Combination effect of azthreonam with four aminoglycosides on nosocomial gram-positive cocci and non-fermenting gram-negative bacteria

Abstract

The inhibitory combination effect of azthreonam with gentamicin, tobramycin, amikacin and netilmicin respectively against 50 non-fermenting gram-negative rods and 30 gram-positive cocci was compared using the checkerboard agar dilution technique. On average 49.5% of all non-fermenting strains were inhibited by additive, and 48.5% by synergistic azthreonam-aminoglycoside combinations, but only 4.5% of the gram-positive cocci were inhibited by synergistic combinations. No antagonism occurred. No significant differences could be found between the effects of the respective azthreonam-aminoglycoside combinations.

Combination effect of meropenem with aminoglycosides and teicoplanin onPseudomonas and enterococci

“…Recent years have witnessed a resurgence of interest in enterococci and studies have shown the increasing rate of hospital-acquired enterococcal infections [6,7]. Enterococci are intrinsically tolerant to antibiotics that inhibit cell wall synthesis, such as penicillin, vancomycin, and imipenem, but are killed by the synergistic action of these antibiotics in combination with an aminoglycoside [8]. However, there is no synergy when the enterococcal strain has high-level resistance (MIC > 2,000 mg/1) to the aminoglycoside [9].…”