Cefepime/tazobactam compared with other tazobactam combinations against problem Gram-negative bacteria

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Piperacillin/tazobactam resistance is a growing concern.
• Cefepime combined with tazobactam offers a potential alternative.
• High-dose, prolonged infusion strategies are being explored.

Purpose of the Study:

• To assess the activity of cefepime/tazobactam against challenging bacterial pathogens.
• To compare cefepime/tazobactam with other tazobactam combinations.
• To evaluate its potential as a carbapenem-sparing agent.

Main Methods:

• Antimicrobial susceptibility testing of cefepime/tazobactam against Enterobacterales, Pseudomonas aeruginosa, and non-fermenters.
• Categorization of isolates based on carbapenemase genes and phenotypes.
• Minimum inhibitory concentrations (MICs) determined by agar dilution.

Main Results:

• Cefepime/tazobactam demonstrated broad activity against Enterobacterales with AmpC enzymes and ESBLs, including ertapenem-resistant strains.
• Activity exceeded 90% for OXA-48 and KPC carbapenemases, though higher MICs were observed for KPC ST258.
• It showed wider antipseudomonal coverage than piperacillin/tazobactam but was less active than ceftolozane/tazobactam in specific P. aeruginosa scenarios.

Conclusions:

• Cefepime/tazobactam exhibits a spectrum of activity comparable to or exceeding carbapenems.
• This combination has significant potential to reduce carbapenem usage.
• It represents a promising 'new-combination of old-agents' strategy against resistant infections.