Clostridium difficile

Clostridium Difficile

The Clostridium difficile it is a gram positive, anaerobic, sporogenous, rod-shaped bacterium, widely spread in nature both underground and in the intestinal tract of domestic animals (dog, cat, poultry).

In man, the Clostridium difficile it is found in about 3% of healthy adults, as a constituent of the intestinal saprophytic flora, and in more significant percentages in infants under the age of one year (15-70%).

Pseudomembranous colitis

In the clinical setting. the Clostridium difficile it is known as the main cause of a formidable form of colitis, defined pseudomembranous colitis, characterized by more or less extensive necrosis, mainly affecting the rectum and sigmoid, and accompanied by often profuse diarrhea.

In particular, some strains of Clostridium difficile, defined enterotoxigens as they are capable of producing enterotoxin A and / or cytotoxin B. These toxins are internalized by the intestinal mucosa causing cell death of the enterocyte.

The spectrum of histological lesions varies from a type I form, characterized by sporadic epithelial necrosis associated with inflammatory infiltrate inside the lumen of the colon, to a type III form, characterized by diffuse epithelial necrosis and ulcerations covered by grayish pseudomembranes (from referred to as pseudomembranous colitis), consisting of mucin, neutrophils, fibrin and cell debris.

The lethality of severe Clostridium difficile it is important, to the point of making it essential to adopt prophylactic measures to stem the spread of the disease in nosocomial environments.

Symptoms

As anticipated, the severity of the intestinal infection by Clostridium difficile it is variable: the symptoms can in fact range from mild to profuse diarrhea (up to 10 liters of serous discharges per day), with toxic megacolon, intestinal perforation, hypokalaemia, intestinal haemorrhage, and sepsis. Diarrhea can be accompanied by fever, nausea, anorexia, general malaise, pain, abdominal distension and dehydration. Diarrhea can be associated with mucus, blood and fever. Newborns are often asymptomatic carriers: if on the one hand colonization seems favored by the immaturity of the intestinal bacterial flora, on the other hand the lack of pathological evolution is due to the inability of the toxin to bind to the receptors of the enterocytes, which are also still immature.

Risk factors

In addition to the aforementioned virulence of the bacterium, the immune activity of the subject also determines the severity of the infection: Clostridium difficile they are more frequent in immunocompromised and debilitated subjects, also and above all due to prolonged antibiotic therapies. These drugs, in fact, alter the normal microbial flora of the colon, favoring intestinal colonization by the Clostridium difficile, not surprisingly responsible for 15-30% of cases of antibiotic-associated diarrhea.

Almost all antibiotics can favor the spread of the infection, but above all lincomycin and clindamycin are called into question and, less frequently, penicillins, cephalosporins, tetracyclines, macrolides, chloramphenicol and sulfonamides. evolution, we can more correctly generalize by affirming that the risk increases in the case of combined and / or prolonged antibiotic therapy, and in general when it involves the use of drugs with a broad spectrum of action.

Again, the da Clostridium difficile it is typically of nosocomial origin: as such it has as its primary target hospitalized patients, especially the elderly. Even drugs used in chemotherapy and proton pump inhibitors for the "eradication of"Helicobacter pylori seem to promote infection with Clostridium difficile; the same applies to all other conditions associated with a reduction in gastric acidity, as occurs in patients undergoing particular forms of digestive surgery.

Infection

Transmission of the disease typically occurs via the fecal-oral route, therefore through the hands brought to the mouth after contact with contaminated environmental surfaces or with an infected person. The more severe the diarrhea, the more contaminated the environment where the patient is staying.

Thanks to the spore-hygienic form, the beater can survive for weeks or even months on inert surfaces. Contaminated medical instruments can also be a vehicle for transmission (endoscopes, rectal thermometers, bathtubs ...).

Prognosis and Treatment

The resolution of the Clostridium difficile leads to an almost complete one restitutio ad integrum of the mucosa. Despite the complete recovery, in a high percentage of patients treated correctly relapses appear, usually within four weeks from the end of antibiotic therapy. , on the other hand, it may be necessary to resort to other forms of antibiotic therapy, such as that with metronidazole, vancomycin or fidaxomicin (a recently introduced narrow-spectrum drug, specific to treat adults with intestinal infections due to Clostridium difficile, without significantly altering the physiological intestinal flora).

The rebalancing of the losses of salts and water is also very important; in addition, the use of cholestyramine has also been proposed, a drug likely capable of binding the toxin produced by Clostridium difficile favoring its elimination with the faeces.


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