Abstract
Food, water, pharmaceutical, and medical microbiology ideally need methods of detecting, identifying, and quantifying microorganisms that can give results within a few hours. The many days needed for conventional enrichment, plating, and biochemical/serological methods to give results do not enable problems to be identified soon enough to allow the appropriate remedial action to be implemented. New methods must produce rapid, accurate, and reliable estimates of total viable microbial numbers, spoilage, or indicator organisms or to identify the presence of pathogens.
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References
Pettipher, G. L., Mansell, R., McKinnon, C. H., and Cousins, C. M. (1980) Rapid membrane filter on epifluorescent microscopy technique for the direct enumeration of bacteria in raw milk. Appl. Environ. Microbiol. 39, 423–429.
Pettipher, G. L. (1983) The Direct Epifluorescent Filter Technique for the Rapid Enumeration of Microorganisms. Research Studies Press, Letchworth, UK.
Denyer, S. P. and Lynn, R. (1987) A sensitive method for the rapid detection of bacterial contaminants in intravenous fluids. J. Parenteral Sci. Technol. 41, 60–66.
Easter, M. C., Kroll, R. G., Farr, L., and Hunter, A. C. (1987) Observations on the introduction of the DEFT for the routine assessment of bacteriological quality. J. Soc. Dairy Technol. 40, 100–103.
Pettipher, G. L. and Rodrigues, U. M. (1982) Semi-automated counting of bacteria and somatic cells in milk using epifluorescent microscopy and television image analysis. J. Appl. Bacteriol. 53, 323–329.
Jaeggi, N. E., Simes, U., and Hughes, D. (1989) Evaluation of a television image analyser as an aid to estimation of microbial numbers in food using the direct epifluorescent filter technique. Food Microbiol. 6, 85–91.
Pettipher, G. L., Watts, Y. B., Largford, S. A., and Kroll, R. G. (1992) Preliminary evaluation of COBRA, an automated DEFT instrument, for the rapid emuneration of micro-organisms in cultures, raw milk, meat and fish. Lett. Appl. Microbiol. 14, 206–209.
Pettipher, G. L. and Rodrigues, U. M. (1982) Rapid enumeration of microorganisms in foods by the Direct Epifluorescent Filter Technique. Appl. Environ. Microbiol. 44, 809–813.
Hunter, A. C. and McCorquodale, R. M. (1983) Evaluation of the direct epifluorescent filter technique for assessing the hygiene condition of milking equipment. J. Dairy Res. 50, 9–16.
Walls, I., Sheridan, J., and Levett, P. (1989) A rapid method of enumerating micro-organisms from beef using an acridine orange direct count technique. Irish J. Food Sci. Technol. 13, 23–31.
Pettipher, G. L., Williams, R. A., and Gutteridge, C. S. (1985) An evaluation of possible alternative methods to the Howard Mould Count. Lett. Appl. Microbiol. 1, 49–52.
Rodrigues, U. M. and Kroll, R. G. (1986) Use of the direct epifluorescent filter technique for the enumeration of yeasts. J. Appl. Bacteriol. 61, 139–144.
Rowe, M. T. and McCann, G. J. (1990) A modified direct epifluorescent filter technique for the detection and enumeration of yeast in yoghurt. Lett. Appl. Microbiol. 11, 282–285.
Kelly, A. F. and Kroll, R. G. (1987) Use of the direct epifluorescent filter technique for the enumeration of bacterial spores. J. Appl. Bacteriol. 63, 545–550.
Holah, J. T., Betts, R. P., and Thorpe, R. H. (1988) The use of direct epifluorescent microscopy (DEM) and the direct epifluorescent filter technique (DEFT) to assess microbial populations on food contact surfaces. J. Appl. Bacteriol. 65, 215–222.
Betts, R. P., Farr, L., Bankes, P., and Stringer, M. F. (1988) The detection of irradiated foods using the Direct Epifluorescent Filter Technique. J. Appl. Bacteriol. 64, 329–335.
Back, J. P. and Kroll, R. G. (1991) The differential fluorescence of bacteria stained with acridine orange and the effects of heat. J. Appl. Bacteriol. 71, 51–58.
Pettipher, G. L. and Rodrigues, U. M. (1981) Rapid enumeration of bacteria in heat-treated milk and milk products using a membrane filtration-epifluorescent microscopy technique. J. Appl Bacteriol. 50, 157–166.
Hutcheson, T. C., McKay T., Farr, L., and Seddon, B. (1988) Evaluation of the stain viablue for the rapid enumeration of viable yeast cells. Lett. Appl. Microbiol. 6, 85–88.
Rodrigues, U. M. and Kroll, R. G. (1988) Rapid selective enumeration of bacteria in foods using a microcolony epifluorescence microscopy technique. J. Appl. Bacteriol. 64, 65–78.
Rodrigues, U. M. and Kroll, R. G. (1989) Microcolony epifluorescence microscopy for selective enumeration of injured bacteria in frozen and heat-treated foods. Appl. Environ. Microbiol. 55, 778–787.
Newbury, J. (1991) Analysis of high-quality pharmaceutical grade water by a direct epifluorescent filter technique microcolony method. Lett. Appl. Microbiol. 13, 291–293.
Kroll, R. G., Pinder, A. C., Purdy, P. W., and Rodrigues, U. M. (1989) A laser-light pulse counting method for automatic and sensitive counting of bacteria stained with acridine orange. J. Appl. Bacteriol. 66, 161–167.
Patchett, R. A., Back, J. P., Pinder, A. C., and Kroll, R. G. (1991) Enumeration of bacteria in pure cultures and in foods using a commercial flow cytometer. Food Microbiol. 8, 119–125.
Rodrigues, U. M. and Kroll, R. G. (1985) The direct epifluorescent filter technique (DEFT); increased selectivity, sensitivity and rapidity. J. Appl. Bacteriol. 59, 493–499.
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© 1995 Humana Press Inc.
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Kroll, R. (1995). The Direct Epifluorescent Filter Technique (DEFT). In: Howard, J., Whitcombe, D.M. (eds) Diagnostic Bacteriology Protocols. Methods in Molecular Biology™, vol 46. Humana Press. https://doi.org/10.1385/0-89603-297-3:113
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DOI: https://doi.org/10.1385/0-89603-297-3:113
Publisher Name: Humana Press
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