肠杆菌科细菌质粒介导β-内酰胺类抗生素耐药性研究

发布时间：2018-06-16 08:22

  本文选题：肠杆菌科细菌 + β-内酰胺酶　； 参考：《天津医科大学》2006年硕士论文

【摘要】：[目的]研究肠杆菌科细菌中产超广谱β-内酰胺酶(ESBLs)及质粒介导AmpC酶菌株的分布。[方法]收集天津胸科医院2004年临床分离肠杆菌科细菌396株,以K-B法测定细菌对抗生素的敏感性;以NCCLS推荐纸片确证试验检测其产ESBLs情况,以头孢西丁试验粗筛产AmpC酶菌。以细菌接合试验辅助耐药基因的定位。提取质粒DNA作模板,采用聚合酶链反应(PCR)和多重PCR方法及序列分析确定ESBLs及质粒介导AmpC酶的基因型[结果]396株肠杆菌科细菌对氨苄西林耐药率高达91.4%,一、二代头孢菌素耐药率高于40%,三代头孢菌素中头孢噻肟耐药率达25.70%,庆大霉素耐药率达26.5%,环丙沙星耐药率达23.2%,复方磺胺耐药率达31.8%,三耐以上的多重耐药菌株达71.2%。其中产ESBLs菌株检出率为25.0%(99/396),疑似产AmpC酶菌株检出率为16.9%(67/396);产ESBLs菌株除对亚胺陪南仍保持较好的敏感性(99.0%)以外,对其他抗生素耐药率均高于40%,青霉素类和一、二代头孢菌素耐药率均为100%,三代头孢菌素中头孢噻肟耐药性最高,达79.6%。产ESBLs菌株接合试验阳性率为40.4%(40/99),疑似产AmpC酶菌株接合试验阳性率为10.4%(7/67),接合子药敏试验证实供体菌的耐药标妼部分或全部传递给受体菌;以40株接合试验阳性的产ESBLs菌株的质粒DNA为模板用PCR方法进行基因分型,结果显示TEM、SHV、CTX-M阳性率分别为50.0%、20.0%和67.5%,产2种型别ESBLs的菌株达61.3%;对7株接合试验阳性疑似产AmpC酶菌株提取其质粒DNA为模板,用PCR方法进行基因分型,结果有4株为DHA型阳性,其中2株菌同时产ESBLs,高度疑似为产超超广谱β-内酰胺酶(SSBL)菌株。随机抽取5株ESBLs扩增阳性的PCR产物进行序列分析,其结果证实2株TEM型扩增产物均属TEM-1型,经NCBI基因库查询和BLASTn比对,与奇异变形杆菌(AY729027)注册的相应序列的核
[Abstract]:[Objective] to study the distribution of ultra broad-spectrum beta lactamase (ESBLs) and plasmid mediated AmpC strains in Enterobacteriaceae bacteria. [Methods] 396 strains of Enterobacteriaceae isolated from Tianjin Chest Hospital in 2004 were collected and the sensitivity of bacteria to antibiotics was measured by K-B method; ESBLs was detected by NCCLS paper confirmation test. The bacterial conjugation test assisted the localization of the AmpC enzyme. The plasmid DNA was extracted as a template. The genotype of ESBLs and plasmid mediated AmpC was determined by the polymerase chain reaction (PCR) and multiple PCR methods. [results of the antibiotic resistance rate of ampicillin to 91.4%, one, two generation cephalosporins in]396 strains of Enterobacteriaceae. The rate of drug resistance was higher than 40%, the drug resistance rate of cefotaxime in the three generation cephalosporins was 25.70%, the drug resistance rate of gentamicin was 26.5%, the rate of ciprofloxacin resistance was 23.2%, the drug resistance rate of compound sulfonamides was 31.8%, and three resistant multiple resistant strains were 71.2%., the detection rate of ESBLs producing strains was 25% (99/396), and the detection rate of suspected producing AmpC enzyme strains was 16.9% (67/396). The resistance rate of ESBLs producing strain was higher than 40%, the resistance rate of penicillins and two generation cephalosporins was 100%, and cefotaxime in the three generation cephalosporins was the highest, and the positive rate of the 79.6%. producing ESBLs strain was 40.4% (40/99), and the suspected production of AmpC enzyme bacteria was suspected. The positive rate of the strain joint test was 10.4% (7/67). The drug sensitivity test of the zygote confirmed that the drug resistance of the donor bacteria was partly or all passed to the receptor bacteria, and the plasmid DNA of the ESBLs producing strain of 40 strains of conjugal test was genotyping by PCR method. The results showed that the positive rates of TEM, SHV, and CTX-M were 50%, 20% and 67.5%, respectively, and produced 2 types of ESBL. The strain of S was 61.3%, and the plasmid DNA was extracted from 7 strains of conjugal test, and its plasmid DNA was extracted as a template and PCR was used to genotyping. The results showed that 4 strains were DHA positive, of which 2 strains produced ESBLs at the same time and highly suspected to produce super broad-spectrum beta lactamase (SSBL) strain. 5 ESBLs amplification positive PCR products were randomly selected for sequence. The results showed that the 2 TEM type amplified products belong to the TEM-1 type, the NCBI gene pool query and the BLASTn comparison, and the corresponding sequences of the corresponding sequences registered with Proteus mirabilis (AY729027)
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R378.2

【引证文献】

相关硕士学位论文 前1条

1 吴晓妹;肠杆菌科临床耐药株中ISCR1元件与耐药基因水平传播的关系研究[D];天津医科大学;2011年

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