Food Microbiology

NationWide Laboratories is an ISO 17025 UKAS accredited diagnostic laboratory which has offered Microbiological Testing since 1996. Microbiological contamination is a serious safety issue in many industries, as it can lead to a wide range of diseases causing potential safety issues. Legislation makes it a requirement for all food businesses to guarantee continued safety of their food products through the supply chain, making it vital that high quality testing is part of that process. At NationWide Laboratories we offer microbiological food testing to detect food borne pathogens and spoilage organisms as well as a wide range of microbiological services including environmental, water, pool hydrotherapy and equipment hygiene testing. The close nature of our relationship with our clients means that we can create personalised test packages based on your requirements and our skilled team of microbiologists will work to provide reliable accurate results, helping you to ensure consumer safety.

Sample Types

We currently test a variety of food samples including ice cream, juices and flavours, meat, mushrooms, milk, biscuits, fresh produce including cress and beansprouts, smoked salmon, crabs, whelks, cheese and swabs.

Our range of test methods comply with industry standards and are designed to meet your requirements.

Food

Detection of:

Listeria spp including species identification

Salmonella spp

Enumeration of:

Bacillus cereus (presumptive)

Coliforms (presumptive)

Clostridium perfringens and sulphite reducing bacteria

Enterobacteriaceae (presumptive)

Enterococci

Escherichia coli (beta glucuronidase positive)

Listeria spp including species identification

Total Aerobic Colony Count at 30⁰C

Yeasts and Moulds

Pseudomonas species (presumptive)

Staphylococcus aureus

Lactic Acid Bacteria

Escherichia coli 0157

Environmental Swabs

Detection of:

Listeria spp including species identification

Salmonella spp

Enumeration of:

Bacillus cereus (presumptive)

Coliforms (presumptive)

Enterobacteriaceae (presumptive)

Enterococci

Escherichia coli (beta glucuronidase positive)

Listeria spp including species identification

Staphylococcus aureus

Total Aerobic Colony Count at 30⁰C

Yeasts and Moulds

Pseudomonas species (presumptive)

Potable Water

Enumeration of:

Coliforms (total)

Escherichia coli

Presumptive Enterococci

Pseudomonas aeruginosa

Total Aerobic Colony Count at 22⁰C and 37⁰C

Sulphite reducing clostridia and Clostridium perfringens (sporulated)

Additional Tests and Services

Campylobacter

Vibrio parahaemolyticus

Legionella

Phosphatase

Water activity

pH foods

Salt over aqueous

Oil/Fat

Nutritional analysis

Various allergen testing

Pool hydrotherapy: Total viable count, Escherichia coli, Pseudomonas aeruginosa and Coliforms

Equipment and facilities hygiene: including Enterobacteriaceae, Coliforms and Total viable count

Hand swabs: monitoring for Staphylococcus aureus and Enterobacteriaceae

Directory of Micro-organisms

Please click for a directory

Bacillus cereus
The spores of Bacillus cereus bacteria commonly contaminate raw foods and food materials, particularly foods:

in contact with the soil

of vegetable origin

Clostridium perfringens
Clostridium perfringens is widely distributed in the environment and foods, and forms part of the normal gut flora in man and animals. They can also be found in drinking water. Food and drink contaminated with large numbers of Clostridium perfringens bacteria can produce enough toxin in the intestines to cause illness.

Coliforms
Coliforms can be found in the aquatic environment, in soil and on vegetation; they are universally present in large numbers in the faeces of warm-blooded animals. Testing for total coliform reflects general hygiene during food production or handling and the quality of the measures used to minimise bacterial contamination.

E. coli
Escherichia coli (known as E. coli) is a type of bacteria that can be found in the intestines of animals and humans. Many strains of E. coli are harmless to humans, but some can cause serious illness.

Enterobacteriaceae
Enterobacteriaceae live in the intestines of animals and the environment. Control measures that reduce the number of Enterobacteriaceae, E. coli and the aerobic colony count will reduce the risk of the presence of pathogenic bacteria being present on meat carcases and processed meat.

Listeria
Listeria is widespread in the environment and can contaminate a wide range of foods. It is of most concern in chilled ready-to-eat foods that do not require further cooking or reheating, such as:

cooked sliced meats

cured meats

smoked fish

cooked shellfish

blue veined and mould-ripened soft cheeses

pâté

pre-prepared sandwiches and salads

Pseudomonas aeruginosa
Pseudomonas aeruginosa is present in the environment and can be spread to people in healthcare settings when they are exposed to water or soil that is contaminated with these germs. Resistant strains of this bacteria can also spread in healthcare settings via person to person contact through contaminated hands, equipment, or surfaces.

Salmonella
Salmonellas are a group of common bacteria that cause food poisoning. People and animals can carry salmonella in their intestines and their faeces. The bacteria often spreads through contaminated foods. This can happen when foods are not cooked enough. It also spreads through cross-contamination. Salmonella bacteria are most often found in:

raw meat

undercooked poultry such as chicken or turkey

eggs

unpasteurised milk

Staphylococcus aureus
Foods that are associated with staphylococcus food poisoning include:

Meats

Poultry and egg products

Salads such as egg, tuna, chicken, potato, and macaroni

Bakery products such as cream-filled pastries, cream pies, and chocolate eclairs

Sandwich fillings

Milk and dairy products

Faecal streptococci (Enterococci)
Faecal streptococci (Enterococci) can be found within stomachs and intestines of humans and animal. Like faecal coliforms, faecal streptococci are applied as indicators for water pollution. The presence of faecal streptococci indicates the presence of faecal pathogens in water.

