1. Institute for Medical Microbiology and Hygiene, University of Regensburg, D-93053 Regensburg,1
2. Institute for Laboratory Diagnosis, Zentralkrankenhaus Gauting, D-82131 Gauting,2 Germany, and
3. Laboratory of Bacteriology, Division of Infectious Diseases, Hopital Cantonal Universitaire, 1211 Geneva, Switzerland3