[Third-generation cephalosporins programmed restriction in the context of an outbreak of AmpC β-lactamase-producing gram-negative bacilli in critical units: a real-life experience]

Rev Chilena Infectol. 2021 Oct;38(5):597-604. doi: 10.4067/s0716-10182021000500597.
[Article in Spanish]

Abstract

Background: Programmed restriction (PR) of antimicrobials can selectively decrease the rate of infections by certain microorganisms. In this sense, AmpC β-lactamase-producing gram-negative bacilli (GNB-blaAmpC) are selected for the overuse of third generation cephalosporins (3GC). These bacteria also acquire genes and co-produce other β-lactamases, such as New Delhi ones (GNB-blaNDM).

Aim: To decrease the isolation rate of GNB- blaAmpC and GNB- blaNDM in cultures from ICU patients after a PR of 3GC.

Methods: Quasi-experimental study, before (P1= 12 months) and after (P2= 12 months) a PR of 3GC in an adults' hospital. The use of antibiotics was expressed as "percentage days of treatment (%DOT)" /100 beds occupied per day (100-BOD). The rates of GNB-blaAmpC and GNB-blaNDM were compared in blood cultures (BC), mini-bronchio alveolar lavages (mB) and urine cultures (UC) in the ICU.

Results: In P2, 3GC consumption was 2.5% DOT/100-COD. There was a decrease in GNB-blaAmpC from BC (RR 0.48 [0.2-0.9] p < 0.02) and mB (RR 0.52 [0.3-0.9] p < 0.02), as well as of GNB-blaNDM from BC (RR 8.1 [1.6-39.4] p < 0.00).

Conclusions: PR of 3GC was linked to the reduction of GNB-blaAmpC and GNB-blaNDM in BC, as well as GNB-blaAmpC in mB from ICU patients.

MeSH terms

  • Adult
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins
  • Cephalosporins / pharmacology
  • Disease Outbreaks
  • Gram-Negative Bacteria / genetics
  • Gram-Negative Bacterial Infections* / epidemiology
  • Gram-Negative Bacterial Infections* / microbiology
  • Humans
  • beta-Lactamases / genetics

Substances

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