Historical data on salmonellosis. The impact of salmonellosis on the body
Among the pathogenic bacteria that affect the human digestive system, salmonella is often found. Microorganisms of this kind usually penetrate the gastrointestinal tract with contaminated food, causing negative disruptions in the functioning of organs and severe poisoning.
Salmonella causes severe poisoning of the body
Salmonella - what is it?
The causative agent of intestinal infection (salmonellosis) belongs to the genus Salmonella (shigella, salmonella) and is a gram-negative enterobacterium that does not form spores. In appearance, the microorganisms resemble a longitudinal rod with slightly rounded edges. Length of Salmonella spp. – 1–5 µm, width – from 0.33 to 0.7 µm. What it looks like is shown in the photo.
Bacteria are facultative anaerobes, most of which are motile thanks to flagella (located peritrichially). During their life activity, pathogenic microorganisms are capable of fermenting carbohydrates and alcohols, releasing acid and gas. They most often live in the intestines of humans or animals.
The favorable temperature for existence is 35–37 degrees above zero. Salmonella can also survive during cold weather (from +7) or significant warming (up to +45). Bacteria are resistant to external factors, and their life cycle can last a very long time in environments such as:
- room dust (up to 90 days);
- open reservoirs (from 10 to 125 days);
- sausages, meat, milk (2–6 months, frozen – up to a year);
- eggs (10–12 months), in shell up to 1 month;
- butter (up to 4 months).
Salmonella is capable of multiplying in meat, even if it is stored in the refrigerator at low temperatures.
Pathogens usually live in the intestines
Types and classification
According to the principle of taxonomy, salmonella are classified into two main types:
- bacteria that do not pose a danger to humans - Salmonella bongori;
- pathogenic microorganisms for humans – Salmonella enterica.
Let us dwell in more detail on the second type of pathogenic enterobacteria. They have 6 subspecies and have their own serotype:
- l enterika;
- ll salamae;
- arizonae llla;
- darizonae lllb;
- lV houtenae;
- Vl indica.
A common cause of intestinal infections is Salmonella subspecies Salmonella enterika enterika. It is the causative agent of such pathologies as:
- typhoid fever (Salmonella typhi);
- paratyphoid fevers A, B, C (Salmonella paratyphi);
- salmonellosis (Salmonella typhimurium, newport, agona, etc.).
The most common pathology of the digestive system caused by Salmonella enterica is salmonellosis. This is an acute infectious disease that affects the human gastrointestinal tract, causing serious violations in his work.
Salmonellosis is caused by the bacteria Salmonella enterika
How does salmonella infection occur?
Migration of Salmonella from the carrier to the external environment and again to the host occurs through the fecal-oral route. There are several main reasons why bacteria enter the human body.
- Infection through food. Pathogenic microorganisms live in the meat of cattle, pigs, sheep, goats, in milk, and are less common in fish. If waterfowl are infected or bacteria develop in the body of a chicken, then salmonella will certainly be in the eggs.
- Poor hand hygiene after contact with sick animals.
- Infection from a human carrier through contact and household contact. This usually happens through dirty hands.
A small amount of salmonella in food is not enough to cause an intestinal infection. The source of salmonellosis is contaminated meat, milk, or eggs, which are stored for a long time without proper treatment, and pathogenic bacilli multiply intensively in them.
The insidiousness of bacteria of this kind is that, being in products, they do not spoil either the appearance or taste of the food. Therefore, it is impossible to identify contaminated meat, milk or eggs without appropriate analysis.
Contaminated meat is no different from normal meat
Symptoms
After Salmonella enters the human intestine, its incubation period begins (from 6 hours to several days), which does not manifest itself in any way. During this time, the pathogenic bacillus manages to get comfortable in the gastrointestinal tract of the carrier and begins to poison it.
In this case, the patient experiences the following symptoms:
- migraine, dizziness, loss of strength;
- temperature fluctuations;
- problems with bowel function ( loose stool with mucus and unpleasant smell, flatulence, painful sensations in a stomach);
- loss of appetite, nausea, vomiting.
When infected with salmonella, headaches and migraines appear
Besides obvious signs, there may also be hidden symptoms that a doctor can detect during a thorough examination: low blood pressure, rapid pulse, enlarged liver and spleen.
When salmonella enters the body, it becomes dehydrated. The elasticity of the skin decreases, the mucous membranes become dry, and the amount of urine produced decreases. At this time, there is hoarseness of the voice, thirst, as well as convulsive contraction of some muscle groups.
In children
Intestinal infections caused by enterobacteriaceae are difficult to tolerate in young patients. The pathology is especially dangerous for children under 1 year of age. In them, salmonella infection appears within a few hours after the bacteria enters the intestines. The first symptoms are similar to acute poisoning.
An older child initial signs appear 3–4 days after infection. In addition to intoxication, there is fever (up to 39 degrees), weakness, loss of appetite and intense diarrhea with a frequency of urination more than 10 times per day. At first, the stool contains mucus, and then streaks of blood may appear. All these are obvious manifestations of salmonellosis, which, if ignored, can provoke death.
Salmonella causes sharp deterioration child's well-being
How dangerous is salmonella?
The accumulation of a large number of pathogenic bacilli is dangerous for humans because it can provoke serious poisoning of the body. The patient experiences shortness of breath and is practically unable to move. Heat indicates the fight of the immune system against infection. But its decrease means that protective forces are unable to eliminate the threat, and the patient’s condition is extremely serious.
Advanced stages of salmonellosis lead to severe disease (generalized form). In this case, bacteria penetrate through the blood into other organs (stomach, lungs, liver), poisoning them with the products of their vital activity.
Salmonella can develop into a septic stage, in which purulent processes. Most often, such lesions affect the heart, liver, lungs, and kidneys, which can lead to the death of the patient.
Diagnostics
The symptoms of salmonellosis are very similar to dysentery, E. coli, tropical hemorrhagic fever, typhoid fever or acute food poisoning. Therefore, it is very important to correctly diagnose the disease. To do this, the doctor conducts a thorough examination, questioning and prescribes a number of tests using microbiological methods:
- bacteriological examination of biological material (blood, urine, gastric and intestinal lavage, vomit, rectal discharge are studied);
- blood test to determine the titer of antibodies to the causative agent of the disease;
- general blood test - determination inflammatory processes and the condition of internal organs in general.
