【摘要】 目的分析亚-MIC头孢哌酮（cefoperazone,CFP）诱导大肠埃希菌生物膜形成过程中的浓度变化,为深入探索亚-MIC CFP诱导大肠埃希菌生物膜形成的作用机制奠定基础。方法参照CLSI标准,以标准琼脂平板倍比稀释法测定CFP对大肠埃希菌临床分离株E11的MIC;采用PCR方法观察E11携带的常见ESBL相关基因;以结晶紫染色法评价E.coli生物膜形成;采用高效液相色谱法（HPLC）观察CFP在LB培养基中的稳定性。结果 E11对CFP耐药,其携带bla_CTX-M-15和bla_TEM基因。亚-MIC CFP剂量依赖性诱导E11生物膜形成,18h达峰值。CFP在含E11的LB培养基中2h完全降解。结论亚-MIC CFP剂量依赖性诱导E.coli生物膜形成;作用过程中,CFP降解迅速。更多还原

【Abstract】 Objective To analyze the concentrations of cefoperazone during inducing biofi lm formation by an Escherichia coli clinical isolate and to investigate the mechanism of cefoperazone at sub-MIC on biofi lm formation by E. coli strains. Methods The minimum inhibitory concentration（MIC） on Escherichia coli clinical isolate E11 was tested by the agar double dilution methods according to "Performance Standards for A ntimicr obial Suscep tibility Testing" published by Clinical and Laboratory Standards Institute（CLSI）. Polymerase chain reaction（PCR） was used to detect the expression of superspectrum β-lactamase（ESBLs） genes. Then, high effi ciency liquid chromatography（HPLC） was used to observe the stability of CFP in LB culture medium. Results E11 was resistant to cefoperazone, and the MIC was 256μg/m L. PCR results showed that the isolated strain carried two types of ESBL enzyme genes, bla_TEM and bla_CTX-M-15. The sub inhibitory concentration of cefoperazone induced biofi lm formation by E11 in a dosedependent manner, and the maximal effect appeared within 18 h. The concentrations of cefoperazone gradually decreased during inducing biofilm formation by E11, and cefoperazone was totally degradated within two hours. Conclusion The sub inhibitory concentration of cefoperazone induce biofi lm formation by Escherichia coli clinical drug r esistant isolate E11, but the concentrations of cefoperazone is signifi cantly degraded over time.更多还原