Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
Biofouling. 2012;28(10):1129-39. doi: 10.1080/08927014.2012.735231.
Water in healthcare environments can be a source for healthcare-associated infections (HAI). However, information on the exposure risk to opportunistic pathogens in potable water distribution systems (PWDS) is lacking. Laboratory studies characterizing the interaction of opportunistic pathogens with biofilms are needed to understand their role in water systems within healthcare facilities. A stable, repeatable, PWDS multi-species biofilm model comprising Sphingomonas paucimobilis, Methylobacterium sp., Delftia acidovorans, and Mycobacterium mucogenicum was developed in the CDC Biofilm Reactor (CBR), reaching 6 log(10) CFU cm(-2) within 6 days. The model was used to investigate the interaction of the opportunistic pathogen M. mucogenicum with the other species, and to determine the efficacy of monochloramine (NH(2)Cl) as a disinfectant against 2-week-old biofilms. Addition of 1 or 2 mg l(-1) NH(2)Cl resulted in the same or an increased log density of viable M. mucogenicum in the biofilm while inactivating some of the Proteobacteria. Although M. mucogenicum preferentially resided in the biofilm, NH(2)Cl exposure caused release of viable M. mucogenicum from the biofilm into the water. Additional studies with this model should determine if sodium hypochlorite has a comparative effect and if other nontuberculous mycobacteria (NTM) respond to NH(2)Cl similarly.
医疗机构中的水可能成为医源性感染（HAI）的源头。然而，关于在饮用水分配系统（PWDS）中机会性病原体暴露风险的信息却很缺乏。需要进行实验室研究，以了解这些机会性病原体在医疗机构内水系统中的作用，这些研究要对其与生物膜的相互作用进行特征描述。在疾控中心生物膜反应器（CBR）中构建了一种稳定的、可重复的多物种 PWDS 生物膜模型，其中包含粘质沙雷氏菌、甲基杆菌、食酸戴尔福特菌和黏液分枝杆菌，6 天内达到 6 log(10) CFU cm(-2)。该模型用于研究机会性病原体黏液分枝杆菌与其他物种的相互作用，并确定单氯胺（NH(2)Cl）作为消毒剂对 2 周龄生物膜的杀菌效果。添加 1 或 2 mg l(-1) NH(2)Cl 导致生物膜中存活的黏液分枝杆菌的密度相同或增加，同时使一些变形菌失活。尽管黏液分枝杆菌优先存在于生物膜中，但 NH(2)Cl 暴露会导致生物膜中的存活黏液分枝杆菌释放到水中。使用该模型的进一步研究应确定次氯酸钠是否具有类似的效果，以及其他非结核分枝杆菌（NTM）是否对 NH(2)Cl 有类似的反应。
