SIST-TP CEN/TR 15214-1:2006
(Main)Characterization of sludges - Detection and enumeration of Escherichia coli in sludges, soils, soil improvers, growing media and biowastes - Part 1: Membrane filtration method for quantification
Characterization of sludges - Detection and enumeration of Escherichia coli in sludges, soils, soil improvers, growing media and biowastes - Part 1: Membrane filtration method for quantification
This part of the CEN Technical Report specifies a membrane filtration procedure for the quantitative detection, by culture of individual colonies on chromogenic agar media, of Escherichia coli. in sludges, soils, soil improvers, growing media and biowastes. This part of the Technical Report is not suitable for materials whose treatment will significantly reduce bacterial levels to less than 10 viable E. coli per g wet weight, such as lime addition, drying or pasteurisation. A liquid enrichment and most probable number estimation method may be suited for such purpose.
This membrane filtration method is not appropriate for enumeration and detection of other coliform bacteria without modifications to the chromogenic agar media.
It is suitable to evaluate the log reduction of E.coli through treatment, as well as the quality of the end product.
This method is for materials with dry residues less than 20 %. For materials with dry residues greater than 20 % and low numbers of E. coli, CEN/TR 15214-2 and CEN/TR 15214-3 should be used.
Charakterisierung von Schlämmen - Quantitativer Nachweis von Escherichia coli in Schlämmen, Böden, Bodenverbesserungsmitteln, Kultursubstraten sowie Bioabfällen - Teil 1: Membranfiltrationsverfahren zur quantitativen Bestimmung
Dieses Dokument legt ein Membranfiltrationsverfahren für den quantitativen Nachweis von Escherichia coli in Schlämmen, Böden, Bodenverbesserungsmitteln, Kultursubstraten und Bioabfall durch Züchtung von einzelnen Kolonien auf chromogenen Agarmedien fest. Dieses Dokument ist nicht für Materialien geeignet, deren Behandlung zu einer wesentlichen Verringerung der Bakterienkonzentration auf weniger als 10 lebensfähige E. coli je Gramm Feuchtmasse führt, wie z. B. Hinzufügen von Kalk, Trocknen oder Pasteurisierung. In diesem Fall können die Anreicherung in einem flüssigen Medium und das Verfahren der wahrscheinlichsten Keimzahl (MPN-Schätzverfahren) geeignet sein.
Dieses Membranfiltrationsverfahren ist ohne Modifikation der chromogenen Agarmedien nicht für die Zählung und den Nachweis von anderen coliformen Bakterien geeignet.
Es eignet sich für die Bewertung der logarithmischen Abnahme von E. coli durch Behandlung sowie der Qualität des Endproduktes.
Das vorliegende Verfahren ist für Materialien mit einem Trockenrückstand von weniger als 20 % vorgesehen. Bei Materialien mit einem Trockenrückstand von mehr als 20 % und einer geringen Anzahl an E. coli sollten CEN/TR 15214-2 und CEN/TR 15214-3 Anwendung finden.
Caractérisation des boues - Détection et dénombrement des Escherichia coli dans les boues, les sols, les amendements du sol, les supports de culture et les biodéchets - Partie 1 : Méthode de quantification par filtration sur membrane
La présente partie du Rapport Technique CEN spécifie un mode opératoire de filtration sur membrane pour la détection quantitative par culture de colonies individuelles sur un milieu chromogène gélosé, d’Escherichia coli dans les boues, les sols, les amendements du sol, les supports de culture et les biodéchets. La présente partie du Rapport Technique ne convient pas aux matériaux soumis à un traitement (tels que l’ajout de chaux, le séchage ou la pasteurisation) réduisant de façon significative les niveaux bactériens à un niveau inférieur à 10 E. coli viables par gramme de masse humide. Pour cela, une fertilisation liquide et une estimation en utilisant la technique du nombre le plus probable peuvent convenir.
Cette méthode de filtration sur membrane ne convient pas pour la détection et le dénombrement d’autres bactéries coliformes si le milieu chromogène gélosé n’est pas modifié.
Elle convient en revanche pour évaluer la réduction log d’E. coli pendant le traitement ainsi que la qualité du produit fini.
