Use of two presence/absence systems for the detection of E. coli and coliforms from water

Fricker, E.J.; Fricker, C. R.

doi:10.1016/0043-1354(96)00082-6

Cited by 25 publications

(18 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our experience is that there are other organisms which could fulfil these criteria (notably Klebsiella oxytoca) and for this reason we included an additional confirmation test, the production of the enzyme b-D-glucuronidase. 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this test is not completely specific for E. coli (Rice et al 1991;Fricker & Fricker 1996a) other studies (Fricker, unpublished) have suggested that this test is a more useful confirmatory test than production of indole from tryptophan at 448C.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).…”

Section: Introductionmentioning

confidence: 94%

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

Fricker¹,

Bullock

Murrin

et al. 2008

Journal of Water and Health

View full text Add to dashboard Cite

Disinfected and non-disinfected samples have been used to determine the accuracy of the ISO procedure (ISO 9308-1) for detection of E. coli in drinking water. Samples were analysed using the ISO procedure at both 36 and 448C and using the defined substrate technology method -18). Utilizing the confirmation procedure described in ISO 9308-1, large numbers of false positive E. coli results were obtained using the ISO primary isolation procedure at 368C. However, when glucuronidase production was used as the confirmation procedure, the 'confirmed' count of E. coli was lowest with ISO 9308-1 performed at 368C. When TTC medium was incubated at 368C confirmation using production of indole at 448C resulted in 29% more 'E. coli' being recovered than when confirmation was performed using production of glucuronidase. When 448C was used as the primary isolation temperature the difference between the number of 'confirmed' E. coli identified using the two confirmation procedures was less than 1% and was not significant. Identification of isolates which 'confirmed' when using production of indole at 448C as the test method but 8which failed to produce b-D-glucuronidase, showed that the majority of these isolates were Klebsiella oxytoca.

show abstract

Section: Introductionmentioning

confidence: 94%

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

Fricker¹,

Bullock

Murrin

et al. 2008

Journal of Water and Health

View full text Add to dashboard Cite

show abstract

“…Actual food extracts inoculated with P. aeruginosa and S. aureus were also tested, and the DOX system did not detect these non-coliform bacteria. Fricker and Fricker (1996) showed that 10 6 CFU per ml of Aeromonas hydrophila which is noncoliform bacteria could not grow in COLILERT 18 medium. This result was in agreement with our experimental data and the current measured value (nA) always showed an even value.…”

Section: Specificity Test Of Dox Systemmentioning

confidence: 99%

Comparison of Traditional Culture Method with DOX System for Detecting Coliform and <i>Escherichia coli</i> from Vegetables

Kawasaki

Nazuka

Bari

et al. 2003

FSTR

View full text Add to dashboard Cite

The methods of sanitary inspection performed primarily by traditional culture methods are time consuming, laborious, and require complicated laboratory techniques. A number of instrumental methods have been introduced for the rapid determination of viable cells based on the metabolic activities of microorganisms. The DOX system is one of the newly developed rapid inspection methods. It has three independent incubators that hold 60 vials each can estimate viable bacterial cell number by measuring the respiration speed of microorganisms and also has a high correlation between the detection time (Dt) and the viable bacterial cell number. We made a quantification analysis of coliform, and identified the presence of Escherichia coli from various kinds of vegetable samples. A total of 131 vegetable samples were tested to compare the plate count of coliform to the count using the DOX method. The correlation coefficient for the estimation of coliform-bacterial cell number was 0.85, which theoretically suggested that the DOX system was able to detect one cell of coliform-bacteria after 17.7 h of incubation. Among the 131 samples, 20 samples were confirmed for the presence of E. coli-positive cells using the UV-lamp method. This study suggested that the DOX system performs better than the conventional method for the routine inspection of coliform and E. coli from vegetable samples. Therefore, this system could be useful for the rapid detection of coliform and E. coli from vegetable samples with minimum labor and cost.

