Biological Food Contamination Under a Microscope

Biological contamination is the most common cause of foodborne illnesses. Proper food handling techniques helps reduce the risk.

What causes biological contamination are pathogens also known as germs or bugs or, more scientifically, microorganisms. Microorganisms are tiny living organisms that can only be seen with a microscope. But not all microorganisms are bad, just the ones that make you feel sick and those are known as pathogens. Food or drink contaminated with pathogens is what causes foodborne illnesses.

Where do Pathogens come From?

This may not be very reassuring but pathogens are found naturally in the food we consume. They are also transferred to our food and drink from people, equipment and other food.

Can I See or Smell Contaminated Food?

Unfortunately, the answer is no. Often, foods that are contaminated with pathogens still taste and smell normal.

How Serious is Biological Food Contamination?

Very. Certain types of biological contamination such as Clostridium Botulinum can cause death. Often found in improperly canned foods and garlic-oil mixtures, Clostridium Botulinum is a bacterium that produces deadly toxins.

What are the Six Different Types of Pathogens?

  1. Viruses. Because hands most commonly transmit viruses, handwashing is the best way to prevent spread. Hepatitis A and Avian Flu are examples of viruses. Other factors:
    • Viruses don’t grow in food. They only grow in living cells but can be transmitted into food through cross contamination.
    • Viruses are highly contagious and cannot be treated. You need to wait for the virus to go away on its own.
    • Symptoms generally last one or two days. You can be infected and not show symptoms.
  2. Protozoa. This pathogen usually gets into food thanks to contaminated water. Once consumed, people get sick. Other factors:
    • There are many types of Protozoa. The type that causes foodborne illnesses live in the digestive tracts of humans and animals.
    • Similar to other pathogens, Protozoa can get into food from cross contamination.
  3. Yeast. Yeast can spoil food by slowly eating away at it. Never use spoiled food. Other factors:
    • Signs of yeast spoilage include bubbles, an alcohol smell and the appearance of pink slime.
    • Yeast needs sugar and water to survive. Foods that share these ingredients include honey, jellies and jams.
  4. Mould. A good motto with mould is, when in doubt, throw it out. Examples of mould include Alternaria, Cladosporium and Mucor. Other factors:
    • The mould that is on food is not the only mould present. Mould spreads throughout food and may not be visible to the naked eye.
    • Several moulds produce poisons known as mycotoxins, which are invisible and penetrate deep into food.
    • Mould grows in virtually any food under most temperatures.
  5. Parasites. Cooking food thoroughly helps control the spread of parasites. Common examples include Trichinosis and Anisakiasis. Other factors:
    • Parasites don’t grow in food. Instead, they breed on or in humans and animals, using them to grow.
    • People can get parasites from contaminated water, including food washed in such.
    • Eating undercooked meat from a contaminated animal is another way someone can get parasites.
    • Cross contamination is another way parasites can get into food.
  6. Bacteria. Due to its characteristics, bacteria are the most common cause of biological contamination. Examples of such include Listeria, Salmonella and E. Coli. Other factors:
    • Bacteria grows in food, unlike other types of pathogens.
    • Bacteria grow quickly, doubling, in some cases, in 10 to 20 minutes with the right surroundings. It can hit dangerous levels in a short amount of time.
    • Some types of bacteria are so strong that neither heat nor chemicals can destroy them.
    • The difference between bacterial infection versus intoxication is slight but worth noting. Bacterial infection makes us sick from eating the bacteria in our food. The bacteria in our system grows in our intestines and causes us to experience symptoms. Bacterial intoxication is when we fall ill due to the waste produced by the bacteria. The waste is known as toxins, which are poisonous and a danger to our health.
    • A bacterium that resists heat and chemicals creates inactive bacteria known as bacterial spores. Once temperatures begin cooling, the spores turn into active bacteria and they begin to multiply.

Does Freezing Kill Pathogens?

No. What happens is pathogens once frozen become inactive and no longer grow. However, once defrosted, the pathogens can pose a threat again as they can become active and multiply.

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