安氏隐孢子虫ITS-1序列的PCR扩增、克隆及分析

通过对国内三株安氏隐孢子虫(Cryptosporidium andersoni)即GD株、HN株和AH株的rDNA的内转录间隔区Ⅰ(ITS_1)序列进行PCR扩增、克隆、测序和序列分析,旨在确定ITS_1是否可作为C.andersoni分子分类的遗传标记。结果表明:GD株、HN株和AH株的ITS_1序列基本一致,仅AH株有三个碱基的差异;但与GenBank注册的C.muris和C.parvum存在种间差异,而且差异显著。说明ITS_1可作为C.andersoni种的遗传标记,从而为隐孢子虫属的种间鉴定以及进一步的分子流行病学调查和分子诊断学研究奠定了基础。     

犬弓首蛔虫ITS1基因的克隆及序列分析

通过对国内5个犬弓首蛔虫株(T.canis)即GD株、CQ株、YN株、HN株和GZ株的rDNA的内转录间隔区Ⅰ(ITS1)序列进行PCR扩增、克隆、测序和序列分析,旨在确定ITS1是否可作为T.canis分子分类的遗传标记。结果显示:GD株、CQ株、YN株、HN株和GZ株的ITS1序列基本一致,仅GD株有2个碱基的差异,HN株和GY株分别有1个碱基的差异;与GenBank中登录的T.canis(序列号为AB110024、AB110026)的ITS1序列同源性高达98.9%～99.4%。结果表明ITS1可作为分子标记用于T.canis与其它蛔虫的种间鉴定,但不适合用于T.canis种内遗传变异的研究,为进一步的分子遗传学和分子诊断学研究奠定基础。     

鸡蛔虫ITS rDNA的PCR扩增克隆及序列分析

鸡蛔虫(Ascaridia galli)寄生于鸡、火鸡、鸭、鹅、鹌鹑、雉鸡等鸟禽类的小肠,偶见于嗉囊、胃和食道.鸡蛔虫病分布于全世界和全国各地,在我国具有分布广、感染率高、感染强度较高的特点[1].     

Detection of natural Trypanosoma vivax infections in pigs with microhaematocrit centrifugation and amplification of ITS1 rDNA

Different species of trypanosomes may infect their mammalian hosts both singly or in combination. This study was undertaken to determine the trypanosome species that may be afflicting pigs in Uganda. Blood was collected from pigs of all ages and sexes from two districts, Kasese in Western and Jinja in Central Uganda. Of the 133 pig blood samples from Kasese that were tested for trypanosomes using the microhaematocrit centrifugation technique (MHCT), none was found to be infected. However, of the 253 pigs from Jinja district, nine were infected with trypanosomes of which three had T. vivax as determined by MHCT. However, application of the ITS1 rDNA PCR test revealed that eight pigs had T. vivax in mixed infections and one pig had T. vivax monolithic infection. These observations show that under certain circumstances, pigs may be important reservoirs for, as well as hosts to, T. vivax, contrary to earlier reports.     

山羊美丽筒线虫ITS序列的PCR扩增及分析

以神木山羊体内分离出的美丽筒线虫为研究对象,用保守引物进行PCR扩增其核糖体DNA(rDNA)的内转录间隔区(ITS)和5.8S序列,并进行克隆、转化、测序和序列分析,对样品进行分子鉴定.结果获得一个美丽筒线虫样品的ITS及5.8 S rDNA序列,总长均为1 035 bp.将序列与GenBankTM公布的相关序列进行比较分析,结果显示美丽筒线虫分离株ITS1与参考株的相似性为98.1％～99.7％,ITS2、5.8S序列与参考株相似性均达到100％.本研究是第一次从山羊体内获得美丽筒线虫ITS序列,为其分子学的进一步研究提供了基础资料.     

斑鼻羚毛首线虫ITS序列的PCR扩增及分析

以茂名野生动物园斑鼻羚体内分离出的毛首线虫为研究对象,用保守引物PCR扩增其核糖体DNA(rDNA)的内转录间隔区(ITS)和5.8 S序列,并进行克隆、转化、测序和序列分析,对样品进行分子鉴定.结果获得2个毛首线虫样品的ITS及5.8 S rDNA序列,总长为1 316 bp,样品间序列相似性为99.2%.将序列与G...     

