本文選題：鮑曼不動桿菌 + 16S　； 參考：《浙江大學》2007年碩士論文

【摘要】： 不動桿菌是一類不發(fā)酵糖的革蘭陰性桿菌，廣泛分布于水、土壤、醫(yī)院環(huán)境和人體的皮膚表面，已成為醫(yī)院獲得性感染的主要致病菌之一，主要引起醫(yī)院獲得性肺炎尤其是呼吸機相關性肺炎、菌血癥、尿路感染、繼發(fā)性腦膜炎等。隨著廣譜抗菌藥物的廣泛使用，，多重耐藥不動桿菌日趨增多，極易造成流行，給臨床抗感染治療帶來很大的困難，也對院內(nèi)感染的控制提出了新的要求。氨基糖苷類抗生素是臨床上治療革蘭陰性菌所致嚴重感染的常用藥，常與細菌細胞壁活性抗菌藥物聯(lián)合應用。近年來我國鮑曼不動桿菌分離率明顯增加，耐藥率也不斷上升。且已出現(xiàn)對β-內(nèi)酰胺類、氨基糖苷類、氟喹諾酮類抗菌藥物同時耐藥的多重耐藥菌株的流行。對多重耐藥鮑曼不動桿菌中新出現(xiàn)的耐藥機制進行研究有利于進一步了解耐藥的分子機理，指導臨床用藥。 本研究收集了2004年12月-2005年12月我國6省市8家省級醫(yī)院、浙江省11個地區(qū)17家市級醫(yī)院臨床分離的700株鮑曼不動桿菌；采用瓊脂稀釋法測定其對5種氨基糖苷類抗生素的MIC值；PCR篩選三種16S rRNA甲基化酶基因armA、rmtA、rmtB，克隆測序明確基因型；脈沖場凝膠電泳(PFGE)分析菌株的同源性；接合試驗、質粒抽提，以及Southern雜交確定armA基因定位。 結果顯示：700株鮑曼不動桿菌對妥布霉素、阿米卡星、慶大霉素、異帕米星、奈替米星耐藥率分別為67.7％、70.9％、75.7％、63.5％、71.5％；對5種氨基糖苷類抗生素全部耐藥菌株377株，其中334株檢出armA基因；未發(fā)現(xiàn)rmtA、rmtB基因陽性菌株。armA基因陽性菌株PFGE分型以A、B、C 3型為主。堿裂解法反復抽提未得到質粒，多次接合試驗未成功；Southern雜交顯示armA基因分別位于克隆A、B、C菌株染色體ApaI酶切片段約220kb、300kb、220kb大小的片段上。 以上研究表明16S rRNA甲基化酶基因armA在我國鮑曼不動桿菌中廣泛存在。armA基因位于鮑曼不動桿菌的染色體上。
[Abstract]:Acinetobacter is a class of gram-negative bacilli that do not ferment sugar. It is widely distributed in water, soil, hospital environment and the skin surface of human body, and has become one of the main pathogens of nosocomial infection. Hospital-acquired pneumonia, especially ventilator-associated pneumonia, bacteremia, urinary tract infection, secondary meningitis and so on. With the wide use of broad-spectrum antimicrobial agents, Acinetobacter multidrug resistance is increasing day by day, which is easy to cause epidemic, which brings great difficulties to clinical anti-infection treatment, and puts forward new requirements for the control of nosocomial infection. Aminoglycoside antibiotics are commonly used in the treatment of serious infections caused by Gram-negative bacteria, and are often used in combination with active antimicrobial agents of bacterial cell walls. In recent years, the isolation rate and drug resistance of Acinetobacter baumannii have increased. Multidrug resistant strains with simultaneous resistance to 尾-lactams, aminoglycosides and fluoroquinolones have been found. The study of the new mechanism of drug resistance in Acinetobacter baumannii is helpful to further understand the molecular mechanism of drug resistance and to guide clinical drug use. From December 2004 to December 2005, 700 strains of Acinetobacter baumannii were isolated from 8 provincial hospitals in 6 provinces of China and 17 municipal hospitals in 11 regions of Zhejiang Province. Three 16s rRNA methylase genes were screened by Agar dilution assay for five aminoglycoside antibiotics. The genotypes of three 16s rRNA methylase genes were identified by cloning and sequencing. The homology of the strains was analyzed by pulsed field gel electrophoresis (PFGE). And Southern hybridization to determine the location of armA gene. The results showed that the resistance rates of seven hundred strains of Acinetobacter baumannii to tobramycin, amikacin, gentamicin, isopamicin and netilmicin were 67.77.70.90 and 75.55.55%, respectively, and 377 strains were resistant to all 5 aminoglycoside antibiotics, of which 334 had armA gene. There was no PFGE typing of rmtAgna rmtB gene positive strain and armA gene positive strain. The plasmid was repeatedly extracted by alkaline cleavage method. Southern blot analysis showed that the armA gene was located on the ApaI fragment of the cloned strain Abora C with the size of about 220kb ~ 300kb ~ (2 +) ~ 220kb respectively. These results indicate that the 16s rRNA methylase gene armA is widely present in Acinetobacter baumannii in China, and the gene is located on the chromosome of Acinetobacter baumannii (Acinetobacter baumannii).
【學位授予單位】：浙江大學
【學位級別】：碩士
【學位授予年份】：2007
【分類號】：R378

【參考文獻】

相關期刊論文 前2條

1 沈依群,趙敏;氨基糖苷類抗生素的耐藥機制及控制耐藥性的策略[J];國外醫(yī)藥(抗生素分冊);2002年03期

2 鄭衛(wèi);氨基糖苷類抗生素研究的新進展[J];國外醫(yī)藥(抗生素分冊);2005年03期

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