[Infectious cellulitis and Shewanella alga septicemia in an immunocompetent patient]

Shewanella alga 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.

A 66 year-old man with a heel wound had developed, after numerous sea baths in the Atlantic ocean (Oleron island, France), an infectious cellulitis of the leg with Shewanella alga septicemia. Despite the absence of immunodeficiency in this patient, infectious cellulitis and septicemia occurred via a wound to the skin and contact with sea water. Healing was seen after treatment with cefotaxime, ciprofoxacin and gentamicin IV, relayed with ciprofloxacin and erythromycin. Shewanella alga 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.

We report a case of infectious cellulitis with Shewanella alga 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.