Cette méthode s’applique aux matériaux ayant une teneur en matière sèche inférieure à 20 %. Il convient d’utiliser le CEN/TR 15214-2 et le CEN/TR 15214-3 lorsque les matériaux ont une teneur en matière sèche supérieure à 20 % et des nombres faibles de E. coli.
Karakterizacija blata – Ugotavljanje prisotnosti in števila Echerichia coli v blatu, zemljini, izboljševalcih tal, rastnih substratih in bio-odpadkih - 1. del: Metoda membranske filtracije za kvantifikacijo
General Information
Overview
CEN/TR 15214-1:2006 - Characterization of sludges: Detection and enumeration of Escherichia coli (Part 1) specifies a membrane filtration method for quantification of E. coli in sludges, soils, soil improvers, growing media and biowastes. The method uses chromogenic membrane lactose glucuronide agar (MLGA) to culture and enumerate green, β‑glucuronidase‑positive E. coli colonies. It is intended for materials with dry residue < 20% and has a practical detection limit of about 10 cfu per g (wet weight). For treated materials with very low counts or high dry residues, the related CEN/TR 15214-2 and -3 methods are recommended.
Key topics and technical requirements
- Principle: Filter diluted sample through a 0.45 µm membrane; incubate on MLGA; E. coli appear as green colonies from BCIG hydrolysis.
- Sample prep: Typical test portion is 10 g + 90 ml maximal recovery diluent (MRD); homogenise, centrifuge aliquot and pre-filter through glass-fibre to remove fine debris.
- Filtration and culture: Apply 1 ml of diluted sample to membrane; transfer membrane to MLGA plate.
- Incubation regimen: Initial incubation at (30 ± 1) °C for (4 ± 0.5) h (resuscitation), then at (44 ± 1) °C for (14 ± 2) h for colony development.
- Enumeration and confirmation: Count green colonies visually; optional biochemical confirmation (e.g., API 20E).
- Performance limits: Not suitable when treatments reduce E. coli to <10 cfu/g (e.g., pasteurisation, drying, lime treatment) or when dry residue >20% without pre-dilution.
- Health & safety: Samples can contain pathogens and flammable gases - chill samples (5 ± 3 °C), use PPE, avoid sealed glass containers, follow national biosafety regulations.
- Equipment & reagents: Sterile membrane filters, MLGA with BCIG, homogeniser (Stomacher®), vacuum manifold, incubators, MRD diluent.
Applications and users
This standard is used to:
- Monitor E. coli contamination in sludge, compost, soil improvers, growing media and biowastes.
- Evaluate treatment efficacy (log reduction) for processes such as digestion, composting or stabilization.
- Verify end-product quality for agricultural reuse and regulatory compliance. Primary users:
- Environmental and microbiology laboratories
- Municipal wastewater and sludge treatment facilities
- Compost and soil improver producers
- Regulatory authorities and quality control teams
- Environmental consultants and agronomy laboratories
Related standards
- CEN/TR 15214-2 and CEN/TR 15214-3 (semi-quantitative/MPN methods for low-count or high-dry-matter materials)
- EN 12880 (determination of dry residue/water content)
- ISO 8199 (general guidance on microbial enumeration)
Keywords: CEN/TR 15214-1:2006, membrane filtration method, Escherichia coli, MLGA, sludge characterization, enumeration, chromogenic agar, biowaste testing, E. coli detection.
Frequently Asked Questions
SIST-TP CEN/TR 15214-1:2006 is a technical report published by the Slovenian Institute for Standardization (SIST). Its full title is "Characterization of sludges - Detection and enumeration of Escherichia coli in sludges, soils, soil improvers, growing media and biowastes - Part 1: Membrane filtration method for quantification". This standard covers: This part of the CEN Technical Report specifies a membrane filtration procedure for the quantitative detection, by culture of individual colonies on chromogenic agar media, of Escherichia coli. in sludges, soils, soil improvers, growing media and biowastes. This part of the Technical Report is not suitable for materials whose treatment will significantly reduce bacterial levels to less than 10 viable E. coli per g wet weight, such as lime addition, drying or pasteurisation. A liquid enrichment and most probable number estimation method may be suited for such purpose. This membrane filtration method is not appropriate for enumeration and detection of other coliform bacteria without modifications to the chromogenic agar media. It is suitable to evaluate the log reduction of E.coli through treatment, as well as the quality of the end product. This method is for materials with dry residues less than 20 %. For materials with dry residues greater than 20 % and low numbers of E. coli, CEN/TR 15214-2 and CEN/TR 15214-3 should be used.
