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Development and characterization of a fluorescent-bacteriophage assay for detection of Escherichia coli O157:H7.

ABSTRACT: In this paper we describe evaluation and characterization of a novel assay that combines immunomagnetic separation and a fluorescently stained bacteriophage for detection of Escherichia coli O157:H7 in broth. When it was combined with flow cytometry, the fluorescent-bacteriophage assay (FBA) was capable of detecting 10(4) cells/ml. A modified direct epifluorescent-filter technique (DEFT) was employed in an attempt to estimate bacterial concentrations. Using regression analysis, we calculated that the lower detection limit was between 10(2) and 10(3) cells/ml; however, the modified DEFT was found to be an unreliable method for determining bacterial concentrations. The results of this study show that the FBA, when combined with flow cytometry, is a sensitive technique for presumptive detection of E. coli O157:H7 in broth cultures.

SUBMITTER: Goodridge L

PROVIDER: S-EPMC91198 | biostudies-literature | 1999 Apr

REPOSITORIES: biostudies-literature

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Development and characterization of a fluorescent-bacteriophage assay for detection of Escherichia coli O157:H7.

Goodridge L L Chen J J Griffiths M M

Applied and environmental microbiology 19990401 4

In this paper we describe evaluation and characterization of a novel assay that combines immunomagnetic separation and a fluorescently stained bacteriophage for detection of Escherichia coli O157:H7 in broth. When it was combined with flow cytometry, the fluorescent-bacteriophage assay (FBA) was capable of detecting 10(4) cells/ml. A modified direct epifluorescent-filter technique (DEFT) was employed in an attempt to estimate bacterial concentrations. Using regression analysis, we calculated tha ...[more]

PMID: 10103228

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