Susceptibility of gentamicin sensitive and resistant gram negative bacilli to ceftazidime.

The in-vitro activity of ceftazidime was compared with other third-generation cephalosporins and gentamicin against 409 isolates. Ceftazidime was the most active agent against Enterobacter sp., Proteus mirabilis, Serratia sp., Proteus sp. and Pseudomonas aeruginosa. It was less active against Escherichia coli and Klebsiella than moxalactam and cefotaxime but more active than cefoperazone. Against gentamicin resistant E. coli, Klebsiella, Enterobacter and P. aeruginosa, ceftazidime was more active than moxalactam, cefotaxime or cefoperazone but was as active as moxalactam against gentamicin-resistant Proteus sp. and more active than cefotaxime and cefoperazone.