Severe Respiratory Diphtheria-Like Illness Caused by Toxigenic Corynebacterium ulcerans.

We report a possible zoonotic case of severe diphtheria-like respiratory illness in Norway caused by a previously unreported toxigenic Corynebacterium ulcerans sequence type. This case highlights C. ulcerans as an emerging pathogen that can cause life-threatening disease. Clinicians should be aware of C. ulcerans infection, even in regions where diphtheria is rare.