Infectious cellulitis and Shewanella alga septicemia in an immunocompetent patient

Background. Shewonello olgo is a Gram-negative bacilla often found in water or soil. Clinical infections in humans are rare, with serious infections described generally in immunocompromised hosts. Case report. A 66 year-old man with a heel hound had developed, after numerous sea baths in the Atlantic ocean (Oleron island, France), an infectious cellulitis of the lea with Shewonello olgo septicemia. Despite the absence of immunodeficiency in this patient, infectious cellulitis and septicemia occurred via a wound to the skin and contact with seawater. Healing was seen after treatment with cefotaxime, ciprofoxacin and gentamicin IV, relayed with ciprofloxacin and erythromycin. Shewonello olgo was also susceptible to ticarcillin, piperacillin and ceftazidime but was resistant to ampicillin, amoxicilline-clavulanate, colistin, cyclines, fosfomycin and cefsulodin. No immunological anomaly was found. Discussion. We report a case of infectious cellulitis with Shewonello olgo septicemia. This has not previously been described in an immunocompetent patient. Antibiotic therapy must be longer than usual treatment for streptococcal erysipelas and first-line antibiotherapy with ampicillin alone may not be sufficient.