The in vitro activity of ceftazidime against a multi-resistant serotype 12 Pseudomonas aeruginosa.

Highly resistant isolates of Pseudomonas aeruginosa serotype 12 accounted for 42.2% of the pseudomonads isolated from patients in a 600-bed hospital over a period of 18 months. In vitro studies showed that this organism was resistant to tobramycin, gentamicin, apalcillin, piperacillin, azlocillin, ticarcillin, cefotaxime and cefsulodin. All serotype 12 isolates were completely sensitive to ceftazidime. Its geometric mean MIC was 3.4 mg/l. This new cephalosporin seems promising for the treatment of patients infected with pseudomonas, especially when a resistant strain such as serotype 12 is involved.