Activity of cefepime against nosocomial blood culture isolates

Cefepime is a new aminothiazolylacetamido cephalosporin with a wider spectrum and greater potency than many currently available cephalosporins. Since the blood culture isolates from patients of the study centre in Saudi Arabia are significantly more resistant to antimicrobial agents in clinical practice, we evaluated the in-vitro activity of cefepime and six other beta-lactam antibodies against 390 and 273 isolates of Gram-negative and Gram-positive bacteria, respectively. Cefepime had a broad spectrum of activity against the Enterobacteriaceae (MIC50 < 0.12 mg/L), Pseudomonas aeruginosa, Acinetobacter spp. and methicillin susceptible Staphylococcus aureus (MIC50 2.0 mg/L). The activity of cefepime was generally two-to four-fold greater than that of ceftazidime. Resistance to cefepime was most often encountered with Serratia spp. (45%), Citrobacter spp. (25%), Enterobacter cloacea (22%), and Stenotrophomonos mattophilia (45%). It had little or no activity against methicillin-resistant S. aureus and enterococci. Cefepime was highly active, with a spectrum better than ceftazidime against Gram-negative, and better than cephalothin against Gram-positive blood culture isolates.