[1] Vanderbilt Univ, Sch Med, Div Infect Dis, Dept Microbiol & Immunol, Nashville, TN 37232 USA
[2] Vanderbilt Univ, Sch Med, Dept Med, Nashville, TN 37232 USA
[3] Vet Affairs Tennessee Valley Healthcare Syst, Nashville, TN 37212 USA
[4] Univ Illinois, Dept Microbiol, Urbana, IL 61801 USA
[5] Univ Illinois, Inst Genom Biol, Urbana, IL 61801 USA