08 December 2011

Detecting E-Coli Contamination in Public Beaches

Contamination of public beaches by fecal matter caused be sewage overflow is dangerous to the public and also impacts the local economy.

32% of monitored beaches in 2006 were closed at least once due to elevated levels of fecal contamination indicator organisms (USEPA, 2007). In 2005–2006, the Center for Disease Control (CDC) reported 78 separate waterborne disease outbreaks that caused 4,412 illnesses and resulted in 5 deaths.

Escherichia coli is one of the most frequent causes of many common bacterial infections, including cholecystitis, bacteremia, cholangitis, urinary tract infection (UTI), and traveler's diarrhea, and other clinical infections such as neonatal meningitis and pneumonia. Current methods to detect E-coli requires around 24 to 48 hours to produce a result (see the 2nd video: Do you like swimming at a beach?).

A new, accurate, and economical sensor-based device capable of measuring E. coli levels in water samples in less than 1 to 8 hours could serve as a valuable early warning tool and make it easier to detect such contamination. It is described in an article in Environmental Engineering Science, a peer-reviewed journal published by Mary Ann Liebert, Inc.

The article also provides a detailed description of the Autonomous, Wireless, In-Situ (AWISS), battery-powered device, which contains a prototype optical sensor that can measure changes in fluorescence intensity in a water sample. Simply put, Fluorescence is the emission of light by a substance.

Video: Pathogenic Microorganisms in Recreational Waters

In the presence of E. coli bacteria an enzymatic reaction will cause an increase in fluorescence. The AWISS can detect high concentrations of bacteria in less than 1 hour and lower concentrations in less than 8 hours.

Jeffrey Talley of Johns Hopkins University, Baltimore, MD) and colleagues at the Environmental Technology Solutions, Gilbert, AZ, and the U.S. Army Corps of Engineers, Vicksburg, MS, present the results of a demonstration project using the AWISS device spanning 7 days. The detection system developed was able to collect and analyze a water sample every 6 hours and send the data collected to remote monitoring stations thru wireless transmissions. They compare the effectiveness of the AWISS to other E. coli detection methods currently approved by the U.S. Environmental Protection Agency (EPA).

"Pathogens in the aquatic environment pose significant human and ecological health risks. The work of Professor Talley and his colleagues in developing a remote sensing instrument to detect and transmit pathogen water quality information is a major advance in helping safeguard human health," says Domenico Grasso, PhD, Editor-in-Chief and Vice President for Research, Dean of the Graduate College, University of Vermont (Burlington).

Video: Detecting E-coli and other pathogens in the waters

Environmental Engineering Science is an authoritative, interdisciplinary monthly online peer-reviewed journal publishing state-of-the-art studies of innovative solutions to problems in air, water, and land contamination and waste disposal. The Journal features applications of environmental engineering and scientific discoveries, policy issues, environmental economics, and sustainable development. Complete tables of content and a sample issue may be viewed online.

Mary Ann Liebert, Inc is a privately held, fully integrated media company known for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research, including Sustainability: The Journal of Record, Environmental Justice, and Industrial Biotechnology. Its biotechnology trade magazine, Genetic Engineering & Biotechnology News (GEN), was the first in its field and is today the industry's most widely read publication worldwide. A complete list of the firm's 70 journals, books, and newsmagazines is available.