多重耐药鲍曼不动杆菌基因组多态性及耐药基因组的研究

发布时间：2018-05-20 12:18

  本文选题：多重耐药 + 鲍曼不动杆菌　； 参考：《中国人民解放军军医进修学院》2011年博士论文

【摘要】：背景： 多重耐药鲍曼不动杆菌是引起医院感染的重要条件致病菌,给院内感染防控和治疗提出了严峻的挑战。本文报道了多重耐药鲍曼不动杆菌临床分离株的基因组多态性,以及代表性流行克隆株AB07104、AB0868和AB0715的全基因组序列,并进行了耐药基因组的初步分析。 方法： 采用多重PCR方法快速鉴定多重耐药鲍曼不动杆菌；分别应用DiversiLab微生物基因组分型系统、基于序列型多重PCR方法和MLST分型技术对194株多重耐药鲍曼不动杆菌的分子流行特征进行分析,将上述3种基因分型技术进行合理组合,建立了多重耐药鲍曼不动杆菌的分子溯源系统；利用在线细菌基因组注释系统BASys对3株菌(AB07104、AB0868和AB0715)的全基因组序列进行注释,确定了编码基因,在此基础上,综合利用相关的分子生物信息学分析软件,在全基因组水平扫描所有与耐药相关的基因元件,从耐药基因组的角度探讨了鲍曼不动杆菌多重耐药性的形成机制。 结果： 194菌株中均携带有blaOXA-51-like基因,对鲍曼不动杆菌的鉴定率为100%,全部实验菌株具有9种耐药基因组合,其中以blaOXA-51-like+blaOXA-23-like+intI组合为主(n=139,71.65%),而blaOXA-23-like、blaOXA-24-like、blaOXA-58-like和intI的检出率分别为76.29%、1.55%、1.55%和89.18%；多重耐药鲍曼不动杆菌主要流行克隆株MLST的等位基因谱为ST2(2-2-2-2-2-2-2),与英国流行克隆OXA-23 clone 1也具有相同的MLST等位基因谱,研究还发现了一个新的携带blaOXA-58-like基因的多重耐药鲍曼不动杆菌流行克隆ST23(Institute Pastuer MLST Scheme)/ST91(Bartual et al. MLST Scheme);多重耐药鲍曼不动杆菌全基因组具有非常丰富的插入序列ISAbal,位于blaOXA-23-like、ampC、sulⅡ等耐药基因的上游,blaOXA-23-like基因的转移载体为Tn2008；耐药基因组不仅包含有丰富的特异性耐药相关基因,同时也具有多拷贝的外排泵编码基因、多重耐药蛋白编码基因、重金属抗性相关基因、外膜蛋白编码基因等,另外,还发现3株菌gyrA(Ser83Leu)和parC(Ser80Ile)基因的QRDR发生了突变,但未发现具有典型结构的‘'AbaR型耐药岛”。 结论： 本研究解决了医院感染监测中多重耐药鲍曼不动杆菌的快速鉴定问题,以及在临床实验室如何合理应用基因分型技术进行主要流行克隆株溯源的难题；我国多重耐药鲍曼不动杆菌临床分离株的主要流行克隆以欧洲克隆谱系Ⅱ为主,不具有典型结构的‘'AbaR型耐药岛”；通过在全基因组水平分析耐药相关的基因元件,使我们对我国多重耐药鲍曼不动杆菌流行克隆株的“耐药基因组”有了更加清晰的认识,为进一步研究多重耐药鲍曼不动杆菌“组合式耐药机制”奠定了基础。
[Abstract]:Background: Acinetobacter baumannii multidrug resistance is an important condition of nosocomial infection, which poses a severe challenge to the prevention, control and treatment of nosocomial infection. This paper reports the genomic polymorphism of the clinical isolates of Acinetobacter baumannii and the complete genome sequences of AB07104, AB0868 and AB0715, and makes a preliminary analysis of the drug-resistant genome. Methods: The multidrug resistant Acinetobacter baumannii was quickly identified by multiplex PCR, and the genomic typing system of DiversiLab microbes was used. The molecular epidemiological characteristics of Acinetobacter baumannii were analyzed based on sequence multiple PCR method and MLST typing technique, and the three genotyping techniques were reasonably combined. The molecular traceability system of Acinetobacter baumannii with multidrug resistance was established, and the whole genome sequence of three strains of Acinetobacter baumannii AB07104, AB0868 and AB0715 were annotated by the online bacterial genome annotation system (BASys). The mechanism of multidrug resistance of Acinetobacter baumannii was discussed from the point of view of drug resistance genome by comprehensively scanning all the gene elements related to drug resistance at the whole genome level using the relevant molecular bioinformatics analysis software. Results: The identification rate of Acinetobacter baumannii was 100. All the strains had 9 combinations of drug resistance genes. The detection rates of blaOXA-23-like blaOXA-24-like blaOXA-58-like and intI were 76.295.55% and 89.18%, respectively. The allele profile of MLST, the main prevalent clone of Acinetobacter baumannii, was ST2O2-2-2-2-2-2-2-2-22G, which also had the same MLST allele profile as the British popular clone OXA-23 clone 1. A new multidrug resistant Acinetobacter baumannii clone ST23(Institute Pastuer MLST Scheme)/ST91(Bartual et alwas also found. The whole genome of Acinetobacter baumannii has a very rich insertion sequence, ISAbal. the transfer vector of the upstream of the resistant genes such as blaOXA-23-like ampcsul 鈪，

本文编号：1914591