Antimicrobial activity of broad-spectrum agents tested against gram-negative bacilli resistant to ceftazidime: report from the SENTRY Antimicrobial Surveillance Program (North America, 2001)

Abstract

To assess the effect of ceftazidime resistance on the activity of other antimicrobial agents, 4,175 Gram-negative bacilli isolates, designated as ceftazidime-susceptible (3,759, 90%) or -resistant (416, 10%) were tested against a panel of nine agents. Cefepime was the most active of the agents tested, against both ceftazidime-susceptible and -resistant isolates, with a particularly low incidence (0.3%, 10/3152 isolates) of resistance among the Enterobacteriaceae. Tobramycin had the best activity against Pseudomonas aeruginosa and ticarcillin/clavulanate was the least active of the tested agents. This study confirms the need for constant monitoring of in vitro antimicrobial efficacy to direct empiric treatment regimens.