CEN/TS 17710:2022

SLOVENSKI STANDARD
01-februar-2023
Rastlinski biostimulanti - Ugotavljanje prisotnosti Listeria monocytogenes
Plant biostimulants - Detection of Listeria monocytogenes
Pflanzen-Biostimulanzien - Nachweis von Listeria monocytogenes
Biostimulants des végétaux - Détection de Listeria monocytogenes
Ta slovenski standard je istoveten z: CEN/TS 17710:2022
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 17710
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
March 2022
TECHNISCHE SPEZIFIKATION
ICS 65.080
English Version
Plant biostimulants - Detection of Listeria monocytogenes
Biostimulants des végétaux - Détection de Listeria Pflanzen-Biostimulanzien - Nachweis von Listeria
monocytogenes monocytogenes
This Technical Specification (CEN/TS) was approved by CEN on 3 January 2022 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 17710:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
4.1 General . 5
4.2 Pre-enrichment in non-selective liquid medium . 5
4.3 Enrichment in/on selective media . 6
4.4 Plating out on selective solid media . 6
4.5 Confirmation . 6
5 Culture media, reagents, antisera . 6
6 Equipment and consumables . 6
7 Sampling . 7
8 Preparation of test sample . 7
9 Preparation procedure . 7
9.1 Test portion and initial suspension . 7
9.2 Non-selective pre-enrichment . 8
9.3 Selective enrichment. 8
9.4 Plating out . 8
9.5 Confirmation of L. monocytogenes . 9
9.6 Interpretation of morphological and physiological properties and of the biochemical
reactions . 12
9.7 Additional characterization of isolated strains (optional) . 12
10 Expression of results . 12
11 Performance characteristics of the method . 13
11.1 Interlaboratory studies . 13
11.2 Sensitivity . 13
11.3 Specificity . 13
11.4 LOD . 13
12 Test report . 13
13 Quality assurance . 13
Annex A (normative) Diagram of the procedures . 14
Annex B (normative) Composition and preparation of culture media and reagents . 15
Bibliography . 25

European foreword
This document (CEN/TS 17710:2022) has been prepared by Technical Committee CEN/TC 455 “Plant
Biostimulants”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Introduction
This document was prepared by the experts of CEN/TC 455 “Plant Biostimulants”. The European
Committee for Standardization (CEN) was requested by the European Commission (EC) to draft
European standards or European standardization deliverables to support the implementation of
Regulation (EU) 2019/1009 of 5 June 2019 laying down rules on the making available on the market of
EU fertilizing products (“FPR” or “Fertilising Products Regulation”).
This standardization request, presented as M/564, also contributes to the Communication on
“Innovating for Sustainable Growth: A Bio economy for Europe”. The Working Group 5 “Labelling and
denominations”, was created to develop a work program as part of this request. The technical committee
CEN/TC 455 “Plant Biostimulants” was established to carry out the work program that will prepare a
series of standards. The interest in biostimulants has increased significantly in Europe as a valuable tool
to use in agriculture. Standardization was identified as having an important role in order to promote the
use of biostimulants. The work of CEN/TC 455 seeks to improve the reliability of the supply chain,
thereby improving the confidence of farmers, industry, and consumers in biostimulants, and will
promote and support commercialisation of the European biostimulant industry.
Biostimulants used in agriculture can be applied in multiple ways: on soil, on plant, as seed treatment,
etc. A microbial plant biostimulant consists of a microorganism or a consortium of microorganisms, as
referred to in Component Material Category 7 of Annex II of the EU Fertilising Products Regulation.
This document is applicable to all microbial biostimulants in agriculture.
The Table 1 below summarizes many of the agro-ecological principles and the role played by
biostimulants.
Table 1 — Agro-ecological principles and the role played by biostimulants
Increase biodiversity
By improving soil microorganism quality/quantity
Reinforce biological regulation and interactions
By reinforcing plant-microorganism interactions
- symbiotic exchanges i.e. Mycorrhizae
- symbiotic exchanges i.e. Rhizobiaceae/Faba
- secretions mimicking plant hormones (i.e. Trichoderma)
By regulating plant physiological processes
- for e.g. growth, metabolism, plant development…
Improve biogeochemical cycles
- improve absorption of nutritional elements
- improve bioavailability of nutritional elements in the soil
- stimulate degradation of organic matter

WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices and to ensure compliance
with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably trained staff.
1 Scope
This document provides a method for the detection of Listeria monocytogenes in microbial plant
biostimulants for verifying that the concentration of this human pathogen does not exceed the
respective limits outlined in the EU Regulation on Fertilising Products [1].
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
CEN/TS 17724, Plant biostimulants — Terminology
CEN/TS 17708, Plant biostimulants — Preparation of sample for microbial analysis
EN ISO 11290-1:2017, Microbiology of the food chain — Horizontal method for the detection and
enumeration of Listeria monocytogenes and of Listeria spp. — Part 1: Detection method (ISO 11290-
1:2017)
EN ISO 11133, Microbiology of food, animal feed and water — Preparation, production, storage and
performance testing of culture media
EN ISO 7218, Microbiology of food and animal feeding stuffs — General requirements and guidance for
microbiological examinations (ISO 7218)
3 Terms and definitions
For the purposes of this document, the terms and definitions are given in CEN/TS 17724 and the
following apply.
3.1
Listeria monocytogenes
microorganisms which form typical colonies on solid selective media described and which display the
morphological, physiological and biochemical characteristics described when the analysis is carried out
in accordance with this document
[SOURCE: EN ISO 11290-1:2017, 3.1]
4 Principle
4.1 General
The detection of Listeria monocytogenes requires four successive stages as specified in Annex A.
NOTE L. monocytogenes can be present in small numbers and is often accompanied by considerably larger
numbers of bacteria belonging to different taxonomic groups or different Listeria species. Pre-enrichment is used
to permit the detection of low numbers of L. monocytogenes or injured L. monocytogenes.
4.2 Pre-enrichment in non-selective liquid medium
Half-Fraser broth (225 ml) at ambient temperature is inoculated with the test portion sample (25 g or
25 ml), then incubated at 30 °C ± 1 °C for 24 h to 26 h.
...