1. Immunology and Molecular Diagnostic Research Unit, Elizabeth Macarthur Agriculture Institute, New South Wales Department of Primary Industries, Woodbridge Rd., Menangle, New South Wales 2568, Australia
2. Department of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
3. School of Veterinary Science, The University of Queensland, St. Lucia, Queensland 4072, Australia
4. Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria 3010, Australia
5. Department of Primary Industries, Midland Hwy. and Taylor St., Epsom, Victoria 3554, Australia