1. Center for Research in Anti-Infectives and Biotechnology, Creighton University School of Medicine, Omaha, Nebraska
2. University of Puerto Rico School of Medicine, Department of Microbiology and Medical Zoology, San Juan, Puerto Rico
3. University of Puerto Rico School of Medicine, Department of Pathology and Laboratory Medicine, San Juan, Puerto Rico
4. Creighton University School of Medicine, Omaha, Nebraska