泵抑制剂对嗜麦芽寡养单胞菌氟喹诺酮主动外排表型特征的影响

Effect of efflux pump inhibitor on phenotypic characterization of fluoroquinolones in Stenotrophomonas maltophilia

目的:探讨主动外排泵在嗜麦芽寡养单胞菌对氟喹诺酮类药物耐药中的作用。方法:用泵抑制剂氰氯苯腙(CCCP)和利血平对5种氟喹诺酮类药物抗菌活性进行干预。采用琼脂二倍稀释法检测泵抑制剂存在时,嗜麦芽寡养单胞菌对莫西沙星、加替沙星、左氧氟沙星、洛美沙星、环丙沙星敏感性的变化。结果:主动外排泵不仅存在于耐药菌株,而且也存在于敏感菌株,但对耐药菌株影响更大。与泵阴性组比较,泵阳性组敏感率降低在左氧氟沙星、洛美沙星、环丙沙星组有统计学差异;耐药率增加在洛美沙星、环丙沙星组有统计学差异。结论:主动外排泵抑制剂CCCP和利血平可增强氟喹诺酮类药物对嗜麦芽寡养单胞菌的抗菌活性,对其耐药表型有影响。主动外排机制是嗜麦芽寡养单胞菌对氟喹诺酮类药物耐药的原因之一。

Objective： To explore the role of efflux pump in drug resistance to fluoroquinolones in Stenotrophomonas maltophilia. Methods： The antibiotic activities of moxifloxacin, gatifloxacin, levofloxacin, lomefloxacin, and ciprofloxacin in Stenotrophomonas maltophilia were detected by 2-fold agar dilution method with or without efflux pump inhibitors, carbonylcyanidem-chlorophenylhydrazone （CCCP） and reserpine. Results： Positive efflux pump existed not only in resistant strains but also in susceptible strains. Compared with negative efflux pump group, the susceptibilities to levofloxacin, lomefloxacin, and ciprofloxacin significantly decreased and the drug resistances to lomefloxacin and ciprofloxacin significantly increased in positive efflux pump group. Conclusion： CCCP and reserpine could enhance the antibiotic activities of fluoroquinolones. Efflux pump is related to floroquinolone resistance in Stenotrophomonas maltophilia.