Thumbnail of Pulsed-field gel electrophoresis profiles of XbaI-digested genomic DNAs from eight Klebsiella pneumoniae isolates. Lanes 1 and 2, profiles for isolates A1 and A2 (from patient A); lines 3 to 6, profiles for isolates B1 to B4 (from patient B), respectively; and lanes 7 and 8, isolates of K. pneumoniae from two other patients used as control strains. Lane M, bacteriophage lamdba DNA concatemers (GibcoBRL, Gaithersburg, MD)