ISO updates: Microbiological food and water analysis

New EN ISO 11290-1 and -2:2017 Amendment 1:2026-07

Microbiology of the food chain — Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. —
Part 1: Detection method;
Part 2: Enumeration method

Amendment 1: Inclusion of storage of the samples before analysis and changes in the control strain for performance testing of culture media and reagents 

Note: It is one amendment for each part.

These amendments contain revised details on sampling, transportation and storage of samples including supporting data.

They contain the replacement of the control strain of Listeria monocytogenes WDCM 00109 by Listeria monocytogenes WDCM 00231 including supporting data.

Performance testing for the quality assurance of all culture media and reagents for detection, enumeration and confirmation used in part 1 and part 2 is described in the amendments.

New EN ISO 13647:2026-08

Water quality — Enumeration of culturable microorganisms — Colony count by spread plate inoculation on R2A medium

This document specifies a method for the enumeration of culturable microorganisms in water by counting colonies on a low-nutrient agar culture medium by spread plate inoculation after incubation at 22 °C for 7 d.

This document is applicable to:

• water from the treatment process of public drinking water supplies (e.g. process water in the waterworks)
• chlorinated and non-chlorinated tap water in distribution systems and containers
• bottled water
• well water intended for human consumption.

Detailed information on the performance characteristics is included.

This document can be applied to other water matrices if the appropriate validation of performance of this method has been undertaken by the laboratory prior to use.

Revised ISO/TS 27265 | IDF/RM 228:2026-05

Heat-processed milk and dried milk products — Enumeration of thermoresistant spores of thermophilic bacteria

This document specifies methods for the enumeration of thermoresistant spores of thermophilic bacteria in heat-processed milk and dried milk products by using a colony-count technique at 55 °C after heating the sample at 106 °C or 100 °C.

The applicability of this document is limited to heat-processed milk including pasteurized, ultra-high temperature (UHT) processed and sterilized milk; as well as dried whole milk, skim milk, buttermilk and whey products.

This second edition cancels and replaces the first edition (ISO/TS 27265 | IDF/RM 228:2009), which has been technically revised.

The main changes are as follows:

• Addition of an alternative water bath heating procedure at 100 °C for 30 min to provide a more feasible approach and to improve the uniformity of analysis among different laboratories
• Annex C on modification of pressure cooker for performing the thermophilic spore test has been deleted.

The main technical changes introduced in this document compared to ISO/TS 27265 | IDF/RM 228:2009 are considered as minor (see ISO 17468).

These technical changes in Procedure A (heat treatment at 106 °C for 30 min) have a minor impact on the performance characteristics of the method.
NOTE: Procedure B (heat treatment at 100 °C for 30 min) was not included in the first edition of this document.

New EN ISO 23691:2026-02

Microbiology of the food chain — Determination and use of cardinal values

This document establishes basic principles and specifies requirements and methods to determine the cardinal values of bacteria and yeast strains and use them to predict microbial growth.

The four main steps of the approach are:

1. determination of the cardinal values in culture medium
2. determination of the correction factor in the target food
3. validation of the model
4. simulations

Four environmental factors are considered: temperature, pH, aw and inhibitors (e.g. organic acids).

The determination of cardinal values is performed in a two-step approach:

• the determination of maximum specific growth rates of the studied strain grown in broth under a defined range of values of the studied environmental factor(s)
• the use of recognized predictive microbiology secondary models to fit the obtained experimental data to obtain the cardinal values.

The use of cardinal values in microbial growth simulation is based on predictive microbiology primary and secondary models. The cardinal values are combined with challenge test data to consider the matrix effect. Depending on the goal of the growth simulation, it is important to account for variation of cardinal values between strains within a bacterial or yeast species.

Cardinal values are a good indicator of a strain growth ability for the studied environmental factors. They are therefore used as criteria to select strains, in addition to their origin and virulence, when performing growth challenge tests (see EN ISO 20976-1) or in methods validation (see EN ISO 16140 series). 

