1. Department of Infectious and Tropical Diseases, ASST Spedali Civili, Brescia and University of Brescia, 25123 Brescia, Italy
2. Clinical Chemistry Laboratory, ASST Spedali Civili of Brescia, 25123 Brescia, Italy
3. Section of Microbiology, University of Brescia, P. le Spedali Civili, 1, 25123 Brescia, Italy