1. Eastman Department of Dentistry and Center for Oral Biology, Department of Microbiology and Immunology, University of Rochester Medical Center, 625 Elmwood Ave., Box 683, Rochester, NY 14620, USA; and
2. Department of Preventive Dentistry, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea