Control options for premise plumbing opportunistic pathogen exposures

加拿大和许多国际司法管辖区都没有直接控制房屋管道水质，但北美超过60%的饮用水爆发和80%的住院保险索赔被认为与机会性房屋管道病原体（OPPP）的增长有关。目前的水质监测是基于传统的粪便指示细菌（如大肠杆菌）。大肠杆菌或肠球菌）对OPPP的存在没有预测能力，总异养菌的存在也没有。随着替代水源使用的增加，通过收集雨水/暴雨水和回收废水用于饮用和非饮用用途以应对水短缺和更可持续的用水做法，暴露于OPPP的可能性也增加了。因此，与肠道、水传播病原体的控制不同，目前没有基于风险的定量指南可用于法规，也没有系统的最佳管理指南用于OPPP控制。 大多数记录在案的疾病爆发是由雾化的OPPP引起的，例如来自淋浴头、加湿器、按摩浴缸和喷雾软管（包括牙科中使用的那些），尽管非结核分枝杆菌（NTM）可能通过皮肤接触水导致伤口/皮肤感染同样重要。重要的是，目前对一类OPPP的控制策略实际上可能导致另一类OPPP的增加。例如，使用一氯胺防治L.医院管道系统内的嗜肺菌爆发，似乎选择各种NTM。而关键的非生物（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（存在生物膜、阿米巴宿主等）虽然已知的因素，以提高OPPP的可能性，但令人惊讶的是，很少有信息的生态相互作用，可以提供洞察持久的控制策略OPPP。 因此，本提案中有三个关键的研究主题： 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，以及与功能基因宏基因组分析的相关性，以描述毒力和抗菌素耐药性（AMR）基因。 2)OPPPs的活性但不可培养以及可培养状态的鉴定本主题将从探索核糖体RNA（rRNA）靶向qPCR开始，以提高检测可行和相关OPPPs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室表征生物膜-水-气溶胶分配系数，以辅助暴露表征，并为浴室和相关水装置的设计和使用制定关键控制目标。

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.