[1] Kagoshima Univ, Dept Oral Microbiol, Grad Sch Med & Dent Sci, Kagoshima 890, Japan
[2] Kyushu Univ, Fac Agr, Dept Biosci & Biotechnol, Grad Sch, Fukuoka 812, Japan
[3] Fukuoka Dent Coll, Dept Funct Biosci, Sect Infect Biol, Fukuoka, Japan
[4] Kyushu Univ, Sect Prevent & Publ Hlth Dent, Div Oral Hlth Growth & Dev, Fac Dent Sci, Fukuoka 812, Japan
[5] Miyazaki Univ, Div Microbiol, Dept Infect Dis, Fac Med, Miyazaki, Japan