A comparative study of the in-vitro activity of cefepime and other antimicrobial agents against penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae.

Using the national surveillance programme of USA hospitals, we selected 162 strains of Streptococcus pneumoniae for sensitivity testing using the NCCLS breakpoints for benzylpenicillin and the oxacillin discs screen test. Included in the group of isolates were 85 relatively penicillin-resistant and 33 penicillin-resistant strains. The activity of cefepime, a new cephalosporin, was compared with other cephalosporins and penicillins as well as some non-beta-lactam antimicrobials. Imipenem was the most active agent but, cefepime, cefotaxime, ceftriaxone and ciprofloxacin were only slightly less active. The least active agents were ceftazidime, cefuroxime, piperacillin/tazobactam and ticarcillin/clavulanate. Cefepime is a potential alternative treatment to penicillin, particularly when penicillin-resistant and relatively penicillin-resistant S. pneumoniae are encountered. The clinical importance of screening for penicillin resistance by the use of the oxacillin disc is emphasized.