Isolation of Yersinia enterocoiitica

The Isola ti on of Ycrslnla entoroco/ltlCa has been reported from a suffiCient number of diverse geographical areas to conclude that this organism has a worldwide distribution. There remain, however, a number 0f interspersed areas of the world where isolation has nol been reporled, and Irequently isolations within a country show a very spolly distribution. This non-uniform distribution IS possibly as much the consequence of weaknesses In taboratory methodology and recognition of the organism as In \i1e true distribution of Y enteroco/ltlca and Its association With human Infections. Some of the difficulties associated With Isolat ion Inctude the special incubation conditions and extended times required lor optimum recovery, the unique and vanable anpearancp nf the organism on Isolation media, and the unavailabil ity or reluctance to adopt additional isolation media designed spec itlcatly lorgrowth ot Y enterocolltlca The Isola lion and recognition of Y. enterocolll!ca has possibly been hindered by the Impression thatall strains Within this species have common growth characteristics. This IS nol the case, and there are very great differences In colonial appea rance on agar media and In tolerance to selective agents and conditions provided for Isolation among stra ins 01 Y enterocolilica. Consequenlly. the methods and criteria used lor seeking and IdentifYi ng Y enterocolltlca in one geographic area may be quite Inappropriate tor another because U1e types common to each loca tion are different. Strains of serotypes 0:8 and 0:5.27 (0:5b) found in the United States ' .2 and western Canada, 3 and serotype 0:3 common in eastern Canada, 3 Europe," Japan 5 and many other countries,6 are different organisms in many respects including properties that influence successful isolation in the laboratory. The design of precise Isolation and identification methods woufd greatly be facili tated by a beUerunderstanding of just which types of Y. enlerocofitica are pathogenic for man.