Aminoglycosides 고도내성인 enterococci에 대한 항균제 병합요법의 in-vitro 효과

Abstract

For serious enterococcal infections, synergistic combination of penicillin and aminoglycosides is recommended for bactericidal therapy. However, an optimal synergistic combination for infection caused by enterococcal strains demonstrating a high-level resistance to aminoglycosides has not been established. The present study ezamined the in-vitro effects of combinations of penicillin plus trimethoprim/sulfamethoxazole(Sxt), ciprofloxacin, teicoplanin, vancomycin, and fosfomycin and compared with single drug therapy of ampicillin of low(5㎍/mL) and high doses(10, 20㎍/mL) in strians of Enterococcus with high-level resistance to gentamicin, amilkacin, and streptomycin by time kill studies. The minimal bactericidal concentrations of these antibiotics were also determined. Sxt and ampicillin were most active single agents on both MIC/MBC test and time kill study, but not consistently bactericidal. Only penicillin-ciprofloxacin combination exhibited significant bactericidal synergy but the bactericidal effect was strain and inoculum-size dependent and not more significantly effective than high-dose ampicillin or Sxt only.

For serious enterococcal infections, synergistic combination of penicillin and aminoglycosides is recommended for bactericidal therapy. However, an optimal synergistic combination for infection caused by enterococcal strains demonstrating a high-level resistance to aminoglycosides has not been established. The present study ezamined the in-vitro effects of combinations of penicillin plus trimethoprim/sulfamethoxazole(Sxt), ciprofloxacin, teicoplanin, vancomycin, and fosfomycin and compared with single drug therapy of ampicillin of low(5㎍/mL) and high doses(10, 20㎍/mL) in strians of Enterococcus with high-level resistance to gentamicin, amilkacin, and streptomycin by time kill studies. The minimal bactericidal concentrations of these antibiotics were also determined. Sxt and ampicillin were most active single agents on both MIC/MBC test and time kill study, but not consistently bactericidal. Only penicillin-ciprofloxacin combination exhibited significant bactericidal synergy but the bactericidal effect was strain and inoculum-size dependent and not more significantly effective than high-dose ampicillin or Sxt only.