1. Department of Medical Biotechnologies, University of Siena, Siena, Italy
2. Department of Molecular and Development Medicine, University of Siena, Siena, Italy
3. Programma Interdipartimentale Diagnostica Microbiologica, Sorveglianza e Caratterizzazione Patogeni Nosocomiali, Azienda Ospedaliera Universitaria Senese, Siena, Italy