Plasmid profiles (A) and plasmid hybridization with an sfpA probe (B) of SF EHEC O157:H− Czech and German strains and EHEC O157:H7 strain EDL933. Lanes 1, strain 3072/96 (SF EHEC O157:H−, Germany); lanes 2, strain 258/98 (SF EHEC O157:H−, Czech Republic); lanes 3, strain 269/98 (SF EHEC O157:H−, Czech Republic); lanes 4, strain EDL933 (NSF EHEC O157:H7, United States); lanes 5, molecular mass marker (plasmid 39R861) (69). The plasmids of strains 258/98 and 269/98 that hybridized with the sfpA probe are marked by arrows in panel A, and the sizes of the sfpA-hybridizing plasmids are indicated in panel B.