The in-vitro activity of ceftazidime against clinically important pathogens.

A total of 1414 strains of Gram-negative bacilli and 250 strains of Gram-positive cocci were tested for antimicrobial susceptibility using the broth dilution method. The strains were clinical isolates from 26 hospitals in the Rhein-Main area. All the strains were tested against ceftazidime and ten other cephalosporin antibiotics. Ceftazidime was found to exhibit an in-vitro activity against Enterobacteriaceae similar to that of cefotaxime, moxalactam and other new members of the cephalosporin class, but was more active against Acinetobacter species. Ceftazidime shows extremely high activity both against carbenicillin-sensitive and -resistant strains of Pseudomonas aeruginosa. Similarly, ampicillin-sensitive and -resistant strains of Haemophilus influenzae are susceptible to ceftazidime. The activity of ceftazidime against Staphylococcus aureus is limited and, like other cephalosporins, it is inactive against Streptococcus faecalis.