show abstract

“…Various versions of the Colilert system were shown to yield results that are statistically consistent with the standard methods of membrane filtration and multiple-tube fermentation testing used for the detection of coliforms and E. coli in freshwater (2,3,6,7). The U.S. Environmental Protection Agency has approved Colilert for use in drinking water monitoring (9,10), and analyses of E. coli in fresh (6,12,21) and saline (18,22) natural waters have been published.…”

mentioning

confidence: 99%

Marine Bacteria Cause False-Positive Results in the Colilert-18 Rapid Identification Test for Escherichia coli in Florida Waters

Pisciotta

Rath

Stanek

et al. 2002

Appl Environ Microbiol

View full text Add to dashboard Cite

The Colilert-18 system for enumeration of total coliforms and Escherichia coli is approved by the U.S. Environmental Protection Agency for use in drinking water analysis and is also used by various agencies and research studies for enumeration of indicator organisms in fresh and saline waters. During monitoring of Pinellas County, Fla., marine waters, estimates of E. coli numbers (by Colilert-18) frequently exceeded fecal coliform counts (by membrane filtration) by 1 to 3 orders of magnitude. Samples from freshwater sites did not display similar discrepancies. Fecal coliforms, including E. coli, could be cultured from 100% of yellow fluorescent wells (denoting E. coli-positive results) inoculated with freshwater samples but could be cultured from only 17. ؊1 in seawater diluted 1:10 with freshwater to Ϸ5,000 CFU ml ؊1 in seawater diluted 1:20 with freshwater. Estimated E. coli numbers in various marine water samples processed at the 1:10 dilution ranged from 10 to 7,270 CFU·100 ml ؊1 , while E. coli numbers in the same samples processed at the 1:20 dilution did not exceed 40 CFU·100 ml ؊1 . The lower estimates of E. coli numbers corresponded well with fecal coliform counts by membrane filtration. This study indicates that assessment of E. coli in subtropical marine waters by Colilert-18 is not accurate when the recommended 1:10 sample dilution is used. The results suggest that greater dilution may diminish the false-positive problem, but further study of this possibility is recommended.Coliform bacteria are widely used as indicators of fecal contamination of both fresh and marine waters. Certain members of the coliform group live outside of the gastrointestinal tract in the environment and may create a false indication of fecal contamination. A more specific indicator of fecal contamination is Escherichia coli, a thermotolerant fecal coliform bacterium distinguished by its ability to grow at 44.5°C and by its expression of the enzyme ␤-D-glucuronidase. This enzyme hydrolyzes 4-methylumbelliferyl-␤-D-glucuronide (MUG) to form a fluorescent (F) product that is visible with UV light (11,23) and that is used to differentiate E. coli from other fecal coliforms.The Colilert-18 defined-substrate technology system (Idexx Laboratories, Inc., Westbrook, Maine) is intended to provide rapid (18-h), standardized quantitation of total coliforms and E. coli. Various versions of the Colilert system were shown to yield results that are statistically consistent with the standard methods of membrane filtration and multiple-tube fermentation testing used for the detection of coliforms and E. coli in freshwater (2, 3, 6, 7). The U.S. Environmental Protection Agency has approved Colilert for use in drinking water monitoring (9, 10), and analyses of E. coli in fresh (6, 12, 21) and saline (18, 22) natural waters have been published.The Colilert-18 assay system is based on a defined substrate medium containing MUG and ortho-nitrophenyl-␤-D-galactopyranoside (ONPG) and is used for the one-step detection of both total coliforms and E. co...

show abstract

Use of two presence/absence systems for the detection of E. coli and coliforms from water

Cited by 25 publications

References 4 publications

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

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

Comparison of Traditional Culture Method with DOX System for Detecting Coliform and <i>Escherichia coli</i> from Vegetables

Marine Bacteria Cause False-Positive Results in the Colilert-18 Rapid Identification Test for Escherichia coli in Florida Waters

Contact Info

Product

Resources

About