In vitro activity of cefsulodin against multi-resistant isolates of Pseudomonas aeruginosa.

Clinical isolates of Pseudomonas aeruginosa from 245 patients with different infections were tested to determine their in vitro susceptibility to cefsulodin and other anti-pseudomonad antibiotics. Cefsulodin inhibited 90% of the isolates as compared with 89% by ceftazidime, 84% by piperacillin and 73% by ticarcillin. Of the three aminoglycosides used, gentamycin (60%) and netilmycin (77%) were less inhibitory. Amikacin was the most active, inhibiting 92% of the clinical isolates. Over 60% of the isolates resistant to ticarcillin and piperacillin were susceptible to cephalosporin and aminoglycosides used. Among cefsulodin-resistant isolates, ceftazidime was active against 67% and amikacin and netilmycin against 71% of isolates. Sixty percent of ceftazidime-resistant strains were susceptible to cefsulodin.