[Combination therapy against vancomycin-resistant enterococci]

The therapeutic options for patients infected with vancomycin-resistant enterococci are limited. Optimal therapy for serious enterococcal infections requires the use of synergistic combinations of a cell wall-active agent plus an aminoglycoside. Enterococci have acquired aminoglycoside resistance genes that mediate production of aminoglycoside-modifying enzymes, which eliminate this synergistic bactericidal effect. Traditional therapy has been compromised due to the increasing prevalence of enterococci with beta-lactam, glycopeptide, and high-level gentamicin resistance. Arbekacin, a semi-synthetic aminoglycoside, shows excellent activity against a wide variety of bacteria that produce aminoglycoside modifying enzymes, including AAC(6')-APH(2"). In recent studies, the combination of ampicillin and arbekacin demonstrated inhibitory activity against vancomycin-resistant enterococci, and may prove useful in the treatment of enterococcal infections where treatment options are limited.