Conservation of the aur gene among S. aureus strains. (A) Southern blot of BclI-digested chromosomal DNA of 12 S. aureus strains probed with a 1.4-kb fragment of the aureolysin gene. Lanes 1 to 6, strain N75, N66, A12, A9, 017, and 01 representatives of aureolysin type II; lanes 7 to 12, strain N72, N68, A11, A3, 022, and V8-BC10 representatives of aureolysin type I. Molecular size markers (in kilobases) are indicated to the right. (B) Agarose gel electrophoresis of PCR-amplified aureolysin gene products from genomic DNA of representative S. aureus strains. Lanes 1 and 2, representatives of aureolysin-type I digested with ApoI; lanes 3 and 4, representatives of aureolysin type II digested with ApoI; lanes 5 and 6, representatives of aureolysin type I digested with HincII; lanes 7 and 8, representatives of aureolysin type II digested with HincII; lanes 9 and 10, representatives of aureolysin type I digested with HinfI; lanes 11 and 12, representatives of aureolysin type II digested with HinfI; lanes 13 and 14, representatives of aureolysin type I digested with NdeI; lanes 15 and 16, representatives of aureolysin type II digested with NdeI; M, 100-bp ladder.