In-vitro efficacy of ceftazidime in combinations with meropenem,piperacillin/tazobactam,amikacin and ciprofloxacin against extensively drug-resistant pseudomonas aeruginosa

Combination therapy is preferred against p. aeruginosa to make better use of available antimicrobials,subject to the in-vitro evaluation. the activity of combinations is variable depending on the organismal behaviour in different geographical areas. in this study synergistic efficacy of ceftazidime in combinations with meropenem,piperacillin/tazobactam,amikacin and ciprofloxacin was evaluated against xdr (n = 12) and spt (n = 12) clinical strains of p.aeruginosa. in-vitro activity of antimicrobial combinations was determined by broth microdilution checkerboard technique. caz-ak combination exhibited synergism against 58.3% and 16.7% clinical strains of xdr and spt p. aeruginosa,respectively. caz-mem combination exhibited synergism against 8.3% clinical strains of xdr p. aeruginosa. caz-ak combination remained synergistically effective against xdr p. aeruginosa (p-value= 0.001). copyright 2014 zoological society of pakistan.