Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
FEMS Microbiol Rev. 2023 Sep 5;47(5). doi: 10.1093/femsre/fuad050.
In vitro biofilms are communities of microbes with unique features compared to individual cells. Biofilms are commonly characterized by physical traits like size, adhesion, and a matrix made of extracellular substances. They display distinct phenotypic features, such as metabolic activity and antibiotic tolerance. However, the relative importance of these traits depends on the environment and bacterial species. Various mechanisms enable biofilm-associated bacteria to withstand antibiotics, including physical barriers, physiological adaptations, and changes in gene expression. Gene expression profiles in biofilms differ from individual cells but, there is little consensus among studies and so far, a 'biofilm signature transcriptome' has not been recognized. Additionally, the spatial and temporal variability within biofilms varies greatly depending on the system or environment. Despite all these variable conditions, which produce very diverse structures, they are all noted as biofilms. We discuss that clinical biofilms may differ from those grown in laboratories and found in the environment and discuss whether the characteristics that are commonly used to define and characterize biofilms have been shown in infectious biofilms. We emphasize that there is a need for a comprehensive understanding of the specific traits that are used to define bacteria in infections as clinical biofilms.
体外生物膜是微生物群落，与单个细胞相比具有独特的特征。生物膜通常具有物理特征，如大小、附着力和由细胞外物质组成的基质。它们表现出不同的表型特征，如代谢活性和抗生素耐药性。然而，这些特征的相对重要性取决于环境和细菌种类。生物膜相关细菌有多种机制来抵抗抗生素，包括物理屏障、生理适应和基因表达的变化。生物膜中基因表达谱与单个细胞不同，但研究之间几乎没有共识，到目前为止，还没有识别出“生物膜特征转录组”。此外，生物膜内的空间和时间变异性差异很大，具体取决于系统或环境。尽管存在所有这些可变条件，产生了非常多样化的结构，但它们都被定义为生物膜。我们讨论了临床生物膜可能与在实验室中生长和在环境中发现的生物膜不同，并讨论了通常用于定义和表征生物膜的特征是否在感染性生物膜中得到了证明。我们强调，需要全面了解用于定义感染中细菌的特定特征，因为临床生物膜。
