Figure 2. A) Pulsed-field gel electrophoresis (PFGE) fingerprinting patterns of SpeI-digested total DNA preparations from Pseudomonas aeruginosa. M, Lambda ladder PFGE molecular mass marker (Bio-Rad, Hercules, CA, USA). Strains 103 and 109 show similar patterns, which suggests probable nosocomial transmission of rmtA-positive strains in hospital C. Strains 113, 127, and 158 also demonstrate similar patterns, which implies possible nosocomial transmission in hospital D. However, 2 different PFGE patterns are observed in hospitals C, D, and F, which suggests transfer of plasmids carrying 16S rRNA–methylase genes among P. aeruginosa strains with different genetic backgrounds. B) SmaI-digested total DNA preparations from Acinetobacter baumannii isolated from hospital S. Three strains demonstrate the same PFGE pattern, which suggests probable nosocomial transmission of armA-positive A. baumannii in hospital S. M, lambda ladder low-range PFGE molecular mass marker (New England Biolabs, Ipswich, MA, USA).