ISO 11866-2-2005 PDF

Full title and description

ISO 11866-2:2005 — Milk and milk products — Enumeration of presumptive Escherichia coli — Part 2: Colony-count technique at 44 °C using membranes. This Part 2 specifies a membrane‑filtration colony‑count technique, intended for use with samples in which comparatively large numbers of presumptive Escherichia coli are expected.

Abstract

ISO 11866-2:2005 specifies a colony‑count method for enumeration of presumptive Escherichia coli using membrane filtration and incubation at 44 °C. The method is applicable to milk and a wide range of milk products (liquid milk products, dried milks and whey derivatives, cheese and processed cheese, butter, frozen milk products including edible ices, custard, desserts and cream) and is the preferred procedure when relatively high counts (>100 per g or >10 per mL) are suspected.

General information

• Status: Published / International Standard (confirmed stage).
• Publication date: 2005 (edition 2 — published December/November 2005).
• Publisher: International Organization for Standardization (ISO), published as ISO/IDF (IDF reference: IDF 170‑2:2005).
• ICS / categories: 07.100.30; 67.100.01 (microbiology of food and milk/milk products).
• Edition / version: Edition 2 (2005).
• Number of pages: 9 pages.

Information compiled from the ISO catalogue and standards listings.

Scope

This standard specifies a membrane‑filtration colony‑count technique for the enumeration of presumptive Escherichia coli in milk and milk products. It defines the principle, required media and materials, sample preparation guidance for the listed dairy matrices, incubation conditions (44 °C), colony counting and interpretation, and the method’s recommended range of application (preferred where comparatively large numbers of presumptive E. coli are expected). The method is intended for routine analytical and regulatory testing in dairy microbiology.

Key topics and requirements

• Membrane filtration as the primary technique for concentrating organisms from liquid samples.
• Use of appropriate selective/differential media allowing presumptive Escherichia coli colonies to be enumerated after incubation at 44 °C.
• Specified incubation temperature and time to support presumptive E. coli development (44 °C conditions described).
• Guidance on sample types and preparation (milk, dried milk products, cheese, butter, frozen dairy products, custard/desserts, etc.).
• Recommended application range: preferred when high numbers of presumptive E. coli are suspected (more than ~100/g or 10/mL).
• Procedures for colony counting, calculation of results (counts per gram or per millilitre), and interpretation of presumptive E. coli counts.

Key method details and scope statements are taken from the ISO standard entry.

Typical use and users

Used by dairy industry quality laboratories, food microbiology testing laboratories, regulatory and public‑health laboratories, certification bodies and research groups concerned with dairy product safety and hygiene. Typical applications include routine quality control, compliance testing, investigation of contamination incidents, and shelf‑life or process validation studies for dairy products.

Related standards

ISO 11866 is a multi‑part standard. The closely related Part 1 (ISO 11866-1:2005) specifies a most probable number (MPN) technique using MUG and is preferred for samples expected to contain low numbers of presumptive E. coli. Earlier historic versions of Part 2 (for example ISO 11866-2:1997) were withdrawn and superseded by later revisions/parts. Laboratories commonly use ISO 11866 parts together with other microbiological standards for sample preparation and general methods (for example standards on microbiological methods for food sample handling and media preparation).

Keywords

Milk; milk products; Escherichia coli; E. coli; enumeration; colony count; membrane filtration; dairy microbiology; selective media; 44 °C; ISO 11866; IDF 170.

FAQ

Q: What is this standard?

A: ISO 11866-2:2005 is the International Standard that specifies a membrane‑filtration colony‑count technique for the enumeration of presumptive Escherichia coli in milk and milk products.

Q: What does it cover?

A: It covers the materials, media, procedures and incubation conditions (44 °C) for counting presumptive E. coli colonies on membranes, sample types to which the method applies (various milk and dairy products), and the method’s intended application range (preferred for comparatively high counts).

Q: Who typically uses it?

A: Dairy industry QC/analytical laboratories, food microbiology testing laboratories, regulatory/public‑health laboratories, and researchers involved in dairy safety and quality assessment.

Q: Is it current or superseded?

A: ISO 11866-2:2005 is published and listed as the Part 2 edition from 2005 (edition 2). Earlier versions (for example the 1997 edition of Part 2) have been withdrawn and superseded by later parts/editions; users should confirm the current status in the ISO catalogue or with their national standards body before relying on a standard for compliance purposes.

Q: Is it part of a series?

A: Yes — ISO 11866 is a multi‑part standard on enumeration of presumptive Escherichia coli in milk and milk products. Part 1 (ISO 11866-1:2005) covers the MPN technique using MUG and Part 2 (this document) covers the membrane‑filtration colony‑count technique.

Q: What are the key keywords?

A: Milk, milk products, Escherichia coli, E. coli, enumeration, colony count, membrane filtration, dairy microbiology, 44 °C, ISO 11866.