A comprehensive examination is supported by anamnesis (information about past illnesses, nutrition, lifestyle, concomitant diseases). Only after confirmation of salmonellosis can you begin treatment, which is selected by the doctor taking into account individual characteristics course of the disease.
A blood test is necessary to accurately detect salmonella in the body.
How to get rid of salmonella
Pathogenic bacteria are very resistant microorganisms to the external environment. It is almost impossible to detect and neutralize the infection on your own.
At what temperature does a bacterium die?
Salmonella is not afraid of low temperatures. It lives in meat even when it is frozen. She is not afraid of such food processing as salting and smoking. The pathogenic bacillus dies at temperatures above 50 degrees in an hour. Within 3–5 minutes, salmonella dies when heat treatment meat from 80 degrees and above (boiling).
But when frozen meat products the infection is “preserved” and after thawing continues to multiply intensively. Therefore, if there is no a large number of salmonella, long-term storage of such products increases the risk of contracting salmonellosis several times.
Salmonella is not afraid of low temperatures
Treatment of salmonellosis
Self-medication can lead to worsening of the disease and serious consequences. Therefore, therapy for salmonellosis must be comprehensive and carried out under the supervision of a doctor in a hospital.
- Restoring water balance in the body and replenishing lost fluid. Depending on the severity of the disease and the electrolyte composition of the patient’s blood, droppers with a solution of glucose, sodium chloride, Acesol, Ringer, Trisol, Philips can be used. The patient is given Regidron liquid to drink.
- Detoxification. At this time, the maximum possible doses of sorbents are prescribed - Polysorb, Smecta - for removal from the body harmful substances that are produced by pathogenic bacteria.
- Treatment with antibiotics (Ceftriaxone, Norfloxacin). This approach reduces inflammation and reduces the level of intoxication. Initially, the medicine is administered by injection (into a vein or muscle), and as the person’s condition improves, the tablet form is prescribed.
In addition to drug treatment, the patient is recommended special diet, which does not overload the digestive system. Meals are fractional, in small portions 6–7 times a day.
At the initial stage of treatment, Ceftriaxone must be taken by injection.
How to protect yourself from infection
There are many sources of salmonella infection. Even a person who has recovered from such a pathology remains a carrier of the disease for several months. Therefore, in order to protect yourself from pathogenic bacilli, you must adhere to basic prevention:
- hygiene (wash hands after contact with animals or visiting public places, use only your own household items);
- food processing (boil meat well, boil milk, do not eat eggs raw or in the form of “fried eggs”);
- vaccination of pets.
Intestinal disease caused by salmonella has a severe impact on the entire human digestive system. Pathogenic bacteria have many sources of entry into the body, especially through food. It is important to heat treat meat, eggs, milk, fish, and maintain hygiene. If symptoms of poisoning occur, it is recommended to immediately consult a doctor to avoid further pathology.
Salmonella dublin, etc.
The vast majority of salmonella - the causative agents of salmonellosis (from total number more than 700) belongs to the enterica subspecies and are its serovars. The full name of the most common pathogens of salmonellosis is Salmonella enterica subspecies enterica serovar typhimurium, Salmonella enterica subspecies enterica serovar enteritidis, Salmonella enterica subspecies enterica serovar choleraesuis, Salmonella enterica subspecies enterica serovar dublin, Salmonella enterica subspecies enterica serovar heidelberg, Salmonella enterica subspecies enterica serovar typhimurium.
Salmonellosis can occur in people of any age. But among children younger age it is 5 times higher than among adults and older children. Older people get sick more often than others.
Morphology– rods with rounded ends measuring 0.7–1.5 x 2.0–3.0 µm, with a few exceptions they are mobile and do not form spores or capsules.
Tinctorial properties– stain well with aniline dyes, gram-negative.
Cultural properties. Pathogens actively grow and multiply on ordinary nutrient media at temperatures from +6 to +46 ° C (optimum growth +37 ° C), and pH 7.2–7.4. On plain agar they give smooth, round, translucent, convex, moist (S-shape) and rough, dull, dry, irregular shape(R-form) colonies.
When growing in broth, smooth forms of colonies cause uniform turbidity of the medium, rough forms give sediment, and the supernatant liquid is transparent.
Enzymatic properties. Biochemically active, ferment glucose, maltose and mannitol to acid and gas, release hydrogen sulfide, do not produce indole, and do not liquefy gelatin (Table 8).
Table 8
Biochemical properties some species (old name) or serotypes (name corresponding to modern classification) Salmonella - the causative agent of salmonellosis
Note: “K” – splitting of the substrate to acid; “KG” – splitting of the substrate into acid and gas; “+” positive reaction; “–” – negative reaction.
Toxin formation. The causative agents of salmonellosis have factors contributing to the development of the disease:
1. Adhesion factor (adhesion of salmonella to the surface of the enterocyte, Ads F);
2. Adhesion factor (salmonella with the surface of the enterocyte, Adr F);
3. Colonization factor (CF);
4. Invasion factor (IF, internalin), which ensures the penetration of Salmonella into the intestinal epithelium.
5. The causative agents of salmonellosis are capable of producing exotoxins (cytotonins) LT (labile toxin) and ST (stable toxin), which provide excessive formation of c-AMP and c-GMP, which leads to diarrhea in patients.
6. Cytotoxin SLT, which disrupts protein-synthesizing processes in the cells of the intestinal mucosa.
7. Endotoxins - lipopolysaccharides (LPS), released during the breakdown of Salmonella, are one of the main factors of their pathogenicity.
Antigenic structure. Salmonella, which is the causative agent foodborne diseases(salmonellosis) have 2 main antigenic complexes: O- and H-antigens. O-antigen is somatic, thermostable, associated with the body of the microbial cell. H-antigen is heat labile and associated with flagella. Antigenic structure (formula) most often causing salmonellosis bacteria are presented in table. 9.
