Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The galactophilic lectin, LecA, contributes to biofilm development in Pseudomonas aeruginosa.
AU - Diggle, Stephen P.
AU - Stacey, Rachael E.
AU - Dodd, Christine
AU - Cámara, Miguel
AU - Williams, Paul
AU - Winzer, Klaus
PY - 2006/6
Y1 - 2006/6
N2 - LecA (PA-IL) is a cytotoxic lectin and adhesin produced by Pseudomonas aeruginosa which binds hydrophobic galactosides with high specificity and affinity. By using a lecA–egfp translation fusion and immunoblot analysis of the biofilm extracellular matrix, we show that lecA is expressed in biofilm-grown cells. In static biofilm assays on both polystyrene and stainless steel, biofilm depth and surface coverage was reduced by mutation of lecA and enhanced in the LecA-overproducing strain PAO-P47. Biofilm surface coverage by the parent strain, PAO-P47 but not the lecA mutant on steel coupons was also inhibited by growth in the presence of either isopropyl-β-D-thiogalactoside (IPTG) or p-nitrophenyl-α-D-galactoside (NPG). Furthermore, mature wild-type biofilms formed in the absence of these hydrophobic galactosides could be dispersed by the addition of IPTG. In contrast, addition of p-nitrophenyl-α-L-fucose (NPF) which has a high affinity for the P. aeruginosa LecB (PA-IIL) lectin had no effect on biofilm formation or dispersal. Planktonic growth of P. aeruginosa PAO1 was unaffected by the presence of IPTG, NPG or NPF, nor was the strain able to utilize these sugars as carbon sources, suggesting that the observed effects on biofilm formation were due to the competitive inhibition of LecA–ligand binding. Similar results were also obtained for biofilms grown under dynamic flow conditions on steel coupons, suggesting that LecA contributes to P. aeruginosa biofilm architecture under different environmental conditions.
AB - LecA (PA-IL) is a cytotoxic lectin and adhesin produced by Pseudomonas aeruginosa which binds hydrophobic galactosides with high specificity and affinity. By using a lecA–egfp translation fusion and immunoblot analysis of the biofilm extracellular matrix, we show that lecA is expressed in biofilm-grown cells. In static biofilm assays on both polystyrene and stainless steel, biofilm depth and surface coverage was reduced by mutation of lecA and enhanced in the LecA-overproducing strain PAO-P47. Biofilm surface coverage by the parent strain, PAO-P47 but not the lecA mutant on steel coupons was also inhibited by growth in the presence of either isopropyl-β-D-thiogalactoside (IPTG) or p-nitrophenyl-α-D-galactoside (NPG). Furthermore, mature wild-type biofilms formed in the absence of these hydrophobic galactosides could be dispersed by the addition of IPTG. In contrast, addition of p-nitrophenyl-α-L-fucose (NPF) which has a high affinity for the P. aeruginosa LecB (PA-IIL) lectin had no effect on biofilm formation or dispersal. Planktonic growth of P. aeruginosa PAO1 was unaffected by the presence of IPTG, NPG or NPF, nor was the strain able to utilize these sugars as carbon sources, suggesting that the observed effects on biofilm formation were due to the competitive inhibition of LecA–ligand binding. Similar results were also obtained for biofilms grown under dynamic flow conditions on steel coupons, suggesting that LecA contributes to P. aeruginosa biofilm architecture under different environmental conditions.
U2 - 10.1111/j.1462-2920.2006.001001.x
DO - 10.1111/j.1462-2920.2006.001001.x
M3 - Journal article
VL - 8
SP - 1095
EP - 1104
JO - Environmental Microbiology
JF - Environmental Microbiology
SN - 1462-2912
IS - 6
ER -