Cluster analysis of multidrug-resistant
(MDR-Ab) isolates by repetitive extragenic palindromic polymerase chain reaction (REP-PCR). Forty-eight MDR-Ab isolates were classified into eight genotypes according to 90% similarity by REP-PCR. Among these, 38 isolates inside the long panel demonstrate type A, the major type. The other isolates were not identical and corresponded to other types. A percent genetic similarity scale is shown above the dendrogram. Band position tolerance and optimization were each set at 2.0%.