Pathogenicity for animals. Salmonella causes enteritis in cattle, piglets, mice and rats. They infect seabirds (gulls, cormorants) and waterfowl (ducks, geese), which transmit the pathogen transovarially. The spread of salmonellosis depends on the conditions in which poultry is raised, transported, slaughtered and sold. Contamination of milk and eggs can lead to large outbreaks of the disease. Salmonella persists for a long time in the external environment: in the water of stagnant reservoirs for up to 5 months, in meat and sausages for 2 to 4 months, in frozen animal meat for about 6 months, in frozen bird carcasses for more than a year, in butter– up to 4 months, in cheeses – up to 1 year, in egg powder – from 3 to 9 months, in beer – up to 2 months, in soil – up to 18 months. In some products, salmonella can not only persist, but also multiply without changing appearance and taste of products. Salting and smoking have very little effect on them.
Table 9
Antigenic structure (formula) of some species (serovar) of Salmonella - the causative agents of salmonellosis
| Group | Serovar | O-antigen | H – antigen | ||||
| 1st phase | 2nd phase | ||||||
| B group | S. typhimurium | i | 1,2 | ||||
| S.heidelberg | r | 1,2 | |||||
| C group | S. cnoleraesuis | - | - | c | 1,5 | ||
| D group | S. enteritidis | - | g, m | - | |||
| S. dublin | - | g, p | - |
Note: in bold group antigen was isolated.
Pathogenesis. The source of infection for people is animals, birds, fish, and less often a sick person or a bacteria carrier.
Transmission mechanism pathogens are alimentary, less often - fecal-oral.
Transmission routes– food (food), rarely household contact (household items, hands).
Entrance gate infections.Salmonella enters the small intestine with food. Further processes of their interaction with epithelial cells of the mucosa occur in the same way as during interaction with Salmonella of the typhoparatyphoid group. Salmonella ligands are serovar-specific repeating blocks of oligosaccharides in the side chains of lipopolysaccharide (LPS). Adhesion of Salmonella to the surface of enterocytes occurs due to receptors for monosaccharides located on their surface. After adhesion and colonization of enterocytes, Salmonella, due to the invasion factor they produce (internalin), penetrates into the epithelial cells of the mucosa. The penetration process can also be carried out by endocytosis. In this case, Salmonella quickly leave the endosome territory with the help of the F factor they produce and enter the cytosol of enterocytes. Then, without multiplying in enterocytes and without destroying them, salmonella are transported through epithelial cells with subsequent release in the lamina propria of the mucosa (infection phase, incubation period).
Dynamics of pathogen spread. There are two possible options for the further spread of pathogens: local and generalized.
Having overcome the epithelial barrier, salmonella penetrate into the tissue of the small intestine, where they are captured by macrophages. Inside macrophages, they multiply and partially die with the release of endotoxin, which affects the neurovascular system of the intestine and increases the permeability of cell membranes. This contributes to the further spread of salmonella through the lymphatic tract into the mesenteric The lymph nodes. At this stage, the infectious process acquires a localized (gastritis, gastroenteritis, gastroenterocolitic) form and can be completed (local variant).
With a deep violation of the barrier function of the intestinal lymphatic system, the process generalizes, long-term bacteremia develops, Salmonella enters various internal organs, causing dystrophic changes or the formation of secondary purulent foci (typhoid-like and septicopyemic forms).
The heat-labile enterotoxin of Salmonella induces a mechanism for activating adenylate cyclase in enterocytes, which leads to an increase in the concentration of c-AMP in them. This entails the entry into the intestinal lumen of a large amount of liquid, potassium, sodium, and chlorides. Patients experience vomiting and diarrhea. Symptoms of dehydration increase. Dehydration leads to tissue hypoxia, with disruption of cellular metabolism, which, in combination with electrolyte changes, contributes to the development of acidosis.
The most affected organs. Depending on the dynamics of the spread of Salmonella, pathomorphological processes can affect mainly the gastrointestinal tract or spread to other internal organs - the liver, spleen (cholecystitis, cholangitis, abscesses of the liver and spleen).
The pathogen is released into the external environment through feces from the first to the last day of the disease. It is possible to form a carrier state (up to several months), without the manifestation of clinical symptoms of the disease.
Mechanisms of sanogenesis. As with typhoid paratyphoid diseases in the preimmune phase, the destruction of Salmonella occurs due to the activation of complement along the lectin and alternative pathways. During the immune phase of the disease, the emerging IgM, due to immune lysis, prevents the penetration of Salmonella into the tissues of internal organs. In patients with a deficiency of IgM formation, internal organs are involved in the pathological process. IgG to the outer membrane proteins of Salmonella is formed in low titers. Short-term immunity is type-specific.
Salmonella is one of the most commonly isolated pathogens during outbreaks food poisoning in health care facilities (33.3-66.7%). In this case, different mechanisms of pathogen transmission can be implemented:
a) nutritional (food products - meat and meat dishes, milk and dairy products, eggs and egg products, powder baby food etc.), reproducing ordinary food outbreaks of the zooanthroponotic type as a result of the use of infected food products that have not been subjected to the necessary processing.
b) fecal-oral mechanism (presence of carriers among food service workers, violations of technological processes of food preparation, improper storage and processing of finished and raw products), reproducing salmonellosis of the anthroponotic type, caused by contamination with Salmonella various products by a person;
c) aspiration (airborne dust path, in the absence of proper sanitary conditions in health care facilities).
Nosocomial Salmonella infection most often occurs in children's somatic hospitals (children early age), in multidisciplinary health care facilities for adults (elderly and old age) and occurs, as a rule, against the background serious illnesses (acute leukemia, chronic diseases liver, kidneys, lungs, heart) or joins in the postoperative period.
Within one health care facility (or a number of health care facilities in one city), several strains of Salmonella can circulate that have multiple drug resistance (primarily polyantibiotic resistance), high resistance to a number of factors (ultraviolet irradiation, drying, exposure to disinfectants and etc.). Such strains, which have selective advantages, are designated as nosocomial (hospital) strains. Among them, S. typhimurium, S. enteritidis, S. heidelberg, S. haifa, S.agama, S. infantis, S. newport, S. panama, S. derby are often found.
