Septic shock caused by Chromobacterium haemolyticum following initial misidentification as Chromobacterium violaceum in China

We report a case of bloodstream infection caused by Chromobacterium haemolyticum in an 80-year-old man following traumatic exposure to contaminated rice field water. The patient presented with rapidly progressive lower extremity soft tissue infection and septic shock. Preliminary MALDI-TOF MS identification indicates that it is C. violaceum ; however, the absence of violacein pigmentation and presence of β-hemolysis raised concern regarding species-level misidentification. Definitive identification by whole-genome sequencing (WGS) confirmed C. haemolyticum . Antimicrobial susceptibility testing revealed high-level resistance to β-lactam antibiotics, including carbapenems, while the isolate remained susceptible to fluoroquinolones and tetracyclines. WGS identified the bla CRH-1 gene, likely contributing to the resistance phenotype. This case emphasizes the importance of accurate species-level identification and antimicrobial susceptibility testing in managing Chromobacterium infections, especially in immunocompromised or severely ill patients. Increased awareness of C. haemolyticum as a distinct clinical pathogen is essential, given its potential for misidentification and multidrug resistance.