Yersinia enterocolitica and Yersinia pseudotuberculosis, the two Yersinia species that are enteropathogenic for humans, are distributed worldwide and frequently cause diarrhea in inhabitants of temperate and cold countries. Y. enterocolitica is a major cause of foodborne disease resulting from consumption of contaminated pork meat and is further associated with substantial economic cost. However, investigation of enteropathogenic Yersinia species is infrequently performed routinely in clinical laboratories because of their specific growth characteristics, which make difficult their isolation from stool samples. Moreover, current isolation procedures are time-consuming and expensive, thus leading to underestimates of the incidence of enteric yersiniosis, inappropriate prescriptions of antibiotic treatments, and unnecessary appendectomies. The main objective of the study was to develop fast, sensitive, specific, and easy-to-use immunoassays, useful for both human and veterinary diagnosis. T he genus Yersinia belongs to the family of Enterobacteriaceae and is composed of three human-pathogenic species: Yersinia pestis, the causative agent of the plague, and Yersinia enterocolitica and Y. pseudotuberculosis, responsible for human enteric yersiniosis. Enteric yersiniosis is a foodborne disease caused by consumption of contaminated food or water (1) and can be transmitted between humans through the fecal-oral route. The disease is usually characterized by a self-limiting acute infection beginning in the intestine and is often limited to the ileocecal junction for Y. enterocolitica. In contrast, Y. pseudotuberculosis often disseminates deeply to the mesenteric lymph nodes. Clinical presentation is characterized by enterocolitis (diarrhea, abdominal pain, fever, and sometimes vomiting) (2), which predominates in young children and is often self-limiting. However, diarrhea is a predominant symptom of Y. enterocolitica infection whereas abdominal pain is more usual in Y. pseudotuberculosis infection. Moreover, Y. pseudotuberculosis can also cause different clinical symptoms such as scarlatinoid rash, conjunctivitis, acute organ failure, and toxic shock syndrome often reported in Far East (3). For both enteropathogenic Yersinia species, more-serious infections and sepsis can also occur, particularly in new-born, elderly, and immunocompromised patients. Sometimes, the infection appears as a pseudoappendicular syndrome in which mesenteric lymph nodes are involved, thus possibly leading to unnecessary appendectomies (4). Some secondary complications such as reactive arthritis and erythema nodosum are sometimes observed (5, 6). Rarely, Y. enterocolitica is responsible for a serious sepsis incident after transfusion of contaminated red blood cell preparations (7).Y. enterocolitica and Y. pseudotuberculosis are widespread worldwide, with a higher incidence in cold and temperate regions. pseudotuberculosis serotypes I and III are the prevailing isolated strains (9). The incidence of human enteric yersiniosis has been estimated to...