氟喹诺酮类药物对嗜麦芽寡养单胞菌的抗菌活性及羰基氰氯苯腙对其的影响

目的　了解氟喹诺酮类药物 (FQNs)对嗜麦芽寡养单胞菌的抗菌活性及羰基羟基氰氯苯腙(CCCP)对其抗菌活性的影响。方法　采用琼脂二倍稀释法测定抗菌药物的最低抑菌浓度 (MIC) ,同时测定CCCP对 FQNs的 MIC值的影响。结果　 14 4株嗜麦芽寡养单胞菌对多种常用抗生素呈现多重耐药 ,但对SMZ/ TMP、替卡西林 /克拉维酸以及 FQNs的耐药率较低 ,尤其是新型 FQNs具有很高的抗菌活性 ,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的抗菌活性 ,主动外排机制不仅存在于 FQNs耐药菌株 ,而且也存在于 FQNs敏感菌株 ,但是CCCP对 4种 FQNs耐药菌株的影响更大。结论　嗜麦芽寡养单胞菌的感染经验上可选用 SMZ/ TMP或 FQNs治疗 ,对于严重感染可采用 SMZ/ TMP和替卡西林 /克拉维酸联合或用新型 FQNs治疗。主动外排泵抑制剂在体外的确能降低 FQNs对嗜麦芽寡养单胞菌的 MIC,若能保证安全性 ,可望用于临床克服细菌的耐药性。

Surveillance on fluoroquinolones resistances of Stenotrophomonas maltophilia and the effect of CCCP on it

Objective To survey the fluoroquinolones (FQNs) resistances of Stenotrophomonas maltophilia and the effect of carbonyl cyanide m-chlorophenylhydrazone (CCCP) on it. Methods Minimum inhibitory concentrations (MICs) of antibiotics against Stenotrophomonas maltophilia were assayed by two-fold agar dilution method and MICs of FQNs combined with 5mg/L of CCCP against S.maltophilia were determined simultaneously. Results A total of 144 strains of Stenotrophomonas maltophilia were multi-drug resistant, but the resistant rates against trimethoprim-sulfamethoxazole, ticarcillin-clavulanic acid and FQNs were lower, especially those of newer FQNs have stronger antimicrobial activities. In vitro CCCP enhanced the activities of FQNs. Efflux mechanism existed not only in FQNs resistant strains, but also in FQNs susceptible strains. But the effect of CCCP against FQNs resistant strains was much stronger than that of FQNs susceptible strains. Conclusions The empirical treatment of Stenotrophomonas maltophilia infection is trimethoprim-sulfamethoxazole and FQNs. For serious infection therapy, trimethoprim-sulfamethoxazole combined with ticarcillin-clavulanic acid or newer FQNs may be used. In vitro CCCP decreased the MIC of Stenotrophomonas maltophilia against FQNs. In certain cases, it could be used to overcome the bacterial resistances in clinic.