金黄色葡萄球菌对亲水性氟喹诺酮类药物摄入的研究

Study on Uptake of Fluoroquinolones by Staphylococcus aureus

为了解金黄色葡萄球菌对氟喹诺酮的耐药机理 ,作者用荧光测定法研究了细菌对洛美沙星、氧氟沙星的摄入以及能量抑制剂对两药摄入的影响。结果显示 :耐药菌 SAR、SA70 1、SA6 87对上述两种药物的摄入量均低于敏感菌 SA2、SA3、SA4;加入能量抑制剂后上述细菌对药物的摄入量均有不同程度的增加。诱导菌对上述两药的摄入量均低于母株 ,加入能量抑制剂后 ,其摄入量增加非常明显 ,但仍未达母株稳态浓度。由此表明细菌对氟喹诺酮摄入减少是细菌对其耐药的机理之一 ,但泵出增加导致的细菌内药物浓度减少 。

This study aimed to investigate the mechanism of Staphylococcus aureus' resistance to fluoroquinolones. The uptake of lomefloxacin,ofloxacin by Staphylococcus aureus and the effect of CCCP on the uptake were studied by the fluorescence method. The uptake of lomefloxacin, ofloxacin by sensitive organisms is higher than that by resistant organisms;CCCP had different influences on different organisms, but no significant difference between the effects of CCCP on sensitive strains and on resistant strains was noted. The uptake of lomefloxacin, ofloxacin by SA2 16 was much lower than that by SA2 16's parent, and after the addition of CCCP, the uptake of both quinolones by SA2 16 increased rapidly, but the concentration did not reach its parent's concentration in stable condition. These results indicate that the decreasing of the uptake of fluoroquinolones is one of the mechanisms responsible for Staphylococcus aureus to resistance fluoroquinolones, and as a mechanism of resistance to drugs, it plays different roles in different strains.