Bacteremia by multidrug-resistant Capnocytophaga sputigena

A case of bacteremia caused by a multiresistant strain of Capnocytophaga sputigena in a patient with hematological malignancy is described. The strain presented with a pattern of marked resistance to beta-lactams, with MICs of > 256 mg/liter for ampicillin, ticarcillin, piperacillin, cefazolin, and cefuroxime, 64 mg/liter for cefotaxime, and 32 mg/liter for ceftazidime. In addition, the MIC of ciprofloxacin was 16 mg/liter. Both of these groups of antimicrobial agents are frequently used in the empiric treatment of infections in immunocompromised patients. The appearance of resistant strains suggests the need for antimicrobial susceptibility studies in all patients with severe infections caused by Capnocytophaga spp. or other capnophilic organisms present in the oral microflora of these patients.