Rapid, High-Throughput Identification of Contaminated Drinking Water

Safe and readily available water is perhaps one of the most fundamental requirements in any society. According to the World Health Organization (WHO)⁽¹⁾, access to clean water is a leading factor in raising a country’s economic growth and contributes greatly to a reduction in poverty. Even in first-world countries where most people don’t give a second thought to their water or where it comes from, outbreaks of disease spread through municipal water supplies are far from being uncommon. According to the Centers for Disease Control (CDC)⁽²⁾, the five leading causes of outbreaks in the United States are, in order of prevalence: Giardia, Legionella, Norovirus, Shigella, and Campylobacter, with other diseases including Salmonella, E.coli, Cryptosporidium, and Hepatitis A also putting in an appearance.

Since we cannot reliably predict where bacteria might enter our municipal water supplies, rapid water testing becomes the front-line tool in preventing outbreaks. Current detection methods largely rely on cell culture and microscopy techniques. However, these methods are slow, time-consuming, and can produce inaccurate results for some types of bacteria, which can lead to a delayed response and allow pathogens to spread further through a population before action is taken.

An alternative testing method already in use by the research, food, and healthcare industries relies on the detection of microbial cellular adenosine triphosphate (ATP). As ATP is produced by all bacteria it enables detection of the presence of bacteria without needing to specify a priori which bacteria we want to test for. Once a positive ATP test has been confirmed, additional targeted water testing can be used to determine the species and source of the contamination. However, the method is generally used on a single sample basis and is thus not useful as a front-line method for high-throughput sample testing..

A rapid high-throughput method for ATP quantification in drinking water

Scientists at Dalhousie University in Halifax, Nova Scotia have been working to devise rapid, high-throughput drinking water testing protocols without sacrificing accuracy. In a 2020 publication⁽³⁾ they describe a modified ATP analysis method that can be used as a rapid, simple, and high-throughput water quality screen to identify bacterial contamination in drinking water.

ATP assays traditionally use luciferase as a reporter enzyme; the amount of light emitted when luciferin and ATP react is directly proportional to the amount of ATP in the sample. The researchers wanted to incorporate this reporting mechanism into their new assay, while at the same time developing a high-throughput format suitable for front-line screening.