【摘要】： 產(chǎn)超廣譜β-內(nèi)酰胺酶(extended spectrumβ-lactamases, ESBLs)是革蘭陰性菌對(duì)β-內(nèi)酰胺類(lèi)抗菌藥物廣泛耐藥的重要原因。本研究采用三相水解試驗(yàn)、聚合酶鏈反應(yīng)(PCR)、限制性片斷長(zhǎng)度多態(tài)性分析(RFLP)、PCR-mapping、重復(fù)一致序列PCR(rep-PCR)、接合轉(zhuǎn)移試驗(yàn)、質(zhì)粒圖譜分析以及克隆測(cè)序表達(dá)等方法,對(duì)產(chǎn)ESBLs腸桿菌科細(xì)菌和多重耐藥銅綠假單胞菌的分子耐藥機(jī)制進(jìn)行了探討。結(jié)果顯示:革蘭陰性菌臨床分離株中產(chǎn)超廣譜β-內(nèi)酰胺酶(ESBLs)細(xì)菌的檢出率高,且常為多重耐藥菌株,所攜帶的ESBLs基因型以CTX-M型為主,可與廣譜β-內(nèi)酰胺酶基因、其它型別ESBLs基因以及DHA-1型質(zhì)粒介導(dǎo)的AmpC酶基因共存。產(chǎn)ESBLs菌株I類(lèi)整合子攜帶率較高,整合子內(nèi)含有氨基糖苷類(lèi)、甲氧芐胺嘧啶類(lèi)和利福平等多種耐藥基因盒,參與形成細(xì)菌的多重耐藥表型,并可由質(zhì)粒介導(dǎo)在不同菌株間通過(guò)接合方式傳遞其多重耐藥性。本研究在整合子內(nèi)發(fā)現(xiàn)了一個(gè)未知功能的開(kāi)放讀碼基因,經(jīng)克隆、測(cè)序、誘導(dǎo)表達(dá)及藥敏試驗(yàn)分析,初步確定為一種新型二氫葉酸還原酶基因,編碼對(duì)甲氧芐胺嘧啶類(lèi)藥物的耐藥性。在海南地區(qū)首次發(fā)現(xiàn)產(chǎn)PER-1型ESBLs的銅綠假單胞菌,該菌株是其院內(nèi)感染的主要流行株。本研究結(jié)果豐富和完善了我國(guó)東北及海南地區(qū)產(chǎn)ESBLs革蘭陰性菌的分子流行病學(xué)資料,揭示了其多重耐藥性產(chǎn)生和播散的作用機(jī)制,為臨床更有效地預(yù)防和控制產(chǎn)ESBLs細(xì)菌感染提供了重要的科學(xué)依據(jù)。
[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.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2007
【分類(lèi)號(hào)】：R378

【引證文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 張若文;燒傷病房耐碳青霉烯類(lèi)銅綠假單胞菌耐藥機(jī)制及分子流行病學(xué)研究[D];吉林大學(xué);2012年

相關(guān)碩士學(xué)位論文 前1條

1 張利娟;鮑曼不動(dòng)桿菌16SrRNA甲基化酶基因檢測(cè)及流行病學(xué)分析[D];天津醫(yī)科大學(xué);2012年

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本文編號(hào)：2148026