In-vitro interactions of DX-8739, a new carbapenem, meropenem and imipenem with amikacin against multiresistant Pseudomonas aeruginosa

Abstract
In order to investigate the antimicrobial interactions against multiresistant Pseudomonas aeruginosa, thirty-seven strains resistant to antimicrobial agents of five different chemical classes were exposed in vitro to the combmation of three carbapenems, DX-8739, a novel DHP-1 stable analogue, meropenem and imipenem with amikacin. The tested combinations expressed an enhanced killing activity against 38–46% of strains and an additive effect against 5–13%. These effects were the same whether the applied carbapenem was DX-8739, meropenem or imipenem; they were also independent of the MIC of any antimicrobial.