmucoid phenotype. This study proposes a novel strategy that can be potentially applied to treat persistent infection by recalcitrant mucoid P. aeruginosa.
authors.affiliation: Department of Microbiology and Immunology, Brain Korea PLUS Project for Medical Science, Seoul, Korea.
authors.forename: Kyung Bae
authors.initials: KB
authors.lastname: Min
authors.forename: Kang-Mu
authors.initials: KM
authors.lastname: Lee
authors.forename: Young Taek
authors.initials: YT
authors.lastname: Oh
authors.forename: Sang Sun
authors.initials: SS
authors.lastname: Yoon
mesh_terms: D000464:Alginates / Q000378:metabolism*; D019677:Artificial Gene Fusion; D020869:Gene Expression Profiling; D017930:Genes, Reporter; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D006801:Humans; D011550:Pseudomonas aeruginosa / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D013431:Sulfates; D020723:Glucuronic Acid
keywords: Pseudomonas aeruginosa; alginate; mucoid; nonmucoid reversion; sulfate