Effect of carbenicillin, gentamicin, and their combination on experimental Pseudomonas aeruginosa urinary tract infection.

The therapeutic efficacy of a combination of gentamicin with carbenicillin was compared with those of each antibiotic alone. The efferent urinary ducts of rats were infected with Pseudomonas aeruginosa and antibiotic therapy was started six days later. After seven days' therapy quantitative bacteriological findings in the urine and renal tissue were compared with those of untreated rats that had been infected. The degree of infection was least in the group treated with concurrent gentamicin and carbenicillin. It was concluded that the therapeutic efficacy of the gentamicin-carbenicillin combination exceeded those of each antibiotic administered alone.