Abstract
A defined substrate method was applied to drinking water to simultaneously enumerate total coliforms and total Escherichia coli directly from samples. After incubation at 35 degrees C for 24 h, the development of yellow in an initially colorless solution was specific for total coliforms; fluorescence at 366 nm in the same tube(s) or vessel demonstrated the presence of E. coli. No confirmatory or completed steps were necessary. Known as autoanalysis colilert (AC), this method was constituted as a presence-absence test and compared with the methods described in Standard Methods (SM) in the P-A format. Seven water utilities representing a wide geological and hydrological spectrum participated in the evaluation. A total of 702 split drinking water samples were analyzed. Of these, 358 were negative in both tests (SM- and AC-); 302 were positive (SM+ and AC+); and 42 were mixed (SM+ and AC-, 20; AC+ and SM-, 22). The overall agreement rate was 94%. Comparison of the SM and AC results by nonparametric statistics demonstrated no differences. Heterotrophic plate count bacteria exerted no discernible effect on the AC test. By subculture, each time the AC test was yellow, a total coliform was present; when the test was fluorescent, E. coli was isolated.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Christian R. R., Pipes W. O. Frequency distribution of coliforms in water distribution systems. Appl Environ Microbiol. 1983 Feb;45(2):603–609. doi: 10.1128/aem.45.2.603-609.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clark J. A. A presence-absence (P-A) test providing sensitive and inexpensive detection of coliforms, fecal coliforms, and fecal streptococci in municipal drinking water supplies. Can J Microbiol. 1968 Jan;14(1):13–18. doi: 10.1139/m68-003. [DOI] [PubMed] [Google Scholar]
- Clark J. A. The detection of various bacteria indicative of water pollution by a presence-absence (P-A) procedure. Can J Microbiol. 1969 Jul;15(7):771–780. doi: 10.1139/m69-135. [DOI] [PubMed] [Google Scholar]
- Clark J. A., Vlassoff L. T. Relationships among pollution indicator bacteria isolated from raw water and distribution systems by the presence-absence (P-A) test. Health Lab Sci. 1973 Jul;10(3):163–172. [PubMed] [Google Scholar]
- Edberg S. C., Allen M. J., Smith D. B. National field evaluation of a defined substrate method for the simultaneous enumeration of total coliforms and Escherichia coli from drinking water: comparison with the standard multiple tube fermentation method. Appl Environ Microbiol. 1988 Jun;54(6):1595–1601. doi: 10.1128/aem.54.6.1595-1601.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edberg S. C., Atkinson B., Chambers C., Moore M. H., Palumbo L., Zorzon C. F., Singer J. M. Clinical evaluation of the MICRO-ID, API 20E, and conventional media systems for identification of Enterobacteriacea. J Clin Microbiol. 1979 Aug;10(2):161–167. doi: 10.1128/jcm.10.2.161-167.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edberg S. C., Edberg M. M. A defined substrate technology for the enumeration of microbial indicators of environmental pollution. Yale J Biol Med. 1988 Sep-Oct;61(5):389–399. [PMC free article] [PubMed] [Google Scholar]
- Evans T. M., Waarvick C. E., Seidler R. J., LeChevallier M. W. Failure of the most-probable-number technique to detect coliforms in drinking water and raw water supplies. Appl Environ Microbiol. 1981 Jan;41(1):130–138. doi: 10.1128/aem.41.1.130-138.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jacobs N. J., Zeigler W. L., Reed F. C., Stukel T. A., Rice E. W. Comparison of membrane filter, multiple-fermentation-tube, and presence-absence techniques for detecting total coliforms in small community water systems. Appl Environ Microbiol. 1986 May;51(5):1007–1012. doi: 10.1128/aem.51.5.1007-1012.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moyer N. P. Clinical significance of Aeromonas species isolated from patients with diarrhea. J Clin Microbiol. 1987 Nov;25(11):2044–2048. doi: 10.1128/jcm.25.11.2044-2048.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pipes W. O., Minnigh H. A., Moyer B., Troy M. A. Comparison of Clark's presence-absence test and the membrane filter method for coliform detection in potable water samples. Appl Environ Microbiol. 1986 Sep;52(3):439–443. doi: 10.1128/aem.52.3.439-443.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]