CLAMPED HOMOGENOUS ELECTRIC-FIELDS (CHEF) GEL-ELECTROPHORESIS OF DNA RESTRICTION FRAGMENTS FOR COMPARING GENOMIC VARIATIONS AMONG STRAINS OF YERSINIA-ENTEROCOLITICA AND YERSINIA SPP

Yersinia enterocolitica gastroenteritis was first recognized in the ea rly 1960s and has since been reported with increasing frequency. To de termine if strains of Y. enterocolitica, within a restricted region is olated over 8 years (1985-1993), originated from a single or multiple clones, pulsed-field gel electrophoresis (PFGE) of large chromosomal D NA restriction fragments generated by XbaI or NotI was used. A total o f 27 isolates of Y. enterocolitica were analyzed, 24 from Austria (Vie nna and Graz) consisting of serogroups 0:3 (17 isolates), 0:9 (6 isola tes), 0:5 (1 isolate); 2 from Germany of serogroups 0:3 and 0:9 (1 iso late each); 1 from the U.S.A. of serogroup 0:8. Genomic fingerprints o f these strains were compared to those of 8 other Yersinia species to ascertain if their restriction endonuclease digestion profiles (REDP) were serogroup and/or species specific. The 27 Y. enterocolitica strai ns could be divided into 16 genomic varieties according to their restr iction patterns with NotI and XbaI. PFGE was highly discriminatory as strains belonging to the same serogroup could be subdivided into diffe rent genomic groups. Furthermore, Y. enterocolitica strains isolated f rom the same region, over an 8 year period, belonged to a few closely related clones. The genomic fingerprints of Yersinia were found to be species and serogroup specific.