Abstract
The in vitro and in vivo antibacterial activity of a new cephalosporin, ceftazidime (CAZ, SN401) was compared with other cephalosporins against gram-positive and negative bacteria.
CAZ had a broad antibacterial spectrum; especially it was more active than or as active as cefmenoxime against indole-positive Proteus (P. vulgaris, P. morganii, P. rettgeri, P. incostans) and E. cloacae. CAZ was shown to have greater activity than other cephalosporins against Serratia, P. aeruginosa, P. cepacia, Acinetobacter calcoaceticus, Achromobacter xylosoxidans.
CAZ was as stable as latamoxef to inactivating enzymes (penicillinase and cephalosporinase) which were produced by facultative anaerobes. However, it was as unstable as cefmenoxime to inactivating enzymes produced by B. fragilis; its stability was not so good as that of cefmetazole and latamoxef.
In a protection test in mice, CAZ was as effective as cefmenoxime and latamoxef in the infections due to E. coli, Klebsiella, and it was more effective than cefmetazole and cefazolin. In Serratia infections, CAZ was not affected by inoculum size and its effectiveness was equivalent or superior to to cefmenoxime and latamoxef. The effects of CAZ in P. aeruginosa infections were superior to those of cefmenoxime, latamoxef, cefoperazone and cefsulodin.
