Ashbolt Nicholas J
School of Public Health, University of Alberta, Rm 3-57D South Academic Building, Edmonton, AB T6G 2G7, Canada.
Pathogens. 2015 Jun 19;4(2):390-405. doi: 10.3390/pathogens4020390.
Major waterborne (enteric) pathogens are relatively well understood and treatment controls are effective when well managed. However, water-based, saprozoic pathogens that grow within engineered water systems (primarily within biofilms/sediments) cannot be controlled by water treatment alone prior to entry into water distribution and other engineered water systems. Growth within biofilms or as in the case of Legionella pneumophila, primarily within free-living protozoa feeding on biofilms, results from competitive advantage. Meaning, to understand how to manage water-based pathogen diseases (a sub-set of saprozoses) we need to understand the microbial ecology of biofilms; with key factors including biofilm bacterial diversity that influence amoebae hosts and members antagonistic to water-based pathogens, along with impacts from biofilm substratum, water temperature, flow conditions and disinfectant residual-all control variables. Major saprozoic pathogens covering viruses, bacteria, fungi and free-living protozoa are listed, yet today most of the recognized health burden from drinking waters is driven by legionellae, non-tuberculous mycobacteria (NTM) and, to a lesser extent, Pseudomonas aeruginosa. In developing best management practices for engineered water systems based on hazard analysis critical control point (HACCP) or water safety plan (WSP) approaches, multi-factor control strategies, based on quantitative microbial risk assessments need to be developed, to reduce disease from largely opportunistic, water-based pathogens.
主要的水传播（肠道）病原体已得到较好的了解，并且在管理良好的情况下，治疗控制措施是有效的。然而，在工程水系统（主要在生物膜/沉积物中）中生长的水基腐生病原体，在进入配水系统和其他工程水系统之前，仅靠水处理是无法控制的。在生物膜内生长，或者如嗜肺军团菌的情况，主要在以生物膜为食的自由生活原生动物内生长，是由竞争优势导致的。这意味着，要了解如何管理水基病原体疾病（腐生菌病的一个子集），我们需要了解生物膜的微生物生态学；关键因素包括影响变形虫宿主和对水基病原体具有拮抗作用的生物膜细菌多样性，以及生物膜基质、水温、水流条件和消毒剂残留的影响——所有这些都是控制变量。文中列出了主要的腐生病原体，包括病毒、细菌、真菌和自由生活原生动物，但如今，饮用水造成的大多数公认健康负担是由军团菌、非结核分枝杆菌（NTM）以及在较小程度上由铜绿假单胞菌引起的。在基于危害分析关键控制点（HACCP）或水安全计划（WSP）方法制定工程水系统的最佳管理实践时，需要制定基于定量微生物风险评估的多因素控制策略，以减少主要由机会性水基病原体引起的疾病。
