Food Safety and Food Poisoning Bacteria
by Jeff Skinner
Some examples of food poisoning bacteria include:
Salmonella was discovered in the 19th century by a scientist named Daniel Salmon. Salmonella spp come in over 2 1/2 thousand different strains known as serotypes or species (spp). Many of the serotypes are named after where they were discovered. Salmonella Montevideo caused food poisoning with a major chocolate manufacturer.
Salmonella was discovered in the 19th century by a scientist named Daniel Salmon. Salmonella spp come in over 2 1/2 thousand different strains known as serotypes or species (spp). Many of the serotypes are named after where they were discovered. Salmonella Montevideo caused food poisoning with a major chocolate manufacturer.
Two types of Clostridia are known to cause food poisoning. Namely Clostridium perfringens and Clostridium botulinum. C botulinum is responsible for producing the world's most virulent toxin, known as Botox. 1g of Botox can kill up to 100,000 people. There were experiments carried out during the Second World War by the British in Portadown to use Botox as a biological weapon. It was never, however, used. Botox can cause death in young infants. This is called infant botulism. If infants under three months old ingest C botulinum spores they can die. C botulinum spores can be found in many natural foods such as honey. That is why it is important not to feed any to children under three months, although honey labels state not to feed to children under 12 months, for further safety. During the manufacture of honey, bees inadvertently pickup C botulinum spores from hedgerows, soil and plants and contaminate the honey.
Bacillus cereus is well known from causing rice poisoning. Cooked rice from a takeaway or rice prepared incorrectly can lead to B cereus poisoning.
Staphylococcus aureus and other bacteria start off as commensals. Humans are caked in this bacteria from head to toe. They act as protective bacteria. As these bacteria grow they release chemicals which prevent infection from other pathogens. They are, however, opportunistic and can cause infection through a small cut. If we cough or sneeze over the food, or over handle food without washing hands, then we can contaminate food with our bacteria. The bacteria will grow in the food and release toxins, which will poison the consumer.
Other bacteria which cause foodborne disease include: E. coli, Listeria and Campylobacter.
In the UK in the late 1990s a voluntary system was introduced for egg producers to vaccinate their flocks of chickens. This allowed them to put lion stamps on their eggs. Salmonella has almost been eradicated from poultry and eggs. The main problem with poultry tends to be Campylobacter contamination, which is the biggest cause of diarrhoea in the UK. Eggs without lion stamps should be avoided as they could be infected with Salmonella enteridis. (Infected eggs very rarely cause illness if eaten as a cooked product. The bacteria are only present in the white of the egg. Providing the eggs are cooked sufficiently to congeal the white then they are safe to eat. The bacteria will not penetrate the membrane surrounding the yoke. The problem is that products made from raw egg which are allowed to remain at ambient temperature (for example, tiramisu, mayonnaise, and mousses) can cause food poisoning. By whisking the eggs the bacteria in the white of the egg are allowed to come into contact with the yoke, which is a good food supply for the bacteria.)
In the UK in the late 1990s a voluntary system was introduced for egg producers to vaccinate their flocks of chickens. This allowed them to put lion stamps on their eggs. Salmonella has almost been eradicated from poultry and eggs. The main problem with poultry tends to be Campylobacter contamination, which is the biggest cause of diarrhoea in the UK. Eggs without lion stamps should be avoided as they could be infected with Salmonella enteridis. (Infected eggs very rarely cause illness if eaten as a cooked product. The bacteria are only present in the white of the egg. Providing the eggs are cooked sufficiently to congeal the white then they are safe to eat. The bacteria will not penetrate the membrane surrounding the yoke. The problem is that products made from raw egg which are allowed to remain at ambient temperature (for example, tiramisu, mayonnaise, and mousses) can cause food poisoning. By whisking the eggs the bacteria in the white of the egg are allowed to come into contact with the yoke, which is a good food supply for the bacteria.)
Apart from C perfringens and C botulinum there is also one serotype called C difficile, which causes major diarrhoeal problems in hospitals. Clostridia are a major source of infection with large joints of meat, large pots of gravy or soup which are allowed to simmer slowly for several hours without being stirred. The bacteria grow in the cool spots within liquids. The bacteria release a toxin which is heat-stable. So even if the liquid is brought to the boil it will not deactivate the toxin and poisoning will ensue.
Bacillus cereus is a major cause of poisoning with rice and rice products. This will be covered in more detail when the best way to handle rice to prevent food poisoning is discussed under spores.
Listeria are bacteria that will grow in a fridge in cold conditions. These bacteria can be found in unpasteurised food products such as milk, cheese and pates. Listeria is a major problem with pregnant women. It affects the unborn child by preventing oxygen and nutrients from reaching the foetus. Abortion, miscarriage or stillbirth could arise.
Campylobacter is the major cause of infection with poultry. Campylobacteriosis has flulike symptoms. Campylobacter are also present in live birds. This includes wild and domestic birds.
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