A characterization of DNA release in Pseudomonas aeruginosa cultures and biofilms
A characterization of DNA release in Pseudomonas aeruginosa cultures and biofilms
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DOI：
10.1111/j.1365-2958.2005.05008.x
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发表时间：
2006-02-01
影响因子：
3.6
通讯作者：
Tolker-Nielsen, T
中科院分区：
文献类型：
--
作者：
Allesen-Holm, M;Barken, KB;Tolker-Nielsen, T
铜绿假单胞菌产生细胞外DNA，其在生物膜中充当细胞与细胞互连基质组分。用聚合酶链反应和Southern杂交技术对细胞外DNA和染色体DNA进行了比较，结果表明细胞外DNA与全基因组DNA相似。铜绿假单胞菌生物膜和培养物中的细胞外DNA经由细菌亚群的裂解产生的证据通过实验获得，其中评估从含lacZ的铜绿假单胞菌菌株释放的细胞外β-半乳糖苷酶。用野生型和laslrhII、pqsA、pqsL和fliMpilA突变体进行的实验表明，细胞外DNA是通过依赖于酰基高丝氨酸内酯和假单胞菌喹诺酮信号传导以及鞭毛和IV型皮利的机制产生的。用不同的DNA染色剂染色的流动室生长的野生型铜绿假单胞菌生物膜的显微镜调查表明，细胞外DNA主要位于蘑菇状多细胞结构的柄中，特别是在柄的外部具有高浓度，形成柄形成细菌和帽形成细菌之间的边界。由laslrhll、pqsA和fliMpilA突变体形成的生物膜比由野生型形成的生物膜含有更少的细胞外DNA，并且突变体生物膜比野生型生物膜更容易受到十二烷基硫酸钠的处理。
Pseudomonas aeruginosa produces extracellular DNA which functions as a cell-to-cell interconnecting matrix component in biofilms. Comparison of extracellular DNA and chromosomal DNA by the use of polymerase chain reaction and Southern analysis suggested that the extracellular DNA is similar to whole-genome DNA. Evidence that the extracellular DNA in P. aeruginosa biofilms and cultures is generated via lysis of a subpopulation of the bacteria was obtained through experiments where extracellular beta-galactosidase released from lacZ-containing P. aeruginosa strains was assessed. Experiments with the wild type and laslrhll, pqsA, pqsL and fliMpilA mutants indicated that the extracellular DNA is generated via a mechanism which is dependent on acyl homoserine lactone and Pseudomonas quinolone signalling, as well as on flagella and type IV pili. Microscopic investigation of flow chamber-grown wild-type P. aeruginosa biofilms stained with different DNA stains suggested that the extracellular DNA is located primarily in the stalks of mushroom-shaped multicellular structures, with a high concentration especially in the outer part of the stalks forming a border between the stalk-forming bacteria and the cap-forming bacteria. Biofilms formed by laslrhll, pqsA and fliMpilA mutants contained less extracellular DNA than biofilms formed by the wild type, and the mutant biofilms were more susceptible to treatment with sodium dodecyl sulphate than the wild-type biofilm.