Determination of the synergy of antibiotic combinations by an overlay inoculum susceptibility disc method.

A method involving an overlay inoculum agar and antibiotic susceptibility discs in the determination of synergy of gentamicin and disc antibiotics against clinical isolates of Pseudomonas aeruginosa has been described. Gentamicin combinations with carbenicillin showed synergism against all test isolates. Combinations containing fosfomycin had indifferent effects.