Human Clinical Isolates ofCorynebacterium diphtheriaeandCorynebacterium ulceransCollected in Canada from 1999 to 2003 but Not Fitting Reporting Criteria for Cases of Diphtheria

A 5-year collection of Corynebacterium diphtheriae and Corynebacterium ulcerans human clinical isolates yielded nine isolates from blood cultures of patients with invasive infections, stressing the importance of C. diphtheriae as a serious blood-borne pathogen. Seven percent of C. diphtheriae and 100% of C. ulcerans isolates produced diphtheria toxin, demonstrating that toxigenic corynebacteria continue to circulate.