ROI Series: Advancing detection of microorganisms in sea water and seafoodPosted: 10 01, 2015
Written by Mimi Huang
PhD Student in Toxicology at the University of North Carolina at Chapel Hill
Going to the beach? In addition to keeping an eye out for sharks, public health officials are also watching for smaller microorganisms that probably won’t take an arm off, but could turn a day at the beach into a day in the hospital.
Conventional methods for microbial water quality testing require at least a day for the microorganism cultures to grow for further analysis. However, bacterial concentrations in the water tend to fluctuate within hours, so current analytical techniques prevent effective and timely protection of public health. Ineffective microbial analysis of recreational waters can result in contaminated beaches remaining open for use. At the same time, other beaches may be closed even though bacterial contamination may have already subsided. The capacity to quickly test bacterial contamination of water would substantially improve the ability of officials to protect public health.
Professor Rachel Noble, PhD and her laboratory at the UNC Institute of Marine Sciences are doing just that. The Noble lab is developing rapid, molecular techniques for detecting microbial contamination in food and water, such as species of Enterrococcus or E. coli. These microbes could cause severe illness in individuals who eat contaminated seafood such as raw oysters or in susceptible individuals who swim in contaminated water.
Quantitative polymerase chain reaction (qPCR) is a technique used to detect particular genes or genetic sequences encoded in DNA. All living organisms contain DNA, and genes and sequences can vary among species and individuals. The Noble lab has identified unique DNA sequences for various species of bacteria commonly found in contaminated water or seafood. These bacterial “fingerprints” can be quantified using qPCR and help to identify if harmful bacteria are present in a water sample. Most importantly, these qPCR analyses are time effective: They are completed in 2-4 hours! This means that contaminated beaches could be closed almost immediately and contaminated seafood could be prevented from entering the market.
Last year, Noble and her collaborators organized a weeklong workshop where people of all backgrounds (academics, government employees, industry representatives, and students) were trained to use pre-packaged test kits.These molecular diagnostic kits designed by the Noble lab have great potential for improving the speed of water and food quality testing, enabling earlier detection and better protection of public health. As such, this research received one of six grants distributed by the UNC Research Opportunities Initiative (ROI), which funds “innovative and potentially game-changing research projects” that advance North Carolina economic development and the wellbeing of its citizens.
Next time, before you head to the beach, check out EPA’s database about which beaches are closed and which ones are monitored: http://www2.epa.gov/beaches/find-information-about-your-beach
Peer edited by Amy Rydeen & Nicole Carlson
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This article was co-published on the SWAC Blog, The Pipettepen.