肺炎克雷伯分离株耐药性和毒力基因的相关性研究

发布时间：2017-12-28 10:31

本文关键词：肺炎克雷伯分离株耐药性和毒力基因的相关性研究　出处：《苏州大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的:为了解肺炎克雷伯菌的耐药性和毒力基因的相关性,本研究通过对肺炎克雷伯菌临床分离株的耐药性及毒力基因进行分析,了解其耐药谱和毒力基因分布,并分析两者间的相关性,为临床治疗提供理论基础。同时作同源性分析,分析肺炎克雷伯菌间的种系发生关系,为菌株的变异、分化、传播寻找规律。方法:通过收集119株肺炎克雷伯分离株,对其采用药敏纸片法分析耐药性,用PCR技术检测耐药基因SHV、TEM、CTX-M、OXA筛选肺炎克雷伯菌株中的ESBLs菌株,用PCR技术检测7种毒力基因rmp A、aer-1、aer-2、mag A、gyrb-2、ybt、wca G,比较ESBLs肺炎克雷伯菌菌株与非ESBLs肺炎克雷伯菌菌株之间毒力基因分布率,分析多重耐药和毒力基因分布,并分析两者间的相关性。用Bio Edit软件编辑序列,截成有相同数目位点的片段,用MEGA-4作聚类性和种系发生树进行同源性分析。结果:119株肺炎克雷伯分离株筛选耐药基因SHV、TEM、CTX-M、OXA检测出的阳性菌分别为18、20、26、6株,筛选出ESBLs肺炎克雷伯菌32株。119株肺炎克雷伯菌临床分离株进行多重耐药谱的分析,耐三种及以上抗菌药物的多重耐药率达可达41.17%,耐8-12种抗生素的菌株占得30.25%。119株肺炎克雷伯临床分离株中不同毒力基因的检出率之间差异具有统计学意义(P0.05)。119株肺炎克雷伯临床分离株中含有2种、3种、4种、5种不同毒力基因的菌株占有率相对较高,均在15%以上。对ESBLs与非ESBLs肺炎克雷伯菌菌株之间毒力基因分布率的比较,可明显看出ESBLs的肺炎克雷伯菌的毒力基因分布率较非ESBLs分布率低很多。对分离株的多重耐药率和毒力基因数进行相关性分析,毒力基因分布数与耐药性间的相关系数为-0.227(P0.05),呈负相关,具有显著性差异,表明毒力基因数与耐药性间有显著相关性;也就是说,毒力基因分布数越多的菌株,多重耐药现象出现的几率就越小。毒力基因分布数与耐药基因数间的相关系数为-0.195(P0.05),呈负相关,具有显著性差异,表明毒力基因数与耐药基因数间有显著相关性;也就是说,毒力基因分布数越多的菌株,耐药基因分布数出现的几率就越小。用MEGA-4作出种系发生树如下图,共有A、B、C、D、E、F六个群,由图表看出A群为优势群,其次为B群。ESBLs主要在A群,其他群主要以非ESBLs为主。在A群中,非ESBLs中含有的毒力基因相对其他群非ESBLs中含有的毒力基因少,通过对应前面的耐药与毒力的关系,可发现B、C、D、E、F分类群是多毒力基因群,A群是少毒力基因群。各菌群间同源性较高,存在某一克隆群的暴发。结论:肺炎克雷伯菌的耐药性与毒力基因分布存在着相关性,更倾向于存在负相关,毒力基因分布数越多的分离株,多重耐药现象出现的概率就越小,为临床上对该菌合理的治疗及抗生素的合理的使用提供了一些理论依据。根据种系发生树看出,院内感染的肺炎克雷伯菌有某一克隆株的流行和传播。
[Abstract]:Objective: to correlation between antibiotic resistance and virulence gene solutions of Klebsiella pneumoniae isolated from this study, through the analysis of drug resistance and virulence genes of Klebsiella pneumoniae clinical isolates, the resistance spectrum distribution and virulence genes, and to analyze the correlation between the two, providing a theoretical basis for the clinical treatment of. At the same time, the homology analysis was used to analyze the relationship between Klebsiella pneumoniae (Klebsiella pneumoniae) and the variation, differentiation and propagation of the strains. Methods: by collecting 119 strains of Klebsiella pneumoniae isolates, the Kirby Bauer method analysis of drug resistance, screening ESBLs isolates of Klebsiella pneumoniae strains using PCR technique for the detection of resistance genes SHV, TEM, CTX-M, OXA, PCR detection of 7 virulence genes RMP, A, aer-1, aer-2, MAG, A gyrb-2, YBT, WCA, G, ESBLs between Klebsiella pneumoniae strains and non ESBLs Klebsiella pneumoniae virulence gene distribution, analysis of the distribution of multidrug resistance and virulence genes, and to analyze the correlation between the two. The sequence of Bio Edit software was used to cut into fragments with the same number of loci, and MEGA-4 was used as a clustering and phylogeny tree to analyze the homology. Results: 119 strains of Klebsiella pneumoniae isolates were screened for resistance genes SHV, TEM, CTX-M and OXA. The positive bacteria were 18, 20, 26 and 6, respectively. 32 strains of ESBLs Klebsiella pneumoniae were screened out. 119 strains of Klebsiella pneumoniae clinical isolates were analyzed for multi drug resistance. The multi drug resistance rate of three or more antibiotics was up to 41.17%, and that of 8-12 kinds of antibiotics accounted for 30.25%. The differences in the detection rates of different virulence genes in 119 klebber clinical isolates were statistically significant (P0.05). The 119 strains of klebber clinical isolates containing 2, 3, 4 and 5 different virulence genes were relatively high, all of which were above 15%. Comparing the distribution of virulence genes between ESBLs and non ESBLs Klebsiella pneumoniae, it is obvious that the distribution of virulence genes in ESBLs is much lower than that in non ESBLs. The correlation analysis of the rate of multi drug resistance and virulence gene number of isolates, the distribution of the correlation coefficient between the number of virulence genes and drug resistance of -0.227 (P0.05), negative correlation, with a significant difference, indicate the number of virulence genes and drug resistance are significantly correlated; that is to say, the more the number of virulence gene distribution of strains, probability the emergence of multi drug resistance phenomenon is smaller. The correlation coefficient distribution of virulence genes and resistance genes between the number of the number of -0.195 (P0.05), negative correlation, with a significant difference, indicate the number of virulence genes and resistance gene number was significantly correlated; that is to say, the more the number of virulence gene distribution of strains, the probability distribution of resistance genes in the number of smaller. Using MEGA-4 to make the tree of lineage generation as below, there are six groups of A, B, C, D, E, F, and the chart shows that A group is the dominant group, followed by the B group. ESBLs is mainly in the A group, and the other groups are mainly non - ESBLs. In the A group, the virulence genes in non ESBLs contain less virulence genes than those in other ESBLs groups. By means of the corresponding relationship between resistance and virulence, it can be found that B, C, D, E and F have multiple virulence genes, and A group is a virulence gene group. The homology of each group was high, and there was a outbreak of a clone. Conclusion: the drug resistance and virulence gene distribution of Klebsiella pneumoniae correlation exists, more likely to have negative correlation, the distribution of virulence genes number of isolates, the probability of the emergence of multi drug resistance phenomenon is smaller, and provides some theoretical basis for clinical treatment of the bacteria and antibiotics reasonable reasonable use. According to the phylogeny tree, the infection of Klebsiella pneumoniae has the prevalence and spread of a clone.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R446.5

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