1. Department of Bacteriology; Faculty of Medical Sciences, Kyushu University; Fukuoka Fukuoka 812-8582 Japan
2. Department of Health Science; School of Medicine, Yamaguchi University; Ube Yamaguchi 755-8554 Japan
3. National Institute of Infectious Diseases; Leprosy Research Center; Higashimurayama Tokyo 189-0002 Japan
4. Kurume University, School of Medicine; Kurume Fukuoka 830-0011 Japan