本文關(guān)鍵詞：大腸桿菌超突變子產(chǎn)生的分子基礎(chǔ)及其在耐藥性發(fā)生和轉(zhuǎn)移中的作用　出處：《吉林大學(xué)》2007年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 超突變子 大腸桿菌 耐藥性 甲基導(dǎo)向錯(cuò)配修復(fù)系統(tǒng) 防突變濃度 耐藥性發(fā)生和轉(zhuǎn)移

【摘要】： 超突變子的突變頻率是正常菌株突變頻率的1000倍以上，超突變子的出現(xiàn)，可能使細(xì)菌更適應(yīng)目前治療量的抗菌藥物濃度，加速耐藥性的產(chǎn)生。本研究首先測定了318株不同來源大腸桿菌對環(huán)丙沙星等12種抗菌藥物的MIC、MPC，抑菌作用最強(qiáng)的是獸醫(yī)臨床上使用較少的AM，耐藥率僅為0.94％，AMO、TET耐藥率最高，達(dá)到90％以上：其中以耐6種抗菌藥物的菌株數(shù)最多，達(dá)到88株；ENR的MPC_(90)與MPC_(90)／MIC_(90)均最小，AM、CIP、OFL次之，說明這幾種藥物在臨床選擇耐藥突變菌株的能力較小，GEN、NOR、SPE等藥物的MPC_(90)／MIC_(90)較大，有較強(qiáng)的選擇突變能力。測定24株菌株的突變頻率，篩選出3株超突變子，PFGE分型表明，，其帶型與其他菌株差異顯著。采用長片段PCR、Western-blotting、質(zhì)�；パa(bǔ)實(shí)驗(yàn)對大腸桿菌野生型和超突變子的MMR重要組分MutS進(jìn)行研究，超突變子mutS基因存在大片段缺失，MutS無表達(dá)，無活性，說明大腸桿菌超突變子發(fā)生的分子基礎(chǔ)是其MMR系統(tǒng)重要組分MutS存在缺陷。耐藥基因檢測和膜蛋白分析表明，其耐藥表型和基因型相符。進(jìn)行濾膜接合試驗(yàn)表明，以超突變子為受體菌的轉(zhuǎn)接合子的轉(zhuǎn)化頻率較高，接合在超突變子中容易發(fā)生，超突變子促進(jìn)了耐藥基因在不同菌株之間的轉(zhuǎn)移。
[Abstract]:The mutation frequency of super mutator is normal strain mutation frequency of more than 1000 times, super mutants, may make the bacteria more adapt to the current treatment volume concentration of antibiotics, accelerate resistance. In this study, the determination of 318 different strains of Escherichia coli to ciprofloxacin 12 antibacterial agents such as MIC, MPC, antibacterial the strongest effect is to use fewer veterinary clinical AM, drug resistance rate is only 0.94%, AMO TET, the highest resistant rate reached more than 90%: one to 6 kinds of antimicrobial resistant strains was the most, to reach 88 strains; ENR MPC_ (90) and MPC_ (90) / MIC_ (90) was the smallest. AM, CIP, OFL, showed this kind of drug resistant mutant strains in the clinical ability of small, GEN, NOR, SPE and other drug MPC_ (90) / MIC_ (90), there is a strong selection of mutations ability. The mutation frequency was determined in 24 strains, 3 strains were screened with super mutants. PFGE type table Ming, the belt type and other strains were significantly different. The PCR long fragment, Western-blotting, plasmid complementation of Escherichia coli mutants and wild type super important constituent of MMR MutS were studied. The super mutant mutS gene deletions in MutS, no expression, no activity, said the molecular basis of Escherichia coli from super bright which place is an important group of the MMR MutS system defects. Detection of drug resistance genes and membrane protein analysis showed that the phenotype and genotype of resistance. Conjugation test shows that the membrane, with ultra high frequency of transformation for the mutator conjugations of receptor strain, joint easily occurred in the super mutants, super mutants to promote the transfer of resistance genes between different strains.

【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
【分類號(hào)】：S852.61;R378.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

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2 郭成明;喹諾酮類藥物發(fā)展概況[J];天津藥學(xué);1997年04期

本文編號(hào)：1417719