ISO 11866-1-2005 PDF

Full title and description

ISO 11866-1:2005 — Milk and milk products — Enumeration of presumptive Escherichia coli — Part 1: Most probable number technique using 4‑methylumbelliferyl‑beta‑D‑glucuronide (MUG). This part specifies a combined culture/MPN technique for enumeration of presumptive E. coli and presumptive coliforms in a wide range of milk and milk products.

Abstract

Specifies a combined method using a liquid medium containing MUG and the most probable number (MPN) calculation after incubation at 30 °C to enumerate presumptive Escherichia coli and presumptive coliforms in milk, liquid milk products and many dried or processed dairy matrices. The method is particularly recommended for samples expected to contain relatively low numbers of target organisms.

General information

• Status: Published (International Standard; confirmed).
• Publication date: Edition 2 — 2005 (published 23 November 2005; edition shown as 2005‑12).
• Publisher: International Organization for Standardization (ISO) — also published jointly as IDF 170‑1:2005.
• ICS / categories: 07.100.30 (Food microbiology) / 67.100.01 (Dairy products).
• Edition / version: Edition 2 (2005).
• Number of pages: 11.

Details above (title, status, edition, publication date, ICS codes and page count) are taken from the ISO bibliographic record for ISO 11866‑1:2005.

Scope

Defines a laboratory method — a liquid‑medium MUG culture combined with most probable number (MPN) statistics after incubation at 30 °C — for enumeration of presumptive Escherichia coli and presumptive coliforms in milk and many milk‑derived products (including liquid milks, dried milks and whey powders, cheeses and processed cheeses, butter, frozen dairy products and cream‑based desserts). The protocol is intended primarily for samples where low counts (<100 per g or <10 per ml) are suspected.

Key topics and requirements

• Use of 4‑methylumbelliferyl‑β‑D‑glucuronide (MUG) in a liquid culture medium to detect β‑glucuronidase activity associated with presumptive E. coli.
• Most probable number (MPN) statistical enumeration procedure to report cells per gram or per millilitre.
• Incubation conditions: typically 30 °C for the prescribed incubation period defined in the method.
• Definition and distinction of “presumptive Escherichia coli” (MUG‑positive and indole‑producing characteristics) and “presumptive coliforms” (lactose fermentation with gas production at 30 °C).
• Applicability statements listing the dairy matrices covered and recommendation that the method is preferred for comparatively low target organism numbers.

(Key method elements and applicability summarized from the ISO standard abstract and method description.)

Typical use and users

Used by dairy testing laboratories, food microbiology labs, quality assurance departments in dairy manufacturers, regulatory and public‑health laboratories, and researchers validating dairy hygiene and safety. Employed when enumeration of low levels of presumptive E. coli/coliforms is required for product release, shelf‑life studies or contamination investigations.

Related standards

Part of the ISO 11866 series (other parts address alternative colony‑count and membrane methods); published jointly with the IDF as IDF 170‑1:2005. Other complementary dairy microbiology standards (same technical committee) cover alternative enumeration techniques and confirmatory testing for E. coli and coliforms.

Keywords

ISO 11866, milk, milk products, Escherichia coli, presumptive E. coli, coliforms, MUG, 4‑methylumbelliferyl‑β‑D‑glucuronide, MPN, most probable number, dairy microbiology, enumeration, IDF 170‑1.

FAQ

Q: What is this standard?

A: An ISO method (ISO 11866‑1:2005, Edition 2) for enumeration of presumptive Escherichia coli and presumptive coliforms in milk and milk products using a liquid‑medium MUG test combined with the most probable number (MPN) technique.

Q: What does it cover?

A: It covers the culture medium (MUG), incubation conditions (30 °C), use of MPN calculations and the list of dairy matrices to which the method applies; it is intended for samples expected to contain low numbers of target organisms.

Q: Who typically uses it?

A: Dairy industry and contract testing laboratories, food safety/regulatory labs, public‑health microbiologists and academic researchers working on dairy microbiology and product quality.

Q: Is it current or superseded?

A: The publication (Edition 2, 2005) remains published and has been reviewed and confirmed by ISO; the ISO bibliographic record indicates the publication was last reviewed and confirmed in 2025, so this version remains current.

Q: Is it part of a series?

A: Yes — it is Part 1 of the ISO 11866 series (other parts provide alternative colony‑count and membrane filtration techniques) and is published jointly with the International Dairy Federation as IDF 170‑1:2005.

Q: What are the key keywords?

A: MUG, MPN, presumptive Escherichia coli, presumptive coliforms, dairy microbiology, milk testing, ISO 11866, IDF 170‑1.