Background: In May 2004, an outbreak of a diarrheal disease occurred among tourists returning from Mt. Geumgang in North Korea; Shigella dysenteriae type 8 was isolated from 12 of the 36 patients who were suffering from diarrhea. We investigated the genetic relatedness of the isolates.

Methods: The isolates were identified by VITEK system and serotyped by a slide agglutination test. Antimicrobial susceptibility was determined by the disk diffusion method and genetic relatedness was examined by pulsed-field gel electrophoresis (PFGE).

Results: All 12 isolates were identified as Shigella spp., and agglutinated by S. dysenteriae type 8 antisera. All of these isolates showed the same antibiotic susceptibility pattern, and were resistant to streptomycin, tetracycline and trimethoprim/sulfamethoxazole. PFGE patterns were classified into 2 types, sdx1 and sdx2, and the relatedness between these two types was 80.5%. Eleven isolates belonged to sdx1.

Conclusion: The antibiotic susceptibility pattern and genetic relatedness of the isolates strongly suggest that they were from the same origin. Because this is the first report of S. dysenteriae type 8 isolation in Korea, and all of these cases were related to foreign travel, the surveillance system and the ability of the clinical laboratory should be strengthened to prevent the entry and spread of rare and hitherto not reported infectious agents into Korea. (Korean J Clin Microbiol 2005;8(2):153-159)