發(fā)布時(shí)間：2018-06-07 18:45

  本文選題：鼠疫耶爾森菌 + 編碼序列　； 參考：《中國疾病預(yù)防控制中心》2009年碩士論文

【摘要】： 鼠疫是一種自然疫源性疾病,曾引起三次世界性的大流行,我國發(fā)生過6次較大規(guī)模的鼠疫流行,發(fā)病人數(shù)超過百萬。目前,我國存在著12種類型的鼠疫疫源地,鼠疫菌可分為18個(gè)生態(tài)型。其中,布氏田鼠和青海田鼠鼠疫菌具有區(qū)別于其它類型鼠疫菌的特點(diǎn),對小白鼠等小型動(dòng)物毒力強(qiáng),對豚鼠、兔、羊等大型動(dòng)物幾乎無毒,從發(fā)現(xiàn)至今,尚無關(guān)于該類鼠疫菌感染人類的相關(guān)報(bào)道。而對于田鼠型鼠疫菌的特殊致病力,一直是亟待解決的問題。 2005年,云南省玉龍縣發(fā)生了一起肺鼠疫疫情,發(fā)病5人,死亡2人。在隨后的鼠疫流行病學(xué)調(diào)查過程中,在當(dāng)?shù)氐膰�齒類動(dòng)物中分離到了鼠疫菌,確定了玉龍為新發(fā)鼠疫自然疫源地。為了進(jìn)一步了解這一新發(fā)疫源地性質(zhì)和流行規(guī)律,對所分離鼠疫菌及相鄰疫源地鼠疫菌進(jìn)行了全基因組序列測定和分析。 本研究通過對全世界不同來源鼠疫菌的全基因組序列分析,獲得了已測序各株鼠疫菌編碼序列(CDS)的兩兩比較結(jié)果,并確定了CDS之間一一對應(yīng)的同源關(guān)系。在此基礎(chǔ)上,通過對玉龍及相鄰疫源地鼠疫菌間的CDS、SNP和基因組重排的比較,顯示玉龍菌株D106004與西藏菌株Z176003 CDS的同源性最高,重排片段最少,親緣關(guān)系最相近。 對于所測序三株菌在生化性狀上的差異,利用全基因組序列資料,對麥芽糖相關(guān)基因進(jìn)行了搜索比較,并根據(jù)突變位點(diǎn)情況在我國72株鼠疫菌中進(jìn)行實(shí)驗(yàn)研究,發(fā)現(xiàn)malT、malZ兩個(gè)基因在我國部分麥芽糖酵解陰性的鼠疫菌株中存在基因的移碼突變,推測這兩個(gè)基因的突變可能是引起我國部分鼠疫菌株麥芽糖酵解陰性的原因。 根據(jù)所獲得的CDS分析比較結(jié)果,根據(jù)致病基因在強(qiáng)毒株中表現(xiàn)為一種類型,在弱毒株中則表現(xiàn)另外一種類型的特點(diǎn),尋找田鼠型菌株特殊致病力相關(guān)突變基因,發(fā)現(xiàn)91001(布氏田鼠鼠疫菌測序菌株)特殊致病力相關(guān)突變基因21個(gè)。對21個(gè)基因突變位點(diǎn)設(shè)計(jì)引物,在我國兩類田鼠型鼠疫菌和其它疫源地鼠疫菌共131株進(jìn)行研究驗(yàn)證,實(shí)際比較這些基因的分布和變化情況。 實(shí)驗(yàn)結(jié)果顯示,1)3個(gè)基因(T2,T18,T24基因均為點(diǎn)突變)事實(shí)上在我國的兩類田鼠型鼠疫菌中均未發(fā)生突變。2)T13基因點(diǎn)突變,在部分布氏田鼠鼠疫菌中未發(fā)生突變。3)2個(gè)基因(T30點(diǎn)突變,Q5基因缺失)對照組鼠疫菌株中基因表現(xiàn)不一致。4)3個(gè)基因(S1、T29基因點(diǎn)突變,T3基因缺失)在布氏田鼠鼠疫菌中發(fā)生了突變,而青海田鼠鼠疫菌未發(fā)生變化,這一特征具有分型和溯源的流行病學(xué)意義。5)確證12個(gè)基因(9個(gè)點(diǎn)突變,3個(gè)基因缺失)在所有田鼠型鼠疫菌中均發(fā)生了突變,這12個(gè)基因可能是引起田鼠型菌株特殊致病力的突變基因,其中有2個(gè)基因突變表現(xiàn)為基因缺失,功能與信息儲(chǔ)存加工相關(guān),屬于變異較快的基因類型,一個(gè)T6基因功能注釋為DEAD盒蛋白家族的解螺旋酶,另一個(gè)T8基因注釋為AraC蛋白家族的轉(zhuǎn)錄調(diào)控蛋白,它們均與細(xì)菌的致病力相關(guān),在下一步的研究中可以對這些基因進(jìn)行功能研究。 T6基因在我國田鼠型鼠疫菌中較其它疫源地的鼠疫菌缺失了510bp的片段而發(fā)生了較大的突變,其可能對田鼠型鼠疫菌在血清中的生長速度產(chǎn)生影響。在進(jìn)一步的研究中,采用基因一步缺失法對T6基因進(jìn)行缺失替換,以判斷其對田鼠型鼠疫菌的致病性所產(chǎn)生的實(shí)際影響。
[Abstract]:Plague, a natural epidemic disease, has caused three worldwide pandemics, and there have been 6 large scale plague epidemics in China. There are 12 types of plague foci in our country, and Yersinia pestis can be divided into 18 ecotypes. Among them, the plague bacteria of Bryonia bryoni and Qinghai vole are different from other types The characteristics of Yersinia pestis are very toxic to small mice and other small animals, and they are almost non-toxic to large animals such as guinea pigs, rabbits and sheep. Since the discovery, there has been no related report on the infection of the Yersinia pestis. The special pathogenicity of Yersinia pestis has been a problem to be solved urgently.
In 2005, a lung plague epidemic occurred in ERON County, Yunnan Province, with 5 people and 2 deaths. In the subsequent epidemiological investigation of the plague, Yersinia pestis was isolated in the local rodent, and ERON was identified as the natural foci of the new plague. Complete genome sequencing and analysis of Yersinia pestis and its adjacent foci were carried out.
