1. The Open University of The Netherlands, Dept. Natural Siences, Heerlen, The Netherlands
2. The Limburg University, Dept. Biochemistry, Maastricht, The Netherlands
3. The Gaubius Laboratory IVVO-TNO, Leiden, The Netherlands
4. The Limburg University, Dept. Medical Microbiology, Maastricht, The Netherlands
5. The Limburg University, EM Unit, Dept. of Pathology, Maastricht, The Netherlands