ISO 7251: Escherichia coli Enumeration - Food Safety with EMS Technique

Horizontal method for detection and enumeration of probable Escherichia coli - EMS technique

What is Escherichia coli?

Escherichia coli is a bacterium that is usually found in the intestines, but some strains, particularly E. coli O157:H7, can cause serious health problems. E. coli can be transmitted to humans through food and can be found in foods such as thawed meat, unpasteurized milk and vegetables watered with contaminated water. The toxin production of this bacterium in the body can lead to food poisoning and, in more severe cases, life-threatening conditions such as hemolytic uremic syndrome (HUS).

What is the Scope of the ISO 7251 Standard?

ISO 7251 defines a test method for determining the Escherichia coli count in food. This method is widely used, particularly by food manufacturers, supervisory authorities and microbiology laboratories. Usingthe EMS technique, the bacterium is counted. This technique is often used to obtain faster and more accurate results.

What is EMS (Enzyme-Mediated Staining) Technique?

EMS stands for enzyme-mediated staining and is a method used in microbiological analysis. This technique allows bacteria such as Escherichia coli to be visually detected by staining for their specific characteristics. In particular, EMS takes advantage of the fact that these bacteria have the enzyme β-glucosidase. This enzyme reacts with certain chemicals to stain the bacteria with a color-changing substance, making them easier to count.

Counting with the EMS technique involves the following steps:

1. Sample Preparation: The food sample is homogenized with appropriate solutions.
2. Incubation: The prepared sample is inoculated and incubated in special media.
3. Staining: The EMS reaction interacts with enzymes in bacteria, causing a color change.
4. Colony Counting: The stained bacteria are counted under a microscope and the amount of E. coli is calculated.

ISO 7251 Application Areas and Importance

ISO 7251 is used especially in food safety and microbiological inspection processes. This test is of great importance for food production facilities, laboratories and public health agencies. Here are the main application areas of ISO 7251:

1. Hygiene Control in Food Production: Food manufacturers use E. coli tests to assess the hygiene of their production processes. This helps to detect bacterial contamination early during production.
2. Consumer Health: To prevent foodborne transmission of E. coli, these assays play a critical role in protecting consumer health.
3. Public Health Monitoring: Health authorities conduct E. coli counts to prevent foodborne illness and protect public health.
4. Regulatory Enforcement and Certification: Food safety regulations require these tests to control specific levels of microorganisms and ensure compliance with the law.

Why is ISO 7251 Testing Performed?

E. coli plays an important role in the spread of foodborne illness. ISO 7251 testing is performed for the following reasons:

1. Prevention of Foodborne Diseases: Detecting the presence of E. coli in food products is a critical step in the prevention of foodborne illness.
2. Hygiene Control in Production and Processing Processes: Regular E. coli tests are conducted to improve hygiene conditions in food production facilities.
3. Legal and Regulatory Compliance: Food safety regulations require that levels of microorganisms are controlled and legal limits are not exceeded.

Nanolab Laboratories Group continues to provide services under ISO 7251: Escherichia coli Enumeration. We also provide services for Yeast and Mold Detection in Foods.

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