Comparative in-vitro activities of ertapenem against aerobic bacterial pathogens isolated from patients with complicated intra-abdominal infections

The in vitro activities of ertapenem, ceftriaxone, amoxicillin-clavulanate, ampicillin-sulbactam, and piperacillin-tazobactam were compared against 1018 aerobic bacterial pathogens isolated from 531 patients with complicated intra-abdominal infection. Enterobacteriaceae accounted for 66.3% of the aerobic bacteria; Escherichia coli was the most common isolate. The ertapenem minimal inhibitory concentration was less than or similar to2 mug/mL for 74.6% of isolates and greater than or equal to8 mug/mL for 21.9% (including isolates of enterococci, methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa). Against Enterobacteriaceae, ertapenem was the most potent and the most active drug evaluated (100% susceptible), followed by ceftriaxone (98% susceptible), piperacillin-tazobactam (96% susceptible), amoxicillin-clavulanate (80% susceptible), and ampicillin-sulbactam (64% susceptible). Piperacillin-tazobactam was the only drug evaluated with clinically useful activity against P. aeruginosa. In summary, ertapenem was highly active in vitro against many clinically important aerobic intra-abdominal bacterial pathogens, especially Enterobacteriaceae.