1. Department of Microbiology & Immunology; University of Illinois at Chicago; 835 S. Wolcott (M/C 790) Chicago IL 60612 USA
2. Departments of Medicine and Microbiology and Immunology; Loyola University Chicago; Maywood Illinois USA
3. Department of Microbiology; The University of Texas; Southwestern Medical Center at Dallas; Dallas TX 75390 USA
4. Edward Hines Jr. VA Hospital; Hines Illinois USA