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Foodborne Toxic Infections
Foodborne infections include food poisoning arising from the use of foods containing a large number of toxigenic pathogenic microorganisms that multiply in them (more than 105-106 g). Endotoxins are released only after the death of the pathogen and the destruction of the cells that occur in the human digestive tract after ingestion of infected food.
Conditionally pathogenic include microorganisms of normal microflora of humans and animals, constantly living on the skin, in the intestines, respiratory tract, etc. Under normal physiological conditions, they do not cause diseases, but when weakened, they can cause food poisoning. Some of the conditionally pathogenic microorganisms are found in soil and water. When ingested in food products and favorable conditions, they accumulate in large quantities, so such poisoning is the result of sanitary and technological violations in the manufacture, storage and sale of the product, leading to infection and multiplication of pathogens in them. The emergence of foodborne toxic infections is often associated with the use of finished products infected after cooking (salads, vinaigrettes, jellies, meat, fish, etc.). According to organoleptic indicators, infected products do not differ from benign.
Hygienic standards govern the content of conditionally pathogenic microorganisms in food products.
E. coli (Escherichia coli) - refers to the bacteria of the Escherichia coli group of the genus Escherichia of the Enterobacteriaceae family. She is a constant representative of the microflora of the intestines of humans and animals.
E. coli are small gram-negative bacilli, do not form a spore, some are motile, facultative anaerobes. The optimum development temperature is 37 ° C, but they can also multiply at room temperature (20-25 ° C). They have high stability and are stored for a long time in water, soil and other environmental objects. At a temperature of 55 ° C they die after 2 hours, at a temperature of 60 ° C - after 15 minutes, when boiled - instantly.
Distinguish between saprophytic and pathogenic strains of E. coli. Foodborne toxicoinfections are caused only by enterotoxigenic Escherichia coli strains that secrete enterotoxin, which damages the intestinal mucosa.
With human or animal feces, through dirty hands, equipment, implements, water, enterotoxigenic Escherichia coli enter food products, in which under favorable conditions they multiply rapidly. Diseases mainly occur with the unsanitary state of a food object.
The clinical manifestations of colibacterial toxicoinfection are similar to those of the gastrointestinal form of salmonella toxicoinfection.
The incubation period is 4-10 hours, the course of the disease is rapid and violent (abdominal pain, nausea, diarrhea or vomiting). The temperature in patients remains normal. Recovery occurs in 1-3 days. Outbreaks are often observed in summer.
The disease most often occurs when ready-made culinary products are consumed: meat, fish dishes, especially minced meat products, salads, vinaigrettes, mashed potatoes, milk, etc.
For the prevention of toxic infections of colibacterial nature, it is necessary:
• timely treatment of workers in food facilities suffering from colibacillary infections;
• identification among them of carriers of pathogenic serotypes of E. coli and their rehabilitation;
• thorough veterinary and sanitary surveillance of animals and identification of sick animals (meat of such animals is sold as conditionally suitable using appropriate processing methods);
• strict implementation of sanitary rules for the technology of manufacturing food products that are not subjected to heat treatment (cold meat, fish, egg, dairy, vegetable dishes, jellies, jellies, side dishes, etc.);
• constant maintenance of the sanitary regime at food facilities: storage of products in cold conditions separately from raw materials and semi-finished products; strict observance of the established terms of implementation; transportation of products in specially designed vehicles; thorough washing and disinfection of inventory and equipment; strict observance of the rules for the separate use of inventory; careful observance of industrial and personal hygiene.
Bacteria of the genus Proteus are widely distributed in soil, water, and food products. They are found in the human intestines. Relate to putrefactive bacteria.
Bacteria of the genus Proteus - indisputable sticks, g-, motile, facultative aerobes. The optimum growth temperature is 25-37 ° C, can multiply at temperatures from 6 to 43 ° C. Resistant to drying and high salt concentration, withstand heating at 65 ° C for 30 minutes.
