摘要
目的 调查上海华山医院2007-2009年间VRE的分离率,并对耐药菌株的分子特性进行研究,为本地区VRE的预防和控制提供有价值的信息.方法 通过琼脂平板稀释法（ADSP）从临床鉴定的890株肠球菌中筛选VRE菌株,并通过微量肉汤稀释实验测其对万古霉素及替考拉宁的MIC;采用PCR及测序方法检测万古霉素耐药基因以及可能毒力基因esp,hyl;运用MLST对VRE进行克隆分型并通过PFGE分型技术进行验证.结果 ADSP法及微量肉汤稀释实验共筛选出13株VRE菌株.其中6株VRE（2007-2008年）只对万古霉素耐药,但对于替考拉宁敏感（万古霉素MIC64～256μg/ml）;耐药基因PCR产物测序结果提示这6株VRE均携带同一种可能导致万古霉素耐药的新型基因,该基因序列与已报道的耐药基因均不同;MLST及PFGE分型提示其属于不同型别.另外7株VRE（2009年1-7月）对万古霉素和替考拉宁的MIC结果分别为32～64μg/ml和16～32 μg/ml,耐药基因检测均为vanA.MLST分型结果提示13株VRE共分为4个不同的ST型,其中11株均属克隆复合型CC-17.13株VRE毒力基因esp和hyl的阳性率分别为69.2%和30.8%.结论 上海华山医院VRE克隆分型以CC17为主,同时发现上海华山医院存在一种可能导致万古霉素耐药的新型基因介导的VRE,该新基因的功能和定位尚待进一步研究.
Objective To investigate the prevalence of VRE in Huashan hospital of Shanghai from 2007 to 2009, and to examine the molecular characteristics of the VRE isolates.Methods A total of 890 non-repetive clinical isolates of Enterococcus were screened by the agar screening method （ ADSP method）.Broth dilution susceptibility test was performed to determine the antimicrobial susceptibility of Enterococcus isolates to vancomycin and teicoplanin.The resistant genes and virulent genes of VRE isolates were investigated by PCR and sequencing methods.VRE isolates were classified by MLST and six isolates of VRE from 2007 to 2008 were analyzed by PFGE.Results Thirteen VRE isolates were identified by ADSP method and broth dilution susceptibility test. Six of them were resistant to vancomycin but sensitive to teicoplanin （ vancomycin MICs were from 64 to 256 μg/ml）.The sequencing data of PCR products indicated these isolates might harbor a potential novel vancomycin resistant gene, which was different from the one reported in previous studies. The rest 7 isolates harbored vanA gene. The MICs of these isolates to vancomycin and teicoplanin were 32 - 64 μg/ml and 16 - 32 μg/ml, respectively.MLST results revealed 4 STs were identified in 13 VRE isolates.Eleven isolates belonged to clonal complexes（CC） 17.The positive rates of esp gene and hyl gene were 69.2% and 30.8%, respectively.Conclusions This study suggests that the most common VRE clone in Huashan Hospital was CC17.A potentially novel vancomycin resistance gene was identified, and further work needs to be done to investgate the function and the location of this novel gene.
出处
《中华检验医学杂志》
CAS
CSCD
北大核心
2010年第5期430-434,共5页
Chinese Journal of Laboratory Medicine
基金
上海市医学重点学科基金资助项目
上海市科务医学引导项目（09411967900）
关键词
万古霉素抗药性
肠球菌属
序列同源性
细菌分型技术
电泳
凝胶
脉冲场
vancomycin resistance
Enterococcus
Sequence homology
Bacterial typing techniques
Electrophoresis,gel, pulsed-field
