产志贺毒素大肠埃希菌多重耐药分子机制的研究

发布时间：2018-01-02 16:30

本文关键词：产志贺毒素大肠埃希菌多重耐药分子机制的研究　出处：《吉林大学》2006年博士论文　论文类型：学位论文

【摘要】：产志贺毒素大肠埃希菌(Shiga toxin-producing E.coli,STEC)是世界范围内最严重的食源性致病菌。STEC耐药性产生与传播已受到世界广泛关注。为探讨STEC多重耐药性产生和传播机制,本研究采用PCR、接合与转化、克隆测序、Southern blot和酶切图谱分析等技术,在测定抗菌药物敏感性的基础上,对STEC分离株携带整合子、R质粒和耐药基因进行研究分析。结果表明多重耐药STEC染色体、R质粒携带1500bp ~750bp第1类整合子和dfrA1、aadA1基因盒及sul1、tem、tet、erm等耐药基因,传递对磺胺类、氨基糖苷类、β-内酰胺类、四环素类和红霉素类等抗菌药物的耐药性。发现了染色体上一种缺陷型及编码宋内志贺菌(S.sonnei)跨膜转运蛋白基因的第1类整合子。证明了STEC多重耐药菌株的出现和流行与农业、畜牧业将磺胺类、氨基糖苷类等抗菌药物作为动物生长促进剂长期使用有关。STEC在抗菌药物的选择压力下不断进化,通过整合子与R质粒促进多重耐药性的产生和扩散。本研究结果揭示了STEC在耐药性表达及耐药性传递方面的作用机制,为进一步更好地控制STEC基因水平的耐药性传播提供重要的科学依据。
[Abstract]:Shiga toxin producing Escherichia coli (Shiga toxin-producing, E.coli, STEC) is the world's most serious food borne pathogens, drug resistance and the spread of.STEC has received extensive concern in the world. In order to investigate the multi drug resistance of STEC generation and propagation mechanism, this study adopts PCR, engagement and conversion, cloning and sequencing, restriction map analysis technology Southern blot and enzymes, based on Determination of antimicrobial susceptibility of isolates carrying STEC, integron, research and analysis of R plasmid and resistant genes. The results show that the multidrug resistance of STEC chromosome, R plasmid carrying 1500bp ~ 750bp class first integron and dfrA1 gene cassette, aadA1 and sul1, TEM, Tet, ERM and other resistance genes. Transfer of sulfonamides, aminoglycosides, beta lactams, tetracyclines and erythromycin resistance such as antibiotics. Found a defective chromosome and encoding Shigella sonnei (S.sonnei) membrane Transporter gene class first integron. It is proved that the emergence of multi drug resistance strain STEC and popular with agriculture, animal husbandry will be sulfonamides, as animal growth promoter on.STEC in the long-term use of antimicrobial drug selection pressure evolving antibacterial aminoglycoside, through the production and diffusion of integrons and multiple R plasmid to promote drug resistance.
Our findings reveal the mechanism of STEC in drug resistance and drug resistance delivery, and provide important scientific evidence for further better control of drug resistance in STEC gene level.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2006
【分类号】：R378.2

【引证文献】