产超广谱β-内酰胺酶革兰阴性菌分子耐药机制研究
发布时间：2018-07-27 13:48
【摘要】： 产超广谱β-内酰胺酶(extended spectrumβ-lactamases, ESBLs)是革兰阴性菌对β-内酰胺类抗菌药物广泛耐药的重要原因。本研究采用三相水解试验、聚合酶链反应(PCR)、限制性片断长度多态性分析(RFLP)、PCR-mapping、重复一致序列PCR(rep-PCR)、接合转移试验、质粒图谱分析以及克隆测序表达等方法,对产ESBLs肠杆菌科细菌和多重耐药铜绿假单胞菌的分子耐药机制进行了探讨。结果显示:革兰阴性菌临床分离株中产超广谱β-内酰胺酶(ESBLs)细菌的检出率高,且常为多重耐药菌株,所携带的ESBLs基因型以CTX-M型为主,可与广谱β-内酰胺酶基因、其它型别ESBLs基因以及DHA-1型质粒介导的AmpC酶基因共存。产ESBLs菌株I类整合子携带率较高,整合子内含有氨基糖苷类、甲氧苄胺嘧啶类和利福平等多种耐药基因盒,参与形成细菌的多重耐药表型,并可由质粒介导在不同菌株间通过接合方式传递其多重耐药性。本研究在整合子内发现了一个未知功能的开放读码基因,经克隆、测序、诱导表达及药敏试验分析,初步确定为一种新型二氢叶酸还原酶基因,编码对甲氧苄胺嘧啶类药物的耐药性。在海南地区首次发现产PER-1型ESBLs的铜绿假单胞菌,该菌株是其院内感染的主要流行株。本研究结果丰富和完善了我国东北及海南地区产ESBLs革兰阴性菌的分子流行病学资料,揭示了其多重耐药性产生和播散的作用机制,为临床更有效地预防和控制产ESBLs细菌感染提供了重要的科学依据。
[Abstract]:The production of extended-spectrum 尾 -lactamases (ESBLs) is an important reason for the widespread resistance of gram-negative bacteria to 尾 -lactam antibiotics. In this study, three phase hydrolysis test, polymerase chain reaction (PCR),) restriction fragment length polymorphism analysis, (RFLP) sequencing, repeat sequence PCR (rep-PCR), conjugation transfer test, plasmid map analysis and clone sequencing expression were used. The molecular resistance mechanism of ESBLs producing Enterobacteriaceae and multidrug resistant Pseudomonas aeruginosa was studied. The results showed that the detection rate of extended-spectrum 尾 -lactamase (ESBLs) bacteria in clinical isolates of Gram-negative bacteria was high, and it was often multidrug resistant. The ESBLs genotype was mainly CTX-M, which could be associated with the broad-spectrum 尾 -lactamase gene. Other types of ESBLs gene and DHA-1 plasmid mediated coexistence of AmpC gene. ESBLs producing strain I integron carries high rate, integron contains aminoglycoside, methoxybenzylamine, rifampicin and other multidrug resistant gene cassette, participate in the formation of multi-drug resistance phenotype of bacteria. The multidrug resistance of different strains can be transferred by the way of conjugation mediated by plasmids. In this study, an open reading gene with unknown function was found in integron. After cloning, sequencing, induced expression and drug sensitivity analysis, a novel dihydrofolate reductase gene was preliminarily identified. To encode resistance to methoxybenzylamine. Pseudomonas aeruginosa producing PER-1 type ESBLs was first found in Hainan. The results of this study enrich and improve the molecular epidemiological data of ESBLs producing gram-negative bacteria in Northeast China and Hainan, and reveal the mechanism of its multidrug resistance. It provides an important scientific basis for clinical prevention and control of ESBLs-producing bacterial infection.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2007
【分类号】：R378
本文编号：2148026
[Abstract]:The production of extended-spectrum 尾 -lactamases (ESBLs) is an important reason for the widespread resistance of gram-negative bacteria to 尾 -lactam antibiotics. In this study, three phase hydrolysis test, polymerase chain reaction (PCR),) restriction fragment length polymorphism analysis, (RFLP) sequencing, repeat sequence PCR (rep-PCR), conjugation transfer test, plasmid map analysis and clone sequencing expression were used. The molecular resistance mechanism of ESBLs producing Enterobacteriaceae and multidrug resistant Pseudomonas aeruginosa was studied. The results showed that the detection rate of extended-spectrum 尾 -lactamase (ESBLs) bacteria in clinical isolates of Gram-negative bacteria was high, and it was often multidrug resistant. The ESBLs genotype was mainly CTX-M, which could be associated with the broad-spectrum 尾 -lactamase gene. Other types of ESBLs gene and DHA-1 plasmid mediated coexistence of AmpC gene. ESBLs producing strain I integron carries high rate, integron contains aminoglycoside, methoxybenzylamine, rifampicin and other multidrug resistant gene cassette, participate in the formation of multi-drug resistance phenotype of bacteria. The multidrug resistance of different strains can be transferred by the way of conjugation mediated by plasmids. In this study, an open reading gene with unknown function was found in integron. After cloning, sequencing, induced expression and drug sensitivity analysis, a novel dihydrofolate reductase gene was preliminarily identified. To encode resistance to methoxybenzylamine. Pseudomonas aeruginosa producing PER-1 type ESBLs was first found in Hainan. The results of this study enrich and improve the molecular epidemiological data of ESBLs producing gram-negative bacteria in Northeast China and Hainan, and reveal the mechanism of its multidrug resistance. It provides an important scientific basis for clinical prevention and control of ESBLs-producing bacterial infection.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2007
【分类号】：R378
【引证文献】
相关博士学位论文 前1条
1 张若文;烧伤病房耐碳青霉烯类铜绿假单胞菌耐药机制及分子流行病学研究[D];吉林大学;2012年
相关硕士学位论文 前1条
1 张利娟;鲍曼不动杆菌16SrRNA甲基化酶基因检测及流行病学分析[D];天津医科大学;2012年
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