[1] Univ Calif Los Angeles, David Geffen Sch Med, Los Angeles, CA 90095 USA
[2] Harbor UCLA Med Ctr, Lundquist Inst Biomed Innovat, Div Infect Dis, Torrance, CA 90509 USA
[3] Univ Alberta, Dept Biochem, Edmonton, AB, Canada
[4] Georgetown Univ, Med Ctr, Dept Microbiol & Immunol, Washington, DC 20007 USA