Control options for premise plumbing opportunistic pathogen exposures

场所管道机会性病原体暴露的控制选项

• 批准号: RGPIN-2017-04004
• 负责人: Ashbolt, Nicholas
• 金额: $ 2.99万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=644203
• 关键词: Control; options; premise; plumbing; opportunistic

There is no direct control of premise plumbing water quality in Canada nor in many international jurisdictions, yet over 60% of drinking water outbreaks and 80% of hospitalization insurance claims in North America are thought to be associated with the growth of opportunistic, premise plumbing pathogens (OPPP). Current water quality monitoring based on traditional faecal indicator bacteria (such as E. coli or enterococci) provides no predictive capability for the presence of OPPP, nor do the presence of total heterotrophs. With the growth in the use of alternative water sources, there is also increased potential for exposures to OPPP via harvested rainwater/stormwater and recycled wastewaters for potable and non-potable uses to deal with water scarcity and more sustainable water practices. Hence, unlike the control of enteric, waterborne pathogens, there is currently no risk-based, quantitative guidance available for regulations nor systematic best management guidance for OPPP control. ******The majority of documented disease outbreaks result from aerosolized OPPP, such as from shower heads, humidifiers, jacuzzis, and spray hoses (including those used in dentistry), although non-tuburculous mycobacteria (NTM) are probably as important via dermal contact of water that results in wound/skin infections. Importantly, current control strategies for one class of OPPP may actually cause an increase in another. For example, use of monochloramine to control L. pneumophila outbreaks within hospital plumbing systems, appear to select for various NTM. While key abiotic (temperature, flow conditions, pipe material, presence of pipe corrosion products, disinfectant type etc.) and biotic (present of biofilm, amoebal hosts etc.) factors are known to enhance the likelihood of OPPP, there is surprisingly little information on the ecological interactions that may provide insights into lasting control strategies for OPPP. ******Therefore there are three key themes of research within this proposal:***1) Pipe biofilm community and functional gene responses to control options Analysis to describe bacterial and microeukaryotic (principally free-living protozoa) community members under bio-augmentation and other control strategies, and correlation with functional gene metagenomic analyses to describe virulence and antimicrobial resistance (AMR) genes.***2) Identification of active but non-culturable as well as culturable states of OPPPs This theme will start by exploring ribosomal RNA (rRNA) targeted qPCR to improve sensitivity and specificity in detecting viable and relevant OPPP versus DNA-gene targeted approaches.***3) Characterization of biofilm-to-water-to-aerosol partitioning coefficients via use of novel bathroom aerosolization chambers to aid exposure characterization and develop critical control targets for design and use of bathroom and related water fixtures.

加拿大和许多国际司法管辖区都没有对室内管道水质进行直接控制，但北美 60% 以上的饮用水爆发和 80% 的住院保险索赔被认为与机会性室内管道病原体 (OPPP) 的增长有关。目前基于传统粪便指示菌（例如大肠杆菌或肠球菌）的水质监测无法预测 OPPP 的存在，也无法预测总异养生物的存在。随着替代水源使用的增加，通过收集的雨水/暴雨和回收废水用于饮用水和非饮用水以应对水资源短缺和更可持续的用水实践，OPPP 暴露的可能性也随之增加。因此，与肠道、水源性病原体的控制不同，目前没有针对 OPPP 控制的基于风险的定量指导，也没有系统的最佳管理指导。 ******大多数记录在案的疾病爆发都是由雾化的 OPPP 引起的，例如来自淋浴喷头、加湿器、按摩浴缸和喷雾软管（包括牙科中使用的软管），尽管非结核分枝杆菌 (NTM) 可能通过皮肤接触水而导致伤口/皮肤感染，这也很重要。重要的是，目前针对一类 OPPP 的控制策略实际上可能会导致另一类 OPPP 的增加。例如，使用一氯胺来控制医院管道系统内嗜肺军团菌的爆发，似乎可以选择各种 NTM。虽然已知关键的非生物因素（温度、流动条件、管道材料、管道腐蚀产物的存在、消毒剂类型等）和生物因素（生物膜的存在、变形虫宿主等）会增加 OPPP 的可能性，但令人惊讶的是，有关生态相互作用的信息却很少，这些信息可能为 OPPP 的持久控制策略提供见解。 ******因此，本提案中存在三个关键研究主题：***1) 管道生物膜群落和功能基因对控制选项的反应 分析以描述生物增强和其他控制策略下的细菌和微真核生物（主要是自由生活的原生动物）群落成员，并与功能基因宏基因组分析相关以描述毒力和抗菌素耐药性 (AMR) ***2) 鉴定 OPPP 的活性但不可培养以及可培养状态 本主题将从探索核糖体 RNA (rRNA) 靶向 qPCR 开始，以提高检测可行且相关的 OPPP 与 DNA 基因靶向方法的灵敏度和特异性。***3) 通过使用新型浴室雾化来表征生物膜到水到气溶胶的分配系数 室，以帮助暴露表征并制定浴室和相关水装置的设计和使用的关键控制目标。