Cefepime : The Last Generation or the First Enhanced-Potency Broad Spectrum Cephalosporin?

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Gram-negative bacterial resistance to beta-lactam antibiotics is a growing clinical concern.
• Various resistance mechanisms, including beta-lactamases, contribute to treatment challenges.

Purpose of the Study:

• To compare the in vitro activity of cefepime against other beta-lactam antibiotics.
• To evaluate the efficacy of cefepime against Gram-negative bacteria with diverse resistance mechanisms.

Main Methods:

• In vitro susceptibility testing of 134 clinical isolates of Gram-negative bacteria.
• Comparison of cefepime, ceftazidime, and imipenem against Enterobacteriaceae and Pseudomonas aeruginosa.
• Assessment of cefepime's ability to select for resistant mutants.

Main Results:

• Cefepime exhibited high activity against Enterobacteriaceae (93%) and moderate activity against Pseudomonas aeruginosa (55%) at ≤8 mg/L.
• Cefepime was more active than ceftazidime against both bacterial groups.
• Imipenem showed the highest overall activity, but some carbapenem-resistant strains remained susceptible to cefepime.
• Cefepime was less likely to select for resistant mutants compared to ceftazidime.

Conclusions:

• Cefepime possesses enhanced in vitro activity compared to other cephalosporins against resistant Gram-negative bacteria.
• Improved Gram-negative cell penetration and lower affinity for beta-lactamases may contribute to cefepime's efficacy.
• Cefepime represents a valuable therapeutic option for infections caused by resistant Gram-negative pathogens.