Comparative In Vitro Evaluation of the Effects of Ticarcillin and Carbenicillin upon Pseudomonas aeruginosa

An in vitro comparison of the effects of ticarcillin and carbenicillin was performed upon 164 strains of Pseudomonas aeruginosa . The two drugs displayed nearly identical inhibitory activities: for each, about 82.5% of the strains were inhibited by doses of 256 μg/ml or less. A low bactericidal activity was also observed. Strains of P. aeruginosa that were highly resistant to carbenicillin were also resistant to ticarcillin.