This part of the CEN Technical Report specifies a membrane filtration procedure for the quantitative detection, by culture of individual colonies on chromogenic agar media, of Escherichia coli. in sludges, soils, soil improvers, growing media and biowastes. This part of the Technical Report is not suitable for materials whose treatment will significantly reduce bacterial levels to less than 10 viable E. coli per g wet weight, such as lime addition, drying or pasteurisation. A liquid enrichment and most probable number estimation method may be suited for such purpose. This membrane filtration method is not appropriate for enumeration and detection of other coliform bacteria without modifications to the chromogenic agar media. It is suitable to evaluate the log reduction of E.coli through treatment, as well as the quality of the end product. This method is for materials with dry residues less than 20 %. For materials with dry residues greater than 20 % and low numbers of E. coli, CEN/TR 15214-2 and CEN/TR 15214-3 should be used.
SIST-TP CEN/TR 15214-1:2006 is classified under the following ICS (International Classification for Standards) categories: 13.030.20 - Liquid wastes. Sludge; 13.080.30 - Biological properties of soils; 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST-TP CEN/TR 15214-1:2006 is associated with the following European legislation: EU Directives/Regulations: TP136. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
You can purchase SIST-TP CEN/TR 15214-1:2006 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of SIST standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2006
Karakterizacija blata – Ugotavljanje prisotnosti in števila Echerichia coli v blatu,
zemljini, izboljševalcih tal, rastnih substratih in bio-odpadkih - 1. del: Metoda
membranske filtracije za kvantifikacijo
Characterization of sludges - Detection and enumeration of Escherichia coli in sludges,
soils, soil improvers, growing media and biowastes - Part 1: Membrane filtration method
for quantification
Charakterisierung von Schlämmen - Quantitativer Nachweis von Escherichia coli in
Schlämmen, Böden, Bodenverbesserungsmitteln, Kultursubstraten sowie Bioabfällen -
Teil 1: Membranfiltrationsverfahren zur quantitativen Bestimmung
Caractérisation des boues - Détection et dénombrement des Escherichia coli dans les
boues, les sols, les amendements du sol, les supports de culture et les biodéchets -
Partie 1 : Méthode de quantification par filtration sur membrane
Ta slovenski standard je istoveten z: CEN/TR 15214-1:2006
ICS:
13.030.20 7HNRþLRGSDGNL%ODWR Liquid wastes. Sludge
13.080.30 Biološke lastnosti tal Biological properties of soils
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT
CEN/TR 15214-1
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
January 2006
ICS 07.100.99
English Version
Characterization of sludges - Detection and enumeration of
Escherichia coli in sludges, soils, soil improvers, growing media
and biowastes - Part 1: Membrane filtration method for
quantification
Caractérisation des boues - Détection et dénombrement Charakterisierung von Schlämmen - Quantitativer
des Escherichia coli dans les boues, les sols, les engrais, Nachweis von Escherichia coli in Schlämmen, Böden,
les amendements organiques et les biodéchets - Partie 1 : Düngemitteln und Bodenverbesserern, Kultursubstraten
Méthode de quantification par filtration sur membrane sowie Bioabfällen - Teil 1: Membranfiltrationsverfahren zur
quantitativen Bestimmung
This Technical Report was approved by CEN on 3 September 2005. It has been drawn up by the Technical Committee CEN/TC 308.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15214-1:2006: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Introduction.4
1 Scope.5
2 Normative references.5
3 Terms and definitions.5
4 Principle.6
5 Apparatus.6
6 Sampling and hazards .7
7 Reagents, diluents and culture media.7
8 Procedure.8
9 Expression of results.9
10 Test report.10
11 Performance data.10
Annex A (informative) Performance data of the interlaboratory comparison.11
Bibliography.13
Foreword
This Technical Report (CEN/TR 15214-1:2006) has been prepared by Technical Committee CEN/TC 308
“Characterization of sludges”, the secretariat of which is held by AFNOR.
