ISO 21567-2004 PDF

Full title and description

ISO 21567:2004 — Microbiology of food and animal feeding stuffs — Horizontal method for the detection of Shigella spp. This international reference describes a standardized, culture-based (phenotypic) horizontal procedure intended for the detection of Shigella species in food, feed and relevant environmental samples in the food chain.

Abstract

ISO 21567:2004 specifies a horizontal method for the detection of Shigella spp. Subject to specified limitations, the method is applicable to products intended for human consumption and animal feeding-stuffs as well as environmental samples taken in food production and handling environments. The standard covers sample preparation, enrichment, selective isolation, presumptive identification and confirmation steps for recovery and reporting of Shigella spp.

General information

• Status: Published (International Standard; confirmed at latest systematic review).
• Publication date: 8 November 2004 (ISO edition 1:2004).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 07.100.30 — Food microbiology.
• Edition / version: Edition 1 (2004).
• Number of pages: 26 (typical published PDF length for the ISO text).

Scope

This standard gives a horizontal (i.e., broadly applicable) culture-based procedure for detection of Shigella spp. in foodstuffs, animal feeding stuffs and related environmental samples in the food-production and food-handling sectors. It is intended for laboratories performing microbiological safety and surveillance testing and describes the steps from sample preparation through enrichment, selective isolation on appropriate media, presumptive identification and confirmation of isolates. Limitations and applicable sample types are defined within the standard text.

Key topics and requirements

• Principles of a horizontal detection method applicable across multiple sample matrices (food, feed, environmental swabs).
• Sample preparation and recommended portion sizes and diluents for enrichment.
• Primary and selective enrichment procedures to promote recovery of stressed or low-level Shigella cells.
• Use of recommended selective agar(s) for isolation and morphological colony selection criteria for presumptive isolates.
• Presumptive biochemical and serological tests for preliminary identification.
• Confirmatory identification procedures to achieve a confirmed positive result (biochemical/serotyping as specified).
• Reporting conventions, interpretation of results and notes on method limitations and interfering organisms.

Typical use and users

Primary users are food and feed testing laboratories, public health and veterinary diagnostic laboratories, food safety authorities, contract testing laboratories and manufacturers’ quality-control teams who need a validated, internationally recognized cultural reference method for detecting Shigella in products or production environments. The standard is used for routine surveillance, outbreak investigation support, regulatory compliance testing and method verification/validation activities.

Related standards

ISO 21567 is part of the suite of ISO reference methods for food microbiology produced by ISO/TC 34/SC 9. Related guidance and standards include the ISO 16140 series (method validation and verification for microbiological methods) and other organism-specific reference methods such as ISO standards for Salmonella, Listeria and E. coli detection and confirmation. Laboratories implementing ISO 21567 should consider ISO 16140 when performing method validation or verification for in-house or alternative methods.

Keywords

Shigella, detection, horizontal method, food microbiology, animal feeding stuffs, enrichment, selective media, confirmation, ISO 21567, method validation, ISO/TC 34/SC 9.

FAQ

Q: What is this standard?

A: ISO 21567:2004 is an ISO international standard that specifies a horizontal, culture-based method for the detection of Shigella species in food, feed and related environmental samples in the food chain.

Q: What does it cover?

A: It covers sample preparation, enrichment, selective isolation, presumptive identification and confirmatory procedures for Shigella spp., plus notes on applicability and limitations for different sample types.

Q: Who typically uses it?

A: Accredited and routine testing laboratories, public health authorities, food producers and contract laboratories performing microbiological testing, surveillance or outbreak investigations.

Q: Is it current or superseded?

A: The standard was published in November 2004 (Edition 1:2004) and has been through ISO periodic reviews; it was confirmed as current in ISO’s systematic review cycle (most recently confirmed in 2021). Users should verify on the ISO catalogue or with their national standards body for any revisions or replacement after 2021 before relying on it as the single authoritative reference for regulatory purposes.

Q: Is it part of a series?

A: It is part of the body of ISO reference methods for microbiology of the food chain maintained by ISO/TC 34/SC 9; method validation and verification for these methods is addressed by the ISO 16140 series.

Q: What are the key keywords?

A: Shigella, food microbiology, horizontal method, enrichment, selective agar, confirmation, ISO 21567.