Definition

Type of bacterium belonging to the family of Enterobacteriaceae and comprising three species that can cause disease: Yersinia enterocolitica Yersinia pseudo-tuberculosis Yersinia pestis responsible for plague (bacilli of Yersin) these bacteria in the form of rods (bacilli) are stainable by negative Gram stains. Yersiniosis is an infection caused by one of these three bacteria. It is a zoonotic disease (disease transmissible animal to human and vice versa) attended. Animal reservoir of this bacterium are pork and other wild and domestic animals. Generally, the Yersinia are transmitted to the human oral. Yersinia, which is widely distributed around the world, is a Pleomorphic bacteria. This means that it has the ability to take different forms in certain conditions or under determined influences. Yersinia enterocolitica, which is the most common variety, is the source of some forms of gastroenteritis with hyperthermia (fever), abdominal pain, vomiting and diarrhea. Very common soil, Yersinia enterocolitica occurs also in the water and plants. It has also been isolated from a wide variety of food contaminated as meat, vegetables and milk, but also in the stools of many individuals, in lesser quantities (called these people of the carriers). It is in some responsible for cases of enterocolitis, i.e. of inflammation of the intestinal mucosa (mucous membrane is the layer of cells covering the inside of the intestines). Finally Yersinia has been isolated from a wide variety of wild and domestic animals including mammals, fish, birds, amphibians and crustaceans. Outbreaks of gastroenteritis to Yersinia enterocolitica are mediated by pasteurized or milk and foods prepared with contaminated water. In Belgium, there is a regional custom of consuming raw Minced pork. It appears that this gastronomic habit is a significant risk factor for Yersinia enterocolitica infections with the serotype O: 3 and O: 9. transmission of the bacteria by the feces of cats and dogs has also been demonstrated. The transmission between the members of a family is also possible: it is on the orofécal mode (mouth – excrement). Finally, Yersinia enterocolitica can also (although very rarely) be transmitted through transfusions and in this case the evolution is generally fatal. Indeed, blood donors sometimes have in their blood Yersinia enterocolitica in asymptomatic manner (without sign). Microorganisms can reach very high concentrations over a period of 10 to 20 days in the refrigerated blood. After Salmonella (which is the most frequently found bacteria), Campylobacter and Shigella, Yersinia enterocolitica is the fourth bacterial agent of disease identified fecal (of excrement) blood samples from patients. Yersinia enterocolitica infections mainly affect children 1 to 4 years. On the other hand, it seems that this bacteria infections are more frequent in winter than in warm weather months. Yersinia enterocolitica is complicated some time in sepsis (crossing the bacterium in the blood) with an infringement of the mesenteric lymph nodes (present at the level of the digestive tract), Erythema Nodosum (red staining of the skin) of arthritis (inflammation of the joints). Erythema Nodosum is a rash accompanied by nodules (small hard swellings) of Red stain more or less dark, installed in the DermIS or epidermis (surface layer of the skin). The volume of these nodules can range from the size of a pea to that of a nut. The mechanism of the occurrence of such pathology is now obscure. Low-grade fever (small fever) symptoms, more rarely hyperthermia (significant temperature rise). Abdominal pain resulting in cramps nausea vomiting in 20 to 40% of digestive hemorrhage cases more than 30% of the skin eruption case generalized in only a few individuals enteritis (inflammation of the layer of cells covering the inside of the intestines with diarrhea and bleeding sometimes). Mesenteric adenitis (inflammation of the lymph nodes in the vicinity of the terminal gut). Inflammation of the pharynx (more rarely) but requiring monitoring because sometimes of poor prognosis especially in adults. Erythema Nodosum (see above) sepsis (see above) evolution, some (rare) serious cases was described with: perforation of bowel inflammation of the peritoneum, inflammation of the gallbladder of thrombosis (blood clots present) in the mesenteric vein of diverticula megacolon (dilation of the colon) of bleeding (nékros) destruction of the small intestine, the colon. Yersinia pseudo-tuberculosis infection is very similar to that described above. The lab Most human infections are caused by serotypes that specialists call O: 3, O: 5, O: 8, O: 9. Serotypes are the categories in which some virus or bacteria are classified according to their reaction in the presence of serum (part fluid blood) that contains specific antibodies against the bacteria or viruses in question. Agglutination tests (Elisa tests) are the most commonly used. Treatment diarrhea should be treated as symptomatic. Some individuals require infusion. It is necessary to prevent contamination by stool in patients hospitalized with diarrhea in Yersinia. The treatment involves antibiotics is generally reserved for patients with enterocolitis, sepsis, an infection that tend to expand and in individuals with immune problems finally. In some cases, it is necessary to do a sensitivity: this is a test designed to show the sensitivity of a microbial germ (bacteria, parasite, fungal) to various antibiotics, to select the most effective antibiotic against this germ. The sensitivity allows the selection of drugs. Yersinia enterocolitica is generally susceptible to aminoglycosides, third generation cephalosporins chloramphenicol, to Quinolone, tetracyclines, and trimethoprim sulfamethoxazole. Prevention Measures of hygiene in the preparation of the transport of food are very important to prevent the yersinioses. It is particularly inappropriate to eat raw or undercooked pig meat. With regard to blood transfusions, highlighting, simply by looking at the blood containing pockets, staining dark (reflecting the decrease in the amount from the oxygen in the blood and hemolysis corresponding to the breakdown of red blood cells) is sometimes sufficient to contraindicate the use of these pockets. BIBLIO Harrison, volume 1, Edition 1998, internal medicine, other infections to Yersinia page 1134-1138. Revised 23/12/2002