New EN ISO 24914:2026-01

Microbiology of the food chain — Loop-mediated isothermal amplification (LAMP) for the detection of microorganisms and associated genetic markers — General requirements and definitions 

This document specifies the general requirements and provides guidance for the development and application of loop-mediated isothermal amplification (LAMP) to detect microorganisms and associated genetic markers (e.g. antimicrobial resistance genes, virulence genes) in the food chain.

This document is applicable to all LAMP methods, platforms, and items from the food chain and laboratories.

This document does not apply to the use of LAMP for quantification.

This document has been established for microorganisms in the food chain and is applicable to:

• products intended for human consumption
• products for feeding animals
• environmental samples in the area of food and feed production and handling
• samples from the primary production stage for the above items.

Revised EN ISO 7889 | IDF 117:2026-01

Yoghurt — Enumeration of characteristic microorganisms — Colony-count technique

This document specifies a method for the enumeration of the characteristic microorganisms Lactobacillus delbrueckii subsp. bulgaricus (in short: L. bulgaricus) and Streptococcus thermophilus (in short: S. thermophilus) by means of the colony-count technique.

The method is applicable to yoghurts (for the definition see CXS 243‑2003).

This second edition cancels and replaces the first edition (ISO 7889 | IDF 117:2003), which has been technically revised.

The main changes are as follows:

• The culture medium M17 has been amended: lactose is replaced by sucrose to (also) enumerate lactose negative strains of S. thermophilus.
• The concentration ß-glycerophosphate, the main selective agent of M17 culture medium and a powerful buffer,[14][15] is lowered from 1,9 % to 1 %. This reduction improved the size and morphology of S. thermophilus colonies during pilot studies and can improve the productivity.
• For better performance, microaerobic incubation of M17-S has been changed to mandatory.
• Spread plates have been added to the method as alternative for pour plates.
• Performance characteristics, with the results of an interlaboratory study, which are based on the method of this second edition have been included as Annex C.

The main technical changes introduced in this document compared to ISO 7889 | IDF 117:2003, are considered as major (see ISO 17468). 

These technical changes have a major impact on the performance characteristics of the method.

The full report of the interlaboratory study is available in the bulletin of the IDF No 538 (2025) Interlaboratory study on the enumeration of characteristic microorganisms in yoghurt.

Revised ISO/TS 11059 | IDF/RM 225:2025-12

Milk and milk products — Method for the enumeration of Pseudomonas spp. 

This document specifies the enumeration of Pseudomonas spp. by the colony-count technique.

This document is applicable to:

• milk and milk products
• environmental samples in the area of dairy production and handling.

The method allows the isolation of all pigmented and non-pigmented psychrotrophic Pseudomonas spp.

This second edition cancels and replaces the first edition (ISO/TS 11059 | IDF/RM 225:2009), which has been technically revised.

The main changes are as follows:

• biochemical confirmation tests on oxidase reaction and glucose fermentation test have been aligned with the same confirmation tests used for presumptive Enterobacteriaceae
• the flow diagram in Annex A giving the main steps of the procedure has been added
• in Annex B, the criteria for the performance testing of culture media and reagents have been added.

The main technical changes introduced in this document compared to ISO/TS 11059 | IDF/RM 225:2009, are considered as minor (see ISO 17468). 

These technical changes have a minor impact on the performance characteristics of the method. 

New EN ISO 7899-3:2025-07

Water quality — Enumeration of intestinal enterococci — Part 3: Most probable number method 

This document specifies a method for the enumeration of intestinal enterococci in water, including Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Enterococcus avium, Enterococcus gallinarum, Enterococcus hirae, Enterococcus casselifavus.

The method is based on the growth of target organisms in a liquid medium and calculation of the most probable number (MPN) of microorganisms by reference to MPN tables or using suitable MPN informatic programs.

This method can be applied to drinking water and bathing water (fresh or marine), together with other similar water types including those containing an appreciable amount of suspended matter.

