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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710634
• 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住宅水管水质的直接控制，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住宅水管病原体(OPPP)的增长有关。目前基于传统粪便指示细菌(如大肠杆菌或肠球菌)的水质监测不能预测是否存在OPPP，也不能预测总异养生物的存在。随着替代水源使用的增加，通过收集雨水/雨水和回收废水用于饮用水和非饮用水以应对缺水和更可持续的用水做法，也增加了接触OPPP的可能性。因此，与肠道、水媒病原体的控制不同，目前没有基于风险的定量法规指南，也没有针对OPPP控制的系统最佳管理指南。 大多数已记录的疾病暴发是由雾化OPPP引起的，例如淋浴喷头、加湿器、按摩浴缸和喷雾软管(包括牙科中使用的那些)，尽管非结节分枝杆菌(NTM)可能通过与水的皮肤接触而导致伤口/皮肤感染，但也同样重要。重要的是，当前对一类OPPP的控制策略实际上可能会导致另一类OPPP的增加。例如，使用一氯胺控制医院管道系统内的嗜肺乳杆菌暴发，似乎适用于各种非结核分枝杆菌。而关键的非生物因素(温度、流动条件、管道材料、管道腐蚀产物的存在、消毒剂种类等)和生物性(存在生物膜、阿米巴宿主等)已知的因素会增加OPPP的可能性，但关于生态相互作用的信息令人惊讶地很少，这些信息可能为OPPP的持久控制战略提供见解。 因此，在这项提议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的响应选项分析描述生物强化和其他控制策略下的细菌和微真核(主要是自由生活的原生动物)群落成员，并与功能基因元基因组分析相关联来描述毒力和抗菌素耐药性(AMR)基因。 2)OPPP活性但不可培养和可培养状态的鉴定本主题将从探索以核糖体RNA(RRNA)为靶标的定量聚合酶链式反应开始，以提高检测可行和相关的OPPP与DNA基因靶向方法的敏感性和特异性。 3)通过使用新型浴室喷雾室来表征生物膜-水-气溶胶分配系数，以帮助确定暴露特征，并为浴室和相关水装置的设计和使用制定关键控制目标。