Mutation Rate of AmpC β-Lactamase-Producing Enterobacterales and Treatment in Clinical Practice: A Word of Caution

Clin Infect Dis. 2024 Jul 19;79(1):52-55. doi: 10.1093/cid/ciae160.

Abstract

In a retrospective multicenter study of 575 patients with bloodstream infections or pneumonia due to wild-type AmpC β-lactamase-producing Enterobacterales, species with low in vitro mutation rates for AmpC derepression were associated with fewer treatment failures due to AmpC overproduction (adjusted hazard ratio, 0.5 [95% CI, .2-.9]). However, compared to cefepime/carbapenems, using third-generation cephalosporins as definitive therapy remained associated with this adverse outcome (15% vs 1%).

Keywords: AmpC β-lactamase; Enterobacterales; antibiomicrobial therapy; bloodstream infection; pneumonia.

Publication types

  • Multicenter Study

MeSH terms

  • Aged
  • Anti-Bacterial Agents* / pharmacology
  • Anti-Bacterial Agents* / therapeutic use
  • Bacteremia / drug therapy
  • Bacteremia / microbiology
  • Bacterial Proteins* / genetics
  • Cephalosporins / pharmacology
  • Cephalosporins / therapeutic use
  • Enterobacteriaceae Infections* / drug therapy
  • Enterobacteriaceae Infections* / microbiology
  • Enterobacteriaceae* / drug effects
  • Enterobacteriaceae* / enzymology
  • Enterobacteriaceae* / genetics
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Mutation Rate*
  • Retrospective Studies
  • beta-Lactamases* / genetics
  • beta-Lactamases* / metabolism

Substances

  • beta-Lactamases
  • AmpC beta-lactamases
  • Bacterial Proteins
  • Anti-Bacterial Agents
  • Cephalosporins