Microbiological diagnostics. The material for research can be the patient’s blood, feces, vomit, urine, gastric lavage, bile and duodenal contents, pus or exudate from inflammatory foci, food debris, and washings from dishes. In case of death, pieces are taken for examination parenchymal organs(liver, spleen, kidneys), blood from the heart, bile, mesenteric lymph nodes, bone marrow, sections of the small and large intestines with contents.
Microscopic method. For group diseases of salmonellosis, the method of fluorescent antibodies (direct and indirect) is used without isolating a pure culture of the pathogen.
Bacteriological method. To isolate a pure culture of Salmonella (hemoculture), blood is inoculated into bile broth. Vomit, feces, sectional material, pus, cerebrospinal fluid, products, washings are sown on plates with Ploskirev’s medium or in accumulation media (bile broth, magnesium medium, selenite medium), from which, after 6–10 hours, reseeding is done on Ploskirev’s medium. The crops are incubated. The next day they are examined, colorless lactose-negative colonies are selected and subcultured onto Olkenitsky's three-sugar medium or slanted agar to accumulate a pure culture. On the 3rd–4th day of the study, the isolated pure cultures are identified on the “variegated” series media (Gissa, Russell), and an agglutination reaction (RA) is carried out with adsorbed group sera (A, B, C, D, E). In case of a positive response with one of the groups of sera, RA is performed with adsorbed O-sera characteristic of this group, and then with monoreceptor H-sera (nonspecific and specific phases) to determine the type and serovar of bacteria. On the 4th day, the change in the media of the “variegated” series is taken into account.
Biological method. On the first day of the study, white mice are infected orally. After 1–2 days, the mice die from septicemia. At autopsy, a sharply enlarged spleen and sometimes the liver are discovered; Salmonella cultures can be isolated from the blood and material from the internal organs (liver, spleen, lymph nodes).
Serological method. Apply RNGA with erythrocyte diagnosticums(O-, H-) and with a cysteine or unithiol test to determine the titer of IgM and IgG in the blood sera of people with chronic course diseases.
Allergological emethod not applicable since the type of immune response being formed is Th2.
Prevention. For the treatment of children and adults with salmonellosis, the sanitation of convalescents, carriers of salmonella, and for prophylactic purposes according to epidemiological indications, the salmonellosis bacteriophage of group A B C D E is used. It is a mixture of phagolysates of Salmonella paratyphoid A and B, typhimurium, Heidelberg, cholerasuis, Oranienburg, Newport, Dublin, Anatum, Newlands active against salmonella having greatest distribution and belonging to groups A, B, C, D, E.
Specific prevention not developed due to the abundance of Salmonella serotypes. Vaccines for animals have been created based on mutant strains of Salmonella typhimurium (G30D and aroA), which are expected to be tested in humans.
Salmonellosis is a group of infectious diseases of humans and animals, the causative agents of which are bacteria of the Enterobacteriaceae family, the genus Salmonella, represented by two species - S. enterica and S. bongori, among which seven subspecies are distinguished.
Salmonella has three main antigens:
· O-somatic (thermostable);
· N-flagellate (heat labile);
· K-surface (capsular).
In addition, other antigens have been described in some Salmonella serotypes:
Vi-antigen (one of the components of O-antigen);
· M-antigen (mucous).
Currently, more than 2.5 thousand serological variants of Salmonella are known. Sero- and phage typing of Salmonella is carried out in national Salmonella centers, which provide information on the isolation of new Salmonella serotypes and their epidemiology up to 60 times a year. The identification of new Salmonella serovars is confirmed by the WHO Reference Center for Salmonella Research (Institut Pasteur, Paris), which recommends using the Kaufman-White diagnostic antigen scheme (2001) for serotyping and epidemiological surveillance of salmonellosis (2001), based on the serological identification of Salmonella taking into account their antigenic structure ( O, N, Vi).
Salmonella - gram-negative rods 2–4×0.5 µm; they are mobile and grow well on simple nutrient media at temperatures from 6 to 46 °C (growth optimum 37 °C). Most Salmonella are pathogenic for both humans and animals and birds, but from an epidemiological perspective, only a few serotypes are the most significant for humans, which cause 85–91% of human salmonellosis on all continents of the world: S. typhimurium, S. enteritidis, S. panama , S. infantis, S. newport, S. agona, S. derby, S. london, etc.
Currently, salmonellosis is one of the most common zoonoses in developed countries with a widespread trend towards increasing incidence. This is especially true for large cities with a centralized food supply system.
Outbreaks of salmonellosis, caused by antibiotic-resistant strains of salmonella and characterized by high mortality, are regularly recorded in medical institutions, especially in maternity, pediatric, psychiatric and geriatric departments. This type of salmonellosis has acquired the features
hospital infection with contact and household transmission of the pathogen.
The main pathogenicity factors of Salmonella are cholera-like enterotoxin and LPS endotoxin. Some strains have the ability to invade the epithelium of the colon (S. enteritidis).
The clinical manifestations of the disease caused by different serotypes of Salmonella do not differ significantly from each other, therefore, currently, only the clinical form of the disease and the serotype of the isolated Salmonella are indicated in the diagnosis, which is of epidemiological significance.
Typhoid fever is considered separately from other salmonellosis due to the strict specificity of its pathogen in relation to the host (anthroponosis) and the presence clinical features currents.
Salmonellosis
Salmonellosis - acute zoonotic infectious disease with a fecal-oral transmission mechanism of the pathogen, characterized by predominant damage to the gastrointestinal tract, the development of intoxication and dehydration.
Codes according to ICD -10
A02. Other salmonella infections.
A02.0. Salmonella enteritis.
A02.1. Salmonella septicemia.
A02.2. Localized salmonella infection.
A02.8. Other specified salmonella infection.
A02.9. Salmonella infection, unspecified.
Causes of salmonellosis
Salmonella are gram-negative rods of the genus Salmonella of the Enterobacteriaceae family.
