本文選題：銅綠假單胞菌　切入點(diǎn)：轉(zhuǎn)座突變　出處：《西北大學(xué)》2006年碩士論文　論文類型：學(xué)位論文

【摘要】：銅綠假單胞菌是(Pseudomonas aeruginosa)一種機(jī)會(huì)致病菌,它可以在人群中引起嚴(yán)重的急性和慢性感染,是病人在醫(yī)院期間發(fā)生感染的第三大致病菌。許多抗生素對(duì)其具有一定的治療作用,但銅綠假單胞菌有一個(gè)重要特性是它對(duì)許多抗生素具有很高的內(nèi)在抗藥性。因此開發(fā)新的抗生素是控制銅綠假單胞菌感染的有效途徑。 抗生素作為微生物分泌出來的一種化學(xué)物,它除傳統(tǒng)的殺菌或抑菌外,還表現(xiàn)出了其他的一些活性。在低于最小抑制濃度條件下,它作為一種化學(xué)信號(hào)對(duì)許多基因的表達(dá)起著重要的調(diào)節(jié)作用。研究低于最小抑制濃度抗生素將有助于我們更好的了解病原菌的致病性和耐藥性,從而找到細(xì)菌對(duì)抗生素的耐藥靶點(diǎn)。在本實(shí)驗(yàn)中,通過構(gòu)建的啟動(dòng)子-lux報(bào)道子為載體,研究了低于最小抑制濃度的抗生素對(duì)銅綠假單胞菌中的一些致病因子基因表達(dá)的影響,結(jié)果表明:1.低于最小抑制濃度的抗生素(1/4和1/8 MIC)的四環(huán)素對(duì)所構(gòu)建的31個(gè)基因中的一部分表達(dá)具有明顯的調(diào)節(jié)作用,在所研究的31個(gè)基因中,受到激活作用的有21個(gè),與對(duì)照相比,表達(dá)量變化最高的超過10倍。2.為了了解基因表達(dá)受抗生素調(diào)節(jié)的部分途徑,我們通過轉(zhuǎn)座突變的方法,以受四環(huán)素(Tetracycline)調(diào)節(jié)的吩嗪合成基因pKD-phzAl為研究對(duì)象,找到了30個(gè)負(fù)調(diào)節(jié)基因,這些基因能使四環(huán)素對(duì)pKD-phzAl的調(diào)節(jié)程度降低;20個(gè)正調(diào)節(jié)基因,它們促使四環(huán)素對(duì)pKD-phzA1的調(diào)節(jié)程度提高,其最大程度達(dá)到20倍;3.在所選取的兩個(gè)突變體中,確定這兩個(gè)突變基因是通過細(xì)菌群體感應(yīng)(quorum-sensing)而影響四環(huán)素對(duì)pKD-phzAl表達(dá)水平的調(diào)節(jié),從而可以了解該基因?qū)KD-phzAl表達(dá)的調(diào)節(jié)途徑;
[Abstract]:Pseudomonas aeruginosa, a opportunistic pathogen, can cause severe acute and chronic infections in the population, and is the third leading cause of infection in hospital. Many antibiotics have a certain therapeutic effect on it. However, an important characteristic of Pseudomonas aeruginosa is its high intrinsic resistance to many antibiotics. Therefore, the development of new antibiotics is an effective way to control the infection of Pseudomonas aeruginosa. Antibiotics, as a chemical secreted by microbes, exhibit some other activities in addition to traditional bactericidal or bacteriostatic activities. As a chemical signal, it plays an important role in regulating the expression of many genes. The study of antibiotics below the minimum inhibitory concentration will help us to better understand the pathogenicity and drug resistance of pathogenic bacteria. In this study, the expression of some pathogenic factors in Pseudomonas aeruginosa was studied by using the promoter lux reporter as the vector, and the effect of antibiotics below the minimum inhibitory concentration on the gene expression of some pathogenic factors in Pseudomonas aeruginosa. The results showed that tetracycline (1 / 4 and 1 / 8 MICM) below the minimum inhibitory concentration significantly regulated the expression of some of the 31 genes constructed. Of the 31 genes studied, 21 were activated. In order to understand some pathways of gene expression regulated by antibiotics, the phenazine synthetic gene pKD-phzAl regulated by Tetracycline (Tetracycline) was studied by transposition mutation. Thirty negative regulatory genes were identified, which reduced the regulatory degree of tetracycline to pKD-phzAl, and 20 positive regulatory genes, which increased the regulatory degree of tetracycline to pKD-phzA1 with a maximum of 20 times. It is confirmed that these two mutant genes affect the regulation of tetracycline on the expression of pKD-phzAl by means of bacterial population induction quorum-sensing, so as to understand the regulatory pathway of the gene to the expression of pKD-phzAl.
【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】：2006
【分類號(hào)】：R378

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 李苓苓;銅綠假單胞菌中影響吩嗪合成基因操縱子phzA1的調(diào)節(jié)基因的研究[D];西北大學(xué);2008年

2 劉廣帥;雪豹腸道菌群多樣性研究[D];曲阜師范大學(xué);2013年

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本文編號(hào)：1646186