Gentamicin: Clinical Use with Carbenicillin and In-Vitro Studies with Recent Isolates of Pseudomonas aeruginosa

TLDR: The susceptibility to gentamicin of 33 isolates of Pseudomonas aeruginosa recovered at Memorial Sloan-Kettering Cancer Center before April, 1969, was compared to the susceptibility of 72 organisms recovered in the following 18 months, finding no significant difference in patterns of sensitivity.

Abstract: The susceptibility to gentamicin of 33 isolates of Pseudomonas aeruginosa recovered at Memorial Sloan-Kettering Cancer Center before April, 1969, was compared to the susceptibility of 72 organisms recovered in the following 18 months. No significant difference in patterns of sensitivity was observed; 96 of 105 organisms (91%) were inhibited at or below 3.12 ig/ml. Twenty of 23 isolates from blood cultures were still inhibited at or below 3.12 pIg/ml, despite the fact that they were recovered from patients receiving gentamicin for periods exceeding four days. Of 46 organisms isolated from blood cultures during 19691970, all but two were inhibited by concentrations of 1.56 vtg/ml of gentamicin and 50 [tg/ml of carbenicillin. Fifteen cases of bacteremia due to Pseudomonas were treated with a combination of these two drugs; infection was cured in seven and controlled in two. Success in therapy was associated with remission in leukemia or control of the underlying disease.