[1] S Bortolo Hosp, Dept Infect Dis & Trop Med, I-36100 Vicenza, Italy
[2] VA Puget Sound Hlth Care Syst, Med Serv, Seattle, WA USA
[3] VA Puget Sound Hlth Care Syst, Antibiot Res Clin, Seattle, WA USA
[4] Univ Washington, Dept Med, Seattle, WA USA
[5] Univ Texas, Med Branch, Galveston, TX USA