US 5,510,243 A · Multiple chromogen enzyme targeting (MCET) for use in bacterial contamination monitoring

Abstract

The invention is directed to a process and a medium for simultaneous determination of the number and presence of living fecal coliform and Escherichia coli in a sample comprising 6-O-alpha-D-galactopyranosyl-D-glucose or isopropyl-beta-D-thiogalactoside as a galactosidase inducer and methyl-beta-D-glucuronide as a glucuronidase inducer. The sterile semi-solid medium also comprises non-target bacterial inhibitors, target bacterial enhancers, and multiple fluorogen and/or chromogan substrates that produce color and fluorescence upon cleavage by a specific enzyme expressed by the target bacteria in which expression is enhanced. The simultaneous detection of total coliforms via its expression of beta-galactosidase, and Escherichia coli as the target bacteria via its expression of beta-galactosidase and beta-glucuronidase is achieved rapidly and efficiently using this medium.

Claims8

Dependent claims

A rapid method for the simultaneous detection of total coliforms and Escherichia coli in a sample, comprising:

filtering the sample to capture total coliforms and Escherichia coli present in said sample;
preparing a medium comprising a non-target bacteria inhibitor, 6-O-alpha-D-galactopyranosyl-D-glucose or isopropyl-beta-D-thiogalactoside as the inducer for .beta.-galactosidase, a fluorogenic or chromogenic substrate for said .beta.-galactosidase, methyl-beta-D-glucuronide as the inducer for .beta.-glucuronidase, and a fluorogenic or chromogenic substrate for said .beta.-glucuronidase;
contacting said filtered sample with said medium;
incubating said medium to produce colonies of said total coliforms and Escherichia coli;
detecting and correlating the signal produced by said fluorogenic or chromogenic substrate for said .beta.-galactosidase to total coliforms present in said sample;
and
detecting and correlating the signal produced by said fluorogenic or chromogenic substrate for said .beta.-glucuronidase to the presence of Escherichia coli in said sample.

4 more elements

Dependencies are inferred from the claim text.

Multiple chromogen enzyme targeting (MCET) for use in bacterial contamination monitoring

Life of this patent

Multiple chromogen enzyme targeting (MCET) for use in bacterial contamination monitoring

Life of this patent

Abstract

Claims8