[1] Univ La Rioja, Area Bioquim & Biol Mol, Logrono 26004, Spain
[2] Hosp Ramon y Cajal, Microbiol Serv, Madrid 28034, Spain
[3] Univ Texas, Sch Med, Ctr Study Emerging & Reemerging Pathogens, Houston, TX 77030 USA
[4] Univ Texas, Sch Med, Dept Internal Med, Div Infect Dis, Houston, TX 77030 USA
[5] Univ Texas, Sch Med, Dept Microbiol & Mol Genet, Houston, TX 77030 USA