1. Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
2. Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
3. Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
4. Department of Veterans Affairs, VA Eastern Colorado Healthcare System, Aurora, Colorado, USA