摘要
目的:研究志贺菌中Ⅱ类整合子的流行现状、与耐药的相关性及其携带的耐药基因。方法:K-B法测定26株志贺菌的药敏情况;PCR-限制片段长度多态性(RFLP)筛查整合子并分类;长片段PCR扩增Ⅱ类整合子可变区并进行序列测定。结果:65.4%(17/26例)的志贺菌中检出整合子,PCR-RFLP结果显示均含有Ⅱ类整合子,其中有12例还同时含有Ⅰ类整合子;17例Ⅱ类整合子保守区阳性的标本,有16例可变区扩增亦阳性,大小约为2200bp,对其测序结果显示含有编码对磺胺类抗生素耐药的基因dfrA1、对链丝菌素耐药的基因sat1和对氨基糖苷类抗生素耐药的基因aadA1。结论:在国内率先报道了Ⅱ类整合子广泛存在于志贺菌中。Ⅱ类整合子与志贺菌的耐药具有相关性。
Objective： To investigate the incidence of class Ⅱ integrons in Shigella strains,and to analyze the correlation between integrons and drug resistance of Shigella and to study, resistance genes that class Ⅱ integron containes. Methods： The antibiotic susceptibility of 26 strains of Shigella was tested by K-B methods. The classification of integrons was performed by analyzing the positive PCR products using restriction fragment length pelymorphism （RFLP）. The variable region of class Ⅱ integron was amplified by long fragment PCR, and the PCR products were sequenced. Results： Seventeen of the 26 isolates （65.4%） showed positive integrons, and PCR-RFLP analysis revealed that all contained class Ⅱ integron, 12 strains of which also contained class Ⅰ integron. Sixteen of the 17 strains contained a 2 200 bp gene cassette. The sequence of the fragment revealed three resistance genes encoding resistance against sulfamethoxazole/trimethoprim （dfrA Ⅰ）, streptothricin （satl） and aminoglycosides （aadA Ⅰ）. Conclusion： Class Ⅱ integrons are widespread in Shigella strains in domestic,and closely associated with the resistance of ShigeUa.
出处
《南京医科大学学报（自然科学版）》
CAS
CSCD
北大核心
2006年第4期225-229,共5页
Journal of Nanjing Medical University(Natural Sciences)
关键词
Ⅱ类整合子
志贺菌
耐药
class Ⅱ integron
Shigella
resistance