The most common are two species - Proteus vulgaris and Proteus mirabilis, which have enterotoxigenic properties and cause food poisoning. The source of seeding products can serve as feces of humans and animals. Pollution can occur during the transportation, storage, processing, sale of products. The presence of Proteus in food indicates a violation of the sanitary regime and the shelf life of products.
Proteus quickly multiplies in protein products (minced meat, black pudding, fish, etc.). The disease can also be caused by dairy products, potato dishes, salads, etc.
In the occurrence of proteic toxicosis, contamination of ready-made dishes that have already undergone heat treatment and cold snacks consumed without additional heat treatment is of great importance. Seeding can occur when cutting boiled or fried meat, vegetables and other prepared dishes on the same tables and boards, using the same knives and meat grinders that were used to cut raw foods
The incubation period is short - 3-24 hours. The onset of the disease is acute - there are cramping abdominal pains, vomiting, loose stools, often with an admixture of blood, a slight increase in temperature. The duration of the disease is 2-5 days. There may be severe forms.
Preventive measures are carried out in the same areas as with colibacterial foodborne infections. This is the detection and neutralization of sources of infection, the interruption of distribution routes, the adoption of appropriate measures when using conditionally suitable foodstuffs, the maintenance of a proper sanitary regime at food facilities, especially at catering and trade enterprises, and the hygienic education of workers at these facilities.
Enterococci (Enterococcus) - are widely distributed in nature, located in soil, water, plants, are permanent inhabitants of the intestines of humans and animals.
The main causative agent is fecal streptococcus - Streptococcus faecalis, strains of which possess enterotoxigenic properties.
Fecal streptococci are more resistant than E. coli to the effects of many physicochemical environmental factors and can be stored in food for a long time. They are able to reproduce at temperatures from 10 to 45 ° C. They withstand heating to 60 ° C for 30 minutes, at a temperature of 85 ° C they die within 10 minutes.
For example, after pasteurization of milk, enterococci remain viable and comprise up to 80% of all residual microflora. The source of infection are: humans, warm-blooded animals or bacteria carriers.
Enterococci at room temperature can actively accumulate in a wide variety of products and reach their maximum within 24 hours. Most often, these microbes are found in jellies, salads, and vinaigrettes.
The duration of the incubation period is 3-18 hours. Patients noted: nausea, vomiting, abdominal pain, loose stools. The disease lasts from several hours to a day.
Prevention is the same as other foodborne infections: compliance with the requirements for the storage, transportation and sale of food, as well as personal hygiene.
Bacillus cereus. These bacteria are permanent inhabitants of the soil; therefore, they are widely distributed in environmental objects. In tap water, cereus is found in 43% of cases.
B. cereus are large g + sticks, aerobic, form spores. The optimum growth temperature is 30-32 ° C; they do not develop at pH below 4.0.
Spores are heat resistant. They withstand heating to 105-125 ° C for 10-13 minutes, therefore, they can be stored in products not only during normal heat treatment, but also during sterilization of canned food. Spores germinate already at 3-5 ° C.
The stick of cereus is resistant to low temperatures (its spores can withstand deep freezing), to high concentrations of sodium chloride (10-15%) and sugar (30-60%).
The cause of poisoning is meat, fish, vegetable and confectionery. The bacillus cereus, multiplying in food products, does not cause a change in organoleptic properties.
The incubation period is 4-16 hours. The disease begins acutely: there are colicky abdominal pains, nausea, less often vomiting, diarrhea. The duration of the disease is up to 2 days.
Preventive measures include the identification and neutralization of the source of infection, the strict implementation of the established sanitary and hygienic regime at food facilities, compliance with the conditions and terms for the sale of perishable food products, and hygienic education of the enterprise personnel.
Clostridium perfringens - are large motionless gram-positive spore-forming facultative anaerobic bacilli. There are 6 types of Cl. perfringens: A, B, C, D, E, F, they produce 3 types of toxins.
The optimum growth temperature is perfringens 37-43 ° C, but they reproduce well at 46-48 ° C. The greatest toxin formation is observed at a temperature of 37 ° C. In an acidic environment, at a pH below 4.0, they do not develop. Their development is delayed by 7-10% concentration of sodium chloride. When stored below 4-6 ° C and below, Clostridium perfringens die.
