PFGE patterns of emm12 strains isolated from patients with GAS invasive diseases, scarlet fever, and pharyngitis. Chromosome DNA was digested with SmaI (lanes 1 to 5, 7 to 10, and 12) or SgrAI (lanes 6 and 11). The study periods were divided into the following: period I, 1998 to 1999; period II, 2000 to 2002; period III, 2003 to 2005; and period IV, 2006 to 2007. Lane 1, 5, and 9 represent period I. Lanes 2, 6, and 10 represent period II. Lanes 3, 7, and 11 represent period III. Lanes 4, 8, and 12 represent period IV. Lanes 1 to 4 are the patterns of emm12 strains isolated from patients with invasive diseases; lanes 5 to 8 are those from patients with scarlet fever; lanes 9 to 12 are those from patients with pharyngitis; and lane M shows the lambda DNA reference size markers (size range, 50 to 1,000 kb).