title: Involvement of iron in biofilm formation by Staphylococcus aureus.
abstract: Staphylococcus aureus is a human pathogen that forms biofilm on catheters and medical implants. The authors' earlier study established that 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (PGG) inhibits biofilm formation by S. aureus by preventing the initial attachment of the cells to a solid surface and reducing the production of polysaccharide intercellular adhesin (PIA). Our cDNA microarray and MALDI-TOF mass spectrometric studies demonstrate that PGG treatment causes the expression of genes and proteins that are normally expressed under iron-limiting conditions. A chemical assay using ferrozine verifies that PGG is a strong iron chelator that depletes iron from the culture medium. This study finds that adding FeSO(4) to a medium that contains PGG restores the biofilm formation and the production of PIA by S. aureus SA113. The requirement of iron for biofilm formation by S. aureus SA113 can also be verified using a semi-defined medium, BM, that contains an iron chelating agent, 2, 2'-dipyridyl (2-DP). Similar to the effect of PGG, the addition of 2-DP to BM medium inhibits biofilm formation and adding FeSO(4) to BM medium that contains 2-DP restores biofilm formation. This study reveals an important mechanism of biofilm formation by S. aureus SA113.
authors.affiliation: Department of Medical Biotechnology and Laboratory Science, Chang-Gung University, Taoyuan, Taiwan. thea@mail.cgu.edu.tw
authors.forename: Mei-Hui
authors.initials: MH
authors.lastname: Lin
authors.forename: Jwu-Ching
authors.initials: JC
authors.lastname: Shu
authors.forename: Hsiu-Yun
authors.initials: HY
authors.lastname: Huang
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Cheng
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D006801:Humans; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents; D047348:Hydrolyzable Tannins; D007502:Iron Chelating Agents; C435084:pentagalloylglucose; D007501:Iron