Overview
EN ISO 6888-2:2021/A1:2023 is an important amendment to the international standard for microbiological analysis within the food chain. This document specifies a horizontal method for the enumeration of coagulase-positive staphylococci, including Staphylococcus aureus and other related species. Part 2 of this standard focuses on the method that employs rabbit plasma fibrinogen agar medium to detect and enumerate these bacteria.
The amendment, published by CEN in September 2023 and effective from March 2024, provides clarifications and updates that enhance the original ISO 6888-2:2021, ensuring improved accuracy and applicability in food microbiology testing. This standard aligns with international efforts to maintain food safety and hygiene, providing laboratories a reliable procedure to identify coagulase-positive staphylococci in various food products.
Key Topics
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Enumeration of Coagulase-Positive Staphylococci: The standard details procedures for counting staphylococci that produce the enzyme coagulase, particularly Staphylococcus aureus, known for its role in foodborne illnesses.
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Method Using Rabbit Plasma Fibrinogen Agar Medium: This specialized medium supports the growth and identification of coagulase-positive staphylococci by detecting fibrin clot formation resulting from coagulase activity.
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Amendment Highlights:
- Enhanced suitability for fermented products and raw milk cheeses, which may contain complex microbiota including Staphylococcus xylosus.
- Consideration of background microbiota and atypical colony morphologies, which can affect detection accuracy on traditional Baird-Parker agar.
- Introduction of measurement uncertainty estimation in line with ISO 19036:2019 guidelines, improving quantitative testing reliability.
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Reference Standard: The amendment incorporates ISO 19036:2019 for estimation of measurement uncertainty, promoting better quality control and laboratory consistency.
Applications
This standard serves crucial roles in:
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Food Safety Testing: Monitoring coagulase-positive staphylococci in food products like dairy and meat to prevent staphylococcal food poisoning and ensure consumer safety.
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Quality Control in Fermented Foods: Accurate enumeration supports the evaluation of products containing technological microbiota, such as certain cheeses and fermented meats, where Staphylococcus species contribute to product characteristics.
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Clinical and Environmental Microbiology: Although food-focused, this method is relevant in broader contexts where reliable identification of coagulase-positive staphylococci is essential.
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Regulatory Compliance: Enables laboratories to comply with national and international food safety regulations by providing standardized testing protocols.
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Research and Development: Facilitates microbial studies related to food chain contamination, aiding in developing improved preservation techniques and microbial risk assessments.
Related Standards
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ISO 6888 Series:
- Part 1 - Horizontal method for enumeration using Baird-Parker agar medium.
- Part 3 - Confirmation and identification of coagulase-positive staphylococci.
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ISO 19036:2019 - Microbiology of the food chain - Estimation of measurement uncertainty for quantitative determinations, referenced for improving test result accuracy.
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CEN/TC 463 Standards - Microbiology of the food chain, encompassing a range of methods for microbial detection and enumeration in food products.
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ISO/IEC Directives Parts 1 and 2 - Guidelines on the development, maintenance, and editorial aspects of ISO standards, ensuring consistent quality and reliability.
By adopting EN ISO 6888-2:2021/A1:2023, food microbiology laboratories contribute to enhanced safety of the food supply chain through standardized enumeration of coagulase-positive staphylococci. This ensures early detection of potential health hazards such as Staphylococcus aureus, supporting public health initiatives and fostering consumer confidence.