A Bug’s Life: Staphylococcus Aureus

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Staphylococcus is a common bacteria that has many strains which can cause skin infections, food poisoning and even Toxic Shock Syndrome.

February 17, 2022

Staphylococcus, or Staph., is a type of bacteria most often found in the upper respiratory tract as well as on our skin. Most people will have some of these bacteria on their bodies – which allows for the mildly amusing anecdote that staph is found – on the Staff! It is a common skin infection and can be present in abscesses, and sinus infections (like sinusitis). There are different strains of Staph. including Staphylococcus aureus and Staphylococcus epidermidis.

At EMS, we test for Staphylococcus aureus, which can cause food poisoning by developing toxins in food and when ingested causes food poisoning. Symptoms develop within 1-6 hours and last anywhere from 30 minutes to 3 days. Food poisoning caused by Staphylococcus aureus is one of the quicker routes to a sore stomach.

Outbreaks of food poisoning caused by Staphylococcus aureus are rare, especially documented cases, due to the quick onset and recovery of victims. However, any outbreak is usually associated with products that are subject to handling during preparation or dairy products which can become contaminated from the udders of cows and sheep.

How can you prevent spreading Staph.? Wash your hands thoroughly with soap and water, especially before preparing food. If you are ill, avoid preparing food, and cover any open wounds on the hands or wrists with gloves.

The Micro Profile:

Name: Staphylococcus Aureus

Family: Staphylococcaceae

Type of ‘Bug’: Bacteria

Appearance under a microscope: grape-like clusters with round, golden-yellow colonies

History

First discovered in 1880 by Scottish scientist, Alexander Ogston, while performing a procedure. He described the bacteria as looking like “bunches of grapes”. Later, in 1884, Friedrich Julius Rosenbach found that he could differentiate the bacteria by the colour of their colonies: Staph. Aureus was named because of it’s golden colouring.

How do EMS test for Staphylococcus?

The method we use the most to test for Staph, which we are UKAS accredited to carry out is Method No 16 based on BS EN ISO:6888: Part 1: 1999 using Staphytec plus latex confirmation. If you want more information on this method, you can find it here.

Nutrition Facts: The Science Behind the Label

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All about nutritional values and how they are produced.

February 12, 2021

By Francisca Navarro Fuentes

Have you ever read the nutrition facts on your Friday nights double pepperoni frozen pizza? Did you ever wonder what those values mean, or think about how they are produced? Feed your curiosity with this post and find out about the science behind the label!

Nutrition facts are a powerful tool to help you understand the composition of a product, so that the consumer of the product is informed. Nowadays, the variety of products to choose from is endless, but knowing what is in your food can help you to pick what to buy.

By law, it is mandatory that nutrition facts are included in labels. This is controlled by Regulation (EU) No 1169/2011 [1] on the provision of food information to consumers. Therefore, nutrition declaration must include energy (KJ/Kcal), total fat and saturated fat (g), carbohydrates and sugars (g), proteins (g) and salt (g). Besides, it is optional to include values such as mono-unsaturates and polyunsaturates, polyols, starch, fibers and vitamins or minerals. The values are reported per 100g or 100mL of product, and often per portion too.

But do all products have to have a nutrition label? It may surprise you to learn that the answer is: no. There are products  exempt from this rule, such as waters, spices, salt, sweeteners, tea, food additives, gelatine, yeast and chewing gums, among others.

Most people don’t pay attention to the nutritional information and one of the reasons could be a lack of knowledge on how to interpret them. In order to help the consumer, the NHS has published a list of guidelines, summarized in Table 1.

So how are nutritional values produced?

Nutritional values are produced in analytical chemistry laboratories. A representative portion of the product arrives to the laboratory, this is then blended and homogenized into a paste (like your morning vegetable smoothy, ew!). This paste is stored in an airtight bag, ready for analysis.

Chromatography, flame photometry, spectrophotometry, high temperatures (up to 600 ºC!) and high pressures are techniques and conditions used to determine nutritional values. As you would imagine, in order to provide this information, trained chemistry analysts are required. I know, these techniques sound scary but, believe me, chemists love them! Although these machines are subject to break downs, chemists like me thrive on a broken machine’s challenge.

Now, how can you (or I), as a consumer, trust the values in the nutrition facts table? For that, a governmental body, known as United Kingdom Accreditation Service (UKAS), assesses and accredits analytical chemistry laboratories ensuring that the values obtained in laboratory A would be the same as the ones in laboratory B across the UK.

In conclusion, labels are educational as it helps to understand calories and nutrients. They regulated by Regulation (EU) No 1169/2011 and the values are generated in UKAS accredited analytical chemistry laboratories, ensuring the customer rights and accuracy of the data.

References

[1] EUR-Lex Website: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02011R1169-20180101 Last visited 6/2/21

[2] NHS Website: https://www.nhs.uk/live-well/eat-well/how-to-read-food-labels/#:~:text=Nutrition%20labels%20are%20often%20displayed,certain%20nutrients%2C%20such%20as%20fibre. Last visited 6/2/21