This Technical Report does not replace any existing CEN method.
The standard is divided into three parts, part 1 gives a membrane filtration for quantification, part 2 gives a
miniaturised semi-quantitative MPN method and part 3 gives a semi-quantitative macromethod.
Introduction
Sludges, soils, soil improvers, growing media and biowastes can contain pathogenic micro-organisms such as
Salmonella spp. which occur mainly in the intestinal tract of humans and animals and are transmitted through
faecal contamination. The use of such contaminated materials in agriculture may cause outbreaks of infection
due to the production of contaminated food and animal foodstocks. They may also be transmitted to wild
animals. There is a need to monitor the efficacy of the storage and treatment processes to control pathogens
such as Salmonella spp., and application rates to land.
Escherichia coli is a non-pathogenic, Gram negative bacterium with a faecal origin. Consequently, it can be
used as an indicator of faecal contamination. It can also be used to monitor the effectiveness of pasteurization
or disinfection treatments but it is comparatively sensitive (to heat, high pH) and cannot therefore reflect the
behaviour of all pathogens in these materials.
Suitable quality control procedures, at least those described in ISO 8199, have to be applied.
WARNING — "Waste and sludge samples can contain hazardous and inflammable substances. They
can contain pathogens and be liable to biological action. Consequently, it is recommended that these
samples should be handled with special care. The gases which can be produced by microbiological
activity are potentially inflammable and will pressurise sealed bottles. Exploding bottles are likely to
result in infectious shrapnel and/or pathogenic aerosols. Glass bottles should be avoided wherever
possible. National regulations should be followed with respect to microbiological hazards associated
with this method".
1 Scope
This part of the CEN Technical Report specifies a membrane filtration procedure for the quantitative detection,
by culture of individual colonies on chromogenic agar media, of Escherichia coli. in sludges, soils, soil
improvers, growing media and biowastes. This part of the Technical Report is not suitable for materials whose
treatment will significantly reduce bacterial levels to less than 10 viable E. coli per g wet weight, such as lime
addition, drying or pasteurisation. A liquid enrichment and most probable number estimation method may be
suited for such purpose.
This membrane filtration method is not appropriate for enumeration and detection of other coliform bacteria
without modifications to the chromogenic agar media.
It is suitable to evaluate the log reduction of E.coli through treatment, as well as the quality of the end product.
This method is for materials with dry residues less than 20 %. For materials with dry residues greater
than 20 % and low numbers of E. coli, CEN/TR 15214-2 and CEN/TR 15214-3 should be used.
2 Normative references
The following referenced documents are indispensable for the application 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.
EN 12880:2000, Characterisation of Sludges — Determination of dry residue and water content
ISO 8199, Water quality — General guidance on the enumeration of micro-organisms by culture
3 Terms and definitions
For the purposes of this Technical Report, the following terms and definitions apply.
3.1
Escherichia coli
Escherichia coli, belongs to the family of Enterobacteriaceae, is Gram-negative, non-sporulating, rod-shaped,
lactose positive and able to grow at 44 °C. Most E. coli strains are able to produce indole from tryptophan and
are β-glucuronidase-positive
3.2
method definition
β-glucuronidase-positive and able to hydrolyse 5-bromo-4-chloro-3-indolyl-β-glucuronide (BCIG) when
growing on an MLG agar medium at the temperature of 44 °C
3.3
cfu, colony forming unit
growth of individual bacterial cells into visible colonies on agar media, including on membrane filters
overlaying the agar media
3.4
vegetative bacteria
those bacteria which are capable of normal growth in broth or on agar media without pre-culture resuscitation
3.5
sub-lethally damaged bacteria
those bacteria which have been stressed but not killed by storage or subsequent treatment by, for example,
mesophilic anaerobic digestion, lime stabilisation or composting
3.6
resuscitation
stimulation to vegetative growth of sub-lethally damaged bacteria previously incapable of growth on agar
media
3.7
quantitative resuscitation
stimulation to vegetative growth of sub-lethally damaged bacteria recovered discretely on a membrane filter,
prior to transfer to chromogenic medium for growth of individual colonies
3.8
dry residue
the dry mass portion of the material obtained after the specified drying process. It is expressed as percent or
in grams per kilogram [EN 12880:2000, 3.1]
4 Principle
The diluted sludge sample is filtered, the membrane filter recovered aseptically and incubated on membrane
lactose glucuronide agar (MLGA), initially at (30 ± 1) °C for (4 ± 0,5) h. Subsequently, the temperature is
increased to (44 ± 1) °C for (14 ± 2) hours. The presence of E. coli is indicated by green colonies resulting
-1
from the hydrolysis of BCIG. The method has a limit of detection of approximately 10 cfu g wet weight sludge,
dependent on the solids content which at high concentrations (> 20 % (w/v)) may restrict filtration of the
sample volume through the membrane if not first diluted.
