A 44-year-old male from Mali came to the emergency department with fever of six hours' duration and general malaise. His medical history included Graves-Basedow disease treated with carbimazole 30 mg/day for 6 weeks and the extraction of the third lower molar four days earlier. Physical examination revealed Ta 39.5oC, BP 122/71 and HR 137 l/min. A grade 1a goitre was palpated. In the mouth, caries was observed in several teeth and redness in the tooth extraction area, with the rest of the examination being unremarkable. Blood tests showed 500 leukocytes/mm3 (0% neutrophils) with the rest of the series normal, CRP 321 mg/dL, normal thyroid function and no other data of interest. Urine, sputum and blood samples were taken for microbiological study and broad-spectrum antibiotic treatment was started (amikacin 20 mg/kg/day and cefepime 2 g/8 hours). The bone marrow study performed the following day detected hypercellularity with maturation arrest in myeloid series, with no other data of interest, of probable pharmacological aetiology, for which reason carbimazole was suspended and treatment with G-CSF 5 µ/kg/d was started. On the first three days of admission, the patient had two episodes of fever of 39oC, so on the fourth day the previous antibiotic treatment was changed to meropenem 1 g/8 hours and fluconazole 400 mg/day was added, while a transesophageal echocardiogram was performed, which ruled out the presence of endocarditis. On the fifth day the fever disappeared, coinciding with partial recovery of the neutrophil count to 1,800/mm3, and on the seventh day the patient was discharged due to favourable evolution and resolution of the symptoms.
After 18 hours of incubation, growth of a gram-negative bacillus was detected in aerobic and anaerobic blood cultures, which was subsequently subcultured in different solid media in aerobic, anaerobic and CO2-enriched atmosphere. After 48 hours, pale yellow colonies, embedded in the agar and with a hypochlorite odour, grew on Columbia Agar, Chocolate Agar and Brucella Agar (not McConkey medium). These colonies were oxidase positive, catalase negative, urease and indole negative, reduced nitrates to nitrites and did not ferment carbohydrates. In a parallel sensitivity study using the Kirby-Bauer method with Mueller-Hinton blood plates and the E-Test® AB BIODISK, the isolate was sensitive to all antibiotics tested (ampicillin, amoxicillin-clavulanic acid, amoxicillin-clavulanic acid, amoxicillin-clavulanic acid, amoxicillin-clavulanic acid, amoxicillin-clavulanic acid), amoxicillin-clavulanic acid, azithromycin, levofloxacin, ciprofloxacin, cefotaxime, cefuroxime, imipen, co-trimoxazole and tetracyclines), except for gentamicin and amikacin, with MICs of 16 and 32 µg/mL, respectively. Their identity was confirmed by sequencing of the 16s gene.

