Blaser J, Lüthy R
Department of Medicine, University Hospital, Zürich, Switzerland.
J Antimicrob Chemother. 1988 Jul;22(1):15-22. doi: 10.1093/jac/22.1.15.
The antagonistic effects of physiological levels of Ca++ and Mg++ on the in-vitro activity of aminoglycosides and quinolones against Pseudomonas aeruginosa were studied at both pH 7.4 and 5.5. Adding Mg++ and Ca++ (100 mg/l) to commercial media deficient of these cations increased the MICs and MBCs of ciprofloxacin and enoxacin four-fold (2 P less than 0.01), which was significantly less than the 16-fold increase found for gentamicin and netilmicin (2 P less than 0.01). However, the activity of both aminoglycosides and quinolones was similarly affected by reducing the pH to 5.5 (giving eight-fold increases in MICs) or by the combination of both low pH plus cation supplementation (giving 16-fold increases in MICs). These data raise the question whether antagonizing factors should be considered not only for aminoglycosides, but also for quinolones during routine susceptibility tests on P. aeruginosa.
在pH 7.4和5.5条件下，研究了生理水平的Ca++和Mg++对氨基糖苷类和喹诺酮类药物体外抗铜绿假单胞菌活性的拮抗作用。向缺乏这些阳离子的商业培养基中添加Mg++和Ca++（100 mg/l），可使环丙沙星和依诺沙星的MIC和MBC增加4倍（P<0.01），这明显低于庆大霉素和奈替米星增加16倍的幅度（P<0.01）。然而，将pH降至5.5（使MIC增加8倍）或低pH加阳离子补充的联合作用（使MIC增加16倍）对氨基糖苷类和喹诺酮类药物的活性影响相似。这些数据提出了一个问题，即在对铜绿假单胞菌进行常规药敏试验时，是否不仅应考虑氨基糖苷类药物的拮抗因素，还应考虑喹诺酮类药物的拮抗因素。
