Salmonella - What Is It? Salmonellosis: Symptoms, Treatment

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Salmonella - What Is It? Salmonellosis: Symptoms, Treatment
Salmonella - What Is It? Salmonellosis: Symptoms, Treatment

Video: Salmonella - What Is It? Salmonellosis: Symptoms, Treatment

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Video: Salmonellosis - causes, symptoms, diagnosis, treatment, pathology 2023, February

Salmonella is a dangerous microorganism that can damage human health. When salmonella enters the body, a person begins to feel malaise, weakness, fatigue, indigestion and headache also appear. The symptoms of salmonellosis have been described by medieval doctors. In 1885, the agent of "swine plague" was discovered by the scientist D. Salmon. And in 1888, comparing the microbes isolated from the body of a person who died from a disease and from the meat of a cow, the scientist A. Gertner discovered that this is one and the same bacterium. By 1934, several types of similar microorganisms were already known. They were combined into one group and called Salmonella.

Salmonellosis can develop both in isolated cases and in the form of outbreaks. Cases of the disease are registered throughout the year, most often in the summer season due to faster spoilage of food. You can become infected with salmonellosis through food, water, if the rules of personal hygiene are not followed.

The content of the article:

  • 1 What is Salmonella
  • 2 Causative agents of salmonella
  • 3 How salmonella infection occurs
  • 4 How does salmonellosis get infected and how to avoid it?
  • 5 Features of salmonella
  • 6 Salmonella (non-typhoid)
  • 7 Symptoms of salmonellosis
  • 8 Methods for the prevention of salmonella

What is Salmonella

Salmonella is a large genus of enterobacteriaceae. There are nine types of Salmonella, but there are more than a thousand varieties. Salmonella is not the only cause of salmonellosis, but what is salmonella? This is a special type of bacteria that, when ingested, lead to inflammation of some parts of the digestive system and severe intoxication.

What is Salmonella
What is Salmonella

They are mobile gram-negative rods with flagella. The causative agent of salmonellosis (Salmonella) belongs to the family of intestinal enterobacteria, which is associated with the ability of this type of microorganisms to infect the intestines, although there are other forms of the disease.

Salmonellosis is an acute infectious disease caused by salmonella. This infection is widespread everywhere, both adults and children suffer from it. In most cases, salmonellosis occurs with gastrointestinal disturbances, symptoms of dehydration and intoxication. However, weakened people and young children may develop severe septic forms of the disease, in which various internal organs are affected, including the brain.

There are dozens of species of bacteria in the Salmonella family, the vast majority of which are not dangerous to humans, but there are some that are really better not to meet.

For example, one of the most dangerous representatives of this malicious family - salmonella typhi - is the causative agent of such a disease already forgotten today as typhoid fever, from which, for example, the composer Franz Schubert, the husband of Queen Victoria of England Prince Albert and Lenin's sister Olga Ulyanova died. … Sister typhi - salmonella typhimurium - usually becomes the causative agent of the vast majority of nosocomial infections.

And the salmonella that most often visits our agricultural enterprises is called salmonella enteritidis or, more simply, intestinal salmonella. The intestinal infections that it causes are not as difficult as in cases of the activity of "older" Salmonella, but they are still unpleasant and can be dangerous for children, the elderly and people with reduced immunity.

What is Salmonella
What is Salmonella

One of the most dangerous representatives of this malignant family - salmonella typhi - is the causative agent of such a disease already forgotten today as typhoid fever.

And although the bacterium feels great in the environment - in water (even sea), soil, room dust, but in products (meat, milk, butter, eggs) it is especially well preserved - in them it not only lives, but also multiplies … Therefore, the food route of infection with salmonellosis is the most popular.

The bacterium is not afraid of the cold, loves heat, and only boiling can kill it, which is why doctors insist on boiling suspicious eggs. Salmonellosis is often asymptomatic - the body itself fights the infection that has got inside, but at the slightest sign of the disease, you still need to not tempt fate and not try to treat it with home methods, but immediately consult a doctor, since improper treatment can seriously complicate your situation.

Treatment of salmonellosis in a hospital is indicated for patients with severe forms of the disease - with salmonella sepsis, severe enteritis, severe background diseases. The rest are treated at home.

