BS ISO 7251:2005

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
   4.1 Detection method
   4.2 Enumeration method
5 Diluent, culture media and reagent
6 Apparatus and glassware
7 Sampling
8 Preparation of test sample
9 Procedure
   9.1 Detection method
   9.2 Enumeration method
10 Expression of results
   10.1 Detection method
   10.2 Enumeration method
11 Test report
Annex A (normative) MPN table
Bibliography

Provides general guidelines for the detection and enumeration of presumptive Escherichia coli by means of the liquid-medium culture technique and calculation of the most probable number (MPN) after incubation at 37 degree C, then at 44 degree C.

This International Standard gives general guidelines for the detection and enumeration of presumptive Escherichia coli by means of the liquid-medium culture technique and calculation of the most probable number (MPN) after incubation at 37°C, then at 44°C. This International Standard is applicable to

• products intended for human consumption and the feeding of animals, and

• environmental samples in the area of food production and food handling.

WARNING — Some pathogenic strains of Escherichia coli do not grow at 44°C.

A limitation of the applicability of this International Standard is imposed by the susceptibility of the method to a large degree of variability (see Clause10).