Spatio-temporal disparities of Clonorchis sinensis infection in animal hosts in China: a systematic review and meta-analysis

Background Clonorchis sinensis, one of the most important food-borne zoonotic trematodes, remains prevalent in China. Understanding its infection status in animals is crucial for controlling human clonorchiasis. Here we conducted a systematic review and meta-analysis to focus on the spatio-temporal disparities ofC. sinensis infection in animals in China.Methods Data onC. sinensis prevalence in snails, the second intermediate hosts, or animal reservoirs in China were extracted from electronic dat...     

Genetic diversity and phylogenetic analysis of EG95 sequences of Echinococcus granulosus:Implications for EG95 vaccine application

Objective:To analyse the genetic variability of EG95 sequences and provide guidance for EG95 vaccine application against Echinococcus granulosus(E. granulosus). Methods:We analysed EG95 polymorphism by collecting total 97 different E. granulosus isolates from 12 different host species that originated from 10 different countries. Multiple sequence alignments and the homology were performed by Lasergene 1(DNASTAR Inc.,Madison,WI),and the phylogenetic analysis was performed by using MEGA5.1(CEMI,Tempe,AZ,USA). In addition,linear and conformational epitopes were analysed,including secondary structure,NXT/S glycosylation,fibronectin type ecoⅢ(Fnndary Ⅲ) domain and glycosylphosphatidylinositol anchor signal(GPIanchor). The s structure was predicted by PSIPRED method. Results:Our results indicated that most isolates overall shared 72.6-100% identity in EG95 gene sequence with the published standard EG95 sequence,X90928. However,EG95 gene indeed has polymorphism in different isolates. Phylogenetic analysis showed that different isolates could be divided into three subgroups. Subgroup 1 contained 87 isolates while Subgroup 2 and Subgroup 3 consisted of 3 and 7 isolates,respectively. Four sequences cloned from oncosphere shared a high identity with the parental sequence of the current vaccine,X90928,and they belonged to Subgroup 1. However,in comparison to X90928,several amino acid mutations occurred in most isolates besides oncosphere,which potentially altered the immunodominant linear epitopes,glycosylation sites and secondary structures in EG95 genes. All these variations might change their previous antigenicity and thereby affecting the efficacy of current EG95 vaccine. Conclusions:This study reveals the genetic variability of EG95 sequences in different E. granulosus isolates,and proposed that more vaccination trials would be needed to test the effectiveness of current EG95 vaccine against distinct isolates in different countries.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

4种病原菌特异基因片段阳性蜱的16S rRNA基因克隆文库分析

Objective To develop the method of 16S rRNA gene clone library for tick bacterial flora analysis, and to analyze the detection effective of pathogens in tick and capacity of bacterial flora diversity. Methods Primers were designed according to the specific gene of Borrelia burgdorferi, Bartonella henselae, Anaplasma phagocytophilum, Ehrlichia chaffeensis and templates were choosen by positive PCR result to amplify the DNA extracted from the ticks. One set of primers targeting 16S rRNA gene conserved region were chosen to amplify certain fragments, DNA extraction, PCR reaction, cloning and sequencing. Nucleotide sequences were compared with GenBank database. Calculated Coverage values of clone library and Shannon-Wiener diversity index. Results Sixteen defined genus-or species-bacteria were detected in 103 valid sequences. Eight species were edge type (Clone No. > 5). Three kinds of pathogens were identified (Borrelia burgdorferi, Bartonella henselae and Rickettsia sp). Three kinds of pathogens were not edge type(Clone No. < 5). Coverage value was 96.11%, and Shannon-Wiener index was 2.40. Analysis results of cloning sequence showed that tick-parasitic bacteria mainly were α and γ deformation mycetes which accounted for 56.25% (9/16). Conclusions The 16S rRNA gene sequences technology could make relative quantitative of bacterial flora, and detect many kinds of pathogens in tick. It's a good method for detection of pathogens and bacterial flora analysis.     