In this study, by analyzing the whole genome sequence of Yersinia pestis from different sources of the world, the 22 comparison results of the sequence of CDS were obtained, and the corresponding homologous relationship between CDS was determined. On this basis, the comparison of CDS, SNP and genome rearrangement between ERON and the adjacent Phytophthora was compared. The results showed that ERON strain D106004 had the highest homology with Tibet strain Z176003 CDS, and the rearrangement fragment was the least.
For the differences in the biochemical characters of the three strains, the whole genome sequence data were used to search for the maltose related genes, and the 72 strains of Yersinia pestis were studied in China according to the mutation site. It was found that the genes of malT, malZ and two genes in the plague strains of maltose glycolysis negative in our country Frameshift mutation suggests that the mutation of these two genes may be the cause of maltoglycolysis of some plague strains in China.
According to the results obtained by CDS analysis, according to the manifestation of the pathogenic gene in the strong virulent strain, the special pathogenicity related mutation gene of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the strain of the 91001 strains of the strain of the brucellus plague sequence were found to be 21. A total of 131 strains of Yersinia pestis and other Phytophthora Phytophthora of two kinds of voles in China were studied and verified by the mutation site design primers, and the distribution and change of these genes were compared.
The experimental results showed that, 1) 3 genes (T2, T18, T24 genes were point mutations) in fact, there were no mutation.2 in the two types of Yersinia pestis in China, the mutation of the T13 gene, the 2 genes (T30 point mutation, Q5 based deficiency) in the pestis strain of a part of the brucellus Yersinia pestis, 3 genes in the Yersinia pestis strain S1, T29 gene point mutation, T3 gene deletion) occurred in the Brandt vole Yersinia pestis, and the Qinghai vole Yersinia pestis did not change, this characteristic has the typing and traceability epidemiological significance.5) confirmed that 12 genes (9 point mutation, 3 gene deletion) have been mutated in all field Yersinia pestis, the 12 genes may be It is a mutant gene that causes the special virulence of the strain of the strain of the vole. 2 of the mutations are gene deletion, and the function is related to the processing of information storage. It belongs to the fast variant gene type. One T6 gene function is annotated by the DEAD box protein family of helicase and the other T8 gene is the transcriptional regulation protein of the AraC protein family. They are all related to the pathogenicity of bacteria, which can be studied in the next step.
The T6 gene in the Yersinia pestis of our country is less than the 510bp fragment in the other foci of Yersinia pestis, which may affect the growth speed of the Yersinia pestis in the serum. In the further study, the one step deletion method of gene is used to replace the T6 gene, so as to judge the rat model of the voles. The actual effects of the pathogenicity of Phytophthora.
【學(xué)位授予單位】：中國疾病預(yù)防控制中心
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2009
【分類號(hào)】：R378

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 王娜;中國鼠疫菌單核苷酸多態(tài)性研究[D];中國疾病預(yù)防控制中心;2011年

2 王梅;喜馬拉雅旱獺疫源地鼠疫菌特征研究[D];中國疾病預(yù)防控制中心;2011年

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本文編號(hào)：1992350