The test specified in this document relies upon the detection of intestinal enterococci based upon expression of the enzyme ß-D-glucosidase and provides a confirmed result in 24 h without further testing of positive wells.

This document does not apply to bottled waters, for which the method has not been validated and therefore is outside the scope of this document, unless appropriate validation of performance of this method has been undertaken by the laboratory prior to use.

New EN ISO/TS 16099:2025-07

Water quality — Polymerase chain reaction (PCR) for the detection and quantification of microorganisms and viruses — General requirements, quality assurance and validation 

This document specifies the general requirements for the in vitro amplification of nucleic acid sequences (DNA or RNA). This includes polymerase chain reaction (PCR)-based methods like quantitative PCR, qualitative PCR, reverse transcription-PCR and digital PCR.

The minimum requirements laid down in this document are intended to ensure that comparable and reproducible results are obtained in different organizations. It covers quality assurance aspects to be considered when working with PCR-based methods in a laboratory as well as validation and verification. 

In addition to laboratory PCR-based methods, this document is also applicable to on-site PCR-based methods.

This document is applicable to PCR-based methods used for the analysis of microorganisms and viruses in different water matrices, including but not limited to: 

• drinking water
• groundwater
• pool water
• process water
• surface water
• wastewater

This document is applicable to the detection and quantification of nucleic acids (DNA or RNA) of microorganisms by PCR-based methods in water such as bacteria, yeasts, fungi but also parasites such as Cryptosporidium, Giardia, amoebas and multicellular organisms. In addition, this document is applicable to the detection and quantification of nucleic acids from viruses in water by PCR-based methods.

New EN ISO 6579-4:2025-01

Microbiology of the food chain — Horizontal method for the detection, enumeration and serotyping of Salmonella — Part 4: Identification of monophasic Salmonella Typhimurium (1,4,[5],12:i:-) by polymerase chain reaction (PCR)

In several international, regional and national laws, regulatory limits are set to ensure the so-called absence of Salmonella spp. in samples of the food chain. Moreover, several European Commission (EC) regulations also demand the absence of particular Salmonella serovars which have shown to cause a relatively high percentage of human salmonellosis. One of these Salmonella serovars for which legal criteria are set is Salmonella Typhimurium, including its monophasic variant 1,4,[5],12:i:- (e.g. Regulation (EC) No. 1086/2011).

This document specifies a horizontal in vitro method for the molecular identification and differentiation of the monophasic variant of Salmonella enterica subsp. enterica serovar Typhimurium (1,4,[5],12:i:-) lacking the second H phase H:1,2, starting from isolates. The method detects specific DNA sequences of an intergenic region of the first H phase flagellin cluster for identification of Salmonella enterica subsp. enterica serovar Typhimurium (further called Salmonella Typhimurium) and specific DNA sequences of genes associated with second H phase flagellar antigen expression. The method is applicable for:

• differentiation of the isolate under analysis between monophasic Salmonella Typhimurium and the monophasic variant of another Salmonella non-Typhimurium serovar that has the same antigenic formula
• identification of the isolate under analysis being either monophasic Salmonella Typhimurium or (biphasic) Salmonella Typhimurium.

This document is applicable for the analysis of a pure culture belonging to the genus Salmonella, isolated from:

• products intended for human consumption
• products intended for animal feeding
• environmental samples in the area of food and feed production and handling
• samples from the primary production stage

This document can also be applied in other domains for identification of monophasic Salmonella Typhimurium (e.g. environmental, human health, animal health).

New EN ISO 16140-4:2020 Amendment 2:2025-08

Microbiology of the food chain — Method validation — Part 4: Protocol for method validation in a single laboratory 

AMENDMENT 2: Protocol for single laboratory validation of identification methods of microorganisms

This document describes a protocol for single-laboratory validation of identification methods of microorganisms.  

A single-laboratory method validation study is used to demonstrate the performance of the method in the laboratory that conducted the study. The results are only valid for that particular laboratory.

