Since 2002, the United States Environmental Protection Agency (USEPA) has approved ten enzyme-based total coliform and E. coli detection tests for examination of drinking water. These tests include: Colilert®, Colilert-18®, Colisure®, m-Coli Blue 24®, Readycult® Coliforms 100, Chromocult®, Coliscan®, E*Colite®, Colitag™ and MI Agar. The utility of the enzyme based test systems is based on both the ability of the test to detect the target organisms at low levels and the ability of the test system to suppress the growth of non-target organisms that might result in false positive results. Differences in the ability of some of these methods to detect total coliform and E. coli, as well as suppress Aeromonas spp., a common cause of “false positive” results, have been observed. As a result, this study was undertaken to elucidate the strengths and weaknesses of each method. Water samples were collected from three geographically and chemically diverse groundwaters in Wisconsin. One-hundred milliliter aliquots were individually spiked with both low concentrations (one to ten organisms) and high concentrations (fifty to one-hundred) of each of five different total coliform organisms (Serratia, Citrobacter, Enterobacter, E. coli, & Klebsiella). These spiked samples were used to test the capability of ten enzyme-based test systems to both detect and enumerate the spiked organisms. In addition, 100 ml samples were independently spiked with two different strains of Aeromonas spp. at six different levels, to assess the ability of each enzyme-based test to suppress Aeromonas spp. Analysis of the data indicated that wide variability exists among USEPA approved tests to detect and quantify total coliforms, as well as suppress Aeromonas spp.
Skip Nav Destination
Article navigation
Research Article|
June 01 2007
A comparison of ten USEPA approved total coliform/E. coli tests
Jeremy Olstadt;
1Water Bacteriology Department, Wisconsin State Laboratory of Hygiene, 2601 Agriculture Dr., P.O. Box 7996, Madison, WI 53707-7996, USA
Tel.: 608-224-6262 Fax: 608-224-6267; E-mail: [email protected]
Search for other works by this author on:
James Jay Schauer;
James Jay Schauer
2Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 600 N. Park Street, Madison, WI USA
Search for other works by this author on:
Jon Standridge;
Jon Standridge
3Environmental Health, Department – Water Bacteriology, Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, 2601 Agriculture Drive, Madison, WI 53718, USA
Search for other works by this author on:
Sharon Kluender
Sharon Kluender
3Environmental Health, Department – Water Bacteriology, Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, 2601 Agriculture Drive, Madison, WI 53718, USA
Search for other works by this author on:
J Water Health (2007) 5 (2): 267–282.
Citation
Jeremy Olstadt, James Jay Schauer, Jon Standridge, Sharon Kluender; A comparison of ten USEPA approved total coliform/E. coli tests. J Water Health 1 June 2007; 5 (2): 267–282. doi: https://doi.org/10.2166/wh.2007.008b
Download citation file: