肠杆菌科新（亚）种描述及该科植物源性细菌入境疫情分析

发布时间：2019-01-04 20:31

【摘要】：肠杆菌科细菌在自然界普遍存在,分布于空气、水、土壤、人体、动物、植物中。可存在于人体,引起肺炎、脓毒症、菌血症等疾病,是人体的条件致病菌;可存在于昆虫体内,侵染并杀死昆虫;还可侵染植物,引起杨树溃疡病、梨火疫病、榆树湿心病等。此外,肠杆菌科还可作为生物农药、固氮微生物等,对植物代谢、植物生长、有害生物防治等起着积极作用。因此,对肠杆菌科细菌的研究有着重要意义。肠杆菌科菊迪卡氏菌(Dickeya chrysanthemi)、解淀粉欧文氏菌(Erwinia amylovora)等细菌可以侵染蝴蝶兰、海棠、梨树等植物,造成严重经济损失,其中一些细菌是由国外传入我国。为分析近年来中国进境植物检疫截获细菌的情况,明确当前我国面临的植物病原细菌入侵的严重性及重要性,以对今后林业检疫工作提供参考,本文按照检疫业务类型、来源国(地区)、检疫性细菌情况等对2010-2015年中国进境植物检疫截获细菌情况进行统计分析。2010-2015年,我国各口岸从水果、种苗等进境植物及植物产品中共截获细菌139种、7736批次,分别来自70个国家(地区);截获检疫性细菌16种(其中10种可危害花卉和林木),521批次;花卉、林木病原细菌23种、835批次;肠杆菌科细菌32种、2016批次,杨树枯萎病菌、梨火疫病菌、亚洲梨火疫病菌等重要肠杆菌科细菌未有截获。2010-2015年,进境植物检疫截获细菌的种类及次数总体呈上升趋势,检疫性细菌入侵风险增大,防范形势严峻。以植物源性肠杆菌科细菌为研究对象,选取16S rRNA、gyrB、rpoB、infB、atpD五个基因,采用最大似然法(ML)、邻接法(NJ)、最小进化法(ME)分析了肠杆菌科系统发育关系。结果显示,基于16S rRNA基因构建的ML树、NJ树、ME树各种属间分支节点普遍置信度较低,如ML树的大部分分支置信度低于50%,在不同方法构建的16S rRNA基因系统发育树中,某些种、属的位置不稳定。基于看家基因构建的ML树、NJ树、ME树分支都具有较高的支持率,表明该进化树对肠杆菌科分类的展示效果较好;ML树、NJ树、ME树三种树拓扑结构有较高的一致性,各个属在系统进化树位置比较稳定。利用形态学、生理生化、分子生物学等方法鉴定并描述了肠杆菌科Brenneria属三个细菌新(亚)种,分别是B.populi种的新亚种、B.salicis种的新亚种、Brenneria属的新种。
[Abstract]:Enterobacteriaceae bacteria are ubiquitous in nature, distributed in air, water, soil, human body, animals and plants. May exist in the human body, causes pneumonia, sepsis, bacteremia and other diseases, is the human body condition pathogenic bacteria; may exist in the insect body, infects and kills the insect; also may infect the plant, causes poplar canker disease, pear fire blight, elm wet heart disease and so on. In addition, Enterobacteriaceae can also play a positive role in plant metabolism, plant growth, pest control and so on. Therefore, the study of Enterobacteriaceae is of great significance. Enterobacteriaceae, (Dickeya chrysanthemi), (Erwinia amylovora) and other bacteria can infect Phalaenopsis, Begonia, pear and other plants, causing serious economic losses, some of which were introduced from abroad to China. In order to analyze the situation of intercepting bacteria in the import plant quarantine of China in recent years, to make clear the seriousness and importance of the invasion of plant pathogenic bacteria in China at present, and to provide reference for the future forest quarantine work, this paper is based on the type of quarantine business. Source countries (regions), quarantine bacteria, etc. Statistical analysis was made on the interception of bacteria in import plant quarantine of China from 2010 to 2015. From 2010 to 2015, 139 species of bacteria were intercepted from imported plants and plant products, such as fruits, seedlings, etc. 7736 batches from 70 countries (regions); 16 kinds of quarantine bacteria (10 of which could harm flowers and trees), 521 batches, 23 species of flowers and tree pathogenic bacteria, 835 batches; 32 species of Enterobacteriaceae, 2016 batches of bacteria, Poplar Fusarium wilt, Pyrophytophthora infestans, and other important Enterobacteriaceae bacteria were not intercepted. From 2010 to 2015, the species and frequency of intercepting bacteria in import plant quarantine showed an increasing trend. Quarantine bacteria invasion risk increased, the situation is grim. Five 16s rRNA,gyrB,rpoB,infB,atpD genes were selected from Enterobacteriaceae, and the phylogenetic relationships of Enterobacteriaceae were analyzed by maximum likelihood method (ML),) and (NJ), minimal evolution method (ME). The results showed that the confidence of most branches of 16s rRNA gene in ML tree, NJ tree and ME tree was lower than 50% in most branches of ML tree, and in the phylogenetic tree of 16s rRNA gene constructed by different methods, the confidence of most branches of ML tree was lower than 50%, and the phylogenetic tree of 16s rRNA gene was constructed by different methods. The position of certain species, genera, is unstable. The branches of ML tree, NJ tree and ME tree constructed based on housekeeping gene all had high support rate, which indicated that the phylogenetic tree was effective in displaying the taxonomy of Enterobacteriaceae. The topological structure of ML tree, NJ tree and ME tree has high consistency, and each genus is stable in phylogenetic tree. Three new bacteria (subspecies) of Brenneria genus of Enterobacteriaceae were identified and described by means of morphology, physiology, biochemistry and molecular biology. They are new subspecies of B.populi species, new subspecies of B.salicis species and new species of Brenneria genus.
【学位授予单位】：中国林业科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S41-30

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