Citation
Wu, Jianyong; Stewart, Jill R.; Sobsey, Mark D.; Cormency, Chris; Fisher, Michael B.; & Bartram, Jamie K. (2018). Rapid Detection of Escherichia coli in Water Using Sample Concentration and Optimized Enzymatic Hydrolysis of Chromogenic Substrates. Current Microbiology, 75(7), 827-834.Abstract
Methods for rapid detection of fecal indicator bacteria in water are important to ensure that water is safe for drinking, bathing, recreation, fishing and shellfish harvesting. In this study, we tested experimental conditions for bacterial hydrolysis of two promising enzymatic substrates, 5-Bromo-4-chloro-3-indolyl beta-D-glucuronide (X-Gluc) and Resorufin beta-D-glucuronide (REG), and optimized parameters such as temperature and pH to determine conditions for rapid reactions. We then innovated a membrane filter-based approach to facilitate more rapid enzyme-based detection of Escherichia coli in water based on the combination of an initial concentration step and optimized test conditions. For this approach, a water sample (10100 mL) is filtered through a 0.45-microm pore size filter with a diameter of 4 or 13 mm. After filtration, a newly designed rapid detection broth is added containing the enzymatic inducer Methyl-beta-D-Glucuronide sodium (MetGlu) and the substrate REG or X-Gluc. After a few (17) hours of incubation at 35 degrees C, the filter shows pink color (for REG-containing broth) or green color (for X-Gluc containing broth) if E. coli is present. The study provides insights and approaches towards developing a simple, fast, and low-cost method to detect fecal indicator bacteria in water.URL
http://dx.doi.org/10.1007/s00284-018-1454-8Reference Type
Journal ArticleYear Published
2018Journal Title
Current MicrobiologyAuthor(s)
Wu, JianyongStewart, Jill R.
Sobsey, Mark D.
Cormency, Chris
Fisher, Michael B.
Bartram, Jamie K.