Revised EN ISO 21528:2017 for Detection and Enumeration of Enterobacteriaceae in the Food Chain

The International Organization for Standardization (ISO) published the revised EN ISO 21528-1 and EN ISO 21528-2 standards in 2017. In Part 1, a horizontal method for the detection of Enterobacteriaceae is specified, and in Part 2, the enumeration of these organisms, both in food and animal feed samples is stated. The revised standards are also applicable to environmental samples in the area of primary production, food production and food handling. Part 1 is applicable when the microorganisms sought are expected to need resuscitation by enrichment, and when the number sought is expected to be below 100/mL or gram of test sample. Part 2 is applicable when the number of colonies sought is expected to be more than 100/mL or per gram of the test sample. The new Part 1 edition cancels and replaces the first edition EN ISO 21528-1:2004. Part 2 cancels and replaces the first edition of EN ISO 21528-2:2004. Compared to the previous edition, the main changes in Part 1 are considered as major, and in Part 2 as minor.

Procedure Steps for Detection of Enterobacteriaceae according to new EN ISO 21528:2017

Part 1: Detection of Enterobacteriaceae

Revised EN ISO 21528-1:2017 at a glance...

• The pre-enrichment step in Buffered Peptone Water (BPW), followed by enrichment in Enterobacteriaceae enrichment (EE) broth has been changed to enrichment in BPW. The selective enrichtment step has been deleted.
• Confirmation now takes place in glucose OF medium instead of using glucose agar.
• Performance testing for the quality assurance of the culture media has been added.
• Performance characteristics for this method have been added to Annex C.
• Most probable number (MPN) method has become an informative Annex A.

Procedure for Detection and Enumeration of Enterobacteriaceae in the Food chain according to EN ISO 21528:2017

Part 2: Colony-count Technique

New EN ISO 21528-2 at a glance...

• The confirmation step has been changed by replacing glucose agar with glucose OF medium.
• Precision data based on the results of an interlaboratory study using the method according to this revised edition has been included in annex B (informative).

As a worldwide leading provider of a broad range of dehydrated granulated and ready-to-use culture media for food, beverages and water microbiology, we are closely tracks and supports the development of relevant standards aimed at increasing consumer confidence and safety.

GranuCult^® granulated media, Readybag^® pre-weighed granulated media in ready-to-use bags, ReadyPlate™, and ReadyTube^® ready-to-use media are all compliant with EN ISO 11133:2014. All information regarding compliance with additional reference standards are displayed on the product label and in the product’s technical information available on our website.

Compliance to revised EN ISO 21528:2017

We are implemented all the requirements described in both parts of the revised EN ISO 21528:2017. For more information, please visit EMDMillipore.com/culture-media. The following culture media and accessories described in the revised EN ISO 21528:2017 are available:

Materials

Product Number	Description	Pack Size	Other Packsizes
1.07228.0500	GranuCult® Buffered Peptone Water acc. ISO 6579, ISO 21528, ISO 22964, FDA-BAM and EP0	500 g	5 kg, 25 kg
1.10275.0500	GranuCult® VRBD (Violet Red Bile Dextrose) agar acc. EP, USP, JP and ISO 21528	500 g	5 kg
1.46000.0020	VRBD LI agar	20 plates	120 plates
1.05450.0500	GranuCult® Nutrient agar acc. ISO 6579, ISO 10273 and ISO 21528	500 g
1.05458.0500	GranuCult® Tryptic Soy Agar EP, USP, JP, ISO, FDA-BAM	500 g	5 kg
1.46431.0020	ReadyPlate™ Tryptic Soy Agar ISO, FDA-BAM, EP+USP	20 plates	100 plates
1.12535.0500	Maximum Recovery Diluent (Peptone salt solution)	500 g
1.15525.0001	Ringer tablets	100 tablets
1.13300.0010	Bactident™ Oxidase	50 test strips
1.46435.0006	ReadyTube® 200 VRBG ISO 21528	6x200 mL