Synergism of aminoglycosides and carbenicillin against resistant strains of Serratia marcescens

Abstract

We have isolated 20 strains of Serratia marcescens resistant to carbenicillin and/or aminoglycosides from hospitalized patients and performed in vitro antibiotic susceptibility and synergistic studies. The amikacin-carbenicillin combination showed full synergy against 85% and partial synergy against 15% of the strains. The gentamicin-carbenicillin combination showed full synergy against 75% and partial synergy against 25%; and the tobramycin-carbenicillin combination showed full synergy against 65%, partial synergy against 30%, and an indifferent effect against 5%.