5 Apparatus
With the exception of equipment supplied sterile, the glassware shall be sterilised in accordance with the
instructions given in ISO 8199.
Usual microbiological laboratory equipment, and in particular:
5.1 Apparatus for sterilisation by dry heat (oven) or steam (autoclave).
5.2 Thermostatic incubator(s) regulated at (30 ± 1) °C and/or (44 ± 1) °C.
5.3 Homogeniser (e.g. Stomacher®, Seward
...
本記事は、CEN Technical ReportであるSIST-TP CEN/TR 15214-1:2006において、スラッジ、土壌、土壌改良材、培地、バイオ廃棄物などにおける大腸菌（Escherichia coli）の定量的な検出および培養に関する、膜濾過法の手順が指定されています。このTechnical Reportのこの部分は、核酸性対数平均評価法（most probable number estimation method）も適しているかもしれません。 この膜濾過法は、石灰添加、乾燥、殺菌など、バクテリアレベルが激減し1gの湿潤重量あたりの大腸菌が10個未満となるような物質には適していません。このような場合には、液体培養法や最常数法を使用することが適切かもしれません。 また、この方法は、色素化寒天培地を変更せずに他の腸内細菌の存在量を検出するためには適していません。 この方法は、大腸菌の処理による対数減少の評価や最終製品の品質評価に使用することができます。ただし、乾燥残留物が20％以上で大腸菌数が少ない場合は、CEN/TR 15214-2およびCEN/TR 15214-3を使用する必要があります。
제목: SIST-TP CEN/TR 15214-1:2006 - 슬러지 특성 - 슬러지, 토양, 토양개량재, 배양매체 및 생물폐기물에서 대장균의 검출 및 계수를 위한 부분 1: 양적 측정을 위한 막 여과법 내용: 본 CEN 기술 보고서의 해당 부분은 슬러지, 토양, 토양개량재, 배양매체 및 생물폐기물에서 대장균을 배양하여 염색배지에서 개별 균주의 수량적 검출을 위한 막 여과 절차를 명시한다. 본 기술 보고서의 해당 부분은 석회 첨가, 건조 또는 파스토라이제와 같이 대장균 수량을 10개 미만의 생존 가능한 E. coli/g 생중량으로 크게 감소시키는 물질에 적합하지 않다. 이러한 경우 액상 강화 및 가장 가능한 수 추정법을 사용하는 것이 적합할 수 있다. 이 막 여과법은 염색배지를 수정하지 않는 한 다른 콜리폼 세균의 계수 및 검출에 적합하지 않다. 이 방법은 대책의 품질과 E.coli의 로그 감소를 평가하는 데 적합하다. 이 방법은 건축물의 말끔한 잔여물이 20% 미만인 재료에 대해 적용된다. 건축물의 말끔한 잔여물이 20% 이상이거나 E.coli 수가 적은 경우에는 CEN/TR 15214-2 및 CEN/TR 15214-3으로 설명된 다른 방법을 사용해야한다.
