A preliminary study of the use of Colilert for water quality monitoring

Abstract

The Colilert presence/absence test has been compared with membrane filtration using membrane lauryl sulphate broth for the detection of coliforms and Escherichia coli in a number of different types of water. Colilert appears to give results which are essentially the same as those obtained by membrane filtration whilst taking considerably less time to perform. The data generated in this study are in agreement with a large number of studies published in the United States and suggest that a large comparative study with drinking water samples is warranted.

A long-term study comparing membrane filtration with Colilert® defined substrates in detecting fecal coliforms and Escherichia coli in natural waters

“…Reports indicate b-D-glucuronidase is found in greater than 95% of E. coli strains (Berger, 1994), is expressed globally among these strains (Venkateswaran et al, 1996), and remains stable at 44.5 8C (Tryland and Fiksdal, 1998). Similarly, Colilert sensitivity was also noted in tests of potable water (Cowburn et al, 1994;Fricker et al, 1997;Niemela et al, 2003). In this study, the Colilert method correlated well with the MF method with samples exhibiting low (!300 bacteria/100 ml) E. coli counts (Figs.…”

“…Mounting evidence favors the use of Colilert over other assessment methods for testing freshwater (Edberg et al, 1991;Shadix and Rice, 1991;Cowburn et al, 1994;Fiksdal et al, 1994;Fricker and Fricker, 1996;Eckner, 1998;Grasso et al, 2000;Pisciotta et al, 2002;Yakub et al, 2002;Niemela et al, 2003), drinking water (Edberg et al, 1988;McFeters et al, 1992;Cowburn et al, 1994;Fricker et al, 1997;Niemela et al, 2003), wastewater effluent (Elmund et al, 1999;Kramer and Liu, 2002;Eccles et al, 2004), contaminated soils (Muirhead et al, 2004), and foodstuffs (Venkateswaran et al, 1996;HaraKudo et al, 2001) for these bacteria. MF and Colilert methods are commonly compared and discussed in water quality literature, but more comparisons are needed (Francy and Darner, 2000) to confirm the validity of Colilert.…”

Use of the ISO 9308-1 procedure for the detection of E. coli in water utilizing two incubation temperatures and two confirmation procedures and comparison with defined substrate technology

“…While this test is not completely specific for E. coli (Rice et al 1991;Fricker & Fricker 1996a) other studies (Fricker, unpublished) have suggested that this test is a more useful confirmatory test than production of indole from tryptophan at 448C. Furthermore, these studies have shown that in excess of 99.5% of strains of E. coli recovered Numerous studies have demonstrated that confirmation of positive results is not required (Cowburn et al 1994;Fricker et al 1997;Niemela et al 2003). However, in this study we chose to confirm the identity of all presumptive positive results using tests for cytochrome oxidase, production of b-D-glucuronidase and production of indole from tryptophan at 448C.…”

Comparison between Colifast® Milk and the standard method for the detection of coliforms in pasteurised milk

“…Since 1990 a remarkable development of alternative methods for the detection of coliforms in foods has occurred [5,7,9,13,14], having the purpose of shortening the time of the analytical response. Some rapid techniques exploit the enzymatic activity of coliforms on fluorogenic substrates, such as 4-methylumbelliferyl-b-D-galactoside (MU-Gal) and 4-methylumbelliferyl-b-D-glucoronoside (MU-Glu), monitoring the change of fluorescence in samples incubated under standard conditions in a selective medium.…”