摘要
目的研究整合子在医院感染革兰阴性杆菌中的分布及其与病原菌耐药的相关性，探讨Ⅰ类整合子与临床耐药播散的关系。方法运用K—B法检测临床株的耐药表型，纸片扩散法检测产超广谱β-内酰胺酶（ESBLs），PCR扩增筛选含整合子的临床菌株，接合传递实验、套式PCR、质粒谱分析及DNA测序研究携带耐药基因的Ⅰ类整合子与耐药播散的关系。结果66．4％的医院感染革兰阴性杆菌Ⅰ类整合子阳性，未检测出Ⅱ、Ⅲ类整合子；Ⅰ类整合子可变区扩增片段大小从0．7～2．3kb，编码对氨基糖苷类、磺胺类抗菌药物和氯霉素耐药的基因；整合子阳性组中ESBLs、多药耐药菌均明显高于阴性组；整合子可通过质粒在不同菌属间水平传播。结论Ⅰ类整合子在医院感染革兰阴性杆菌中广泛分布，可通过质粒在不同菌属间水平传播，在耐药基因传播中起重要作用，应引起临床足够的重视。
OBJECTIVE To investigate the distribution of integron in Gram-negative isolates which are causing nosocomial infection the association with drug resistance, and it＇s contribution in horizontal transfer of drug resistance. METHODS Drug resistance test was performed by K-B method. ESBL-positive strains were detected by double-disk synergy test. Integron was determined by PCR assay with integron-specific-primer. Conjugative transfer test, plasmid profile analysis, nested-PCR, and DNA sequence analysis were used to investigate the transferable mechanism of integron mediated. RESULTS 66.4 % of Strains were shown to be positive for classes Ⅰ integron, no class Ⅱ and Ⅲ integrons were detected. Profiles of class Ⅰ integron were 11 types, which sized from 700bp to 2300bp, gene cassettes included genes encoding resistance to aminoglycosides （aadA1, aadA2, aadA5 and aacA4）, sulfamethoxazole/trimethoprim （dfrA12, dfrA5 and dfrA17） and chloramphenicol （eatB8）. Strains positive for class Ⅰ integron were highly related to multidrug resistance and ESBLs. Class Ⅰ integron could horizontal transfer along with plasmid among bacteria. CONCLUSIONS Class Ⅰ integron is widespread in Gramnegative isolates which are causing nosocomial infection. Drug resistance is more liable to horizontal transfer via class Ⅰ integron along with plasmid. It implies the necessary for surveillanee of horizontal transfer of antibiotic resistance gene among bacteria genus.
出处
《中华医院感染学杂志》
CAS
CSCD
北大核心
2008年第12期1651-1655,共5页
Chinese Journal of Nosocomiology
关键词
医院感染
革兰阴性杆菌
整合子
耐药
水平播散
Nosocomial infection
Gram-negative isolates
Integron
Drug resistance
Horizontal transfer