There are two types of Salmonella - S. enterica and S. bongori, which is not pathogenic for humans. There are 2324 serovars, divided according to the set of somatic O-antigens into 46 serogroups. In addition to the somatic thermostable O-antigen, Salmonella have a flagellar thermolabile H-antigen. In many strains, surface Vi antigen is detected. The main pathogenicity factors are cholera-like enterotoxin and lipopolysaccharide endotoxin. Some strains of S. enteritidis are capable of invading the epithelium of the colon. Salmonella persists for a long time in environment: in water - up to 5 months, in soil - up to 18 months, in meat - up to 6 months, in bird carcasses - more than a year, on eggshells - up to 24 days. Low temperature They are well tolerated and die instantly at 100°C.
Epidemiology of salmonellosis
The reservoir and source of the infectious agent are sick animals: large and small cattle, pigs, horses, poultry. Their disease is acute or in the form of bacterial carriage. A person (patient or carrier of the bacteria) can also be a source of S. typhimurium. The transmission mechanism is fecal-oral. The main route of transmission is food, through products of animal origin. Infection of meat occurs endogenously during the life of the animal, as well as exogenously during transportation, processing, and storage. IN last years There has been a significant increase in the incidence of S. enteritidis associated with the spread of the pathogen through poultry meat and eggs. Waterway transmission mainly plays a role in infecting animals. As a rule, the pathogen is transmitted through contact and household contact (through hands and instruments) in medical institutions. Greatest risk salmonellosis infection - in children of the first year of life and persons with immunodeficiency. The airborne dust pathway plays a major role in the spread of infection among wild birds. The incidence of salmonellosis is high in large cities. Cases of the disease are recorded throughout the year, but more often in the summer months due to worse conditions food storage.
Sporadic and group morbidity is observed. People's susceptibility to the pathogen is high. Post-infectious immunity lasts less than a year.
Prevention of salmonellosis
There is no specific prevention.
Nonspecific preventive measures
Veterinary and sanitary supervision over the slaughter of livestock and poultry, carcass processing technology, preparation and storage meat dishes. Compliance with sanitary, hygienic and anti-epidemic standards at trade and catering establishments.
Pathogenesis of salmonellosis
In the lumen of the small intestine, Salmonella attach to the membranes of enterocytes and reach the lamina propria of the mucous membrane. This leads to degenerative changes in enterocytes and the development of enteritis. In the lamina propria, macrophages absorb Salmonella, but phagocytosis is incomplete and generalization of the infection is possible. When bacteria are destroyed, a lipopolysaccharide complex (endotoxin) is released, which plays a major role in the development of intoxication syndrome. In addition, it activates the synthesis of prostanoids (thromboxanes, prostaglandins), which trigger platelet aggregation in small capillaries. Prostaglandins stimulate the secretion of electrolytes and fluid into the intestinal lumen, causing contraction smooth muscle and enhance peristalsis. The main role in the development of diarrhea and dehydration is played by enterotoxin, which activates the synthesis of cAMP by adenylate cyclase of enterocytes, thereby increasing the secretion of Na+, Cl– ions and water into the intestinal lumen. The consequence of dehydration and intoxication is disruption of activity of cardio-vascular system, which is expressed by tachycardia and decreased blood pressure.
Clinical picture (symptoms) of salmonellosis
Incubation period from 6 hours to 3 days (usually 12–24 hours); in case of nosocomial outbreaks, it extends to 3–8 days.
Classification of salmonellosis
Gastrointestinal (localized) form:
- gastric variant;
- gastroenteric variant;
- gastroenterocolitic variant.
Generalized form:
- typhus-like variant;
- septic option.
Bacterial excretion:
- spicy;
- chronic;
- transient.
Main symptoms and dynamics of their development
The gastric variant is characterized by an acute onset, repeated vomiting and epigastric pain. The intoxication syndrome is weakly expressed. Short duration of the disease.
The gastroenteric variant is the most common. The disease begins acutely, with symptoms of intoxication: increased body temperature, headache, chills, a feeling of aching muscles, cramping pain in the abdomen.
Nausea, vomiting, and diarrhea occur. The stools are initially fecal in nature, but quickly become watery, foamy, foul-smelling, sometimes with a greenish tint and have the appearance of “swamp mud.” Pallor of the skin is noted, and in more severe cases, cyanosis. The tongue is dry and coated.
The abdomen is swollen, painful on palpation in all parts, more in the epigastrium and in the right iliac region, rumbling under the arm. Heart sounds are muffled, tachycardia, blood pressure is reduced. Reduced urine output. Convulsions are possible.
With the gastroenterocolitic variant, the clinical picture is the same, but already on the 2nd–3rd day of illness the volume of bowel movements decreases. They contain an admixture of mucus and sometimes blood. When palpating the abdomen, spasm and pain are noted sigmoid colon. Tenesmus is possible.
The generalized form of the disease is usually preceded by gastrointestinal disorders. With the typhus-like variant, the temperature curve becomes constant or wave-like. Headache, weakness, and insomnia increase. The skin is pale, and by the 6th–7th day of illness a roseola rash appears on the skin of the abdomen. Slight bradycardia is observed. Dry scattered rales are heard over the lungs. The stomach is swollen. By the end of the first week of illness, an enlargement of the liver and spleen is noted. The duration of fever is 1–3 weeks. Relapses are rare. In the first days of the disease, the clinical manifestations of septic and typhus-like variants are similar. Subsequently, the condition of the patients worsens. Fluctuations in body temperature become irregular, with large daily changes, repeated chills and profuse sweating, tachycardia, and myalgia. The formation of purulent foci in the lungs, heart, kidneys, liver and other organs is noted. The disease lasts a long time and can be fatal. After suffering from the disease, some patients become bacteria carriers. In case of acute bacterial excretion, the isolation of Salmonella ends within 3 months; if it lasts more than 3 months, it is regarded as chronic. With transient bacterial excretion, single or double seeding of Salmonella from feces is not accompanied by clinical manifestations and the formation of antibodies.
Complications of salmonellosis
Dehydration and ITS, circulatory disorders in the coronary, mesenteric and cerebral vessels, acute renal failure, septic complications.
