Welch Ken, Cai Yanling, Strømme Maria
Division for Nanotechnology and Functional Materials, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, 75121 Uppsala, Sweden.
J Funct Biomater. 2012 Jun 1;3(2):418-31. doi: 10.3390/jfb3020418.
In this study we present a scheme for quantitative determination of biofilm viability offering significant improvement over existing methods with metabolic assays. Existing metabolic assays for quantifying viable bacteria in biofilms usually utilize calibration curves derived from planktonic bacteria, which can introduce large errors due to significant differences in the metabolic and/or growth rates of biofilm bacteria in the assay media compared to their planktonic counterparts. In the presented method we derive the specific growth rate of Streptococcus mutans bacteria biofilm from a series of metabolic assays using the pH indicator phenol red, and show that this information could be used to more accurately quantify the relative number of viable bacteria in a biofilm. We found that the specific growth rate of S. mutans in biofilm mode of growth was 0.70 h-1, compared to 1.09 h-1 in planktonic growth. This method should be applicable to other bacteria types, as well as other metabolic assays, and, for example, to quantify the effect of antibacterial treatments or the performance of bactericidal implant surfaces.
在本研究中，我们提出了一种用于定量测定生物膜活力的方案，与现有的代谢分析方法相比有显著改进。现有的用于量化生物膜中活细菌的代谢分析通常利用从浮游细菌得出的校准曲线，由于与浮游细菌相比，生物膜细菌在分析培养基中的代谢和/或生长速率存在显著差异，这可能会引入较大误差。在本方法中，我们使用pH指示剂酚红通过一系列代谢分析得出变形链球菌生物膜的比生长速率，并表明该信息可用于更准确地量化生物膜中活细菌的相对数量。我们发现，变形链球菌在生物膜生长模式下的比生长速率为0.70 h-1，而在浮游生长模式下为1.09 h-1。该方法应适用于其他细菌类型以及其他代谢分析，例如，用于量化抗菌治疗的效果或杀菌植入物表面的性能。
