Role of Extracellular DNA during Biofilm Formation by Listeria monocytogenes
Role of Extracellular DNA during Biofilm Formation by Listeria monocytogenes
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DOI：
10.1128/aem.02361-09
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发表时间：
2010-04-01
影响因子：
4.4
通讯作者：
Molin, Soren
中科院分区：
文献类型：
--
作者：
Harmsen, Morten;Lappann, Martin;Molin, Soren
单核细胞增生李斯特菌是一种食源性病原体，能够在恶劣的环境中生存。据信，这是通过形成生物膜来实现的，生物膜是包裹在自产基质中的表面相关的多细胞结构。在本文中，我们表明细胞外DNA （eDNA）可能是单核增生乳杆菌生物膜基质的唯一核心成分，并且在41株单核增生乳杆菌的初始附着和早期生物膜形成中都是必需的。dna酶I处理导致生物膜的分散，不仅在微滴盘试验中，而且在流式细胞生物膜试验中。然而，也证明了在没有eDNA的培养中，无论是李斯特菌基因组DNA还是鲑鱼精子DNA本身都不能恢复粘附能力。对其他必要成分的研究表明，肽聚糖（PG），特别是n -乙酰氨基葡萄糖（NAG），可以与DNA相互作用，恢复粘附。如果在加入基因组或鲑鱼精子DNA之前将短DNA片段（长度小于约500 bp）添加到无edna的培养物中，则粘附被阻止，这表明粘附需要高分子量DNA，并且细胞表面的粘附位点数量可以饱和。
Listeria monocytogenes is a food-borne pathogen that is capable of living in harsh environments. It is believed to do this by forming biofilms, which are surface-associated multicellular structures encased in a self-produced matrix. In this paper we show that in L. monocytogenes extracellular DNA (eDNA) may be the only central component of the biofilm matrix and that it is necessary for both initial attachment and early biofilm formation for 41 L. monocytogenes strains that were tested. DNase I treatment resulted in dispersal of biofilms, not only in microtiter tray assays but also in flow cell biofilm assays. However, it was also demonstrated that in a culture without eDNA, neither Listeria genomic DNA nor salmon sperm DNA by itself could restore the capacity to adhere. A search for additional necessary components revealed that peptidoglycan (PG), specifically N-acetylglucosamine (NAG), interacted with the DNA in a manner which restored adhesion. If a short DNA fragment (less than approximately 500 bp long) was added to an eDNA-free culture prior to addition of genomic or salmon sperm DNA, adhesion was prevented, indicating that high-molecular-weight DNA is required for adhesion and that the number of attachment sites on the cell surface can be saturated.