Spores can withstand boiling for 30-60 minutes, and some strains up to 2-6 hours. Therefore, conventional heat treatment does not destroy the spores of heat-resistant strains.
The main role in the occurrence of foodborne toxicoinfections belongs to Cl. perfringens type A. It is a representative of the normal microflora of the intestines of humans and animals, is widespread in the environment (in soil, water). The presence of a pathogen in food indicates a violation of the sanitary regime of the enterprise and the rules of personal hygiene.
Cl. perfringens is found in meat, fish and vegetable canned foods, home-made salted lard, sour-milk mixtures, cold snacks and other products during long-term storage at room temperature. May be present in flour, cereals and spices. Poisoning is often associated with the use of culinary products from meat, fish and vegetable dishes.
Clin. type A perfringens, in most cases, proceed with symptoms of gastroenteritis: repeated vomiting, nausea, cramping and abdominal pain, loose stools are noted. The incubation period is 4-24 hours, the duration of the disease is 1-2 days.
Prevention of foodborne toxicosis due to Cl. perfringens, includes activities aimed at preventing contamination of food products by the pathogen and its reproduction. Due to the wide distribution of Cl. perfringens in the environment, especially in the soil, the importance is attached to the prevention of food contamination of the soil and thorough washing and cleaning of vegetables, raw materials, semi-finished products.
Due to the fact that the pathogen belongs to the spore forms, it is resistant to thermal effects, it multiplies intensively at relatively high temperatures (46-48 ° C), it is necessary to strictly observe the regime of technological processes of processing, temperature conditions of storage of finished dishes (not higher than 4 ° C ) and their timely implementation.
Vibrio parahaemolyticus is a parahemolytic vibrio, extremely widespread in the marine environment. In Japan, for many years, it ranks first among foodborne infections.
Vibrio parahaemolyticus is a gram-negative facultative anaerobic, salt-loving (halophilus). It grows at a salt concentration of 1-8%, optimal growth - at a salt concentration of 2-4%. The range of temperature growth is from 5 to -48 ° C, the optimum growth temperature is 30-37 ° C. It grows better at pH 7.6-8.6. At 60 ° C, it dies after 15 minutes, at 100 ° C - within 1 min. The vibrio produces a thermostable endotoxin with hemolytic properties (it causes hemolysis, i.e. destruction of red blood cells).
It lives everywhere in sea water, especially in polluted coastal waters and estuaries. Seeds of sea species of fish, mollusks and crustaceans are being seized - seeding of pollock, flounder, rasp reaches 74%. Vibrios are found not only in fresh seafood, but also in frozen, salted and dried. Vibrios are detected in the intestines and on the hands of people in contact with fish, therefore, contamination of other products is possible.
Microbes under favorable conditions multiply rapidly. Their number sharply increases in defrosted and soaked fish. The disease occurs only with abundant seeding of food with vibrios (more than 10 6 in 1 g).
The incubation period of the disease is from 1 to 30 hours. With the disease, symptoms of gastroenteritis are observed (acute abdominal pain, loose stools, nausea, vomiting). Recovery occurs in 1-2 days.
Prevention consists in protecting water bodies from pollution by sewage, limiting secondary seeding of salt-containing products, and sufficient heat treatment of fish products.
Vibrio parahaemolyticus is normalized in fresh sea fish, crustaceans (not more than 100 CFU / g), as well as in cold smoked fish products, low-salted fillet in vacuum packaging, fish broth based mayonnaises (not more than 10 CFU / g), etc.
126.96.36.199. Food intoxication
This is a group of food poisoning that occurs when eating foods containing mainly toxins of microorganisms. These include bacterial toxicosis and mycotoxicosis. All pathogens of food intoxication emit exotoxins related to highly toxic substances of a protein nature in a food product. They have selectivity, i.e. affect certain organs and tissues.
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Foodborne Toxic Infections
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