本文選題：銅綠假單胞菌　切入點(diǎn)：啟動(dòng)子　出處：《西北大學(xué)》2007年碩士論文

【摘要】： 銅綠假單胞菌(Pseudomonas aeruginosa，PA)感染是目前各種醫(yī)院內(nèi)感染中最廣泛、最嚴(yán)重的問(wèn)題之一。有報(bào)道指出它所引起的院內(nèi)感染約占10％～35％，居病原菌之首。銅綠假單胞菌為一種條件致病菌，，因天然具有多重耐藥性，臨床治療困難很大。通過(guò)研究其致病機(jī)理和耐藥機(jī)制，人們?cè)噲D了解并最終控制銅綠假單胞菌引起的感染。 在銅綠假單胞菌的耐藥性中起重要作用的因素是細(xì)胞膜的低通透性和在細(xì)胞膜上存在各種RND外排泵。分析銅綠假單胞菌基因組信息的結(jié)果表明，在銅綠假單胞菌中一共有12種已知的及可能的RND外排泵系統(tǒng)。本研究在基因轉(zhuǎn)錄水平對(duì)這12個(gè)已知及可能的RND外排泵進(jìn)行了系統(tǒng)分析。將銅綠假單胞菌中所有編碼RND泵基因的啟動(dòng)子都克隆到一個(gè)帶有報(bào)告基因luxCDABE的低拷貝質(zhì)粒上。通過(guò)檢測(cè)報(bào)道子的發(fā)光量，來(lái)研究這些RND基因的表達(dá)和調(diào)節(jié)。將這些質(zhì)粒轉(zhuǎn)化到銅綠假單胞菌后，在各種條件下研究表達(dá)量的變化，揭示RND外排泵對(duì)不同化合物的外排功能。研究結(jié)果表明：慶大霉素能誘導(dǎo)RND外排泵J和I的表達(dá)，RND外排泵J能被四環(huán)素誘導(dǎo)，但是不能被屬于同一類抗生素土霉素的誘導(dǎo)。12種RND外排泵中，有11種受到氨芐青霉素的誘導(dǎo)。有機(jī)溶劑如乙醚、乙酸乙酯不能誘導(dǎo)RND外排泵的表達(dá)。由基因PA4206、PA4207和PA4208組成的RND外排泵，不僅受抗生素的誘導(dǎo)，而且還受到金屬離子如鋅離子的調(diào)節(jié)。由基因PA2520、PA2521和PA2522組成的RND外排泵不僅能夠向外排出鋅離子、鈷離子，而且還能向外排出抗生素如氯霉素；這些RND外排泵在向外排出的物質(zhì)如抗生素，在結(jié)構(gòu)上沒(méi)有明顯相關(guān)性，并且在某些情況下存在金屬離子和抗生素的協(xié)同作用。
[Abstract]:Pseudomonas aeruginosaformis (PAA) infection is one of the most extensive and serious nosocomial infections at present. It has been reported that the nosocomial infection caused by Pseudomonas aeruginosa is about 103.35%, ranking first among pathogens. Pseudomonas aeruginosa is a conditional pathogen. Because of the natural multidrug resistance, clinical treatment is very difficult. Through the study of its pathogenesis and drug resistance mechanism, people try to understand and ultimately control the infection caused by Pseudomonas aeruginosa. The factors that play an important role in the drug resistance of Pseudomonas aeruginosa are the low permeability of cell membrane and the existence of various RND efflux pumps on the membrane. There are 12 known and possible RND efflux pump systems in Pseudomonas aeruginosa. In this study, 12 known and possible RND efflux pumps were systematically analyzed at the gene transcription level. The promoter of the RND pump gene was cloned into a low copy plasmid with the reporter gene luxCDABE. To study the expression and regulation of these RND genes. After these plasmids were transformed into Pseudomonas aeruginosa, the expression levels were studied under various conditions. The results showed that gentamycin could induce the expression of J and I of RND efflux pump J could be induced by tetracycline. But 11 of the 12 RND efflux pumps that cannot be induced by oxytetracycline belong to the same class of antibiotics, 11 of which are induced by ampicillin. Ethyl acetate could not induce the expression of RND efflux pump, and the RND efflux pump composed of PA4206, PA4207 and PA4208 was not only induced by antibiotics. The RND efflux pump composed of PA2520 + PA2521 and PA2522 can not only excrete zinc ions and cobalt ions, but also release antibiotics such as chloramphenicol. The effluents of these RND efflux pumps, such as antibiotics, have no obvious structural correlation, and in some cases there is a synergistic effect of metal ions and antibiotics.
【學(xué)位授予單位】：西北大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2007
【分類號(hào)】：R378.991

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相關(guān)期刊論文 前2條

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