Infections by OXA-48-like-producing Klebsiella pneumoniae non-co-producing extended-spectrum beta-lactamase: Can they be successfully treated with cephalosporins?

Background: OXA-48 is an Ambler class D β-lactamase that hydrolyses penicillin and imipenem but has poor hydrolytic activity against cephalosporins. However, very few clinical experiences of treating extended-spectrum β-lactamase (ESBL)-negative OXA-48 producers with cephalosporins have been published. Objectives: The aim of this study was to report clinical experience of infections due to ESBL-negative OXA-48-producing Klebsiella pneumoniae (K. pneumoniae) treated with cephalosporins. Patients and methods: A retrospective study was conducted at Vall d'Hebron University Hospital, in Barcelona (Spain). It reviewed all microbiological isolates of OXA-48-producers that did not co-produce ESBL from May 2014 to May 2017, and included only clinical strains of patients treated with a cephalosporin for ≥72 h. Results: From the 75 isolations of OXA-48 producers, there were 17 isolations of ESBL-negative OXA-48-producing K. pneumoniae. Three patients were treated with cephalosporins with successful outcomes: a pneumonia in a neutropenic patient treated with cefepime and amikacin; an acute focal nephritis of a renal graft treated with ceftriaxone; and an intrabdominal post-surgical infection treated with cefepime in combination with tigecycline at the beginning, and ciprofloxacin afterwards. Conclusions: Cephalosporins could be an alternative treatment in selected patients with ESBL-negative OXA-48-producing K. pneumoniae infections, especially to avoid carbapenem use. However, it remains unknown if they should be given in combination.