Interactions of XXXX and @entity206 in vitro.

@entity1597 @entity206 @entity1215
Combination of @entity1215 and @entity206 ( @entity1597 ) has been suggested as a means of preventing the emergence of bacterial resistance to the individual agents and of achieving synergistic antimicrobial activity. By means of standard techniques of antimicrobial susceptibility testing, combinations of @entity1215 and @entity1597 were tested against clinical isolates of a variety of aerobic bacteria. Synergism was defined as a fourfold or greater decrease in the minimal inhibitory concentration (MIC) of the more active agent in the combination. Antagonism was defined as a fourfold or greater increase in the MIC of the more active agent. No change or, at most, a twofold change was considered to represent indifference. Combinations of @entity1215 and @entity1597 in ratios of 7:1, 7:2, and 1:1 demonstrated synergistic activity against 12%, 13%, and 28% of 440 isolates, respectively. Antagonism was observed in 10%, 9%, and 8% of strains tested against the above ratios. Killing curves determined with selected organisms failed to demonstrate synergistic antibacterial activity. Combinations of @entity1215 and @entity1597 failed to prevent the emergence of resistance to both drugs when selected strains of various bacteria were exposed to serial, subinhibitory concentrations. Thus, synergism of @entity1215 and @entity1597 was observed in only a minority of strains tested, and combination of the two agents failed to prevent the emergence of drug resistance in vitro.