The article discusses a CEN Technical Report that outlines a membrane filtration method for detecting and quantifying Escherichia coli (E. coli) in various substances such as sludges, soils, soil improvers, growing media, and biowastes. The method involves culturing individual colonies on chromogenic agar media. However, it is not suitable for materials that have undergone treatments such as lime addition, drying, or pasteurization, which reduce bacterial levels to less than 10 viable E. coli per g wet weight. In such cases, a liquid enrichment and most probable number estimation method may be more appropriate. The membrane filtration method is also not effective for detecting other coliform bacteria without modifications to the agar media. It can be used to evaluate the reduction of E. coli through treatment and assess the quality of the end product. It is specifically designed for materials with dry residues less than 20%, while materials with dry residues greater than 20% and low E. coli numbers require the use of other methods outlined in CEN/TR 15214-2 and CEN/TR 15214-3.
CEN Technical Report인 SIST-TP CEN/TR 15214-1:2006은 슬러지, 토양, 토양 개선제, 재배 매체, 생분해 폐기물 등에서 대장균(Escherichia coli)을 검출하고 산출하기 위한 효과적인 막 여과 방법을 소개하고 있다. 이 Technical Report의 이 부분은 대장균의 수량을 측정하기 위해 핵산성 아가로 매질에 개별 군집을 배양하는 막 여과 절차에 대한 규정을 제시하고 있다. 하지만 이 방법은 석회 첨가, 건조 또는 고온 처리와 같은 물질의 처리로 박테리아의 농도가 1g의 수분 중 10개 미만으로 크게 줄어드는 경우에는 적합하지 않다. 이러한 경우 유체 강화 및 가두예상수법을 사용하는 것이 적합할 수 있다. 또한, 이 막 여과 방법은 염색 원성 아가로 매질에 대한 변경 없이 다른 대장균 속성 세균의 수량 측정과 검출에는 적합하지 않다. 이 방법은 E.coli의 처리를 통한 로그 감소 및 최종 제품의 품질을 평가하는 데에 적합하다. 하지만 건조 잔여물이 20%보다 크고 대장균 수가 적은 경우에는 CEN/TR 15214-2 및 CEN/TR 15214-3을 사용해야 한다.
The CEN Technical Report outlines a membrane filtration method to detect and quantify Escherichia coli in sludges, soils, soil improvers, growing media, and biowastes. The procedure involves culturing individual colonies on chromogenic agar media. However, this method is not suitable for materials that have undergone treatments reducing bacterial levels to less than 10 viable E. coli per gram wet weight. For such cases, a liquid enrichment and most probable number estimation method may be more appropriate. This specific method is not designed for the detection and enumeration of other coliform bacteria unless modifications are made to the chromogenic agar media. It can be used to assess the reduction of E. coli during treatment and the quality of the final product. For materials with dry residues greater than 20% and low numbers of E. coli, CEN/TR 15214-2 and CEN/TR 15214-3 should be used instead.
記事のタイトル: SIST-TP CEN/TR 15214-1:2006 - ヘドロの特性 - ヘドロ、土壌、土壌改良材、育成用基質および生物廃棄物中の大腸菌の検出および数え上げのためのパート 1: 量的評価のための膜ろ過法 記事の内容: このCEN技術報告の一部では、ヘドロ、土壌、土壌改良材、育成用基質、および生物廃棄物中の大腸菌の量的検出のための膜ろ過手法を、色素形成寒天培地上での個別コロニーの培養によって指定している。ただし、この技術報告の一部は、石灰添加、乾燥、またはパスチャライゼーションなど、細菌レベルを10個未満の生存可能なE. coli / g湿重量に劇的に低下させる処理によって細菌のレベルが著しく減少するような材料には適していません。そうした場合は、液体増殖と最も確からしい数推定法が適しているかもしれません。 この膜ろ過法は色素形成寒天培地を修正しない限り、他のコリフォーム菌の数え上げや検出には適していません。 この方法は処理によるE.coliのログ減少を評価したり、最終製品の品質を評価するのに適しています。 この方法は乾燥残留物が20％未満の材料に適用されます。乾燥残留物が20％以上でE.coliの数が少ない材料の場合は、CEN/TR 15214-2およびCEN/TR 15214-3で説明されている他の方法を使用する必要があります。
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