New EN ISO 16140-3:2021 Amendment 1:2025-08

Microbiology of the food chain — Method validation — Part 3: Protocol for the verification of reference methods and validated alternative methods in a single laboratory

AMENDMENT 1: Protocol for verification of validated identification methods of microorganisms

This document describes the technical protocol for the verification of a validated identification method.  

The verification of validated identification methods only requires implementation verification. The sample is an isolated colony on defined selective or non-selective agar plates.

Implementation verification aims to demonstrate the competence of the user laboratory to perform the validated identification method. This is achieved by its ability to obtain the expected results on an isolated colony from specified selective or non-selective agar(s).

Examples of validated alternative identification method verifications are given in the document:

1. example with multiple genera from a single family
2. example with multiple families, genera and species
3. example with multiple families, genera and species
4. example with species identification within a genus.

New EN ISO 16140-7:2024-11

Microbiology of the food chain — Method validation — Part 7: Protocol for the validation of identification methods of microorganisms 

This document specifies the general principle and the technical protocol for the validation of identification methods of microorganisms for microbiology in the food chain. As there is no reference method, no method comparison study can be run. Therefore, this document provides a protocol to evaluate the performance characteristics and validate the method workflow using well-defined strains. When required, an additional dentification method can be used.

This document is applicable to the validation of identification methods of microorganisms that are used for the analysis of isolated colonies from: 

• products intended for human consumption
• products for feeding animals
• environmental samples in the area of food and feed production and handling
• samples from the primary production stage

This document is applicable to bacteria and fungi. Some clauses can be applicable to other (micro)organisms, which can be determined on a case-by-case basis.

Revised EN ISO 29981 | IDF 220:2024-11

Milk products — Enumeration of bifidobacteria — Colony-count technique 

This document specifies a method for the selective enumeration of bifidobacteria in milk products by using a colony-count technique at 37 °C under anaerobic conditions.

The method is applicable to milk products, such as fermented (e.g. yoghurts) and non-fermented milks (e.g. pasteurized milks, skim milks, whey protein concentrates), milk powders and formulae (e.g. infant formulae, follow-up formulae for older infants, products for young children) where these microorganisms are present and viable, in combination with other lactic acid bacteria or alone. The method is also applicable to starter and probiotic cultures.

This second edition cancels and replaces the first edition (ISO 29981 | IDF 220:2010), which has been technically revised.

The main changes are as follows:

• diluents which can be used have been added
• preparation of the test portion and primary dilution in cases of dried milk products has been added
• a new culture medium, TOS agar, has been introduced
• storage of incubated plates has been included
• expression of results has been changed to be in accordance with ISO 7218
• performance testing of the culture media has been introduced
• performance characteristics, with the results of an interlaboratory study, which are based on the method of this second edition, have been included as Annex C.

The main technical changes introduced in this document compared to ISO 29981 | IDF 220:2010, are considered as major (see ISO 17468). These technical changes have a major impact on the performance characteristics of the method.

The full report of the interlaboratory study is available in the bulletin of the IDF No 530 (2024) Multi-laboratory study and interlaboratory study on the enumeration of bifidobacteria in milk products.

New EN ISO 16140-4:2020 Amendment 1:2024-09

Microbiology of the food chain — Method validation — Part 4: Protocol for method validation in a single laboratory Amendment 1: Validation of a larger test portion size for qualitative methods

This document specifies a protocol for the validation of qualitative methods when using a larger test portion size. This protocol is intended to demonstrate the effect of analysing a test portion larger than the test portion initially used to validate the method. Validation of the larger test portion size applies only to the laboratory conducting the study and only to the specific (food) category used. 

Qualitative reference methods which were validated using a larger test portion size in accordance with EN ISO 17468 and qualitative alternative (proprietary) methods which were validated using a larger test portion size in accordance with EN ISO 16140-2 only need to be verified by a laboratory following EN ISO 16140-3.

