[1] Hacettepe Univ, Sch Med, Infect Dis Sect, TR-06100 Ankara, Turkey
[2] Univ Athens, Dept Propaedeut Med 1, Athens, Greece
[3] Univ Athens, Sch Med, Hellen Pasteur Inst, Bacteriol Lab, GR-11527 Athens, Greece
[4] Tel Aviv Univ, Tel Aviv Sourasky Med Ctr, Div Epidemiol, IL-69978 Tel Aviv, Israel
[5] Univ Athens, Sch Med, Dept Microbiol, GR-11527 Athens, Greece