Bush K, Goldschmidt R
RW Johnson Pharmaceutical Research Institute, 1000 Route 202, Raritan, NJ 08869, USA.
Curr Opin Investig Drugs. 2000 Sep;1(1):22-30.
Fluoroquinolones are broad-spectrum and therapeutically effective antibacterial agents that have retained high activity against methicillin-susceptible Staphylococcus aureus (MSSA) and streptococci. Primary targets of these agents in Gram-positive bacteria are DNA topoisomerase and DNA gyrase. High-level resistance is associated with at least two mutations in either target, or combinations of at least two mutations in multiple targets, particularly affecting the ParC subunit of topoisomerase IV and the GyrA subunit of DNA gyrase. This resistance may be enhanced when combined with mutations that increase fluoroquinolone efflux. Data from fluoroquinolone-resistant clinical isolates suggest that as yet unidentified mutations may also be involved in clinical resistance.
氟喹诺酮类是广谱且治疗有效的抗菌剂，对甲氧西林敏感金黄色葡萄球菌（MSSA）和链球菌仍保持高活性。这些药物在革兰氏阳性菌中的主要靶点是DNA拓扑异构酶和DNA旋转酶。高水平耐药性与任一靶点中的至少两个突变相关，或多个靶点中至少两个突变的组合，尤其影响拓扑异构酶IV的ParC亚基和DNA旋转酶的GyrA亚基。当与增加氟喹诺酮外排的突变结合时，这种耐药性可能会增强。来自耐氟喹诺酮临床分离株的数据表明，尚未明确的突变也可能与临床耐药性有关。
