粪肠球菌耐高浓度庆大霉素转座子Tn5281的检测  

Detection of Transposon Tn5281 Mediating High-level Gentamicin Resistance in Enterococcus faecalis

作　　者：沈洪[1] 许淑珍[1] 

机构地区：[1]首都医科大学附属北京友谊医院,北京100050

出　　处：《中华医院感染学杂志》2006年第12期1331-1334,共4页Chinese Journal of Nosocomiology

基　　金：北京市自然科学基金项目(7012013)

摘　　要：目的研究转座子Tn5281在粪肠球菌耐高浓度庆大霉素(HLGR)中的作用。方法用聚合酶链反应(PCR)检测54株HLGR粪肠球菌Tn5281,扩增产物用斑点杂交和测序法验证;质粒接合转移试验采用滤膜法;CLSI/NCCLS推荐的琼脂稀释法进行药敏试验。结果54株粪肠球菌Tn5281转座子总检出率为50.0%,其中6株含完整型,17株含缺失Ⅰ型(缺失右侧IS256末端),4株含缺失Ⅱ型(缺失左侧IS256末端),各型均位于质粒上;4株接合转移成功中,3株为缺失Ⅰ型,1株为完整型;含Tn5281株对青霉素和氨苄西林的耐药率高于不含Tn5281的菌株,对四环素和氯霉素的耐药率低于不含Tn5281的菌株。结论Tn5281普遍存在于HLGR粪肠球菌中,可整合到接合性质粒上,在粪肠球菌HLGR播散中起着重要的作用。OBJECTIVE To explore the role of Tn5281 in high-level gentamicin resistance （HLGR） of Enterococcus faecalis. METHODS Fifty four strains of HLGR E. faecalis were tested for Tn5281 by PCR method. The PCR products were confirmed by dot blot hybridization and sequencing. Filter mating method was used to investigate the conjugative plasmid transfer. Antimicrobial susceptibility test was performed by agar dilution method of CLSI/NCCLS. RESULTS Of 54 HLGR E. faecalis strains, 27 （50. 0%） carried different types of Tn5281, with 6 strains carrying complete type, 17 strains carrying truncated type Ⅰ （lacked IS256 in the right flanking extremity） and 4 strains carrying truncated type Ⅱ （lacked IS256 in the left flanking extremity）. All types of transposons were loaded on plasmids. Among four HLGR E. faecalis in which Tn5281 was successfully transferred to recipient strains by filter mating method, one carried complete type and three carried truncated type Ⅰ . Tn5281 carrying strains had higher resistance rates to penicillin and ampicillin and lower resistance rates to tetracycline and chloramphenicol compared to the strains not carrying Tn5281. CONCLUSIONS Tn5281 is commonly carried by HLGR E. faecalis. It may integrate into conjugative plasmids and play an important role in the dissemination of HLGR among E. faecalis.

关 键 词：粪肠球菌 转座子 庆大霉素 耐药性 

分 类 号：R378.1[医药卫生—病原生物学]