[1] Ist Super Sanita, Lab Bacteriol & Med Mycol, I-00161 Rome, Italy
[2] Univ Palermo, Ctr Enter Pathogens So Italy, Dept Hyg & Microbiol, Palermo, Italy
[3] Univ Florence, Dept Publ Hlth, Florence, Italy
[4] Hellenic Pasteur Inst, Bacteriol Lab, Athens, Greece
[5] Univ Athens, Sch Med, Dept Microbiol, GR-11527 Athens, Greece