Throughout the history of medicine, bacteriologists have repeatedly described diseases that resemble the flow of salmonellosis. The causative agents were periodically detected in the meat of dead animals. At the end of the 19th century, American scientists D.E.Salmon and J. Smith isolated and described the causative agents of salmonellosis in animals, but called the disease swine fever. A few years later, the same bacteria were sown from the intestines of the deceased.

Salmonella pathogens

Salmonella have territorial features, subtle differences within one species or serovariant. Contacting with other microorganisms, they are involved in the exchange of genes and acquire distinctive features - a kind of imprint of the habitat. Such information should facilitate the search for an answer to the question: where do they come from? It became possible to obtain genetic profiles of Salmonella, which are found only in specific poultry farms and industries.

The study of genetic variants of salmonellosis pathogens circulating in the country and the development of methods for determining the origin of bacteria make it possible to raise sanitary and epidemiological control and ensuring food safety to a new level, - says the executive in charge of the assignment Veronica Slizen.

Until recently, there was an outbreak of salmonellosis in a cafe, samples of bacteria were taken from sick people, from products, from objects in the external environment, and it is difficult to prove the similarity between the secreted salmonella.

What is Salmonella
What is Salmonella

And this is despite the fact that molecular genetic approaches for typing the main causative agents of salmonellosis, in principle, are known, but have not yet been introduced into the practice of domestic health care. Phenotypically, all Salmonella - both Salmonella serovar Enteritidis and serovar Typhimurium - are the same. Our methods allow us to see the genetic difference or similarity of pathogens and to judge the possible origin.

Both methods are approved by the instructions of the Ministry of Health and are successfully used in the Republican Center for Hygiene, Epidemiology and Public Health, in the practice of sanitary services, which are very interested in officially registered high-precision technology for conducting epidemiological investigations.

In other words, innovation in complementing known targets for identifying Salmonella with non-traditional ones, which has expanded the possibilities of laboratory diagnostics. At the same time, PCR has remained the same proven method of molecular biology, well mastered by the sanitary services, which successfully operate this "workhorse".

What is Salmonella
What is Salmonella

The second method - modern and more laborious - is based on the use of a sequencer - a device that determines the sequence of nucleotides in DNA. Thanks to him, differences in microorganisms are revealed by the variable number of tandem repeats. The latter, like choruses in songs, are repeatedly repeating fragments of the same type in the DNA of microorganisms, and by their number in different parts of DNA, one can describe the genetic profile of the pathogen, compare microorganisms circulating in Russia, Europe, and the world.

Within the framework of the project, a method was also developed for the simultaneous identification using real-time PCR of the main causative agents of salmonellosis, Salmonella serovar Enteritidis and serovar Typhimurium.

Thus, the developed approaches to the recognition of the main causative agents of salmonellosis and their molecular-epidemiological typing made it possible to obtain information on the territorial distribution of genetic variants of the pathogen and to obtain information on the sources of infection, transmission factors. It is possible to establish or exclude links between individual cases of diseases, to differentiate epidemic outbreaks against the background of sporadic infection, to track the path of its spread, to monitor the epidemiological well-being in medical institutions. As for the development of new methods of treatment, such a goal has not yet been set for scientists.

What is Salmonella
What is Salmonella

Although researchers who have studied the resistance of Salmonella to beta-lactam antibiotics have made interesting observations and advise doctors in scientific publications. For example, a study of more than 400 Salmonella strains isolated in different regions of the republic showed that ampicillin-resistant pathogens circulate, which is associated with the production of beta-lactamase enzymes of the TEM and ACC classes. At the same time, resistant forms with ACC genes may be immune to both inhibitor-protected penicillins and 1–2 generation cephalosporins.

But ciprofloxacin, used to treat adults, continues to be active. Monitoring showed that Salmonella does not yet have resistance to it. All tested bacterial cultures retain their sensitivity to 3rd and 4th generation cephalosporins - cefotaxime, ceftriaxone, cefepime, as well as fluoroquinolones and chloramphenicol.

How salmonella infection occurs

The causative agents of salmonellosis are Salmonella. There are a large number of these microorganisms in nature, but only about ten species of bacteria of the genus Salmonella pose the greatest danger to humans.

