B. cereus – the name of bacteria and the diseases that they cause. The infectious process can be either localized or generalized. Most often, the disease goes away as acute gastroenteritis.
At risk are newborns, weakened, children with immunodeficiency conditions, as well as patients with malignant neoplasms. In such cases, Bacillus cereus is accompanied by persistent bacteremia and often takes the form of sepsis.
Epidemiology . Bacillus bacteria are common in all countries. They “live” in soil, air, on surrounding objects and in water. The infection can be caught from food products, medical instruments, medical equipment, which are used for invasive treatment and research (valve equipment, hemodialysis systems, catheters, etc.). Routes of transmission of Bacillus cereus : alimentary, contact. The incidence is sporadic (individual, unrelated, periodic cases), but outbreaks of acute gastroenteritis can occur with foodborne infections.
What triggers / Causes of Bacillus cereus in children:
B. census belong to the genus Bacillus . They have a rod-shaped shape. The size of the bacteria is 2.2 x 1.2-7 microns, they are motile, possess laterally arranged flagella. Gram stains positively. Relate to strict aerobes, form endospores. Bacillus are divided into 3 morphological groups depending on the shape and bloating of the cell during spore formation. The causative agents of the disease in children, adults and animals belong mainly to the first group.
At present, science knows about 20 serotypes of this bacterium. They cannot be killed by widespread, traditional disinfectant solutions and drugs.
B. cereus produce hemolysin, similar to streptolysin C, proteolytic enzymes, phospholipases, penicillipase, lecithinase, etc.
Pathogenesis (what is happening?) During Bacillus cereus in children:
An infection enters the body through the oropharynx, airways, or skin lesions. Invasive operations play a large role: insertion of catheters, valvular apparatuses, shunts, connection of the hemodialysis system , etc. In such ways, B. cereus can enter the bloodstream in large quantities, being on the instruments listed above.
If the path of infection is alimentary, these bacteria lead to acute gastroenteritis. Enterotoxin in this case leads to damage to the gastrointestinal tract. It also stimulates the system of cyclic nucleotides in the epithelial cells of the small intestine, causes damage to the mucous membrane of the stomach and small intestine and impaired vascular permeability. Because of this, symptoms such as vomiting and diarrhea appear .
The severity of the digestive tract and other organs depends on the amount of pyogenic toxin produced by B. cereus . This toxin causes ulceration of the epithelium of the respiratory tract, destruction of the intestinal mucosa, and abscess formation (including brain tissue).
Food poisoning of B. cereus ends favorably due to the localization of the process. The infection caused by B. cereus becomes septic (and persistent bacteremia is observed) in children weakened by stress or immunodeficiency, as well as in newborns. In these cases, morphological changes in the organs (intestines, lungs, brain) are expressed in the appearance of acute inflammatory foci with zones of necrosis , fibrinoid necrosis of the arteries, in which large accumulations of B. cereus are detected .
Symptoms of Bacillus cereus in children:
The infectious process to which the bacteria in question can lead to various symptoms. Food poisoning “spills out” with acute gastroenteritis. With other ways of infection, the development of meningitis , bronchopneumonia, osteomyelitis, brain abscess , panophthalmitis, endocarditis, sepsis, bacteremia is observed .
The incubation period for acute gastroenteritis is from 1 to 16 hours. The disease has an acute onset, the child is sick, he complains of abdominal pain. There is usually no increase in temperature. Vomiting appears (possibly multiple), and a few hours later watery diarrhea is noted. Painful urge to defecate (“to the toilet”) is noted. In some cases, the disease can pass by analogy with foodborne toxicosis. Then, first of all, profuse vomiting appears, but there is no diarrhea.
Acute gastroenteritis can occur in mild or moderate form. Severe forms are very rare. The disease can last for several hours or 2 days.
Pneumonia caused by Bacillus cereus begins acutely – fever and shortness of breath appear. Pain appears in the sternum. X-ray is indicated X-ray revealed one- or two-sided infiltrative process with the defeat of one or more lobes of the lung and the involvement of the pleura. Pneumonia can be hemorrhagic, in which case deaths are frequent.
Meningitis has an acute onset, the temperature is very high, repeated vomiting, meningeal symptoms, repeated convulsions develop. The condition of the sick child is serious. Significant pleocytosis is detected in the cerebrospinal fluid , and lymphocytes and neutrophils are present in equal amounts. In peripheral blood, there may be leukocytosis with a neutrophilic shift. Symptoms appear for a long time, penicillin drugs do not help.
Septicemia. The infectious process caused by Bacillus cereus can manifest as septicemia with or without foci of inflammation. An indicative symptom is persistent fever, which becomes intermittent (intermittent). The source of infection cannot always be established (as is the “entrance gate”). With this form of infection, B. cereus is secreted in a pure culture.
Diagnosis of Bacillus cereus in children:
For an accurate diagnosis, only the isolation of the pathogen from the biological material from the diseased child and the evidence of the pathogenicity of the isolated bacteria are used. For analysis, blood, vomit, sputum, urine, stool, separated from the focus of inflammation (pus, mucus) are used. A large number of bacteria with acute gastroenteritis are of diagnostic value . For other lesions, it is necessary to obtain a microbe culture in repeated portions of blood.
Since, according to the clinical manifestations, the infection caused by B. cereus cannot be distinguished from other infections, decisive importance is attached to the re-detection of B. cereus in large quantities in the material from the patient in the absence of isolation of other microorganisms. However, it must be borne in mind that B. cereus can cause a pathological process in conjunction with other infectious agents, for example, with protea or Escherichia.
Treatment of Bacillus cereus in children:
Acute gastroenteritis caused by B. cereus is treated by prescribing an appropriate diet and oral rehydration. By rehydration is understood the replenishment of the usual water balance in the body.
Severe processes (meningitis, bronchopneumonia, septicemia , osteomyelitis) require the appointment of antibiotics. B. cereus, due to the production of p-lactamase, is resistant to penicillin and preparations based on it. But they can be destroyed by 3rd and 4th generation cephaloslorins.
Antibiotics are used in doses appropriate for age. The duration of treatment is from 5 to 10 days. Antibiotics are canceled after debridement from the pathogen, the topic has returned to normal temperature and elimination of symptoms.
Colibacterin is also used to treat. This is a drug with antibacterial and antidiarrheal action, it restores the intestinal microflora and the immune system , fights against pathogenic and conditionally pathogenic nonphysiological microorganisms.