几种常见吸虫的分子系统发生学研究

目的 研究日本血吸虫、卫氏并殖吸虫、华支睾吸虫、布氏姜片吸虫和肝片形吸虫分子系统发生学的关系。方法 利用PCR技术特异性扩增日本血吸虫、卫氏并殖吸虫和华支睾吸虫核糖体小亚基(18SrDNA)的V4区基因并测序。根据Genebank,检索布氏姜片吸虫和肝片形吸虫的相关序列,并与上述3种吸虫的V4区基因序列进行排列比较,计算它们的遗传距离并构建系统发生树。 结果 日本血吸虫与其他吸虫的遗传距离远>其他吸虫之间的遗传距离,在分子系统发生树中,日本血吸虫单独形成一个支系,其他吸虫形成另外一个支系。 结论 日本血吸虫与其他吸虫的亲缘关系较远,它们可能来自不同的祖先。     

不同地域株华支睾吸虫基因差异的研究

目的探讨湖北、广东、辽宁和韩国4地华支睾吸虫的基因差异,为华支睾吸虫种下分型提供依据。方法取湖北、广东两地的华支睾吸虫,提取基因组DNA,PCR特异性扩增18S rDNA V4区并测序;登陆GenBank,检索中国辽宁(AF217100)和韩国(AF408144)的华支睾吸虫18S rDNA的登录序列,应用系统发生学分析法对所有序列进行排列比较,分析4地华支睾吸虫的基因差异,并构建系统发生树,分析其亲缘关系。结果获得的湖北和广东两地华支睾吸虫18S rDNA V4区的碱基数分别为392 bp和440 bp。通过对18S rDNA V4区基因序列的比较与进化树的构建,证实4个地域株华支睾吸虫的18S rDNA V4区具有较高的同源性(98%~100%),彼此间遗传距离较小(0~0.013);在系统发生树中,湖北株和广东株华支睾吸虫形成一个支系,韩国株和辽宁株华支睾吸虫形成另外一个支系。结论以18S rDNA V4区为分子标记的DNA序列分析表明,湖北、广东、辽宁和韩国4地华支睾吸虫存在基因差异,但亲缘关系较近,即起源于共同的祖先。     

腔阔盘吸虫18S rRNA及亲缘关系分析

目的 利用分子生物学技术，研究腔阔盘吸虫的分类。 方法 提取腔阔盘吸虫基因组DNA，利用保守引物，PCR扩增18S rRNA片段并测序。应用DNAStar和MEGA3软件，分析腔阔盘吸虫与其他双腔吸虫18S rRNA的同源性，在此基础上绘制出系统进化树，确定它们的进化关系。 结果 腔阔盘吸虫和其他双腔吸虫18S rRNA的同源性很高，其中腔阔盘吸虫和支双腔吸虫（D. dendriticum）的差异最大，为2.42%，而与愁体吸虫（L. collurionis）的差异较小，为1.75%; D. dendriticum和分叶短腺吸虫（B. lobatum）的进化关系相对较近，差异为1.09%。 结论 双腔科吸虫的18S rRNA序列非常保守，腔阔盘吸虫和L. collurionis的亲缘关系最近，而与B. lobatum和D. dendriticum在进化上关系相对较远。     

基氏蠊螨的 18S rDNA 分子鉴定

目的 基于核糖体 18S rDNA 基因对基氏蠊螨进行分子鉴定。 方法 采集和分离储藏物样本,进行螨类的形态学鉴定。 提取单个螨的基因组 DNA,经 PCR 扩增、克隆和测序获得 COⅠ基因和 18S rDNA 基因,将所获序列进行 Blast 对比。 检索 GenBank 数据库中蠊螨属 18S rDNA 基因序列,利用 Clustal X 1. 83 软件进行多序列比对,基于MEGA X 软件进行序列分析并以邻接法(Neighbor-Joining,NJ)构建系统发育树。 结果 采集的样本经形态和 COⅠ基因双重鉴定为基氏蠊螨。 同时,所选取的 10 个基氏蠊螨的 18S rDNA 基因序列完全一致,均表现出 A / T 碱基偏向性,与同属的 Blattisocius tarsalis 和 Blattisocius everti 分别有 98. 73%和 98. 94%的同源性。 基于 18S rDNA 基因序列的系统进化树显示,基氏蠊螨与 Blattisocius tarsalis 和 Blattisocius everti 聚为一支。 结论 本研究建立了基氏蠊螨基于 18S rDNA 基因序列的分子鉴定方法,为基氏蠊螨的准确鉴定奠定基础。     

云南省血吸虫病流行区一种拟钉螺及其寄生吸虫尾蚴的分子鉴定

目的对云南省血吸虫病流行区的一种拟钉螺及其寄生吸虫进行分子生物学鉴定,了解其种属分类地位。方法采集云南省祥云县拟钉螺和钉螺,压碎镜检采集螺软体腹足部组织,并观察其体内尾拗寄生情况。采用逸拗法采集拟钉螺寄生的不同形态尾拗,螺体组织和尾拗样本分别提取基因组DNA,采用PCR法扩增螺体内16S核糖体RNA(16S rRNA)、细胞色素c氧化酶I(COI)、28S核糖体DNA(28S rDNA)基因及其体内寄生吸虫尾拗的NADH脱氢酶亚基1(ND1)、28S rfNA基因,对扩增产物进行测序,并通过序列比对及系统进化分析鉴定样本螺和寄生吸虫种属。结果共检测拟钉螺样本382只,发现无叉形、双叉形、燕子形等3种形态吸虫尾拗,阳性率分别为20.94%(80/382)、3.40%(13/382)、7.07%(27/382)。基于16S rRNA、COI、28S rDNA基因的分子进化分析显示,该拟钉螺与滇池德拉维螺(Delavaya dianchiensis)同源性较高、聚在同一个分支。基于ND1、28S rDNA4基因的序列分析显示,无叉形尾拗吸虫属侧殖吸虫科,燕子形尾拗吸虫属孔肠科,双叉形尾拗吸虫可能为不同于中华血吸虫(Schistosoma sinensium)和勾形卵血吸虫(Schistosoma ovuncatum)的另一种血吸虫。结论初步了解了云南省血吸虫病流行区拟钉螺及其寄生吸虫种属分类,但更明确的分类关系和危害性等尚有待深入研究。     

鸡绦虫寄生菌种的PCR鉴定及其进化关系分析

目的 探明寄生于鸡棘沟赖利绦虫体内的细菌和真菌种类。方法 实验分别设计针对细菌和真菌的16s rDNA、18s rDNA通用引物,提取鸡棘沟赖利绦虫基因组DNA,扩增目的基因并进行测序。使用MEGA5.1软件对测序基因序列进行Neighbor-Joining法系统发育树构建,分析其进化关系。结果 寄生于鸡棘沟赖利绦虫的细菌隶属于无色杆菌属,相似性为99%;真菌在已鉴定的种类中隶属于马拉色氏霉菌属,与限制性马拉色菌进化关系最接近,相似性高达99%。结论 实验首次应用PCR手段鉴定了寄生于鸡棘沟赖利绦虫体内细菌和真菌的种类,为鸡绦虫病继发性感染的防治提供了有效的依据。     

广西地区家畜牛、羊体表硬蜱情况调查及种类鉴定

目的 掌握广西地区牛羊场硬蜱种类及其分子特征,了解该地区蜱类的分类地位,为养殖户防控硬蜱及蜱媒传染病提供参考依据。方法 本实验于2019年1月至2021年11月,采用动物体表法采集寄生的蜱类;提取蜱基因组,PCR扩增3种硬蜱的线粒体16S rDNA 和COI基因片段,并进行同源性分析。基于邻接法,用MEGA6.0软件分别构建系统发生树,进行遗传进化分析。结果 牛羊体表上共采集蜱2 030只,隶属1科2 属3种,其中微小扇头蜱1 968只,长角血蜱49只,具角血蜱13只。PCR扩增微小扇头蜱、长角血蜱和具角血蜱16S rDNA 和COI基因片段长度分别是460 bp和710 bp左右,分别与GenBank 中已登录的相应种类相似较高且在一个进化分支上。结论 广西地区牛羊场优势蜱种是微小扇头蜱且存在长角血蜱和具角血蜱。三蜱种16S rDNA 和COI序列存在多样性和地域差异性。     

湖南省怀化地区山羊胰阔盘吸虫线粒体pcox1基因和核糖体18S rRNA基因序列遗传变异研究

目的　了解湖南省怀化地区山羊体内分离的胰阔盘吸虫遗传变异情况。方法　应用PCR技术对分离自湖南怀化地区山羊体内的18株胰阔盘吸虫分离株线粒体细胞色素c氧化酶亚基I基因部分序列（pcox1）和核糖体18S rRNA基因进行扩增,对扩增产物进行测序并进行遗传变异和系统发育分析。结果　分离自湖南怀化地区山羊体内的18株胰阔盘吸虫分离株pcox1和18S rRNA基因序列长度分别为430 bp和1 857 bp,分别存在14个和35个变异位点,种内遗传差异分别为0 ~ 1.4%和0 ~ 0.8%;与GenBank数据库中收录的胰阔盘吸虫中国株基因序列同源性最高,分别为99.0% ~ 99.8%和99.5% ~ 99.8%。基于两种基因构建的系统发育树分析结果一致,本研究获得的18株胰阔盘吸虫分离株与GenBank数据库中已知胰阔盘吸虫分离株聚为同一分支,与支睾阔盘吸虫等阔盘属吸虫相隔较近,与其他吸虫所属分支相隔较远。结论　湖南省怀化地区山羊源胰阔盘吸虫分离株遗传变异度较低,线粒体pcox1基因和核糖体18S rRNA基因均适合作为羊源胰阔盘吸虫遗传变异研究的分子标记。     

Geographical variation of the liver fluke,Clonorchis sinensis,from Korea and China based on the karyotypes,zymodeme and DNA sequences

Genetic characterization was carried out in order to reveal the geographical variations of the oriental liver fluke, Clonorchis sinensis (Trematoda: Opisthorchiidae), collected in Korea and China. The chromosome number was 2n=56 in both Korean (Kimhae) and Chinese (Liaoning) flukes, and chromosomes were divided into two groups based on their sizes; consisting of 8 pairs of large and 20 pairs of small chromosomes. However, the karyotypes showed some differences between Korean and Chinese flukes. Isozyme analysis showed that two loci from each enzyme of aconitase and esterase (alpha-Na and beta-Na); only one locus each from six enzymes, glucose-6-phosphate dehydrogenase (G6PD), alpha-glycerophosphate dehydrogenase (GPD), 3-hydroxybutyrate dehydrogenase (HBDH), malate dehydrogenase (MDH), phosphoglucose isomerase (PGl) and phosphoglucomutase (PGM). Most of loci in two populations of C. sinensis showed homozygous monomorphic banding patterns and one of them, GPD was specific as genetic markers between two different populations. Two populations were very closely clustered within the range of genetic identity value of 0.998-1.0. We also compared patterns of intraspecific polymorphism of two markers with contrasted modes of evolution, nuclear ribosomal DNA (rDNA) and mitochondrial DNA (mtDNA) of the liver fluke from Kimhae, Guangxi and Liaoning. They showed a high homology. In conclusion, three populations of C. sinensis from Korea and China showed high homogeneity in the nucleotide sequences of the 18S rDNA, ITS2 and mtCOI gene.     

广西两地旋毛虫分离株5S rDNA序列分析

目的 应用5S rDNA序列分析，鉴定广西德保、南丹两地旋毛虫分离株。 方法 PCR扩增2个分离株5S rDNA片段，并对扩增产物进行测序；用相关软件分析序列的同源性、遗传距离，同时构建系统发生树，并与GenBank中旋毛虫相应基因序列进行比较。 结果 广西德保、南丹2地旋毛虫分离株和GenBank中Trichinella spiralis的5S rDNA碱基序列长度相同，为695 bp；变异位点4个，与T. spiralis的相似度分别为99.0%和99.1%，与GenBank中其他相应基因的相似度低于94.2%，2个分离株之间的相似度为98.8%。2个分离株之间及与T. spiralis间的遗传距离最小，均为0.014；而与其他旋毛虫的遗传距离均大于0.056；用邻接法（N-J法）和最大简约法（MP法）构建的2个系统发生树中，2个分离株与T.spiralis位于同一分支，自引导值分别为96及99。 结论 初步鉴定广西德保和南丹旋毛虫分离株均为T.spiralis。