Speeding up E. coli detection: Laser sheds light on tracking source of microbial contamination on beach

January 14, 2011

A simple, automated method of tracking E. coli uses a laser to detect and monitor the microbe in potentially contaminated bodies of water or waterways. The technique described this month in the International Journal of Computational Biology and Drug Design could reduce the incidence of waterborne disease outbreaks.

Microbial contamination of water is a worldwide environmental and health problem. Water related diseases are the leading causes of illness and death in the world. The impacts of water quality on public health and economy are highly significant as evidenced by outbreaks, boil water advisories, contamination of irrigation waters, and beach closures. Considerable government and private efforts have been made to improve and monitor water quality.

Beach managers need reliable methods to determine the origins of contaminants in order to reduce those sources and maintain a healthy beach. Sources of fecal contamination in recreational waters are often unknown and/or of non-point origins. Identifying and reducing the sources of for a particular beach is often hindered by the presence of multiple and diffuse sources, natural variability in bacterial indicator concentrations over space and time, and the dynamic currents, , and natural processes that affect these concentrations.

The Indiana Department of Environmental Management (IDEM), for example, has provided substantial funding support to coastal communities through the BEACH Act to increase the frequency of beach monitoring. Whereas beach monitoring for fecal bacterial indicators such as E. coli is necessary, knowing the source of bacterial contamination is fundamentally important for preventing microbial pollution in water. Simple counts of fecal indicator bacteria do not provide vital information regarding the source of . It is thus necessary to develop scientific techniques for microbial source tracking. With knowledge gained from employment of appropriate methodologies, it would be possible to assess risk, choose effective remediation strategies, and bring polluted waters into compliance with regulatory policies.

Now, Bin Chen of Purdue University Calumet, and colleagues there and at the University of Minnesota, St Paul, have turned to a laser technique for potential use in microbial source tracking. Their technique uses laser imaging of bacterial colonies and high-resolution optical scattering image analysis to identify the host species of E. coli in a sample.

"The water quality of lakes, rivers and streams in many areas has long been monitored in the government and other agencies," the team says, "however, many of them still do not meet the goal of 'fishable and swimmable' because identifying the source of is difficult." The new technology, demonstrated by Chen and colleagues, could address that shortfall allowing contamination to be remediated.

Explore further: Pointing a finger at the source of fecal bacteria

More information: "Laser imaging for rapid Microbial Source Tracking" in Int. J. Computational Biology and Drug Design, 2010, 3, 177-186

Related Stories

Pointing a finger at the source of fecal bacteria

May 23, 2007

Excessive levels of fecal bacteria were to blame for almost 60 percent of Nebraska streams deemed impaired by federal and state environmental laws in 2004. In order to develop effective pollution-control strategies, it is ...

More swimmers means more pathogens in the water

July 2, 2007

The levels of potentially harmful waterborne microorganisms in rivers, lakes and other recreational waterways may be highest when the water is most crowded with swimmers. Researchers at the Johns Hopkins Bloomberg School ...

Real-world proof of hand washing's effectiveness

May 5, 2010

Scientists are reporting dramatic new real-world evidence supporting the idea that hand washing can prevent the spread of water-borne disease. It appears in a new study showing a connection between fecal bacteria contamination ...

Recommended for you

Study reveals how nanochannels select potassium ions

August 25, 2015

(Phys.org)—One of the mysteries in biology is how cells can selectively diffuse potassium across a membrane. Biological systems rely on a delicate balance between these potassium and sodium ion concentrations in the surrounding ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.