Affiliation: | (1) Department of Bacteriology, Institute of Infectious Diseases and Immunology, School of Veterinary Medicine, University of Utrecht, The Netherlands;(2) Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA;(3) Present address: ID-DLO, Dept. Bacteriology, P.O. Box 65, 8200 AB Lelystad, The Netherlands |