亚抑菌浓度三代头孢菌素对耐药质粒接合转移的影响

Influence of subinhibitory concentrations of Third-generation cephalosporine on resisitant plasmid conjugation

目的:探讨不同亚抑菌浓度三代头孢菌素对耐药质粒接合转移的影响。方法:研究不同亚抑菌浓度头孢噻肟(0μg/ml、4μg/ml8、μg/ml、16μg/ml3、2μg/ml)及头孢他啶(0μg/ml、2μg/ml、4μg/ml、8μg/ml、16μg/ml)在不同作用时间下供体菌(临床分离的携带CTX-M型基因肺炎克雷伯菌株)与受体菌(大肠埃希菌E.coli C600 SMR Lac)接合转移率的变化。结果:在4μg/ml头孢噻肟亚抑菌浓度作用下的接合转移率最高,除头孢噻肟空白组(0μg/ml),接合转移率随头孢噻肟亚抑菌浓度的增加而下降。同样,在2μg/ml头孢他啶亚抑菌浓度作用下的接合转移率最高。除头孢他啶空白组(0μg/ml),接合转移率随头孢他啶浓度的增加而下降。结论:不同亚抑菌浓度三代头孢菌素能影响耐药质粒的转移。临床使用抗菌药物时,应考虑到给药间歇期抗菌药物亚抑菌浓度的变化,及时调整治疗方案,防止细菌耐药性的播散。

Objective： To investigate influence of subinhibitory concentrations of Third-generation cephalosporin on resisitant plasmid conjugation.Methods： To analyze the changes of transfer rate of the conjugation between the donar（clinical isolate of CTX-M-producing K.penumonie） and recipient（E.coli C600 SMR Lac-）at the presence of different subinhibitory concentrations of cefotaxime（0 μg/ml,4 μg/ml,8 μg/ml,16 μg/ml,32 μg/ml）,ceftazidime（0 μg/ml,2 μg/ml,4 μg/ml,8 μg/ml,16 μg/ml）,and different time in vitro.Results： In our study,in the presence of subinhibitory concentrations of 4 μg/ml cefotaxime,the transfer rate is the highest.The transfer rate decreased with the increasing concentrations of cefotaxime,except the concentration of 0 μg/ml.And in the presence of 2 μg/ml ceftazidime,the transfer rate is the highest The transfer rate decreased with the increasing concentrations of ceftazidime,except the concentration of 0 μg/ml.Conclusion： In this study,it was found that the presence of different subinhibitory concentrations of Third-generation cephalosporin may effect the transfer of resisitant plasmid.When clinicians use antibiotic,they should consider these changes of subinhibitory concentrations of antibiotic in the treatment,choose a better therapy in time and decrease the spread of resistance bacteria.