IDEXX: Enterolert: Enterolert

Summary
Analytes
Revision
Data and Sites

Official Method Name

Enterolert Test Kit Procedure

Current Revision

1999

Media

WATER

Instrumentation

Most Probable Number

Method Subcategory

Microbiological

Method Source

IDEXX

Citation

Enterolert Test Kit Procedure

Brief Method Summary

Presence/Absence: Add one packet of powder to the 100 ml water sample in a sterile, non-fluorescing vessel. Cap and shake the vessel to dissolve the powder. Incubate at 41C for 24 h. Read the results at 24 h (before 28 h) by placing a 6W, 365 nm UV light within 5 inches of the sample. If no fluorescence, the test is negative. If the sample fluoresces blue, it is confirmed positive. Quantification: See Standard Methods 20th ed. for MPN analysis (5,10,15 tube serial dilution) or or pour the sample reagent mixture directly into a Quanti-Tray and seal according to instructions. Incubate and read the results as indicated above. Count the number of positive fluorescent wells. Determine the MPN/100mL using the table provided with the Quanti-Tray. For details, see the package insert. Requirements: Enterolert kit from IDEXX 98-21374-00 or 98-21375-00. Sterile pipets. Sterile, unbuffered water for dilutions. Incubator for 41^oC controlled within 0.5^oC. Long wavelength (365 nm) ultraviolet lamp for fluorescence readings. Cost of analysis: Presence/Absence approx. $4.00; Quantification approx. $5.00.

Scope and Application

Ambient, compliance monitoring: fresh water, drinking water and saltwater. EPA Fed Reg (Aug 2001) for enterococci, ambient only: fresh, marine, or estuarine surface waters; applicability must be demonstrated for other matrices. USEPA. 2001 (August 30). Guidelines establishing test procedures for the analysis of pollutants; Analytical methods for biological pollutants in ambient water (Final Ambient Guidelines, Aug. 20, 2004). Fed. Reg. 66(169)45811-45829. Clean Water Act section 401. 40 CFR 136.1(c). (State certification, licenses) for compliance monitoring in programs 303(c), 304(a), and 501(a). 136.3 Identification of test procedures. Pending approval for Wastewater FR, Tuesday, Aug 16th, 2005.

Applicable Concentration Range

For samples in wells (excluding dilution factors): 1 to 2419 MPN/100 mL for 97-well Quanti-Tray; 1 to 200 MPN/100 mL for 51-well Quanti-Tray

Interferences

Gram positive & gram negative bacteria at levels greater than one hundred thousand to one million per 100mL
The presence of Bacillus spp. can interfere with the testing of marine water samples. To eliminate interference, a 1:10 dilution is required with sterile water (deionized or distilled)

Quality Control Requirements

1. Control cultures: conducted on each lot of Enterolert received as a minimum. Inoculate sterile water with ATCC bacteria, E. faecium (35667) - positive control, S. marcescens (43862) - negative control. 2. Repeat counts--monthly replicate counts for the same analyst should agree within 5% and between analysts within 10%.

Sample Handling

Sample preservation: chilled, 1^oC to 4^oC; 0.0008% (w/w) Na2S2O3 added to chlorinated waters EPA Fed Reg (Aug 2001). Techniques for collection: Standard Methods, 20th edition, L. Clesceri, A. Greenberg, and A. Eaton (editors). APHA: Washington, DC. 1998. Section 9060A
Sample processing time: less than 5 minutes.

Maximum Holding Time

Sample should be analyzed within 6 h after sampling and within 2 h from receipt of sample in lab for compliance or 24 h for routine monitoring (Standard Methods, 20th ed., Section 9060B); however, a 6 h holding time for all samples is highly recommended (Myers and Sylvester, 1997),

Relative Cost

Less than $50

Sample Preparation Methods

This method has 1 analyte associated with it.

Analyte	Detection Level	Bias	Precision	Pct False Positive	Pct False Negative	Spiking Level
Enterococci(E-12282) Enterococci Enterococcus	1.000 MPN/100mL	N/A	N/A	5	0

Precision Descriptor Notes:	Budnick, G.E.; Howard, R. T.; Mayo, D. R. 1996. Evaluation of Enterolert for enumeration of enterococci in recreational waters. Appl. Environ. Microbiol. 62(10):3881-3884. Fricker, C.R.; Fricker, E. J.; Goodall, T.; Cowburn, J. 1995. Quantitative procedures for the detection of E. coli, coliforms and enterococci in water, using Quanti-tray and Enterolert. Water Quality Technol. Conf. Proc. AWWA: Denver, CO. 7 pp.
Detection Level Note:	For samples in wells (excluding dilution factors), determined by using the largest volume. For example, if 100 mL was the largest volume, the detection would be 1 MPN per 100 ml.

Precision Descriptor Notes:

Budnick, G.E.; Howard, R. T.; Mayo, D. R. 1996. Evaluation of Enterolert for enumeration of enterococci in recreational waters. Appl. Environ. Microbiol. 62(10):3881-3884. Fricker, C.R.; Fricker, E. J.; Goodall, T.; Cowburn, J. 1995. Quantitative procedures for the detection of E. coli, coliforms and enterococci in water, using Quanti-tray and Enterolert. Water Quality Technol. Conf. Proc. AWWA: Denver, CO. 7 pp.

Detection Level Note:

For samples in wells (excluding dilution factors), determined by using the largest volume. For example, if 100 mL was the largest volume, the detection would be 1 MPN per 100 ml.

Revision	PDF/Link
1999

The Water Quality Portal contains sample results from sites that use this method.

Download WQP data

Select data:

Sites only
Sample results only

File format:

Comma-separated
Tab-separated
MS Excel 2007+

Sites where this method was used

Loading Sites ...

IDEXX: Enterolert: Enterolert

WHO WE ARE

LEGAL