Sources of pathogenic Salmonella can be: sick people and carriers (the pathogen is excreted in feces); infected animals (poultry, pigs, cattle, cats, dogs); contaminated water (when feces from people or animals enter it); food (raw eggs, meat, unpasteurized milk, green vegetables contaminated with manure).

Freezing and cold are not harmful to Salmonella, these microorganisms can persist for a very long time, and under favorable conditions, they can multiply in products, not always changing their taste and appearance. Therefore, only high-quality heat treatment can make food safe.

The main route of salmonellosis infection is alimentary, but it is also possible to become infected through dirty hands (after contact with sick animals, after touching objects contaminated with feces of sick people or carriers).

In infants, infection usually occurs when a sick mother or another family member takes care of the child and does not follow the rules of hygiene (in particular, does not wash his hands after using the toilet). It is also important to remember that Salmonella is also excreted by completely healthy bacteria carriers, therefore, hygiene rules should be paramount when caring for newborns.

How does salmonellosis get infected and how to avoid it?

Sources of salmonellosis infection

  • animal meat;
  • a fish;
  • meat of frogs, crabs, oysters;
  • eggs and products prepared from them;
  • milk and dairy products;
  • raw vegetable dishes;
  • unboiled water;
  • isolated cases are described when the infection occurred by airborne droplets, as with colds;
  • sometimes infection occurs from pets through direct contact.

Most often, human infection with salmonella occurs from agricultural (cattle, sheep, pigs, etc.), domestic animals (mainly cats), house rodents (rats, mice). Among wild animals, the disease is often found in bears, arctic foxes, seals, wolves, foxes, and beavers. In birds, especially waterfowl, the pathogen accumulates not only in meat, but also in eggs.

Sick people are also dangerous. Salmonella is excreted in saliva, nasal mucus, urine, feces, breast milk. There are bacteria carriers - people who have no symptoms of the disease, but who are able to infect others.

How to avoid eating low-quality foods that contain salmonella ?

  • meat, eggs, milk and dairy products should be purchased only in stores and in specialized markets;
  • if there is any doubt about the quality of the products, then you can ask the seller for a certificate of RosPodtrebNadzor;
  • carcasses of animals and eggs must be stamped;
  • if you buy products from private sellers, then you should do it only from those who have been trading on the market for a long time and have a good reputation;
  • boil all foods well, do not eat raw eggs;
  • when eating quail eggs, the risk of contracting salmonellosis is lower, but still there;
  • do not eat raw sausages, pies, semi-finished products;
  • do not buy meringues, bird milk candies and other raw egg products if they are made a long time ago, even if they have not yet expired.
  • careful personal hygiene, washing household items with disinfectants and boiling them helps to avoid infection in the foci of infection.

Features of salmonella

What is Salmonella
What is Salmonella

Salmonella have certain characteristics: they are resistant to the action of many environmental factors: they can survive at temperatures of -82 ºC and remain dry for a long time on the surface;

  • on surrounding objects at normal room temperature, bacteria can be viable for up to three months;
  • in animal feces, the causative agent of salmonellosis lives up to four years;
  • they are resistant to salting, smoking and freezing;

Salmonella live in meat of domestic and wild animals, birds, milk, bird eggs. A feature of these bacteria is the ability to multiply in milk and ready-made meat dishes for a long time, while they do not change their appearance, that is, they cannot visually distinguish infected products from clean ones.

  • Where else does Salmonella live? - in water, if it gets there with feces or through contaminated objects, they can stay up to two months;
  • Salmonella can produce or produce exotoxins: enterotoxin and cytotoxin;
  • when bacteria are destroyed, endotoxin is released into the body of an infected person, which leads to the development of severe intoxication;
  • in order to destroy bacteria in products, they have to be subjected to prolonged heat treatment. At what temperature does Salmonella die? - not less than 50 ºC. For example, to kill salmonella in a small piece of meat weighing about 500 mg, you have to cook or stew it for 2.5 hours.

Salmonella (non-typhoid)

What is Salmonella
What is Salmonella
  • most cases of salmonellosis are mild; however, sometimes salmonellosis can be life threatening. The severity of the disease depends on host factors and the Salmonella serotype;
  • antimicrobial resistance is a public health concern worldwide, and Salmonella is among the microorganisms with a number of resistant serotypes found in the food chain;
  • As a preventative measure to protect against salmonellosis, it is recommended that basic food hygiene practices such as thorough cooking are followed.

