[Multicenter study of the in vitro antibacterial activity of ceftazidime on gram-negative bacilli]

This work reports a multicenter study of antibacterial activity of ceftazidime, a new third generation cephalosporin, on hospital Gram negative rods. Enterobacteriaceae are very sensitive to ceftazidime with a maximum number of strains inhibited by 1 microgram/ml or less (modal MIC 0, 125 microgram/ml); some resistant strains are observed, particularly among Enterobacter and Citrobacter. Activity of ceftazidime on Pseudomonas aeruginosa is superior to other third generation cephalosporins; modal MIC is 1 microgram/ml and 88% of the strains are inhibited by 4 microgram/ml or less. Acinetobacter are less sensitive to ceftazidime, with a modal MIC of 8 microgram/ml.