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. 1989 Apr;55(4):778–787. doi: 10.1128/aem.55.4.778-787.1989

Microcolony epifluorescence microscopy for selective enumeration of injured bacteria in frozen and heat-treated foods.

U M Rodrigues 1, R G Kroll 1
PMCID: PMC184202  PMID: 2658804

Abstract

A rapid (less than 6 h) method for selectively enumerating coliforms, pseudomonads, and staphylococci has been developed which involves counting microcolonies grown on the surface of polycarbonate membranes under selective conditions. The method was not directly applicable to foods containing injured bacteria due to the poor formation of or an inability to form microcolonies under selective conditions. However, the introduction of a 3- to 5-h resuscitation step in tryptone soya broth allowed the method to give reliable estimates of these organisms in a variety of frozen and heat-processed foods. Under nonselective conditions, i.e., for total counts, the microcolony method enabled a rapid count to be made of viable bacteria in heat-treated foods, but these results were also made more consistent by the introduction of a resuscitation step. This method makes results from these foods available far faster than conventional enumeration methods.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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