1. Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
2. Centre de Recherche en Infectiologie, Centre Hospitalier Universitaire de Québec, Université Laval, Québec City, Québec, Canada
3. Department of Immunology, University of Manitoba, Winnipeg, Manitoba, Canada
4. Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA