福建省三元区并殖吸虫病疫源地调查和泡囊狸殖吸虫独立性的研究

发布时间：2018-05-07 18:11

本文选题：并殖吸虫 + 斯氏狸殖吸虫　；参考：《福建医科大学》2005年硕士论文

【摘要】：目的:研究福建省三元区并殖吸虫病疫源地的虫种分布和人群感染情况,并通过形态观察和分子生物学鉴定研究泡囊狸殖吸虫的独立性。方法:按常规方法对三元区进行肺吸虫病流行病学调查,并对采集的螺、蟹标本作并殖吸虫尾蚴及囊蚴的检查与观察。提取斯氏狸殖吸虫囊蚴、泡囊狸殖吸虫囊蚴的基因组DNA,用特异引物、PCR扩增其ITS2基因并将PCR扩增产物纯化后测序,然后通过GenBank的Blast程序分析基因序列的同源性,并应用MEGA3.0软件中的ME程序构建种系发生树。结果:检查放逸短沟蜷654只、洱海螺新种468只和235只沼螺,未检出并殖吸虫尾蚴。充当第二中间宿主的福建华溪蟹、福建马来溪蟹、角肢南海溪蟹检出并殖吸虫囊蚴,感染率为44.28%(62/140),平均每只蟹和每g蟹组织携带囊蚴分别为11.03和1.24,囊蚴感染指数为6.07。2份野猫粪便中均查及并殖吸虫虫卵。人群的皮试阳性率为8.64%(21/243),皮试阳性者中血清抗体阳性率23.81%(5/21)。上述表明福建省三元区是以斯氏狸殖吸虫为主的并殖吸虫病高度疫源地。泡囊狸殖吸虫囊蚴正是在重度感染斯氏狸殖吸虫囊蚴的蟹体内才被发现。斯氏狸殖吸虫囊蚴与泡囊狸殖吸虫囊蚴形态差异明显,但观察到泡囊狸殖吸虫囊蚴在自蟹体分离后0.5～2h内有57.14%(12/21)变成同斯氏狸殖吸虫囊蚴近似的特征。基因同源性比较结果显示:泡囊狸殖吸虫与斯氏狸殖吸虫的ITS2基因同源性为100%,碱基差异为0,没有基因差异;泡囊狸殖吸虫与卫氏并殖吸虫、三平正并殖吸虫、巨睾并殖吸虫的ITS2基因同源性分别为90%、93%、92%,碱基差异分别为33、25、29,基因差异较明显。种系发生树显示:斯氏狸殖吸虫、泡囊狸殖吸虫在同一位置,与巨睾并殖吸虫、卫氏并殖吸虫、三平正并殖吸虫的遗传距离较远。结论:三元区是一个以斯氏狸殖吸虫为主的并殖吸虫病高度疫源地。虽然斯氏狸殖吸虫囊蚴和泡囊狸殖吸虫囊蚴的形态特征有较明显的区别。但经一段时间后,57.14%(12/21)的泡囊狸殖吸虫囊蚴变成斯氏狸殖吸虫囊蚴形态相似的特征。而且基因序列的同源性比较分析发现斯氏狸殖吸虫和泡囊狸殖吸虫的ITS2基因高度同源,而且种系发生树也显示二者之间无明显的遗传分化。因此,斯氏狸殖吸虫和泡囊狸殖吸虫为同一物种,泡囊狸殖吸虫为
[Abstract]:Objective: to study the species distribution and population infection of paragonimiasis in Sanyuan District of Fujian Province, and to study the independence of paragonimiasis by morphological observation and molecular biological identification. Methods: the epidemiological investigation of paragonimiasis was carried out in Sanyuan district according to the routine method, and the paragonimus cercariae and cysticercaria were examined and observed in the collected snails and crab samples. The genomic DNAs of Cysticercus skrjabini and Cysticercus sacrata were extracted, the ITS2 gene was amplified by specific primer PCR, the PCR amplified product was purified and sequenced, and the homology of the gene sequence was analyzed by Blast program of GenBank. And the ME program in MEGA3.0 software was used to construct the phylogenetic tree. Results: no paragonimiasis cercariae were detected in 654 snails, 468 new species and 235 snails in Erhai Lake. The second intermediate host, Fujian Huaxi crab, Fujian Malay Creek Crab, the South China Sea Creek Crab, and the paragonimus cysticercaria were detected. The infection rate was 44.28 / 140. The average number of cysticercaria per crab and per g of crab tissue was 11.03 and 1.24 respectively. The infection index of cysticercus was 6.07.2 pieces of wild cat feces and the eggs of paragonimiasis were checked. The positive rate of skin test was 8.64%, and the positive rate of serum antibody was 23.81%. The above results indicate that Sanyuan District of Fujian Province is a high foci of paragonimiasis, which is dominated by paragonimus skrjabini. The cysticercaria is found in the crab infected with the cysticercaria of P. skrjabini. The morphological differences between Cysticercus skrjabini and Cysticercus alveolaris were significant, but it was observed that 57.14% of Cysticercus spp. Was similar to Cysticercus skrjabini within 2 h after separation from crab body, which was similar to that of Cysticercus skrjabini. The results of gene homology comparison showed that the homology of ITS2 gene was 100, the base difference was 0, there was no gene difference between Pagopogonimus spp and P. skrjabini, and there was no genetic difference between Pagobiasis and paragonimus westermani and paragonimiasis Sanpingensis. The homology of ITS2 gene of paragonimiasis megakorchii was 9332, and the base difference was 33,252.The difference of gene was obvious. The phylogenetic tree showed that Pagopogonimus skrjabini was located in the same position, and the genetic distance was far from that of paragonimiasis megakis, paragonimus westermani and paragonimiasis Sanping. Conclusion: Sanyuan District is a high foci of paragonimiasis. Although the morphological characteristics of Cysticercus skrjabini and Cysticercus alveolata have obvious differences. However, after a period of time, the cysticercaria of Pagophorus skrjabini (57.14% / 12 / 21) became similar in shape to that of Cysticercus skrjabini. The homology analysis of gene sequence showed that the ITS2 gene of P. skrjabini and P. skrjabini were highly homologous, and the phylogenetic tree showed that there was no obvious genetic differentiation between them. Therefore, the two species of paragonimus skrjabini are the same species, while those of Pagopogonimus skrjabini belong to the same species.
【学位授予单位】：福建医科大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R181.3

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