Rates of Resistance to Ceftazidime-Avibactam and Ceftolozane-Tazobactam Among Patients Treated for Multidrug-Resistant Pseudomonas aeruginosa Bacteremia or Pneumonia

Clin Infect Dis. 2025 Feb 5;80(1):24-28. doi: 10.1093/cid/ciae332.

Abstract

Among consecutive patients with multidrug-resistant Pseudomonas aeruginosa bacteremia or pneumonia we found those treated with ceftazidime-avibactam were more likely to develop resistance (defined as ≥4-fold increased MIC) than those treated with ceftolozane-tazobactam (40% vs 10%; P = .002). Ceftazidime-avibactam resistance was associated with new mutations in ampC and efflux regulatory pathways.

Keywords: Pseudomonas; MDR; ceftazidime-avibactam; ceftolozane-tazobactam; resistance.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents* / pharmacology
  • Anti-Bacterial Agents* / therapeutic use
  • Azabicyclo Compounds* / pharmacology
  • Azabicyclo Compounds* / therapeutic use
  • Bacteremia* / drug therapy
  • Bacteremia* / microbiology
  • Bacterial Proteins / genetics
  • Ceftazidime* / pharmacology
  • Ceftazidime* / therapeutic use
  • Cephalosporins* / pharmacology
  • Cephalosporins* / therapeutic use
  • Drug Combinations
  • Drug Resistance, Multiple, Bacterial*
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Penicillanic Acid* / analogs & derivatives
  • Penicillanic Acid* / pharmacology
  • Penicillanic Acid* / therapeutic use
  • Pneumonia, Bacterial* / drug therapy
  • Pneumonia, Bacterial* / microbiology
  • Pseudomonas Infections* / drug therapy
  • Pseudomonas Infections* / microbiology
  • Pseudomonas aeruginosa* / drug effects
  • Pseudomonas aeruginosa* / genetics
  • Pseudomonas aeruginosa* / isolation & purification
  • Tazobactam
  • beta-Lactamases / genetics

Substances

  • Ceftazidime
  • Cephalosporins
  • Azabicyclo Compounds
  • avibactam, ceftazidime drug combination
  • Tazobactam
  • ceftolozane, tazobactam drug combination
  • Anti-Bacterial Agents
  • Drug Combinations
  • Penicillanic Acid
  • beta-Lactamases
  • Bacterial Proteins