Open Access Case Report

First Reported Case of Human Infection with Chromobacterium Violaceum in Gabon: Antibiotic Susceptibility Patterns and Treatment Outcome

Romeo Wenceslas Lendamba1*, Pierre Philippe Mbehang Nguema2, Mesmin Yves Moussounda3, Gaël NSI4, Eveline Avoune Epse Ella Missang5, Dearie Glory Okwu1, Claude Bernard Ako’o Mve1, Jacques François Mavoungou2 and Ghyslain Mombo-Ngoma1,6

*1Centre de Recherches Médicales de Lambaréné (Cermel), Lambaréné, Gabon

2Research Institute for Tropical Ecology (IRET), CENAREST, Libreville, Gabon

3Hôpital d’Instruction des Armées Omar Bongo Ondimba (HIAOBO), Libreville, Gabon

4University of Sciences and Technology of Masuku (USTM), Franceville, Gabon

5Centre Hospitalier Régional Amissa Bongo, Franceville, Gabon

6Implementation Research Department, Bernhard Nocht Institute for Tropical Medicine (BNITM) & I. Dep of Medicine, University Medical Center Hamburg- Eppendorf (UKE), Bernhard-Nocht-Straße, Hamburg, Germany

Corresponding Author

Received Date: July 11, 2023;  Published Date: July 31, 2023


Background:Mostly found in soil and still water in the subtropics and tropics, Chromobacterium violaceum is a Gram-negative bacillus that rarely infects humans. Nevertheless, when Chromobacterium violaceum infections do occur, they result in great distress because they are unrecognized and poorly addressed. The aim here is to describe what appears to be the first human case of Chromobacterium violaceum infection in Gabon.

Case presentation: A 12-month-old female was admitted to the paediatric ward of the Centre Regional Hospital Amissa Bongo of Franceville in Gabon with a fever that had been lingering for a week. The child was first put on antimalarial treatment for 3 days (following a positive thick blood smear for Plasmodium falciparum) combined with a 10-day prophylactic course of antibiotics (association of 500mg Ceftriaxone and Tobramycine).

Subsequently, a post-treatment cytobacteriological examination of urine (CBEU) was performed: a urine dipstick (UD) was carried out and then the urine was plated on Cystine-lactose-electrolyte-deficient (CLED) agar medium and incubated for 24 hours at 37°C.

Isolated bacterial colonies were identified with the Vitek 2 system (bioMerieux, France). Antibiotic susceptibility tests were run based on the Kirby-Bauer method (interpretation based on the breaking points given by the CLSI for Escherichia coli).

The UD revealed leukocyturia (30.103μL-1) and greyish non-pigmented bacterial colonies (positive for catalase and oxidase) found on CLED (DGU=104UFC.mL-1) were identified as Chromobacterium violaceum.

Antibiotic susceptibility tests exhibited resistance to beta-lactams (Ticarcillin, Ertapenem, Cefotaxime, Ceftazidime and Ceftriaxone), aminoglycosides (Gentamicin and Tobramycin), urinary quinolones (Nalidixic acid) and sulphonamides (Trimethoprim/Sulfamethoxazole).

Patient outcome: The infectious syndrome disappeared after the probabilistic treatment was adjusted post-CBEU and switched to Cefaclor 125 mg/5ml at a dosage of 25 mg/kg/day.

Conclusion: Chromobacterium violaceum seems to be a severe emerging human pathogen that requires prompt, adequate and lab results antibiotic-based treatment to prevent fatal outcomes.


Chromobacterium violaceum

; Urinary tract infection; Antibacterial resistance; Case report; Gabon

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