What is Staphylococcal Food Poisoning?
The role of staphylococci in the occurrence of food poisoning was first determined by P. N. Lashchenko (1901). He identified staphylococcus cakes with cream that caused the disease of people.
Causes of Staphylococcal Food Poisoning
Among the extensive group of staphylococci distinguish pathogenic and non-pathogenic.
Pathogenic staphylococci of the genus Staphylococcus cause inflammation of the skin, subcutaneous tissue, and nasopharynx (sore throats, rhinitis, catarrh of the upper respiratory tract, etc.). Some types of pathogenic staphylococci, when ingested, can produce enterotoxin, which causes food poisoning. Currently, six serological types of staphylococcal enterotoxins, identified by the letters A, B, C, D, E, F, have been established. Most of these bacteria form a golden pigment.
Staphylococci are indisputable, optional anaerobes. Their optimum reproduction occurs at a temperature of 25-37 ° C. However, they can multiply at a temperature of 20-22 ° C, at a temperature of 10 ° C, their growth slows down, and at 4-6 ° C, it stops. Staphylococci are resistant to environmental factors. They can withstand temperatures of 700 ° C for more than an hour, die at 80 ° C in 20-30 minutes; at the same temperature in a humid environment, staphylococci die in 1-3 minutes. Individual strains tolerate heating to 100 ° C for half an hour (G. A. Noskov). In frozen foods, they remain viable for several months. At the usual temperature of food storage, they remain viable for more than 4 months. Staphylococcus tolerates a high concentration of sugar and salt; the development of staphylococci is delayed at concentrations of sugar in the aqueous phase of more than 60%, of table salt – more than 12%. Staphylococci are sensitive to acidic conditions. So, with active acidity (pH 4.5 and below), their growth stops.
Currently, six serological types of staphylococcal enterotoxins, identified by the letters A, B, C, D, E, F, have been established. Most of these bacteria form a golden pigment. In frozen foods, they remain viable for several months. At the usual temperature of food storage, they remain viable for more than 4 months. Under favorable conditions, intensive development of staphylococci and toxin formation in a wide variety of products (dairy, meat, fish, and vegetables) are possible.
The most favorable environment for the development of staphylococci is milk. This is confirmed by the frequency of intoxications caused by milk and its products. At a temperature of 35-37 ° C, enterotoxin is formed in milk after 5-12 hours, and at room temperature storage (18-20 ° C) – after 8-18 hours. Often intoxication is caused by cottage cheese and cottage cheese products made from non-pasteurized milk. , rennet cheeses, sour cream, young brynza. The formation of enterotoxin is also possible in boiled and pasteurized milk, in the curd mass during infection of these products after heat treatment. A particularly favorable environment for the reproduction of staphylococci and the formation of enterotoxin – confectionery products with custard, which contains a lot of moisture, starch and sugar in relatively low concentrations. Meat and meat products are a good environment for the development of staphylococci and enterotoxin accumulation. Infection of meat with staphylococci can occur during the life of animals as a result of inflammatory diseases they have suffered. However, food toxicosis most often occurs when eating meat products that are seeded with enterotoxic variants of staphylococci.
Staphylococcal food poisoning can occur when eating fish products. The taste and smell of canned inseminated with staphylococcus, do not change, no bombing is observed. Perhaps the intensive production of enterotoxin in products of plant origin. It should be noted that food products that have undergone heat treatment and are exempt from antagonist microbes are more likely to cause staphylococcal intoxications than raw, unprocessed foods.
Pathogenesis during Staphylococcal Food Poisoning
Sources of food contamination by pathogenic staphylococci are humans and animals. The most frequent way of contamination of products is airborne, because patients with staphylococcal diseases of the upper respiratory tract (tonsillitis, rhinitis, pharyngitis) actively excrete them into the environment during breathing, coughing, sneezing.
One of the most dangerous sources of contamination of products is patients with staphylococcal skin lesions (festering cuts, burns, abrasions, abscesses, etc.). In this case, contamination of products occurs when they come into direct contact with the affected organs or through equipment, inventory, and dishes contaminated by staphylococci.
