1. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
2. Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
3. Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
4. Laboratoire de Recherche Génomique, Service des Maladies Infectieuses, Centre Médical Universitaire, Geneva, Switzerland