兰州地区临床分离大肠埃希菌与肺炎克雷伯菌产ESBLs的基因型及耐药性研究

发布时间：2018-01-26 18:24

本文关键词： 细菌耐药性监测超广谱 β-内酰胺酶 TEM SHV CTX-M 大肠埃希菌肺炎克雷伯菌　出处：《宁夏医科大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的:研究2013年兰州地区某三甲医院临床分离菌的分布和耐药特征,并对分离率较高的大肠埃希菌以及肺炎克雷伯菌中产超广谱β-内酰胺酶基因进行分型研究,了解兰州地区某三甲医院ESBLs的基因型,为临床合理选择抗菌药物提供依据。方法:以兰州地区某三甲医院2013年1月至2013年12月从临床分离的所有菌株为研究对象,采用纸片扩散法(K-B法)对分离菌株进行药敏试验根据CLSI 2013年标准判定药敏结果,用WHONET5.6软件对耐药性结果进行分析;用双纸片协同法对大肠埃希菌产超广谱β-内酰胺酶菌株进行表型确证;随机选取40株大肠埃希菌、20株肺炎克雷伯菌,应用PCR、琼脂糖胶凝胶电泳技术检测SHV、TEM以及CTX-M基因的携带情况。结果:2013年兰州地区某三甲医院共分离出细菌3160株(非重复株),其中革兰阴性杆菌占74.4%。大肠埃希菌、肺炎克雷伯菌中产ESBLs株的检出率分别为59.9%(292/870),26.4%(111/536)。碳青霉烯类药物仍然是肠杆菌科等革兰阴性杆菌最敏感的药物。产ESBLs大肠埃希菌中TEM的检出率为5.0%(2/40),SHV的检出率为42.5%(17/40),CTX-M基因检出率为85.0%(34/40);产ESBLs肺炎克雷伯菌中TEM的检出率为20.0%(4/20),SHV的检出率为75.0%(15/20),CTX-M基因检出率为75.0%(15/20)。结论:肠杆菌科细菌是主要的临床分离病原菌,大肠埃希菌和肺炎克雷伯菌是最常见的肠杆菌科病原菌。产ESBLs是大肠埃希菌和肺炎克雷伯菌最主要的耐药机制。产ESBLs是大肠埃希菌和肺炎克雷伯菌对常用的β-内酰胺类、氨基糖苷类、喹诺酮类抗菌药物的耐药率比非产ESBLs菌株的耐药率普遍偏高;大肠埃希菌和肺炎克雷伯菌产ESBLs的基因型主要为CTX-M型,其次为SHV型,TEM型的检出率最低。大肠埃希菌和肺炎克雷伯菌产ESBLs的基因型CTX-M型、SHV型和TEM型单独检出率较低,大部分菌株都含有2种或2种以上的,多种基因型共存于同一株菌中,介导细菌产生复杂的耐药表型。CTX-M型单独或合并有SHV、TEM型ESBLs对头孢噻肟的耐药率比头孢他啶和氨曲南的耐药率高。产ESBLs菌株的广泛传播,应引起广泛的关注只有加强细菌耐药监测并从分子水平对其耐药机制进行研究,才能合理规范使用抗菌药物,预防医院感染流行的发生。
[Abstract]:Objective: to study the distribution and drug resistance of clinical isolated bacteria in a third Class A Hospital in Lanzhou area in 2013. The genotypes of extended-spectrum 尾 -lactamases in Escherichia coli and Klebsiella pneumoniae with high isolation rate were studied to understand the genotype of ESBLs in a third class hospital in Lanzhou. Methods: all strains isolated from clinic from January 2013 to December 2013 in a third class hospital in Lanzhou area were studied. The drug sensitivity test of isolated strains was carried out by using disk diffusion method (K-B method) according to the CLSI 2013 standard, and the results of drug resistance were analyzed by WHONET5.6 software. The phenotype of extended-spectrum 尾 -lactamase producing strains of Escherichia coli was confirmed by double disk synergy method. Forty strains of Escherichia coli and 20 strains of Klebsiella pneumoniae were randomly selected to detect SHV by agarose gel electrophoresis. Results: in 2013, a total of 3160 strains (non-repeats) of bacteria were isolated from a third Class A Hospital in Lanzhou area. The positive rate of ESBLs in Escherichia coli and Klebsiella pneumoniae was 59.9% and 29.2% respectively. 26.4The carbapenem is still the most sensitive drug in Gram-negative bacilli such as Enterobacteriaceae. The detection rate of TEM in ESBLs producing Escherichia coli is 5.0% (. 2 / 40). The detection rate of CTX-M gene in SHV was 42.5% and the detection rate of CTX-M gene was 85.0%. The detection rate of TEM in Klebsiella pneumoniae was 20.0% and 75.0% (15 / 20). The detection rate of CTX-M gene was 75.0 / 20. Conclusion: Enterobacteriaceae is the main clinical isolated pathogen. Escherichia coli and Klebsiella pneumoniae are the most common pathogens of Enterobacteriaceae. ESBLs production is the main drug resistance mechanism of Escherichia coli and Klebsiella pneumoniae. ESBLs production is Escherichia coli and Klebsiella pneumoniae. Primary bacteria against 尾-lactams in common use. The resistance rate of aminoglycosides and quinolones was higher than that of non-producing ESBLs strains. The genotype of Escherichia coli and Klebsiella pneumoniae producing ESBLs was mainly CTX-M type, followed by SHV type. The detection rate of TEM type was the lowest, and that of Escherichia coli and Klebsiella pneumoniae genotype CTX-M and TEM was lower. Most of the strains contain two or more than two genotypes coexisting in the same strain which mediates the production of complex drug-resistant phenotype. CTX-M alone or combined with SHV. The resistance rate of TEM type ESBLs to cefotaxime was higher than that of ceftazidime and aztreonam. ESBLs producing strains were widely spread. Only by strengthening the monitoring of bacterial drug resistance and studying the mechanism of drug resistance at molecular level can the use of antimicrobial agents be reasonably standardized and the prevalence of nosocomial infection be prevented.
【学位授予单位】：宁夏医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R446.5

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