Total Viable Count (TVC) – Bacteria, Yeast and Moulds
TVC gives a quantitative estimate of the concentration of microorganisms such as bacteria, yeast or mould spores in a sample. A high TVC count indicates a high concentration of micro-organisms which may indicate poor quality for drinking water or food. It can be used as a benchmark for the evaluation of the shelf-life of a product.

Legal requirements and industry guidelines

The requirements below are the extracts from the relevant industry guidelines.

Please click requirements and industry guidelines

Meat Industry

Production
The food business operators of slaughterhouses or establishments producing minced meat, meat preparations or mechanically separated meat shall take samples for microbiological analysis at least once a week. The day of sampling shall be changed each week to ensure that each day of the week is covered.

As regards the sampling of minced meat and meat preparations for E. coli and aerobic colony count analysis and the sampling of carcases for Enterobacteriaceae and aerobic colony count analysis, the frequency may be reduced to fortnightly testing if satisfactory results are obtained for six consecutive weeks.

In the case of sampling for Salmonella analysis of minced meat, meat preparations and carcases, the frequency can be reduced to fortnightly if satisfactory results have been obtained for 30 consecutive weeks. The Salmonella sampling frequency may also be reduced if there is a national or regional salmonella control programme in place and if this programme includes testing that replaces the above-described sampling. The sampling frequency may be further reduced if the national or regional Salmonella control programme demonstrates that the Salmonella prevalence is low in animals purchased by the slaughterhouse.

However, when justified on the basis of a risk analysis and consequently, authorised by the competent authority, small slaughterhouses and establishments producing minced meat and meat preparations in small quantities may be exempted from these sampling frequencies.

Reference: Meat Industry Guide – Chapter 13 Microbiological Criteria

Water
ACC and Coliforms should be measured monthly and used to indicate when further investigation is required. All microbiological parameters should be checked at least annually and as part of any follow-up investigation when the ACC and / or Coliform levels exceed the guidelines.

Reference: Meat Industry Guide – Chapter 3 Water Supply

Routine water testing and environmental testing are to be done quarterly depending on schedule.

Dairy Industry

The Food Standards Agency considers that microbiological sampling and testing has an important role in validating and verifying that the controls applied are effective. The frequency of testing would depend on the nature of the business, the risks associated with the production systems and the controls that are already in place.

Reference: Food Standards Agency Guidance for producers of raw drinking milk for direct human consumption

Fish Industry

A number of microbiological tests of fish and fish products are used by industry for contractual and internal purposes and by authorities to check that the microbiological status is satisfactory.

Reference: Food Standards Agency Fish and shellfish

Drinking Water

Samples required to be taken by this regulation must be taken at regular intervals.

Reference: The Water Supply (Water Quality) Regulations 2016; The Water Supply (Water Quality) Regulations 2018

Ready-to-Eat Food

Food within the scope of the revised guidelines includes ready-to-eat food sampled within the retail chain, e.g. retail, wholesale, distribution and food service sectors. These guidelines focus on public health and consumer protection.

Reference: Food Standards Agency Guidelines for assessing the microbiological safety of ready-to-eat foods on the market

Food Safety Criteria Index
Criteria have been set for Escherichia coli, Enterobacter sakazakii, Listeria monocytogenes, Salmonella spp, Staphylococcus enterotoxin.

Reference: EC Regulation on Microbiological Criteria for Foodstuffs

Business Guidance on Microbiological Criteria
Reference: Food Standards Agency General Guidance for Food Business Operators on Microbiological Criteria for Foodstuffs; Chilled Food Association Guidance on the Practical Implementation of the EC Regulation on Microbiological Criteria for Foodstuffs

Healthcare environments

The microbiological examination of food, water and environmental samples from the healthcare environment has a recognised role in the routine monitoring of decontamination procedures and the demonstration of a safe environment for patients, visitors and staff in a range of healthcare environments such as endoscopy departments, pharmacy sterile suites and hydrotherapy pools.

Reference: Examining food, water and environmental samples from healthcare environments – Microbiological guidelines

Pool water

Swimming pool water should be microbiologically tested each month to monitor for the presence of potentially harmful microorganisms. Hydrotherapy pools, even those not in a healthcare setting, should be tested regularly. Note: for animal hydrotherapy please contact your local standards authority as the requirements might differ.

Reference: Pool Water Treatment Advisory Group Code of Practice

Reference: Health and Safety Executive The control of legionella and other infectious agents in spa-pool systems

Disclaimer: The above guidelines are for reference purpose only. Businesses should check the current standards themselves to ensure they adhere to the correct tests/schedules as required.

Working with us

At NationWide Laboratories we pride ourselves in the quality of our service. A team of experienced food microbiology scientists are working with you and your samples to provide a tailored report to suit your needs. We know and value each of our customers.

We will create a personalised test package for you based on your individual requirements.If you have any queries you are guaranteed to speak to our advisor, who will handle your enquiry in a personal, professional and efficient manner. We are committed to delivering excellence and will add value to your business.