Once the larger test portion size has been validated, all test portions smaller than the largest validated test portion can be used for routine testing for this particular (food) category at the same sample/diluent ratio. For example, a method that has been validated for 375 g test portions can be used for 25 g, 100 g, etc., up to 375 g test portions. 

The protocol is intended to demonstrate that a larger test portion size provides a similar or lower level of detection (LOD50) compared to the LOD50 of the (validated) test portion size as specified in the method.

New EN ISO 6887-1:2017 Amendment 1:2024-07

Microbiology of the food chain — Preparation of test samples, initial suspension and decimal dilutions for microbiological examination —
Part 1: General rules for the preparation of the initial suspension and decimal dilutions
AMENDMENT 1: Requirements and guidance on the use of a larger test portion size for qualitative methods

This document describes the handling of larger test portions including larger single test portions and pooled samples. It describes the check of temperature profile to ensure that the time taken to reach the target incubation temperature and overall incubation time are as specified in the individual standard. New figures are included to illustrate the compositing and pooling procedures. 

Validation and verification of larger test portion size is described now in EN ISO 161640 series.

Revised EN ISO 22174:2024-08

Microbiology of the food chain — Polymerase chain reaction (PCR) for the detection and quantification of microorganisms — General requirements and definitions 

This document specifies the general requirements for the in vitro amplification of nucleic acid sequences (DNA or RNA).

This document is applicable to the testing for microorganisms and viruses from the food chain using the polymerase chain reaction (PCR). This document, or parts of it, is applicable to other fields of PCR diagnostics based on a case-by-case evaluation. 

The minimum requirements laid down in this document are intended to ensure that comparable and reproducible results are obtained in different laboratories.

This document has been established for microorganisms from the food chain and is applicable to:

• products intended for human consumption
• products for feeding animals
• environmental samples in the area of food and feed production and handling
• samples from the primary production stage.

This second edition cancels and replaces ISO 22174:2005, ISO 20837:2006, ISO 20838:2006 and ISO 22119:2011, which have been technically revised.

The main changes are as follows:

• inclusion of requirements for the implementation of digital PCR
• inclusion of requirements for laboratory flows monitoring including environmental monitoring for PCR
• extension of Clause 12.2.2 control reaction with descriptions of the different controls
• change of Clause 12.3 to include quantitative evaluation
• inclusion of Clause 14 on validation and verification.

Revised EN ISO 7218:2024-06

Microbiology of the food chain — General requirements and guidance for microbiological examinations 

The purpose of this document is to help to ensure the validity of microbiology examinations in the food chain. In particular, to ensure that general techniques for conducting examinations are the same in all laboratories, to achieve consistent results in different laboratories and to contribute to safety of laboratory personnel by preventing risks of infection.

This document specifies general requirements and gives guidance on microbiological examinations.

It is applicable to:

• the implementation of specific horizontal or vertical International Standards developed by ISO/TC 34/SC 9 or ISO/TC 34/SC 5 for detection or enumeration of microorganisms, named hereafter specific standards
• good laboratory practices for microbiology laboratories testing samples from the food chain
• guidance for microbiological laboratories testing samples from the food chain on the technical requirements for conforming to ISO/IEC 17025.

The requirements of this general standard supersede corresponding ones in existing specific standards.

This document is applicable to examinations for bacteria, yeasts and moulds and can be used, if supplemented with specific guidance, for parasites and viruses. It does not apply to examinations for toxins or other metabolites (e.g. amines) from microorganisms.

This document is applicable to microbiology of the food chain, from primary production stage to food and animal feed products, including the premises where the food or feed production and handling takes place. It is also applicable to the microbiological examination of water where water is used in food production or is regarded as a food in national legislation.

This fourth edition cancels and replaces the third edition (ISO 7218:2007), which has been technically revised. It also incorporates the Amendment ISO 7218:2007/Amd 1:2013.

