[1] Univ Milan, Luigi Sacco Dept Clin Sci, Sect Infect Dis & Immunopathol, I-20157 Milan, Italy
[2] Univ Milan, Luigi Sacco Hosp, Dept Infect Dis, Milan, Italy
[3] CNR, Inst Biomed Technol, Milan, Italy
[4] Luigi Sacco Hosp, Microbiol Unit, Milan, Italy