In vitro combination-effect of temocillin with ticarcillin and aminoglycosides on gram-negative and gram-positive bacteria.

The in vitro efficacy of temocillin in combination with ticarcillin and with gentamicin, tobramycin, amikacin and netilmicin against 80 Gram-negative and 20 Gram-positive bacterial strains was compared by use of the checkerboard agar dilution technique. No synergistic or additive effect was seen on the Gram-positive strains. Great variations occurred between the different bacterial species, and the temocillin-ticarcillin combination had only little effect against the Pseudomonas strains tested. On average, only 12% of all strains tested were inhibited synergistically by temocillin-gentamicin combinations, and only 7 to 10% by combinations of temocillin with the other aminoglycosides. However, 25% of Gram-negative strains were inhibited synergistically and 40% of Gram-negative strains were inhibited additively by the combination of temocillin-gentamicin.