Monday, February 29, 2016

Food Safety and Security: Discussion 8 Staphylococcal food poisoning

Although the CDC records staphylococcal food poisoning as a bacterial infection, it can also be labeled a chemical intoxicant. Even though chemical etiology accounts for 4.7-7.3% of foodborne disease outbreaks from 1988 to 1992 in the United States, however, since it is underreported (foodborne illnesses in general), it actually would closer to be 5-10%. Staphylococcal food poisoning is a result of intoxications resulting from bacteria which are forming on food. It is very common all over the world. Food containing a staphylococcal enterotoxin is consumed and causes intoxication quickly and it lasts a short while and does not have any lasting effects. Doctors are not usually told and therefore most cases go unreported. Dr. M.A. Barber indicated staphylococcal food poisoning caused by staphylococci in 1914.
Symptoms include diarrhea, retching, vomiting, abdominal cramps, faintness and nausea  1-6 hours after they consume it. Headache, prostration, fever and muscle cramps can also happen if it is severe. There have even been examples of the blood pressure going down dramatically in rare cases, In a few hours or a day, usually someone feels better. It will not usually fatal, but it has caused death in older individuals and children. Barber was able locate it and to test it on a couple of people, but in 1929, Dr. Gail M. Dack would discover more details with cakes! Due to improper storage, cream cake made 11 people ill with diarrhea, vomiting and nausea. Staphylococci were found in the cakes and grow in a lab. The toxins were separated by centrifuge and the toxin given to people which caused them to be ill. It was called an enterotoxin. This is because the gastrointestinal tract is affected. Fluids to restore electrolytes may help. 
There are nine types of enterotoxins. Its hard to determine how much someone got. It is also hard to gauge a reaction because everyone reacts differently and some are more susceptible than others. Although common, it is underreported, in fact, it is thought only 1-5% of cases are even reported. Staphylococcus aureus is responsible for mot outbreaks and is easy to tell apart. It contains coagulase and TNase. Some staphylococcus prefer a particular species or medium or condition. Individuals in the medical or hospital regions may have more contact with it since it cause boils and abscesses, , osteomyelitis, enterocolititis, infections, endocarditistoxic shock syndrome or scalded skin.
Appropriate heating and pasteurization are important. Freezing and thawing do not seem to effect S. aureus unless subfreezing, and then only reduced number of staphylococcal is observed. Drying does not kill the Staphylococci. There are enterotoxins A, B, C, D, E, G, H, I, and J (There is no F because toxic shock syndrome toxin was actually labeled F until it was discovered what it really was). There are still some enterotoxins which have not been identified. IN some people the enterotoxins can cause skin reactions, irritated eyes, sore throats, runny noses and blisters. They are considered superantigens and stimulate a lot of T cells.
The stomach is not acidic enough to break down the enterotoxin. They are also heat resistant. They are stable. It has been found in a lots of kinds of food. They are salt resistant. There are only certain ways it will grow though, and they have to take time to make the enterotoxin and be warm long enough. It has been implicated in many outbreaks. Enzyme-linked immunosorbent assay (ELISA) is the most common way to detect the enterotoxins but there are a variety of methods though their practicality varies. Proper preparation and storage of food is necessary. Good hygiene, proper handling of food and maintenance of the proper temperature is important to reduce the chances of growth. 
Although dosage is in itself important in general for toxins, it is difficult to determine how much someone got of it since staphlococci grows in colonies, produces the enterotoxin and it is microscopic. Since it takes only 1 ug for some individuals to get reactions to it, its difficult to determine dosaging effects.

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