Salmonellosis symptoms

There are several clinical forms of salmonellosis, each of which has its own characteristics of the course:

  • What is Salmonella
    What is Salmonella

    the gastrointestinal form is the most common and accounts for 96–98% of all cases. It is accompanied by gastritis, gastroenteritis or gastroenterocolitis. The onset of the disease is characterized by an increase in body temperature (up to 39 ° C), general weakness, headache, chills, nausea and vomiting, abdominal pain, stool disorder (loose stools from 5 to 10 times a day and more). Symptoms appear depending on the severity of the disease. In severe salmonellosis, diarrhea lasts 7 days or more, there is repeated vomiting, loss of fluid by the body. Intoxication and dehydration lead to skin cyanosis, tachycardia, a decrease in blood pressure, acute renal failure may develop;

  • the generalized form (typhoid-like variant) usually has an acute onset. Among her first symptoms are stool disorders, fever and general intoxication. After a couple of days of the disease, intestinal dysfunction disappears, but the fever remains the same, and the symptoms of intoxication are increasing. Patients have apathy, lethargy, pallor of the skin, a rash may appear on the abdomen, the liver and spleen are enlarged, the stomach is swollen;
  • the generalized septic form is the most severe variant of salmonellosis. The body temperature of patients fluctuates greatly, chills, and strong sweating are observed. Septic foci can occur on other organs, therefore the clinical symptoms of this form of the disease are very diverse, difficult to diagnose and difficult to treat.

    With the development of purulent foci in the musculoskeletal system, osteomyelitis and arthritis develop; lymphadenitis, meningitis, tonsillitis, aortitis, endocarditis often occur. The septic form of salmonellosis can last for quite a long time and end fatally, especially for infants and the elderly;

  • What is Salmonella
    What is Salmonella

    bacteriocarrier is a form characterized by the absence of clinical symptoms. It can be diagnosed only with bacteriological and serological examinations. There are several categories of bacterial carriage: acute, chronic and transient. Acute carriage lasts from 15 days to three months and occurs after the transferred manifest forms of salmonellosis. If Salmonella bacilli are shed for more than three months, the carrier becomes chronic. Transient carriage is diagnosed if Salmonella has been found once or twice after a previous negative test result;

the subclinical form of salmonellosis is characterized by the presence of salmonella in the analysis of feces simultaneously with the release of anti-salmonella antibodies. This form proceeds without clinical manifestations

Salmonella prevention methods

Prevention requires control measures at all levels of the food chain, from agricultural production to food processing, production and preparation, both in commercial organizations and at home.

Preventive measures to protect against Salmonella in the home are similar to those used to protect against other bacterial foodborne diseases (see Guidelines for Food Handlers below).

Contact between infants or young children and pets (cats, dogs, turtles, etc.) that may carry Salmonella should be closely monitored.

National and regional foodborne disease surveillance systems are important tools for studying and monitoring the situation of such diseases, as well as for detecting and responding to salmonellosis and other intestinal infections in an early stage, thus preventing the further spread of such diseases.

What is Salmonella
What is Salmonella

Drink only boiled milk!

  • Ensure food is properly cooked and still hot when served;
  • avoiding raw milk and raw milk products. Drink only pasteurized or boiled milk;
  • avoid eating ice, unless it was made from safe water;
  • if there is any doubt about the safety of the water, boil it or, if this is not possible, disinfect it with a reliable, slow-acting disinfectant (usually such substances can be purchased at pharmacies);
  • wash hands thoroughly and use soap frequently, especially after contact with pets or farm animals, and after using the toilet;
  • wash fruits and vegetables thoroughly, especially if consumed raw. If possible, peel vegetables and fruits.

Find out more:

  • Salmonellosis - causes, symptoms, diagnosis and treatment
  • Salmonellosis in children: symptoms, signs, treatment
  • Salmonellosis in a child: signs, symptoms and treatment
  • Treatment of salmonellosis in children: medicines, methods and forms
  • Intestinal Infection: Salmonellosis - Symptoms and Treatment

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