Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 137-701.|Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 137-701.|Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 137-701.|Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 137-701.|Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 137-701.