Mortality and causes of death
Mortality rate is 0.2–0.6%. The cause of death may be one of the above complications.
Diagnosis of salmonellosis
Clinical
Characterized by an acute onset with fever, nausea, vomiting, diarrhea, and abdominal pain.
Epidemiological
Ingestion of food prepared and stored in violation of sanitary standards, consumption raw eggs, group flashes. In megacities, identification group cases disease poses great difficulties if a product contaminated with salmonella is sold through a retail chain or catering establishments. Without confirmation of diagnosis laboratory tests Differential diagnosis of salmonellosis with PTI is very difficult.
Specific and nonspecific laboratory diagnostics
Bacteriological examination of feces (one or two times), vomit, blood, urine, bile, gastric lavage, remains of suspicious products.
Salmonella antigens can be detected in blood and urine using ELISA and DGA. For retrospective diagnosis, the determination of specific antibodies (RNGA and ELISA) is used. Paired sera taken at intervals of 5–7 days are examined. Diagnostic value has an increase in titers four times or more.
Differential diagnosis
Carry out with infectious and non-infectious diseases (Table 17-3, 17-4).
Table 17-3. Differential diagnosis of salmonellosis, dysentery, cholera
| Clinical signs | Salmonellosis | Dysentery | Cholera |
| Chair | Watery, with an unpleasant odor, often mixed with greenery the color of swamp mud | Scanty, fecal-free, mixed with mucus and blood - “rectal spit” | Watery, the color of rice water, odorless, sometimes with the smell of raw fish |
| Defecation | Painful with colitis | With tenesmus | Painless |
| Abdominal pain | Moderate cramping, in the epigastrium or mesogastrium | Strong, with false urges, in the lower abdomen, left iliac region | Not typical |
| Vomit | Repeated, preceded by diarrhea |
Possible with gastroenterocolitic variant | Repeated watery, appears later than diarrhea |
| Spasm and tenderness of the sigmoid colon | Possible with colitis | Characteristic | Not marked |
| Dehydration | Moderate | Not typical | Typical, pronounced |
| Body temperature | Increased | Increased | Normal, hypothermia |
| Chills | Typical | Typical | Not typical |
Table 17-4. Differential diagnosis of salmonellosis, acute appendicitis, thrombosis of mesenteric vessels
| Clinical signs | Salmonellosis | Acute appendicitis | Thrombosis of mesenteric vessels |
| Anamnesis | Eating poor-quality food, the possibility of group outbreaks | Without features | IHD, atherosclerosis |
| Onset of the disease | Acute, with severe intoxication, clinical picture of acute gastroenteritis | Pain in the epigastrium with movement to the right iliac region | Acute, less often - gradual, with abdominal pain |
| Nature of abdominal pain | Moderate cramping, in the epigastrium or diffuse. Disappears before diarrhea stops or simultaneously with it | Severe constant, worse when coughing. Persists or worsens when diarrhea stops | Sharp, unbearable, constant or paroxysmal, without specific localization |
| Chair | Liquid, copious, fetid, mixed with greenery, repeated | Liquid stool, without pathological impurities, up to 3-4 times, most often constipation | Liquid, often mixed with blood |
| Cramps, dehydration, chills | During the height of the illness | None | None |
| Abdominal examination | Moderately swollen, rumbling on palpation, painful in the epigastrium or mesogastrium | Soreness in the right iliac region with muscle tension. Symptoms of peritoneal irritation are positive | Bloated, diffuse soreness |
| Vomit | Repeated, in the first hours | Sometimes, at the beginning of the disease, 1–2 times | Often, sometimes mixed with blood |
| Leukocytosis | Moderate | Pronounced, growing | Pronounced, growing |
Indications for consultation with other specialists
Consultation with a surgeon is necessary if appendicitis, thrombosis of mesenteric vessels, or intestinal obstruction are suspected.
A consultation with a gynecologist is prescribed if an ectopic pregnancy, ovarian apoplexy, or salpingoophoritis is suspected.
Consultation with a cardiologist - to exclude myocardial infarction, hypertensive crisis, correction of therapy for concomitant ischemic heart disease, hypertension.
An example of a diagnosis formulation
A02.0. Salmonellosis. Gastrointestinal form. Gastroenteric variant. Moderate course.
Indications for hospitalization
Severe course of the disease, presence of complications; epidemiological indications.
Treatment of salmonellosis
Mode. Diet
Bed rest is prescribed for severe intoxication and fluid loss. Ward - for moderate and mild course. Diet - table No. 4. Food products that irritate the stomach and intestines, dairy products, and refractory fats are excluded from the diet.
Drug therapy for salmonellosis
Etiotropic therapy
Moderate and severe localized form of the disease - enterix♠ two capsules three times a day for 5–6 days; chloroquinaldol 0.2 g 3 times a day for 3–5 days.
Generalized form - ciprofloxacin 500 mg twice a day; Ceftriaxone 2 g once daily intramuscularly or intravenously for 7–14 days. For all forms of bacterial carriage and the decreed category of persons - Salmonella bacteriophage, two tablets three times a day or 50 ml twice a day 30 minutes before meals for 5–7 days; sanviritrin♠ two tablets 3-4 times a day for 7-14 days.
Pathogenetic agents
Rehydration therapy. Oral (with dehydration of I–II degree and no vomiting): glucosolan♠, citroglucosolan, rehydron♠. Rehydration is carried out in two stages, the duration of the 1st stage is up to 2 hours, the 2nd stage is up to 3 days. Volume 30–70 ml/kg, speed 0.5–1.5 l/h, temperature 37–40 °C. Parenteral: Chlosol♠, Trisol♠. Rehydration is carried out in two stages, the duration of the 1st stage is up to 3 hours, the 2nd - according to indications (switching to oral administration of liquid is possible). Volume 55–120 ml/kg, average speed 60–120 ml/min.
Detoxification therapy. Only when treating dehydration. Glucose♠, rheopolyglucin♠ 200–400 ml intravenous drip.
