【摘要】 目的了解嗜麦芽寡养单胞菌的临床株H407和A26在抗菌药物诱导下耐药性和SmeDEF外排泵表达的变化。方法比较有或无环丙沙星诱导时嗜麦芽寡养单胞菌H407和A26的MIC和EOP值,对在亚抑菌浓度环丙沙星中培育后的菌株smeD基因进行RT-PCR扩增,监测表达水平。结果对抗生素敏感的H407和A26泵抑制呈阳性或阴性反应。2株菌经环丙沙星过夜孵育后测得的对氯霉素和环丙沙星MIC值比正常非诱导时的MIC值高1~3个稀释度;加泵抑制剂CCCP后,2个诱导株的MIC值均有明显下降。H407和A26经环丙沙星诱导后氯霉素的EOP分别有4.8和近4倍的增长。2株菌在抗菌药物过夜和指数期添加生长时smeD的mRNA明显高于无抗菌药物培养株。结论2株嗜麦芽寡养单胞菌临床株在环丙沙星诱导下对部分抗菌药物的耐药性提高,与SmeDEF泵的诱导表达增加有关。更多还原

【Abstract】 Objective To investigate changes of antibiotic resistance of the clinical isolates of S.maltophilia,and the repression level of efflux pump SmeDEF by the induction of antibiotics.Methods To examine the resistance profile of the clinical strains by agar dilution and the efficiency of plate(EOP) to antimicrobes,and their reactions to pump inhibitor CCCP, and to investigate the mRNA level of smeD by RT-PCR,in the presence or not of ciprofloxacin.Results The antibiotic-sensitive strains H407 and A26 were positive and negative to pump inhibitor respectively.MICs of ciprofloxacin and chloramphenicol induced by ciprofloxacin with sub-inhibition level were higher by 1～3 dilutions than those without induction.The incre-ases were inhibited by CCCP.After induction by ciprofloxacin,the EOP to chloramphenicol in H407 and A26 increased by 4.8 and nearly 4 times respectively,and the level of mRNA of smeD in the 2 antimicrobe-induced strains rose as well.Conclusion The resistance to several antimicrobes in the two isolates of S.maltophilia could be induced by ciprofloxacin.The possible antibiotic resistance mechanisms seemed likely by the mvolvement of the increased transcription level of smeDEF.更多还原