Chromobacterium violaceum is a gram-negative, facultative anaerobic, opportunistic pathogenic bacterium that infects both humans and animals. The major symptoms in most of the cases with fatal results seem to be sepsis, multiple liver abscesses, and diffuse pustular dermatitis. Some studies have reported instances of untreated C. violaceum causing brain abscess and diarrhea. Recent findings indicate that the type III secretion system (T3SS) encoded by Chromobacterium pathogenicity islands 1 and 1a (Cpi-1/-1a) is critical for C. violaceum pathogenesis.
The Chromobacterium violaceum type III effector CopE, a guanine nucleotide exchange factor for Rac1 and Cdc42, is involved in bacterial invasion of epithelial cells and pathogenesis.