IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar 4710-057, Braga, Portugal.
Biofouling. 2009;25(4):345-51. doi: 10.1080/08927010902803305.
Legionella pneumophila is a waterborne pathogen that has been isolated sporadically from drinking water distribution systems (DWDS). Resistance to disinfectants is mainly attributed to the association of cells with amoebae, but biofilms are also thought to provide some degree of protection. In the present work, a two-stage chemostat was used to form heterotrophic biofilms from drinking water to study the influence of chlorine on the presence of naturally occurring L. pneumophila. The pathogen was tracked in planktonic and sessile biofilm phases using standard culture recovery techniques for cultivable cells and a peptide nucleic acid fluorescence in situ hybridisation assay for total cells. The results showed that the total number of L. pneumophila cells in biofilms was not affected by the concentrations of chlorine tested, and the presence of L. pneumophila could not be detected by culturing. To restrict the outbreaks of disease caused by this bacterium, efforts need to be concentrated on preventing L. pneumophila from re-entering an infectious state by maintaining residual disinfectant levels through the entire DWDS network so that the resuscitation of cells via contact with amoebae is prevented.
嗜肺军团菌是一种水源性病原体，曾从饮用水分配系统（DWDS）中零星分离出来。对消毒剂的抗性主要归因于细胞与变形虫的关联，但生物膜也被认为提供了一定程度的保护。在本工作中，使用两阶段恒化器从饮用水中形成异养生物膜，以研究氯对天然存在的嗜肺军团菌存在的影响。使用可培养细胞的标准培养恢复技术和总细胞的肽核酸荧光原位杂交检测法，在浮游和固着生物膜相中跟踪病原体。结果表明，生物膜中嗜肺军团菌细胞的总数不受测试氯浓度的影响，并且通过培养无法检测到嗜肺军团菌的存在。为了限制该细菌引起的疾病爆发，需要集中精力通过整个 DWDS 网络维持残余消毒剂水平来防止嗜肺军团菌重新进入感染状态，从而防止通过与变形虫接触使细胞复苏。
