[Study on uptake of fluoroquinolones by Staphylococcus aureus]

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.