氟喹诺酮类药物对嗜麦芽窄食单胞菌主动外排泵表型特征研究

Study of phenotypic characterization of efflux mechanism on fluoroquinolones against Stenotrophomonas maltophilia

目的 研究氟喹诺酮类药物(FQNS)对嗜麦芽窄食单胞菌的抗菌活性及氰氯苯腙(CCCP)对其主动外排泵表型特征的影响。方法 用琼脂二倍稀释法测定FQNS的最低抑菌浓度(MIC),测定CCCP对FQNS的MIC值的影响。结果 111株嗜麦芽窄食单胞菌对FQNS耐药率较低,尤以新型FQNS抗菌活性较高,其中抗菌活性由高到低依次是加替沙星、司帕沙星、左氧氟沙星和环丙沙星。主动外排泵抑制剂CCCP在体外能增强FQNS抗菌活性,主动外排机制即存在于FQNS耐药菌株,也存在于FQNS敏感菌株。但是CCCP对4种FQNS耐药菌株影响更大。结论 主动外排泵抑制剂在体外能降低FQNS对嗜麦芽窄食单胞菌的MIC,若能保证安全性,可能成为临床克服细菌耐药性的一种方法。

Objective To study the fluoroquinolones(FQNS)againstStenotrophomonas maltophilia and the affection of carbonyl cyanide m-chlorophe-nylhydrazone (CCCP) on it. Methods Minimal inhibitory concentrations (MICS) ofantibiotics that of FQNS combined 5 mg.L-1 CCCP against Stenotrophomonasmaltophilia were assayed by two-fold agar dilution method simultaneously.Results Of 111 strains of Stenotrophomonas maltophilia, the resistant ratio ofFQNS were lower, especially new FQNS have stronger antimicrobial activities. Invitro CCCP enhanced the activities of FQNS. Efflux mechanism existed not only inFQNS resistant strains, but also in FQNS sensitive strains. But the affection ofCCCP against FQNS resistant strains was much stronger than that of FQNSsusceptible strains. Conclusion In vitro CCCP decrease the FQNS MICS ofStenotrophomonas maltophilia. If the safety guaranteed, it may be a method whichbe used to overcome the bacterial resistances in clinic.