Comparative activity of seven extended-spectrum cephalosporins against Gram-negative bacilli from blood cultures

Abstract

One hundred sequential Gram-negative rod isolates from patients with hospital-acquired bloodstream infections were tested against seven new cephalosporins. Duplicate broth microdilution tests indicated superior activity for ceftazidime with 97% of strains susceptible to 16 mg/l. Less in-vitro activity was demonstrated cefotaxime (91% susceptible to 16 mg/l, P = 0.07), latamoxef (moxalactam) (90%, P = 0.04), cefoperazone (90%, P = 0.04), ceftriaxone (87%, P = 0.008), cefmenoxime (80%, P = 0.0001), and ceftizoxime (79%, P less than 0.0001). With the exception of cefoperazone, the newer drugs had mean MICs of less than or equal to 0.6 mg/l against Enterobacteriaceae. Ceftazidime and cefoperazone had highest activities against Pseudomonas aeruginosa with MIC90S of 4 and 16 mg/l, respectively. A comparison of recently published data shows important geographic differences in MIC90 data for the new cephalosporins against specific species.

Randomized prospective study of ceftazidime versus ceftazidime plus cephalothin in empiric treatment of febrile episodes in severely neutropenic patients

“…Synergistic schedules consisting of two or three drugs, including aminoglycosides, have been used, and early death due to inadequately treated bacterial infections has been largely overcome. However, concern for nephrotoxicity and ototoxicity can limit the use of aminoglycosidecontaining schedules, especially in the growing group of patients treated concomitantly with other potentially nephrotoxic drugs such as amphotericin B , cis-platinum, and cyclosporin A. Ceftazidirne, in view of its excellent gramnegative spectrum in vitro (10,13), was shown to be comparable to the established aminoglycoside-containing schedules in different studies, as reviewed by Pizzo et al (12), and offers the opportunity of monotherapy in the febrile neutropenic patient.…”