PFGE analysis of genomic DNAs from N. gonorrhoeae strains digested with SpeI. Lanes 1, 7, 13, and 19, lambda DNA ladder; lanes 2 to 6, 8 to 12, and 14 to 18, strains 182/98, 183/98, 193/98, 194/98, 56/98, 63/98, 76/95, 181/95, 72/96, 80/96, 137/97, 163/97, 165/97, 167/97, and 176/97, respectively. (See Table 2 for epidemiologic data.) The DNA preparation of strain 182/98 was tested before and gave the same pattern as that for 183/98, 193/98, and 194/98 (data not shown).