Persistence of a distinct Corynebacterium diphtheriae clonal group within two communities in the United States and Canada where diphtheria is endemic

Molecular characterization of 53 U.S. and Canadian Corynebacterium diphther iae isolates by multilocus enzyme electrophoresis, ribotyping, and random a mplified polymorphic DNA showed that strains with distinct molecular subtyp es have persisted in the United States and Canada for at least 25 years. Th ese strains are endemic rather than imported from countries with current en demic or epidemic diphtheria.