The main changes are as follows:

• the calculations section has been simplified and two further calculators have been added
• the equipment section has been reorganized into groups with similar purposes and requirements
• cross-references have been added to other general microbiology standards such as those for media, validation and verification, and uncertainty to reduce repetition
• information on laboratory quality control and characterization of control microorganisms has been added.

Additional instructions for examinations using the polymerase chain reaction (PCR) are specified in EN ISO 22174.

New ISO/TS 12869-2:2024-04

Water quality — Detection and quantification of Legionella spp. and/or Legionella pneumophila by concentration and genic amplification by quantitative polymerase chain reaction (qPCR) — Part 2: On-site methods

This document provides the guidelines, minimum requirements and performance characteristics intended to guarantee that manufactured systems intended for on-site/field use (i.e. outside the laboratory) provide reliable and reproducible results. 

It is intended to be applied in the bacteriological investigation of all types of water (hot or cold water, cooling tower water, etc.), unless the nature and/or content of suspended matter and/or background microorganisms interfere with the determination. 

The results are expressed as the number of genome units of Legionella spp. and/or L. pneumophila per millilitre (or litre) of sample.

New EN ISO 4973:2023-09

Cosmetics — Microbiology — Quality control of culture media and diluents used in cosmetics standards 

This document is intended to provide methods to assess the quality of the media used in cosmetics microbiology standards and define the minimum acceptance criteria required to ensure their performance.

This applies to:

1. commercially ready-to-use culture media
2. culture media prepared from dehydrated culture media plus additional ingredients, or only ingredients

It specifies the minimum requirements for quality control of microbiological culture media and diluents in order to demonstrate their ability to detect microorganisms and to ensure reliability of the microbiological test methods described in the ISO cosmetics microbiology standards.

This document describes mainly growth promotion and microbial control tests and is applicable to both commercially ready-to-use culture media and culture media prepared from dehydrated culture media or basic constituents in the user’s laboratory.

Other methods can be substituted provided that their equivalence has been demonstrated.

New EN ISO 7704:2023-01

Water quality — Requirements for the performance testing of membrane filters used for direct enumeration of microorganisms by culture methods 

This document specifies the requirements for performance testing of membrane filters used for the retention and subsequent direct enumeration of microorganisms by culture methods.

It is applicable to membrane filters which are used for retention followed by direct enumeration of specific microorganisms on solid media or on other devices containing media, like absorbent pads.

This document is not applicable for membrane filters used for concentration and elution or for qualitative methods.

These tests are applicable to the membrane filters intended for the microbiological analysis of different types of water, such as: 

• drinking water, bottled water and other types of water with expected low numbers of microorganisms
• water with expected higher numbers of microorganisms, for example, surface water and process water.

These tests are intended to demonstrate the suitability of the whole system (membrane filter together with the culture medium including the filtration step) required for the specific tests described in ISO 6461-2, EN ISO 7988-2, EN ISO 9308-1, EN ISO 9803-4 (in preparation), EN ISO 11731, EN ISO 14189 and EN ISO 16266.

This document applies to:

• manufacturers producing membrane filters
• microbiological laboratories using membrane filters for their own testing or providing these to other end users.

This second edition cancels and replaces the first edition (ISO 7704:1985), which has been technically revised.

The main changes are as follows:

• the scope has been changed to cover the requirements for the performance testing of membrane filters used for retention and direct enumeration
• clauses have been added for terms and definitions, microorganisms, sampling and replicates, procedure, inoculation and incubation, counting, calculation and documentation
• the clauses referencing to culture media and diluents, test strain preparation, performance testing and procedure have been revised to align with ISO 8199 and ISO 11133
• Annex A has been added with a diagram of the batch testing
• Annex B has been added to give an example of a card to record the test results from batch testing and supplementary testing of membrane filters
• Annex C has been added to describe the quantitative additional testing of membrane filters including a diagram of the procedure
• Annex D has been added to describe the qualitative supplementary testing of membrane filters
• Annex E has been added to give a practical example of batch testing and quantitative additional testing by the end user including a diagram of the procedure
• the Bibliography has been added.