1. Department of Infection, Immunity & Inflammation, University of Leicester, Leicester LE1 9HN, United Kingdom
2. Instituto de Tecnologia Química e Biologíca, Universidade Nova de Lisboa, Oeiras 2781-901, Portugal
3. Department of Microbiology, The Dental Institute, King's College London, London SE1 9RT, United Kingdom
4. Pediatric Infectious Disease Unit, Soroka University Medical Center, Faculty of Health Sciences P.O. Box 151, Beer Sheva 84101, Israel