1. Department of Microbiology and Immunology, University of Otago, Post Office Box 56, Dunedin 9054, New Zealand.
2. Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands.
3. Bio-Protection Research Centre, University of Otago, Post Office Box 56, Dunedin 9054, New Zealand.
4. Laboratory of Microbiology, Wageningen University, Wageningen, Netherlands.