The revolution in drinking water microbiology and its impact on regulations and public Health

摘要

Not since the golden era of the 1880s with the first bacteriological identifications of pathogens causing waterborne disease have we seen such a rapid change in microbiology as is occurring today. At the forefront of this new wave are methods that allow genomic amplification and identification, which no longer limit us to target a single organism at a time. So why do we see limited uptake of these new methods, starting with the polymerase chain reaction (PCR) developed in the mid 1980s, microarrays (standard practice in medical diagnosis) or metagenomics (at last characterizing the some 90% of microbes that can not been cultured, including many novel pathogens)? Worse still, why 110 years on, do we still limit ourselves to largely focusing on coliform bacteria as a critical measure of safe drinking water? There are various reasons, particularly the lack of good epidemiologic evidence for endemic waterborne disease, or even a reliable indicator for drinking water outbreaks. Yet as one drills down to tease out the evidence, the frank reason seems to be a lack of integration of the key skills needed to tackle what is not a trivial problem: i.e. where do you see epidemiology, pathogen ecology, direct pathogen/indicator molecular methods and a whole of systems' engineering approach integrated to providing safe water? History too plays an important role here, with routine bacteriological monitoring being seen to provide a sense of security and a key component 'locked' into various regulatory rules and guidance in the US and internationally. But times need to change - not simply because technology could pull us alone. Rather, it would simply be more efficient and reduce the country's health burden to manage safe water provision as we do other key services, in a proactive managed way, rather than reacting to outbreaks (from Cryptosporidium, Salmonella, E. coli O157:H7 etc.). Integrating modern microbiological understanding and methods for managing safe water requires change on various fronts; this presentation focuses on microbiology. Many advances in molecular microbiology should be considered as research tools to gain a far better fundamental understanding of fecal and indigenous waterborne pathogen ecology. With that understanding, and links to mechanistic models of their fate and transport, radical approaches to the provision of safe water should become evident. An example focused on Legionella is discussed. Policies should stimulate this management approach, and ultimately new regulations can mature that utilize the knowledge gained through the application of current and evolving microbiological methods.