环境水军团菌鉴定分型及其致病性研究

发布时间：2018-03-23 03:02

本文选题：军团菌　切入点：分类学鉴定　出处：《中南大学》2009年硕士论文　论文类型：学位论文

【摘要】： 目的:了解广东新会地区环境水源中军团菌的分布状况,对分离株进行分子分型,并检测其致病性,掌握该地区环境水源中军团菌的基本特征,为军团菌病的预防控制提供依据。方法:(1)采取公共场所环境水源,对其进行军团菌的分离培养,并以革兰染色、生化反应、血清学及mip样基因测序等方法进行菌种鉴定,探讨公共场所军团菌分布情况。(2)对已鉴定的嗜肺军团菌,采取扩增片段长度多态性分析、mip基因序列分析等进行分子分型,比较不同分子分型方法的分型能力、重复性、一致率等,并建立本地区军团菌流行病学档案。(3)应用特异性引物检测已鉴定分型的嗜肺军团菌的lvh和rtxA毒力基因,判断其致病性;同时对其毒力岛基因进行检测及基因序列分析,探讨不同分型嗜肺军团菌毒力岛分布情况及其可能起源。结果:(1)8个采样点中7个分离出军团菌,23份水样中20份军团菌培养呈阳性,阳性率为86.9%,检出军团菌32株,其中嗜肺军团菌23株,非嗜肺军团菌9株,包括戈氏军团菌5株,菲氏军团菌2株,长滩军团菌2株,同时发现同一水样中有多种军团菌共存现象。(2)24株嗜肺军团菌可分为21个AFLP型,10个AFLP群,其中AFLP-A群是新会地区优势菌群;采用mip基因序列分析可将该24株嗜肺军团菌分为9个型,且mip基因测序分子分型与AFLP分型具有相关性。(3)本实验室分离的23株嗜肺军团菌,其中强毒株为21株(91.3%),弱毒株为2株(8.7%),未发现无毒株;携带毒力岛的菌株为17株(73.91%),且毒力岛基因与其他基因起源不一致。结论:(1)广东新会地区环境水中军团菌污染较严重,存在多种军团菌种。(2)该地区嗜肺军团菌分子分型多样化,且存在优势菌群。(3)新会地区分离的嗜肺军团菌多为强毒株,亦携带毒力岛,致病性较强,已对人群健康构成潜在威胁。(4)应用合理的检测方法,定期对公共环境水源进行军团菌检测,及时发现问题并采取相关措施将大大减少军团菌爆发流行。
[Abstract]:Objective: to understand the distribution of Legionella in the environmental water source of Xinhui area of Guangdong province, to type the isolated strain, to detect its pathogenicity, and to understand the basic characteristics of Legionella in the environmental water source of this area. To provide the basis for the prevention and control of Legionella disease. Methods the isolated and cultured Legionella was isolated from the water source of public places. The bacteria were identified by Gram staining, biochemical reaction, serology and mip like gene sequencing. To investigate the distribution of Legionella in public places, the identification of Legionella pneumophila was carried out by using amplified fragment length polymorphism analysis and sequence analysis of mip gene to compare the typing ability and repeatability of different molecular typing methods. The consistent rate and so on, and established the local Legionella Epidemiology Archives. 3) using specific primers to detect the lvh and rtxA virulence genes of the identified and typed Legionella pneumophila, and to judge the pathogenicity of Legionella pneumophila. At the same time, the virulence island gene of Legionella pneumophila was detected and its gene sequence was analyzed, and the distribution and possible origin of virulence island of Legionella pneumophila were discussed. Results Legionella was isolated from 7 out of 8 sampling sites, 20 of 23 water samples were positive for Legionella, the positive rate was 86.9. 32 strains of Legionella were detected, including 23 strains of Legionella pneumophila and 9 strains of non-Legionella pneumophila, including 5 strains of Legionella goosenii. Two strains of Legionella philii and two strains of Legionella from long Beach were found to coexist in the same water sample. 24 strains of Legionella pneumophila could be divided into 21 AFLP types and 10 AFLP groups, among which AFLP-A group was the dominant group in Xinhui area. The 24 strains of Legionella pneumophila were classified into 9 types by mip gene sequence analysis, and 23 strains of Legionella pneumophila were isolated in our laboratory. Among them, 21 virulent strains were found to be 91.3%, 2 strains were virulent strains, and no virulent strains were found, and 17 strains carrying virulence island were 73.91%, and the origin of virulence island gene was not consistent with other genes. Conclusion (1) Legionella in environmental water of Xinhui area of Guangdong Province is seriously polluted, and there are many Legionella species. 2) the molecular typing of Legionella pneumophila in this area is diversified, and the dominant bacteria group. 3) the isolates of Legionella pneumophila in Xinhui area are mostly virulent strains. It also carries virulence island, which has a strong pathogenicity, and has posed a potential threat to the health of the population. (4) reasonable testing methods are used to detect Legionella in water sources of the public environment on a regular basis. Timely detection of problems and relevant measures will greatly reduce the outbreak of Legionella.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R378

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