show Abstracthide AbstractThe Pertussis and Diphtheria Laboratory at the Centers for Disease Control and Prevention characterizes isolates of Corynebacterium species recovered from clinical specimens, most notably C. diphtheriae from human respiratory, blood, or cutaneous infection. However, collection does include some isolates from other sources. Isolates of C. diphtheriae and C. ulcerans have been tested for the presence and expression of diphtheria toxin. These data are made available to facilitate genomic study of these pathogens.