''Corynebacterium ulcerans'' is a rod-shaped, aerobic, and
Gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.
Gram-positive bacte ...
bacterium. Most ''Corynebacterium'' species are harmless, but some cause serious illness in humans, especially in immunocompromised humans. ''C. ulcerans'' has been known to cause
diphtheria
Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...
and diphtheria-like infections in patients. Previously thought to simply be contaminants recovered from diphtheria patients, “