ISO 16654: Escherichia coli O157 Detection and Food Safety
Horizontal method for the detection of Escherichia coli 0157
What is Escherichia coli O157?
Escherichia coli O157 is a strain of E. coli that produces Shiga toxin. This type of bacteria can be found in the following foods in particular:
- Raw meat and meat products,
- Unpasteurized milk and milk products,
- Raw vegetables and fruits (especially those irrigated with contaminated water).
E. coli O157 can cause serious health problems in humans, including hemolytic uremic syndrome (HUS), which can be life-threatening, especially in the elderly, children and individuals with weakened immune systems.
Searching for Escherichia coli O157 in Food and Feed
Horizontal Escherichia coli O157 Screening in human consumption or animal feed is carried out within the scope of the “ISO 16654” standard. Definition of Escherichia coli O157 under the ISO 16654 standard: Microorganisms that form typical colonies on the surface of the plating medium used in the standard, produce indole and agglutinate with antiserum, especially against the O157 antigen.
ISO 16654 Analysis Principle
The detection of Escherichia coli O157 according to ISO 16654 is performed in four steps:
- Enrichment of the homogenized test portion in modified tryptone soy broth containing novobiocin (mTSB + N) by incubation at 41.5 °C ± 1 °C for 6 hours followed by 12 hours - 18 hours.
- Separation and concentration of microorganisms by means of immunomagnetic particles coated with antibodies against E. coli O157.
- Isolation by subculture of immunomagnetic particles with bacteria adhering on CT-SMAC (Cefixime tellurite sorbitol MacConkey agar) and selection of a second selective isolation agar by the user.
- Confirmation of sorbitol-negative colonies from CT-SMAC and typical E. coli O157 colonies on second isolation agar by indole production and agglutination with E. coli O157 antiserum.
Normative Standards
- ISO 6887-1, Microbiology of food and animal feeds - Preparation of test specimens for microbiological examination, initial suspension and decimal dilutions - Part 1: General rules for the preparation of initial suspension and decimal dilutions.
- ISO 7218, Microbiology of food and animal feed - General rules for microbiological investigations.
Nanolab Laboratories Group continues to provide services within the scope of Escherichia coli O157 Detection. We also provide services in the Determination of Ammonia in Chicken Meat Products.
Contact us for more information.
You can follow us on LinkedIn for up-to-date news and posts about our services.
Follow our Instagram account to be informed about our latest blog posts.
