<i>Chromobacterium haemolyticum</i> Infection Subsequent to Experiencing a Traumatic Event in a Rice Field: A Case Report and Literature Review

The incidence of infections caused by <i>Chromobacterium haemolyticum</i>, phylogenetically related however distinct from <i>Chromobacterium violaceum</i>, has increased since its identification in 2008. Differences in their unique microbiological features have been highlighted, particularly regarding their phenotypic distinctions in the colony pigmentation and hemolysis. This is largely due to <i>C. haemolyticum</i> being misidentified as <i>C. violaceum</i>, using the current automated microbial identification systems. However, clinical aspects and outcomes of <i>C. haemolyticum</i> infections remain unclear as few clinically relevant cases have been reported and considered similar to <i>C. violaceum</i> infections. Consequently, we reported an extremely rare case of <i>C. haemolyticum</i> bacteremia, which was initially diagnosed as a <i>C. violaceum</i> infection, however was later confirmed to be a <i>C. haemolyticum</i> infection, using 16S ribosomal ribonucleic acid (rRNA) sequence analysis. Abscess formation was not observed, and the patient was treated with a short course of antibiotics. Ultimately, his condition resolved, without recurrence during the 1-year follow-up. Clinicians should be aware that if the isolated organism is originally identified as <i>C. violaceum</i>, however is phenotypically mismatched with colony nonpigmentation and beta-hemolysis; the organism may be <i>C. haemolyticum</i>. Mortality, abscess formation, and recurrence rates are lower than those of <i>C. violaceum</i>, and chronic broad-spectrum antibiotic suppression may not be required, potentially avoiding unnecessary antibiotic use and preventing multidrug resistance.