Abstract
1 Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
2 Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
3 Electron Microscope Unit, University of Cape Town, Cape Town, South Africa
4 Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
5 Department of Microbiology, University of Washington, Seattle, Washington, USA