利奈唑胺体外诱导粪肠球菌中介耐药及机制研究

目的 研究利奈唑胺对粪肠球菌中介耐药的体外诱导作用并探讨其耐药机制.方法 采用多步诱导法对4株临床分离粪肠球菌以及质控菌株进行体外诱导耐药试验,采用琼脂平皿二倍稀释法测定诱导前后的MIC值,采用PCR测序法检测粪肠球菌4个23S rRNA V区基因的变异.结果 4株临床分离粪肠球菌和质控菌株均诱导出中介株和稳定耐药株,在中介株和耐药株中均检测到了G2576U、G2505A和C2424U变异,2株中介株和耐药株还同时存在G2576U和C2424U变异.结论 利奈唑胺可体外诱导粪肠球菌产生中介株和稳定性耐药株,粪肠球菌中介株即可出现23S rRNA V区基因变异.

Intermediate resistance of Enterococcus faecali induced induced by linezolid in vitro and the mechanism

Objective To explore the in vitro linezolid-induced intermediate resistance of Enterococcus faeealis and its mechanism. Methods Multi-step in vitro induction by using linezolid was conducted with 4 Enterococcus faecalis isolates and 1 reference strain. The minimum inhibitory concentrations （MICs） were determined by agar dilution method. And the varia- tions of 23S rRNA V region gene of Enterococcus faeealis were detected by PCR sequencing. Results The intermediate-re- sistant strains from 4 Enterococeus faecalis isolates and 1 reference isolate.were successfully induced The G2576U, G2505A and C2424U mutations were detected in the intermediate-resistant strains. The G2576U and C2424U mutations were both de- tected in 2 intermediary and resistant strains. Conclusion Linezolid can induce intermediate resistance in Enterococcus fae- calis in vitro, 23S rRNA V region gene mutations can be dteteced in the intermediate-resistant strains of Enterococcus faecalis.