Department of Biological Sciences, Biofilm Research Group, University of Calgary, Alberta, Canada.
Biofouling. 2013 Sep;29(8):917-28. doi: 10.1080/08927014.2013.816298. Epub 2013 Jul 24.
A model biofilm, formed of multiple species from environmental drinking water, including opportunistic pathogens, was created to explore the tolerance of multi-species biofilms to chlorine levels typical of water-distribution systems. All species, when grown planktonically, were killed by concentrations of chlorine within the World Health Organization guidelines (0.2-5.0 mg l(-1)). Higher concentrations (1.6-40-fold) of chlorine were required to eradicate biofilm populations of these strains, ~70% of biofilms tested were not eradicated by 5.0 mg l(-1) chlorine. Pathogenic bacteria within the model multi-species biofilms had an even more substantial increase in chlorine tolerance; on average ~700-1100 mg l(-1) chlorine was required to eliminate pathogens from the biofilm, 50-300-fold higher than for biofilms comprising single species. Confocal laser scanning microscopy of biofilms showed distinct 3D structures and multiple cell morphologies and arrangements. Overall, this study showed a substantial increase in the chlorine tolerance of individual species with co-colonization in a multi-species biofilm that was far beyond that expected as a result of biofilm growth on its own.
创建了一个由环境饮用水中的多种物种组成的模型生物膜，包括机会性病原体，以探索多物种生物膜对典型供水管网中氯水平的耐受能力。当所有物种浮游生长时，都会被世界卫生组织指南（0.2-5.0mg l(-1)）规定的氯浓度杀死。需要更高浓度（1.6-40 倍）的氯才能消灭这些菌株的生物膜种群，约 70%的生物膜测试样本未被 5.0mg l(-1)的氯消灭。模型多物种生物膜内的致病菌对氯的耐受性甚至更高；平均需要 700-1100mg l(-1)的氯才能从生物膜中消灭病原体，比由单一物种组成的生物膜高 50-300 倍。生物膜的共焦激光扫描显微镜显示出明显的三维结构和多种细胞形态和排列。总的来说，这项研究表明，在多物种生物膜中，单个物种的共同定殖会导致其对氯的耐受性显著增加，远远超过仅因生物膜生长而产生的预期。
