金黄色葡萄球菌对喹诺酮类耐药的主动外排机制的研究

Study of active efflux mechanism in staphylococcus aureus resistant to Quinolone

目的对临床分离株中主动外排机制介导耐药的流行情况进行调查,为临床合理用药、耐药性控制及新型敏感抗菌药物的开发提供理论依据。方法将金黄色葡萄球菌(金葡菌)标准株ATCC25923及对喹诺酮类敏感临床株接种于含4×MIC氧氟沙星的MH琼脂平板上(含或不含20mg/L的利血平),观察利血平对诱导耐药出现的抑制作用,并测定诱导耐药株对溴乙啶、氧氟沙星、环丙沙星的MIC(含或不含20mg/L的利血平),观察利血平对诱导耐药株MIC的影响,用利血平抑制试验法测定临床上耐喹诺酮类金葡菌中主动外排机制的流行性。结果利血平可抑制喹诺酮类对金葡菌的诱导耐药率,可降低诱导耐药率的MIC。利血平抑制试验是检测金葡菌中主动外排机制简单直观的方法,临床上耐喹诺酮类金葡菌中约50%存在主动外排机制。结论主动外排是临床上金葡菌对喹诺酮类耐药的一种重要机制,利血平可抑制喹诺酮类对金葡菌的诱导耐药率,并可降低耐药菌的MIC,与喹诺酮类可起协同抗菌作用。

Objective It is to investigate the popular instance of the active efflux mechanism in clinical dissociative strain in order to offer theoretical basis on clinical rational administration, resistance control and the development of neotype aeschynomenous antibacterials. Methods Staphylococcus aureus standard strain ATCC25923 and clinic aeschynomenous strain to Quinolone were inoculated onto MH agar plate containing 4×MIC Ofloxacin (containing 20 mg/L Reserpine or not). The inhibiting action of Reserpine on induction resistance was observed. The MIC of the induction resistance strain on ethidium bromide (EB), Ofloxacin and Ciprofloxacin (containing 20 mg/L Reserpine or not) was determined. The influence of Reserpine on the MIC of the induction resistance strain was observed. The popular instance of the active efflux mechanism in resistance Quinolone staphylococcus aureus on clinic was surveyed with Reserpine inhibition test. Results Reserpine can restrain the induction resistance rate of Quinolone on staphylococcus aureus and can debase the MIC of the induction resistance rate. Reserpine inhibition test was a simple and direct method determining the active efflux mechanism in staphylococcus aureus. The active efflux mechanism was existed on about 50% strains of resistance Quinolone staphylococcus aureus on clinic. Conclusion Active efflux is an important mechanism of staphylococcus aureus resistant to quinolone on clinic. Reserpine can restrain the induction resistance rate of Quinolone on staphylococcus aureus and debase the MIC of the resistance strain. Reserpine and Quinolone have cooperativity.