Chromobacterium violaceum: A Review of an Unexpected Scourge

Chromobacterium violaceum is a common environmental bacterium that rarely causes disease in humans but has a high fatality rate if it does. Due to the rarity of the cases, clinicians are often unaware of the rapid progression of C. violaceum infection and its unexpected antibiotic resistance pattern, which contribute to the failure of patient management. Our review provides the clinical characteristics, possible sources of exposure, and comorbidities and determines factors associated with survival. We gathered information on 132 cases of C. violaceum causing disease in humans published between 1953 and 2020. Patients were predominantly male with a median age of 17.5, interquartile range (IQR) of 5.0-40.0 years, and a third of them were known to have immune deficiencies or comorbidities. Portals of entry were mainly through a wound in the leg and feet (28.0%), the torso (8.5%), or hands and arms (6.8%). It is not uncommon to acquire infection through unintended contact with contaminated water or dust through the mouth or inhalation. The median incubation period is 4.0 days (IQR 2.0-8.0 days) with a duration of clinical course of 17.5 days (IQR 8.0-30.8 days). The high rate of positive blood cultures (56.1%) and abscesses in internal organs (36.4%) shows the significant severity of this disease. Sepsis and Bacteremia were related to mortality with a risk ratio (RR) of 5.20 (95% CI, 0.831-32.58) and 2.14 (95% CI, 1.05-4.36), respectively. Appropriate antibiotic use prevented death at a RR 0.33 (95% CI, 0.21-0.52). Most patients who recovered and survived were treated with aminoglycosides, fluoroquinolones and carbapenems. This review shows the malignant nature of C. violaceum infection and the need for clinicians to be aware and provide prompt source management for patients. Appropriate empiric and targeted antibiotic regiment guided by susceptibility test results is of vital importance.

Case Report on Pleural Empyema Thoracis and Urinary Tract Infection Caused by Chromobacterium violaceum from Lagos, Nigeria

Chromobacterium violaceum has been implicated as an important cause of invasive diseases such as septicaemia in neonates and immune-compromised adults with high risk of misdiagnosis, mistreatment, and poor outcomes. Here, we report three new cases of C. violaceum infections in three different hospitalised patients with empyema thoracis (one case) and urinary tract infections (two cases) in a tertiary Hospital in Lagos, Nigeria, and the diagnosis was confirmed with the MALDI-TOF MS instrument. The patients were admitted and treated with parenteral antibiotics (ciprofloxacin, cefotaxime, and ceftriaxone) and discharged after clinical cure. Clinical and Laboratory findings from this study revealed C. violaceum as an emerging and an “underdiagnosed” pathogen causing human infections in Nigeria with ciprofloxacin identified as an effective empirical treatment. Follow-up of cases treated with microbiologically efficacious antibiotics indicates a good treatment outcome.

Pediatric bacteremia caused by Chromobacterium haemolyticum/Chromobacterium aquaticum

We present a case of pediatric bacteremia caused by Chromobacterium haemolyticum, a β-hemolytic, non-pigmented, Gram-negative bacilli recovered from a blood culture and initially identified as Chromobacterium violaceum using phenotypic and proteomic methods. 16S rRNA sequencing of the patient isolated demonstrated a high degree of sequence homology with the type strain of C. haemolyticum. The patient recovered following treatment with meropenem, gentamicin, and trimethoprim/sulfamethoxazole. This case highlights the potential misidentification of C. haemolyticum as non-pigmented C. violaceum due to limitations of the currently available identification methodologies.

Chromobacterium Violaceum Sepsis: Rethinking Conventional Therapy to Improve Outcome

Patient: Male, 11

Final Diagnosis: Chromobacterium violaceum infection

Symptoms: Abscess • fever • rash

Medication: —

Clinical Procedure: ECMO

Specialty: Critical Care Medicine

Relative frequency, characteristics, and antimicrobial susceptibility patterns of Vibrio spp., Aeromonas spp., Chromobacterium violaceum, and Shewanella spp. in the northern territory of Australia, 2000-2013

Vibrio, Aeromonas, Chromobacterium violaceum, and Shewanella (VACS) are water-associated Gram-negative organisms that can cause a variety of infections. The frequency, patient characteristics, and antimicrobial susceptibilities for 468 isolates from 442 patients from the Northern Territory were reviewed. Aeromonas spp. (312 of 468; 67%) were most commonly isolated followed by Vibrio spp. (71 of 468; 15%), Shewanella spp. (61 of 468; 13%), and C. violaceum (24 of 468; 5%). A strong male predominance was found (male to female ratio of 2.3:1). Skin and soft tissue isolations (373 of 468; 80%) from lower limb infections (222 of 371; 60%) were the most common clinical manifestation. The episodes were usually polymicrobial (281 of 468; 60%). Coisolates included Staphylococcus aureus (137 of 468; 29%), β-hemolytic streptococci (74 of 468; 16%), enterobacteriaceae (111 of 468; 24%), non-fermentative Gram-negative bacilli (35 of 468; 7%), and other VACS organisms (37 of 468; 8%). Antimicrobial resistance of VACS organisms to ciprofloxacin (0-4%), cefepime (0-3%), and gentamicin (0-0.8%) and Vibrio spp., Aeromonas spp., and Shewanella to cotrimoxazole (0-3%) was rarely shown. For water-associated lower limb skin and soft tissue infections in the tropics, clinicians should consider empirical antimicrobial therapy with agents active against S. aureus and VACS organisms.

Fatal Chromobacterium violaceum bacteraemia in rural Bandundu, Democratic Republic of the Congo

We describe the first case of bacteraemia caused by Chromobacterium violaceum in the Democratic Republic of the Congo. This diagnosis was made in an apparently healthy adult who was admitted to a rural hospital of the province of Bandundu with severe community-acquired sepsis. The patient developed multi-organ failure and died; to our knowledge, this is the first reported fatal case in an adult in Africa.

Chromobacterium violaceum nosocomial pneumonia in two Japanese patients at an intensive care unit

Chromobacterium violaceum is sensitive to temperature and the infection is usually confined to tropical or subtropical regions. Since Japan has a warm climate, C. violaceum has been scarcely isolated from clinical specimens. With global warming, however, the geographical distribution of C. violaceum infection is likely to change. We report two cases of C. violaceum nosocomial pneumonia that occurred at an intensive care center in Japan. C. violaceum was first detected from a patient in the same center as a pathogenic organism of pneumonia. Later, the organism was isolated from sputum and a ventilator circuit tube of another patient in the center. The two patients were admitted to the center in nearby beds for several days. All of the pathogens were confirmed to be C. violaceum by the nucleic acid sequence of the 16S rRNA gene and were proven to be genetically identical organisms by pulsed field gel electrophoresis. Both patients were managed with well-humidified and heated oxygen using a venturi mask and ventilator to promote excretion of sputum. It was thought that the medical respiratory care devices that provide a humid and warm environment, an optimal condition for proliferation of C. violaceum, can contribute to C. violaceum infection in a hospital environment.

Chromobacterium violaceum and its important metabolites--review

C. violaceum appeared as important bacterium in different applications and mainly these aspects are related to the production of violacein. This review discusses the last reports on biosynthetic pathways, production, genetic aspects, biological activities, pathological effects, antipathogenic screening through quorum sensing, environmental effects and the products of C. violaceum with industrial interest. An important discussion is on biological applications in medicine and as industrial products such as textile and in cosmetics.