[1] Univ Texas Hlth Sci Ctr San Antonio, Dept Microbiol Immunol & Mol Genet, San Antonio, TX 78230 USA
[2] McMaster Univ, St Josephs Healthcare, Hamilton, ON, Canada
[3] Univ Alabama Birmingham, Heersink Sch Med, Dept Med, Birmingham, AL USA
[4] Univ Texas Hlth Sci Ctr San Antonio, Microbiol Immunol & Mol Genet, 7703 Floyd Curl Dr, San Antonio, TX 78230 USA