The bacterium Salmonella typhimurium is known in medicine as Salmonella enterica serovar typhimurium. It is a gram-negative, rod-shaped bacterium with flagella (purple hairy structures), with the help of which this microorganism moves.
The named bacteria is the main cause of food poisoning (salmonellosis) in humans. It is most often infected with pork, poultry, eggs. Pets can transmit it too.
How are salmonella classified?
So, we are interested in salmonella typhimurium - the causative agent of such a dangerous ailment as salmonella. The species salmonella enterica has 6 subspecies in its composition:
- enterica;
- salamae;
- arizonae;
- diarizonae;
- houtenae;
- indica.
The salmonella enterica enterica subspecies includes the following serogroups:
- A (paratyphi A).
- B (derby, typhimurium, agona, heidelberg).
- C (cholerae suis, newport, muenchen, virchowinfantis).
- D (dublin, enteritidis, rostock, sendai, typhi).
- E (anatum).
Salmonella typhimurium (S. typhimurium)
The enterica species is considered pathogenic to humans and animals, as well as birds, but only a few of them are most significant for humans. And most cases of salmonellosis occur in S. typhimurium.
Many strains of Salmonella are resistant to modern antibiotics, and therefore are distributed throughout the world. So, nosocomial salmonellosis is a serious problem at present. And in 80% of cases, the causative agent of nosocomial (nosocomial) salmonellosis is S. typhimurium.
Pathogenicity factors
The course and danger of this disease are determined by the following pathogenicity factors:
- Flagella ensure the rapid movement of the microorganism.
- The capsule protects the bacterium from phagocytes. And because of the inferiority of phagocytosis, sepsis develops.
- The feature of invasion makes its penetration unhindered into deep-lying tissues.
- Due to the good adhesion (attachment) provided by fibrils, pectins, and LP-saccharide complex, the bacterium is retained in the body.
- Exotoxins (products of its vital activity) form diarrhea with further dehydration, and rapid vascular permeability.
- Endotoxin is released against the background of destructive phagocytosis. This is a lipopolysaccharide complex that forms intoxication. Platelet aggregation in small capillaries leads to inflammation, DIC is observed. And the secretion of Na and Cl leads to a reduction in smooth muscle and increased intestinal motility.
How resistant are bacteria?
Salmonella typhimurium are resistant to various environmental factors:
- For three months they are stored at room temperature with household items.
- Four years are stored in dry feces of animals.
- Five months - in water, six months - in dairy products and meat, on an egg shell - up to a month.
- Death occurs only at 100 ° C. In meat products, resistance to high temperature increases (a pound of meat must be boiled for two hours, only after that it will be safe). Salmonella cannot be killed with salting and smoking.
- This pathogen can withstand temperatures down to -80 ° C.
- It is UV resistant.
- The disinfectant must be kept for 20 minutes to destroy the bacterium.
An outbreak of salmonellosis is observed in the summer, more often diagnosed in young children due to imperfections in their immune system.
Pathology is transmitted alimentary, also contact and contact-household. By the way, it is important when eating eggs to pay attention to the type of protein and yolk. With clouding, hemorrhage, rotten smell, the egg is most likely infected. You need to throw it away, pour the dishes with chlorine, and also treat your hands with it. Soap in these cases does not help.
Winter outbreaks, high mortality and contact-household transmission mechanism occur for reasons of antibiotic resistance and because food supply is centralized.
Incubation period
The incubation period lasts from six hours to eight days, but most often the first symptoms appear already in the first day or two after eating an infected product.
There is a violation of water-salt metabolism due to diarrhea, the stool becomes watery, frothy, fetid, with greens resembling “swamp mud”, with a frequency of up to ten times a day, for a week or more.
The disease begins acutely, is characterized by weakness, lethargy, moderate abdominal pain (epigastric region and navel). The abdomen is painful on palpation, rumbling is heard and bloating is noticeable.
Salmonella typhimurium - laboratory diagnosis
The following indicators affect the diagnosis:
- increased ESR;
- white blood cells with a shift to the left;
The causative agent is detected from biological media (feces, blood, urine, affected organs) and suspicious products by the bacteriological method. The final result is usually ready for the fifth day.
When infected with salmonella typhimurium, the symptoms are as follows:
- fever;
- chills;
- severe diarrhea;
- vomiting
Treatment
This disease can have a fatal outcome in infancy, in the elderly, as well as in people with reduced immunity. This is dangerous and salmonella typhimurium.
Treatment consists of antibiotic therapy and rehydration. Antispasmodics, enzyme preparations, sorbents, antidiarrheal drugs are also prescribed. The diet "Table No. 4" is shown.
Therapy should be carried out under the strict supervision of a doctor, and in severe cases, resuscitation measures are used. Of the sorbents for detoxification of the body, it is advisable to use the following drugs:
- Enterosgel;
- "Lieferan";
- activated carbon;
- "Smecta";
- "Enterodesus."
With frequent ongoing vomiting, it is imperative to call an ambulance to prevent dehydration. The patient is usually prescribed "Rehydron". Elevated temperature is reduced by antipyretic drugs.
Antibiotics active against salmonella salmonella enterica
Antibacterial agents active against salmonella salmonella enterica are Furazolidone, Ciprofloxacin, Rifaximin, and Nifuroxazide. But only the attending physician can prescribe them, choosing an individual dosage and taking into account the condition of the patient infected with salmonella typhimurium.