title: Reduction of polysaccharide production in Pseudomonas aeruginosa biofilms by bismuth dimercaprol (BisBAL) treatment.
abstract: Microorganisms in biofilms, cells attached to a surface and embedded in secreted insoluble extracellular polymers, are recalcitrant to chemical biocides and antibiotics. When Pseudomonas aeruginosa ERC1 biofilms were treated continuously with 1 x MIC of bismuth dimercaprol (BisBAL), biofilm density determined by both total cell counts and viable cell counts increased during the first 30 h period then decreased thereafter. After 120 h of treatment there was an approximate 3-log reduction in viable cell areal density compared with the untreated control. Per-cell total polysaccharide production was significantly reduced in biofilms exposed to 12.5 microM BisBAL compared with the untreated control. In biofilm cultures, 1 x MIC of BisBAL did not initially kill attached cells but was enough to reduce polysaccharide production. As treatment proceeded, the normalized polysaccharide content was reduced and those cells attached became susceptible to 1 x MIC of BisBAL.
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan, ROC. cthuang@ccms.ntu.edu.tw
authors.forename: C T
authors.initials: CT
authors.lastname: Huang
authors.forename: P S
authors.initials: PS
authors.lastname: Stewart
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D001729:Bismuth; D015169:Colony Count, Microbial; D003470:Culture Media; D004112:Dimercaprol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004338:Drug Combinations; D008826:Microbial Sensitivity Tests; D009942:Organometallic Compounds / Q000494:pharmacology*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D011135:Polysaccharides, Bacterial; C103324:bismuth dimercaptopropanol; D004112:Dimercaprol; D001729:Bismuth