INRA, UR454 Microbiology, F-63122 Saint-Genès Champanelle, France.
Environ Microbiol. 2011 Apr;13(4):835-50. doi: 10.1111/j.1462-2920.2010.02378.x. Epub 2010 Nov 18.
The opportunistic and facultative intracellular pathogenic bacterium Listeria monocytogenes causes a rare but severe foodborne disease called listeriosis, the outcome of which can be fatal. The infection cycle and key virulence factors are now well characterized in this species. Nonetheless, this knowledge has not prevented the re-emergence of listeriosis, as recently reported in several European countries. Listeria monocytogenes is particularly problematic in the food industry since it can survive and multiply under conditions frequently used for food preservation. Moreover, this foodborne pathogen also forms biofilms, which increase its persistence and resistance in industrial production lines, leading to contamination of food products. Significant differences have been reported regarding the ability of different isolates to form biofilms, but no clear correlation can be established with serovars or lineages. The architecture of listerial biofilms varies greatly from one strain to another as it ranges from bacterial monolayers to the most recently described network of knitted chains. While the role of polysaccharides as part of the extracellular matrix contributing to listerial biofilm formation remains elusive, the importance of eDNA has been demonstrated. The involvement of flagella in biofilm formation has also been pointed out, but their exact role in the process remains to be clarified because of conflicting results. Two cell-cell communication systems LuxS and Agr have been shown to take part in the regulation of biofilm formation. Several additional molecular determinants have been identified by functional genetic analyses, such as the (p)ppGpp synthetase RelA and more recently BapL. Future directions and questions about the molecular mechanisms of biofilm formation in L. monocytogenes are further discussed, such as correlation between clonal complexes as revealed by MLST and biofilm formation, the swarming over swimming regulation hypothesis regarding the role of the flagella, and the involvement of microbial surface components recognizing adhesive matrix molecules in the colonization of abiotic and biotic surfaces.
机会主义兼兼性细胞内病原体李斯特菌会引起一种罕见但严重的食源性病，称为李斯特菌病，其结果可能是致命的。该物种的感染周期和关键毒力因子现在已经得到很好的描述。尽管如此，这一知识并没有阻止李斯特菌病的再次出现，最近在几个欧洲国家都有报道。李斯特菌在食品工业中特别成问题，因为它可以在经常用于食品保存的条件下生存和繁殖。此外，这种食源性病原体还会形成生物膜，从而增加其在工业生产线上的持久性和耐药性，导致食品产品受到污染。不同分离株形成生物膜的能力存在显著差异，但与血清型或谱系之间没有明确的相关性。李斯特菌生物膜的结构因菌株而异，从单层细菌到最近描述的编织链网络不等。虽然多糖作为细胞外基质的一部分在李斯特菌生物膜形成中的作用仍然难以捉摸，但 eDNA 的重要性已经得到证明。鞭毛在生物膜形成中的作用也已被指出，但由于结果相互矛盾，其在该过程中的确切作用仍有待澄清。两个细胞间通讯系统 LuxS 和 Agr 已被证明参与生物膜形成的调节。通过功能遗传分析已经确定了几个额外的分子决定因素，例如（p）ppGpp 合酶 RelA 和最近的 BapL。进一步讨论了李斯特菌生物膜形成的分子机制的未来方向和问题，例如 MLST 揭示的克隆复合体之间的相关性与生物膜形成、鞭毛在游泳调节假说中的作用以及微生物表面成分识别黏附基质分子在非生物和生物表面定殖中的作用。