Eubiotics and biological products: bactisubtil♠ one capsule 3–6 times a day 1 hour before meals, Linex♠ two capsules three times a day for 2 weeks; lactobacilli acidophilus + kefir fungi (atsipol♠) one tablet three times a day; bifidobacterium bifidum (bifidumbacterin♠) five doses three times a day for 1–2 months. Hilak forte♠ 40–60 drops three times a day for 2–4 weeks.
Sorbents: hydrolytic lignin (polyphepan♠) one tablespoon 3-4 times a day for 5-7 days; Activated carbon(carbolong♠) 5–10 g three times a day for 3–15 days; dioctahedral smectite (neosmectin♠) one powder three times a day for 5–7 days.
Enzyme therapy: pancreatin one powder three times a day for 2–3 months; Mezim Forte♠ one tablet three times a day for 1 month; oraza♠ one teaspoon three times a day for 2–4 weeks with meals.
Antidiarrheal drugs: calcium gluconate 1-3 g 2-3 times a day, indomethacin 50 mg three times a day every 3 hours for 1-2 days, Kassirsky powders one powder three times a day.
Antispasmodics: drotaverine (no-spa♠) 0.04 g three times a day, papaverine 0.04 g three times a day.
Additional treatment methods (surgical, physiotherapeutic, sanatorium-resort)
Gastric lavage using a tubeless method is necessary if the patient’s condition allows.
Approximate periods of disability for salmonellosis
The duration of hospital stay for a localized form is up to 14 days, for a generalized form it is 28–30 days. Discharge is carried out after clinical recovery and a negative result of bacteriological examination of stool, which is carried out 2 days after the end of treatment.
Patients in the decreed group are discharged after two control studies feces (the first - no earlier than the 3rd day after the end of treatment, the second - after 1–2 days). Patients who do not excrete pathogens are allowed to work.
Clinical examination
Workers in the food industry and catering establishments are subject to medical examination for 3 months with a monthly one-time stool examination. Persons secreting salmonella are not allowed to perform their main work for 15 days and are given another job. During this period, they undergo a 5-fold examination of stool and a single examination of bile. If bacterial excretion continues for more than 3 months, they are transferred to another job for a period of at least 1 year and examined once every 6 months. After this period, a 5-fold examination of stool and a single examination of bile are carried out with an interval of 1-2 days. At negative results such patients are deregistered and allowed to return to their main work; if positive, they are suspended from work.
Reminder for a patient with salmonellosis
Compliance with the diet for 2–3 months with exceptions spicy food, alcohol, refractory animal fats, milk. After generalized forms, restriction is necessary physical activity for 6 months
"Salmonellosis of rare groups" is salmonellosis caused by Salmonella of rare groups. How relevant is this topic in Russia? This is also discussed in the article. "Salmonellosis of rare groups".
So why Salmonella rare groups?!!
1. These bacteria can only be confirmed by bacteriological research feces, blood and urine.
2. This means that the patient must have clinically expressed form of this intestinal infection.
3. In fact, this rarely happens, since Basically, Salmonella of rare groups behave as opportunistic flora. Therefore, not every one of us, if we have intestinal problems, runs to examine our stool for pathogenic flora, but this should be done at least every time we return from a trip somewhere, even if the trip was within Russia within 7 days after returning. I would recommend examining your stool for microflora or dysbacteriosis!
4. Serological blood tests will not show anything, since the serum of patients in the RPGA is initially examined with a complex preparation of the diagnosticum ABCD group O antigen. Further, in the presence of agglutination with a complex diagnosticum, RPGA is placed with drugs of groups A (1,2,12), B (1,4,12), C1 (6.7), C2 (6.8), D (1, 9.12) and E (3.10).
The table shows the antigenic characteristics of salmonella, on the basis of which the diagnosis of serological variants of salmonella is carried out.
| Group. | Salmonella. | Antigens. | |
| Somatic - O. | Flagellates - Nonspecific. | ||
| A | S. paratiphi A | 1, 2, 12 | a |
| B | S. paratiphi B | 1, 4, 5, 12 | b |
| S. typhimurium | 1, 4, 5, 12 | i | |
| S.heidelberg | 4, 5, 12 | r | |
| S.derby | 1, 4, 12 | f,g | |
| C1 | S. paratiphi C | 6, 7, Vi | c |
| S.choleraesuis | 6, 7, | c | |
| S.newport | 6, 8 | e, h | |
| D1 | S.typhi | 9, 12, Vi | d |
| S. enteritidis | 1, 9, 12 | g, m | |
| E1 | S.anatum | 3, 10 | e, h |
| S.london | 3, 10 | l,v | |
Salmonella of rare groups are included in groups F, G1, Z, K, N, O, P, S, U, V, X and 53, for which there are simply no erythrocyte diagnostic kits and salmonellosis of rare groups cannot be detected today by antibodies in the blood !!!
5. Immunoenzyme diagnosis:
— detection of IgM and IgG;
- anti-LPS by ELISA
are also not yet available for normal use.
6. Used for research purposes:
- polymerase chain reaction(PCR);
- tests for:
a) phage typing;
b) sensitivity to antibiotics;
— plasmid profile of some strains.
So why is diagnostics of rare groups of salmonella necessary?
1.For the sick:
is a timely diagnosis for proper treatment;
- non-formation of carrier state;
- absence of complications;
— favorable outcome diseases.
Draw your attention to the following points in this section:
1.1 In half of newborn children diagnosed with meningitis, the etiological factor is salmonella!
1.2 salmonella tend to localize:
- in atherosclerotic aneurysms, plaques and abnormal endocardial surfaces;
- in bone tissue:
a) weakened by a previous injury;
b) patients with sickle cell anemia and osteomyelitis;
1.3salmonella:
a) causative agents of metastatic infections, such as intracranial abscesses, empyemas, abscesses of the lungs, spleen, etc.
b) the cause of transitional carbuncles ( purulent lesion deep layers of skin):
- in 5% of healthy adults with enterocolitis, more often when there is no underlying disease;
- in infants and children under 3 years of age with severe forms salmonella infection.
1.5 Long-term effect of salmonellosis - arthritis!
Salmonella infection can become complicated and provoke not immediately, but over time, reactive arthritis - Reiter's syndrome!
Reiter's syndrome causes inflammation in various parts body, especially in the spine and joints.
