Successful treatment of Verona integron-encoded metallo-β-lactamase-producing Klebsiella pneumoniae infection using the combination of ceftazidime/avibactam and aztreonam.

The case of a female who had an accident that caused an open fracture is reported. During hospitalisation, Verona integron-encoded metallo-β-lactamase (VIM)-producing Klebsiella pneumoniae was isolated. Antimicrobial susceptibility testing revealed resistance to β-lactam antibiotics, quinolones, trimethoprim/sulfamethoxazole, and susceptibility to tigecycline, colistin, fosfomycin and aminoglycosides. Synergistic activity of ceftazidime-avibactam and aztreonam was proved in vitro and a combined therapy with tigecycline was started. Combination with aminoglycosides was ruled out as it was not described in the literature and also in order to avoid side effects. Colistin was rejected because of its nephrotoxicity profile. The antibiotic treatment was assessed by a multidisciplinary team with a pharmacist who closely monitored adverse effects and interactions with other drugs. The total duration of this combination was 25 days, without any adverse events reported. Fourteen weeks after the accident the patient was discharged. After 2 months of follow-up neither relapses nor reinfections have been reported.