sequences. Sequence alignments of 17 central regions (from 600 to 900 nucleotides) from T. denticola positive clinical specimens. In panel A are shown the clinical samples of Group A. In panel B are shown the clinical samples of Group B. The upper line contains the sequence of T. denticola strain ATCC 35405 and ATCC 33520, respectively, in both panels. The grey areas indicate variations of single nucleotide positions compared with T. denticola ATCC 35405.