广西医科大学在校大学生人芽囊原虫感染情况调查与65例B.h分离株的基因型初步研究

发布时间：2018-05-07 11:14

本文选题：人芽囊原虫 + 感染情况　；参考：《广西医科大学》2012年硕士论文

【摘要】：目的了解在校大学生群体人芽囊原虫(Blastocystis hominis)的感染情况；进一步探明广西B.h的基因型构成,为B.h分类学研究提供科学依据。方法采用随机抽样法选择广西医科大学在校大学生作为流行病学调查对象,采用酸醚离心沉淀法进行粪便检查,光镜下形态鉴定,定性诊断。从B.h感染者粪便中分离虫体,经体外培养后抽提基因组DNA。应用国际通用的STS引物进行PCR扩增基因分型；自行设计elf-1α保守区片段PCR引物,对广西已发现的未知基因型虫株进行DNA序列分析和同源性比较,应用MEGA法构建系统发生树。结果广西医科大学在校大学生B.h的平均感染率为14.93%；汉族感染率13.48%,壮族18.38%,其他民族感染率为17.24%；各年级感染率最低为13.19%,最高达16.28%；男性感染率为14.74%,女性感染率为15.06%；广西本省感染率15.06%,外地生源感染率为13.94%。以7对STS引物对53个样本的基因组DNA进行PCR扩增,共发现5种已知基因型(1、3、4、6、7型)虫株；其中,单纯1型有4株,占7.55%(4/53)；单纯3型17株,占全部人源性分离株的32.08%(17/53)；单纯的4型有4株,占7.55%(4/53)；单纯6型有1株,古1.89%(1/53)；单纯7型有5株,占9.43%(5/53)；22株无特异性区带出现,初步认为是未知基因型；进一步应用elf-1α保守区引物对23株未知基因型B.h(11株来自广西医科大学在校大学生感染者、12株来自桂南沿海地区分离株)进行PCR扩增分析,结果有15株显示特征性片断,8株显示阴性。成功进行了13株elf-1α保守区DNA测序和同源性比较分析,发现这13未知基因型B.h与已报道的S株系同源性达70%左右。系统发生树构建结果发现,13株未知基因型中至少存在3种以上不同类群。结论(1)广西医科大学在校大学生B.h感染率较高,并且存在校内感染的可能性；壮族学生B.h感染率高于汉族。(2)发现基因1型、3型、4型、6型、7型等5种已知基因型虫株,以3型为主；其中7型系我国首次在广西发现。(3)广西存在未知基因型B.h,初步发现与S株系近缘,而且存在不同类群。(4)elf-1α可作为B.h分类的另一项分类依据,我们独立设计的elf-1α保守区PCR引物能揭示未知基因型B.h之间的遗传差异,在B.h的分类学中有应用价值。
[Abstract]:Objective to investigate the infection of Blastocystis hominis in college students and to find out the genotypes of B.H in Guangxi, and to provide scientific basis for the study of B. h taxonomy. Methods the random sampling method was used to select the college students in Guangxi Medical University as the subject of epidemiological investigation, and the acid ether centrifugation precipitation method was used to examine the feces, the morphology was identified under light microscope, and the qualitative diagnosis was made. The genomic DNA was isolated from the feces of B. h infected individuals and cultured in vitro. The elf-1 伪 conserved fragment PCR primer was designed to analyze the DNA sequence and homology of the unknown genotypes found in Guangxi, and the phylogenetic tree was constructed by MEGA method. Results the average infection rate of B.h in college students of Guangxi Medical University was 14.933.The infection rate of Han nationality was 13.4848, that of Zhuang nationality 18.38m, that of other nationalities was 17.24; the lowest infection rate of every grade was 13.19 and the highest was 16.28m; the infection rate of male was 14.74and the infection rate of female was 15.06b; the infection rate of Guangxi was 15.06b. The infection rate in this province was 15.06 and the infection rate was 13.94. The genomic DNA of 53 samples were amplified by PCR using 7 pairs of STS primers. A total of 5 known genotypes were found, among which, 4 strains were isolated from type 1, which accounted for 7.554 / 53; 17 strains were isolated from type 3. Of all the human isolated strains, 32.08 were found in 17 / 53; 4 in type 4 alone (7.55 / 53); 1 in type 6, with 1 / 53 in ancient 1.89g / 53; 5 in type 7, accounting for 9.4355 / 53 / 22 with no specific zone, and initially considered as unknown genotypes. Furthermore, 23 unknown genotype B.h(11 strains were amplified by PCR amplification using elf-1 伪 conserved region primers from 12 strains isolated from the coastal areas of Guangxi Medical University (Guangxi Medical University). Results of the 15 strains, 8 were negative. The DNA sequencing and homology analysis of 13 elf-1 伪 conserved regions were successfully carried out. It was found that the 13 unknown genotype B.h had about 70% homology with the reported S strains. The results of phylogenetic tree construction showed that there were at least 3 different groups in 13 unknown genotypes. Conclusion (1) the infection rate of B. h in Guangxi Medical University students is higher than that in Han nationality students, and the infection rate of B.h in Zhuang nationality students is higher than that in Han nationality. The unknown genotype B.hwas found in Guangxi for the first time in China, and it was found that there is a close relationship with the S strain, and that there are different taxa, I. e., the different taxa, which can be used as another taxonomic basis for B.h classification. Our independently designed elf-1 伪 conserved region PCR primer can reveal the genetic difference between unknown genotypes B.H, and has application value in the taxonomy of B. h.
【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R181.3

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