1. Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
2. Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
3. Division of Medical Microbiology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
4. Division of Infectious Diseases, Department of Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia, USA