Biofilm formation by Pseudomonas aeruginosa:: role of the C4-HSL cell-to-cell signal and inhibition by azithromycin
Biofilm formation by Pseudomonas aeruginosa:: role of the C4-HSL cell-to-cell signal and inhibition by azithromycin
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DOI：
10.1093/jac/dkg397
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发表时间：
2003-10-01
影响因子：
5.2
通讯作者：
Van Delden, C
中科院分区：
文献类型：
--
作者：
Favre-Bonté, S;Köhler, T;Van Delden, C
目的：在铜绿假单胞菌中，生物膜的形成由依赖于3-氧代-C-12-HSL和C-4-HSL分泌的细胞间信号传导回路控制。以前的研究表明，C-4-HSL在生物膜形成中没有显着的作用。然而，在这些研究中用作对照的野生型PAO 1菌株PAO-BI本身在C-4-HSL的产生中受损。因此，我们想知道C-4-HSL在生物膜形成中的作用是否可能被低估，以及阿奇霉素是否通过干扰cell-to-cell signaling.Methods抑制生物膜形成：我们使用了野生型PAO 1菌株PAO-BI和PT 5在静态生物膜模型中的同基因突变体。生物膜的形成进行了定量使用结晶紫染色和胞外多糖measurements.Results：野生型菌株PAO-BI，由于其减少C-4-HSL分泌，产生40%的生物膜相比，野生型PAO 1菌株PT 5。使用菌株PT 5的同基因突变体，我们已经表明，而lasI突变体（3-oxo-C-12-HSL缺陷）产生类似数量的生物膜的野生型，rhlI突变体（C-4-HSL缺陷）产生的生物膜少70%。在后者菌株中，生物膜的形成可以通过添加外源C-4-HSL来恢复。已知减少3-氧代-C-12-HSL和C-4-HSL的产生的阿奇霉素抑制野生型PT 5的生物膜形成45%。这种抑制作用可以被逆转的细胞对细胞signals.Conclusions：我们的研究结果表明，C-4-HSL也发挥了重要作用，在生物膜的形成。此外，我们证明了使用细胞间信号传导阻断剂如阿奇霉素干扰生物膜形成的潜力。
Objectives: In Pseudomonas aeruginosa, biofilm formation is controlled by a cell-to-cell signalling circuit relying on the secretion of 3-oxo-C-12-HSL and C-4-HSL. Previous studies suggested that C-4-HSL plays no significant role in biofilm formation. However the wild-type PAO1 strain PAO-BI, used as a control in these studies is itself impaired in the production of C-4-HSL. We wondered therefore whether the role of C-4-HSL in biofilm formation might have been underestimated, and whether azithromycin inhibits biofilm formation by interfering with cell-to-cell signalling.Methods: We used isogenic mutants of wild-type PAO1 strains PAO-BI and PT5 in a static biofilm model. Biofilm formation was quantified using Crystal Violet staining and exopolysaccharide measurements.Results: Wild-type strain PAO-BI, as a result of its reduced C-4-HSL secretion, produced 40% less biofilm compared with the wild-type PAO1 strain PT5. Using isogenic mutants of strain PT5 we have shown that whereas a lasI mutant (deficient in 3-oxo-C-12-HSL) produced similar amounts of biofilm to the wild-type, a rhlI mutant (deficient in C-4-HSL) produced 70% less biofilm. In the latter strain, biofilm formation could be restored by addition of exogenous C-4-HSL. Azithromycin, known to reduce the production of both 3-oxo-C-12-HSL and C-4-HSL, inhibited biofilm formation of wild-type PT5 by 45%. This inhibition could be reversed by the addition of both cell-to-cell signals.Conclusions: Our results indicate that C-4-HSL also plays a significant role in biofilm formation. Furthermore, we demonstrate the potential of using cell-to-cell signalling blocking agents such as azithromycin to interfere with biofilm formation.