Thus, often no one associates the cause of arthritis in a patient with Reiter's syndrome with the salmonella infection that he had a couple of years ago!!!
1.6 Salmonella is resistant to powerful antibiotics!
These bacteria have developed an antibiotic resistance gene. And since antibiotics are necessary in acute cases of salmonellosis, this is currently considered global problem health care of the whole world!!!
2. For contacts:
— timely medical examination and bacteriological examination;
— carrying out preventive measures with disinfection to eliminate the outbreak and prevent repeated cases of the spread of infection among the population.
Although salmonellosis we are primarily associated with chicken, eggs, food, which means with foodborne transmission this intestinal infection:
Read “Food Salmonellosis” http://site/medicina/pishhevyie-salmonelliyozyi
We must not forget that salmonellosis is a disease dirty hands with contact and household transmission of this infection!
And in this regard, I would like to draw your attention to such statistical reporting data as:
1) carriage of salmonellosis:
— among domestic dogs it ranges from 8 to 13%;
— among cats from 8 to 12%;
2) salmonellosis is widespread among wild birds, amphibians and invertebrates;
3) Salmonella are normal inhabitants of the intestines and skin of reptiles (turtles, snakes, iguanas, lizards), and usually do not cause disease in them;
4) infected rodents such as mice and rats can infect food products through their feces;
5) flies and cockroaches play an important role in the spread of salmonella.
Currently, about 2000 Salmonella serovars are known in the world; only 700 representatives of this genus are pathogenic for humans.
Therefore, any change in the nature of stool, especially with the onset of the epidemic season of this intestinal infection, must have its own explanation and must be laboratory confirmed. Don't rely on chance!
This is, as it is fashionable to say now: “It won’t work!”
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Salmonella enterica(or salmonella intestinalis, lat. Salmonella enterica) is a species of bacteria from the genus Salmonella. Common abbreviation S. enterica. All Salmonella pathogenic to humans belong to this species.
Salmonella in the taxonomy of bacteria
View salmonella enterica to the genus Salmonella (lat. Salmonella), family of enterobacteria (lat. Enterobacteriaceae), order Enterobacteriaceae (lat. Enterobacteriales), class Gammaproteobacteria (lat. γ proteobacteria), type of proteobacteria (lat. Proteobacteria), kingdom Bacteria. Many serotypes Salmonella enterica- pathogens of human diseases, including typhoid fever, paratyphoid fever, salmonellosis. Salmonella species Salmonella bongori not pathogenic for humans. View Salmonella enterica includes 7 subspecies (each of which has many serotypes):
- (I) enterica
- (II) salamae
- (IIIa) arizonae
- (IIIb) diarizonae
- (IV) houtenae
- (VI) indica
Subspecies Salmonella enterica enterica includes the following serogroups: 
Salmonella S. typhimurium, S. enteritidis and other pathogens of salmonellosis
Most Salmonella spp. enterica They are pathogenic both for humans and for animals and birds, but from an epidemiological point of view only a few of them are most significant for humans. 90% of salmonellosis cases occur in S. typhimurium, S. enteritidis, S. panama, S. infantis, S. newport, S. agona, S. derby And S. london. More than 50% of all Salmonella-related illnesses in the United States are caused by Salmonella serotypes S. typhimurium And S. enteritidis, and the number of people sick with salmonellosis, including in developed countries, has been increasing in recent years. This is due to the emergence of salmonella strains S. typhimurium And S. enteritidis, resistant to modern antibiotics, and the spread of these strains throughout the world. Hospital-acquired (nosocomial) salmonellosis is one of the serious problems modern healthcare. In 80% of cases, the causative agent of nosocomial salmonellosis is S. typhimurium.The incubation period is about 2 weeks. Typhoid fever occurs when exposed to Salmonella typhi V human body through the mouth. The infectious dose is 10 3–10 7 bacteria. S. typhi first penetrate the mucous membrane of the small intestine, where they affect lymphoid accumulations. With lymph flow S. typhi enter the blood, where they are destroyed in large quantities. The released endotoxin causes symptoms of the disease. Survivors in blood S. typhi settle in the gallbladder, bone marrow, spleen. The rash on the abdomen contains large amounts Salmonella typhi. During the further development of the disease S. typhi through the bile ducts they return to the intestines, where they actively multiply.
Patients with immunodeficiencies or those with low acidity of gastric juice have a higher risk of infection and disease with more likely will be in severe form. Regardless of the treatment used, the mortality rate reaches 4%. From 1 to 4% of recovered patients remain carriers S. typhi in the intestines or gall bladder for several months or years.
Salmonella typhi has high resistance to various antibiotics. In particular, its resistance to chloramphenicol reaches 100%, and to ampicillin - 85%.
Typhoid fever incidence statistics
According to official data, the number of registered cases of typhoid fever in the Russian Federation in 2009 and 2010, including among children and adolescents under 17 years of age inclusive, is as follows:|
|
Total | from 0 to 17 years | ||
|
year:
|
2009 | 2010 | 2009 | 2010 |
| Russian Federation | 44 | 49 | 5 | 3 |
| Central Federal District | 15 | 12 | 1 | 0 |
| Moscow | 7 | 8 | 0 | 0 |
| Northwestern Federal District | 17 | 24 | 1 | 1 |
| Saint Petersburg | 13 | 20 | 0 | 1 |
Salmonella S. paratyphi A, B and C
The causative agents of paratyphoid A, B and C are Salmonella species enterica subspecies enterica serotypes, respectively paratyphi A, B And C(very often called without specifying the species and subspecies: Salmonella paratyphi A, B or C). Salmonella paratyphi B sometimes also called Salmonella schottmuelleri, A Salmonella paratyphi C - Salmonella hirschfeldii. Salmonella S. paratyphi A And S. paratyphi B only affects humans.Paratyphoid fevers A and B are similar in clinical manifestations and epidemiology typhoid fever, characterized by a more acute onset, less severe course and shorter duration. Paratyphoid C, as an independent disease, is rare; most often it occurs in patients weakened by other diseases and usually occurs in the form of food poisoning.
