%0 Multicenter Study
%T Effectiveness of third-generation cephalosporins or piperacillin compared with cefepime or carbapenems for severe infections caused by wild-type AmpC β-lactamase-producing Enterobacterales: A multi-centre retrospective propensity-weighted study.
%A Maillard A
%A Delory T
%A Bernier J
%A Villa A
%A Chaibi K
%A Escaut L
%A Contejean A
%A Bercot B
%A Robert J
%A El Alaoui F
%A Tankovic J
%A Poupet H
%A Cuzon G
%A Lafaurie M
%A Surgers L
%A Joseph A
%A Paccoud O
%A Molina JM
%A Bleibtreu A
%A  
%J Int J Antimicrob Agents
%V 62
%N 1
%D Jul 2023 6
%M 37028731
%F 15.441
%R 10.1016/j.ijantimicag.2023.106809
%X <B>BACKGROUND: </B>The optimal treatment regimen for infections caused by wild-type AmpC β-lactamase-producing Enterobacterales remains controversial. This study compared the outcomes of bloodstream infections (BSI) and pneumonia according to the type of definitive antibiotic therapy: third-generation cephalosporin (3GC), piperacillin ± tazobactam, cefepime or carbapenem.<BR><B>METHODS: </B>All cases of BSI and pneumonia caused by wild-type AmpC β-lactamase-producing Enterobacterales over 2 years in eight university hospitals were reviewed. Patients who received definitive therapy consisting of either a 3GC (3GC group), piperacillin ± tazobactam (piperacillin group), or cefepime or a carbapenem (reference group) were included in this study. The primary endpoint was 30-day all-cause mortality. The secondary endpoint was treatment failure due to infection by emerging AmpC-overproducing strains. Propensity-score-based models were used to balance confounding factors between groups.<BR><B>RESULTS: </B>In total, 575 patients were included in this study: 302 (52%) with pneumonia and 273 (48%) with BSI. Half (n=271, 47%) received cefepime or a carbapenem as definitive therapy, 120 (21%) received a 3GC, and 184 (32%) received piperacillin ± tazobactam. Compared with the reference group, 30-day mortality was similar in the 3GC [adjusted hazard ratio (aHR) 0.86, 95% confidence interval (CI) 0.57-1.31)] and piperacillin (aHR 1.20, 95% CI 0.86-1.66) groups. The likelihood of treatment failure was higher in the 3GC (aHR 6.81, 95% CI 3.76-12.4) and piperacillin (aHR 3.13, 95% CI 1.69-5.80) groups. The results were similar when stratifying the analysis on pneumonia or BSI.<BR><B>CONCLUSIONS: </B>Treatment of included BSI or pneumonia caused by wild-type AmpC β-lactamase-producing Enterobacterales with 3GC or piperacillin ± tazobactam was not associated with higher mortality, but was associated with increased risk of AmpC overproduction leading to treatment failure compared with cefepime or a carbapenem.