[Effect of a ticarcillin-clavulanic acid (timentin) combination on bacteria resistant to ticarcillin]

Sixty-nine ticarcillin-resistant strains (57 Gram negative bacilli and 12 S. aureus) were tested: MICs and MBCs were determined for clavulanic acid, ticarcillin, and both agents combined using a liquid micromethod. MICs were compared to results of disk antibiotic sensitivity tests. While clavulanic acid exhibits little antibacterial activity, its action is synergistic with that of ticarcillin making 100% of Staphylococci and 84.2% of Gram negative bacilli susceptible. Among the Gram negative bacilli tested, distribution is as follows: E. coli (9/9), Klebsiella (10/14), Enterobacter (1/3), Serratia (8/8), Proteus, Providencia (8/8), Salmonella (2/2), Acinetobacter (4/4), and Pseudomonas (6/9). Although strong bacteriostatic and bactericidal activities are already achieved with 4 mg, the best results are obtained with timentin 8 mg.