(A) PFGE of S1 nuclease-digested plasmids. (B) DNA hybridization with rmtG-specific probe. Lanes M, marker; lanes 1, strain 145/11; lanes 2, strain 1194/11; lanes 3, strain 350/10; lanes 4, strain 84/11; lanes 5, strain 922/11; lanes 6, E. coli DH10B transformant of strain 84/11.