[In vitro effects of combinations of teicoplanin and ceftriaxone against Staphylococcus aureus and Enterococcus]

The in vitro activity of antibiotic combinations of teicoplanin (T) and ceftriaxone (C) was evaluated on 10 methicillin sensitive S. aureus (MSSA), 10 methicillin resistant S. aureus (MRSA), 4 Enterococcus and 2 E. coli. By the checkerboard method the combination T + C showed synergism against 9 MRSA, 2 MSSA, 4 Enterococcus, indifferent effect against the other strains. By the time-kill-curves method synergism was found for the combinations T + C at 1/2 CMI against MRSA, MSSA and Enterococcus, and indifference with the combinations at 1 X CMI, 2 X CMI, 4 X CMI against all the strains. Antagonistic effect was never found. These results suggest that teicoplanin in combination with ceftriaxone can be tested in in vivo study to demonstrate the possible benefits of the synergism particularly in the therapy of the nosocomial infections.