Of great epidemiological importance in the spread of staphylococcal food diseases are people – bacteria carriers. In the nasopharynx of almost every second healthy person pathogenic staphylococcus is found. Equally important is the epidemiological significance of intestinal carriage of staphylococci.
Animals with mastitis, purulent diseases of the liver, muscles, etc. are also a common source of staphylococcal infection. Animal products can become infected with staphylococci while animals are alive (milk for udder mastitis) or during carcass cutting.
Symptoms of Staphylococcal Food Poisoning
The incubation period of staphylococcal food poisoning lasts 2-4 hours, sometimes shortened to 30 minutes. The disease begins acutely with sharp, cramping pains in the stomach, the appearance of multiple vomiting. The body temperature is often low, but it can rise to 38-38.5 ° C. Characterized by weakness, malaise, chills, cold extremities, lowering blood pressure. Diarrhea can be absent or it occurs in 50% of cases. Characteristically, when treatment started in a timely manner, a rapid improvement in the condition – by the end of 1 day.
Diagnosis of Staphylococcal Food Poisoning
Diagnostic tests. The isolation of the same S. aureus phagotype in affected individuals, carriers of the pathogen, and persons preparing food and responsible for its contamination during outbreaks confirms the diagnosis. Damage to the hands of cooks can lead to contamination of food, so you should make the crops. Crops should also be taken from the nose, pharynx and rectum. The identification of staphylococci in suspected food or the phagocytosis of isolated strains can be performed at the Centers for Disease Control through health departments. Emetic masses and stools of patients are subject to investigation, since they may contain suspected types of staphylococcus.
Treatment of Staphylococcal Food Poisoning
Treatment of staphylococcal food poisoning is symptomatic. To remove toxins from the body, the stomach is washed with water or 5% sodium bicarbonate solution, after which a saline laxative can be prescribed for staphylococcal poisoning. With the development of dehydration (clostridium toxin poisoning), a complex of rehydration measures is carried out. In case of moderate form, isotonic solution of sodium chloride or its equal volumes with 5% glucose solution in an amount of 1000-1500 ml is injected into / into the drip. In severe and very severe forms, Trisol solution is successfully used. Its composition is as follows: 1000 ml of pyrogen-free sterile water, 5 g of sodium chloride, 4 g of sodium bicarbonate and 1 g of potassium chloride, it is recommended to combine Trisol with colloidal solutions that help remove toxins from the body and restore migratory circulation. The principles of rehydration therapy are the same as in the treatment of cholera patients. When staphylococcal poisoning antibiotics prescribed. Isolation of the hospitalized patient. Precautions are not recommended.
The prognosis for staphylococcal poisoning is favorable. With clostridia toxins poisoning, the prognosis is serious, especially with the development of anaerobic sepsis.
Prevention of Staphylococcal Food Poisoning
Prevention of staphylococcal toxicosis is reduced to the implementation of measures that exclude the possibility of infectious agents in food, and the creation of conditions that delay the development of staphylococci and enterotoxin accumulation in products.
Measures to prevent contamination of food products with pathogenic staphylococci include the timely detection of persons with purulent inflammatory processes in the skin and upper respiratory tract and their removal from work with ready-made foods. For this purpose, food inspections are carried out on the hands and skin integuments. Persons suffering from significant myopia and therefore low leaning over the products are not allowed to make cream products, ready-made food, sausages, etc.
A special place in the prevention of toxicoses belongs to measures to improve the sanitary regime of enterprises and the observance of personal hygiene rules (especially those engaged in the manufacture of finished culinary and cream products), as well as the systematic increase of hygienic knowledge on the prevention of food poisoning. Equally important in the prevention of staphylococcal toxicosis is to ensure a high sanitary level, improvement and mechanization of production processes.
It is extremely important to create conditions that prevent the formation of enterotoxin in food products: to store products and finished products in the cold and to comply with the terms of their implementation.