Consensus nested PCR amplification and sequencing of diverse reptilian, avian, and mammalian orthoreoviruses

The orthoreoviruses are segmented RNA viruses that infect diverse vertebrate host species. While the most common human orthoreovirus, Mammalian Reovirus, is not typically associated with significant disease, the majority of Orthoreovirus species have been shown to cause significant and often fatal disease in reptiles, birds, and primates. There is significant potential for jumping species. A consensus nested-PCR method was designed for investigation of the RNA-dependent RNA polymerase gene of Orthoreovirus and Aquareovirus. This protocol was used to obtain sequencing template from reoviruses of three different vertebrate classes. Bayesian and maximum likelihood phylogenetic analysis found that all viruses analyzed clustered in the genus Orthoreovirus, that reptile reoviruses formed three distinct clusters, and that an African grey parrot reovirus clustered with Nelson Bay virus from bats. This PCR method may be useful for obtaining templates for initial sequencing of novel orthoreoviruses from diverse vertebrate hosts.     

进境太平洋鳕鱼寄生的异尖科线虫rDNA-ITS 序列的PCR扩增及分析

以日本进境的冻太平洋鳕鱼体内分离出的异尖科线虫为研究对象,采用寄生虫通用引物NC5和NC2扩增其核糖体DNA(rDNA)的内转录间隔区(ITS)序列,进行克隆、转化、测序和序列分析,并对样品进行分子鉴定。结果表明,扩增的异尖科线虫样品的ITS序列片段大小为906 bp,包含部分的18S、28S及全部的ITS1(353 bp)、5.8S(157 bp)和ITS2(299 bp)序列,ITS1和ITS2序列与GenBank登录的伪新地蛔线虫(Pseudoterranova decipiens)同源性均为在99.7%以上,与其他线虫的相似性较低。由ITS1和ITS2序列构建的系统进化树可知,从鳕鱼中分离到的线虫ITS1和ITS2均与伪新地蛔线虫处于同一分支。本研究结果为异尖科线虫种属的确定及进一步的分子生物学研究奠定基础。     

Culicoides arakawae (Diptera: Ceratopogonidae) efficiently blood-fed and infected with Leucocytozoon caulleryi through a natural membrane

Culicoides arakawae, the most common Culicoides sp. on chicken farms in East Asia, is an important blood-sucking insect and Leucocytozoon caulleryi vector. How parasites, in an ingested blood bolus, enter the midgut of insects and deal with this complex and biochemically hostile environment is poorly understood. However, successful blood-feeding through a membrane in C. arakawae is beneficial for studying this phenomenon. Therefore, a membrane-feeding method for C. arakawae was developed in. The blood-feeding success rates of C. arakawae fed through five different membranes were: turkey egg at 43.7+/-11.7%, chicken egg at 45.2+/-12.1%, duck egg at 38.8+/-12.0%, pig gut at 0% and chick skin at 0%. In fertility measurements, the average number of eggs produced for C. arakawae fed through egg-shell membrane, at 77.7+/-15.1 per female, was significantly higher (P<0.01) than the 46.7+/-10.6 found in C. arakawae fed on the breast skin of a live chicken. Meanwhile, in parasite infectivity tests, C. arakawae could be infected by L. caulleryi when the vector was blood-fed with infective blood cells reconstituted with specific pathogen-free (SPF) sera through an egg-shell membrane. The sporozoite average and infection rates of inoculated chicks were 166.8+/-12.5 and 100%, respectively. In conclusion, feeding C. arakawae blood through fowl-egg-shell membranes should be an efficient method for in vitro infection of midges as the engorged midges are infected by parasites and display reproductive potential. Furthermore, the method is practical for feeding a large number of midges.     

弓形虫ITS及5.8S序列的PCR扩增、克隆及分析

通过对国内来源于不同宿主的ZS人株、SH人株、CN猪株、QH绵羊株4个弓形虫虫株，以及国际标准强毒株RH株的核糖体DNA内转录间隔区(ITS)及5．8SDNA序列进行PCR扩增、克隆、测序和序列分析，旨在对国内不同宿主间弓形虫虫株的遗传变异情况进行分析和验证。为分子遗传学和分子诊断学研究提供资料。结果显示：QH绵羊株、ZS人株、SH人株、CN猪株的ITS及5．8S序列完全一致。且与GenBank上注册RH株的ITS及5．8S序列也一致；仅实验室传代保存的RH株的ITS2序列与其它4株的ITS2有2个碱基的差异。结果表明ITS可作为分子标记用于弓形虫与其它原虫的种间鉴定。但不适合用于弓形虫种内遗传变异的研究。     

山东兔场皮肤真菌病病原rDNA-ITS区序列测定及分析

利用皮肤真菌核糖体内转录间隔区（Internal transcribed spacer,ITS）序列通用引物,对采自山东地区主要兔场的皮肤真菌病的16株分离菌进行了PCR扩增,ITS区的克隆、测序、序列变异及遗传进化关系分析。经与Gen-Bank核酸序列数据库数据比对结果表明：16株病菌分别为须癣毛癣菌（12/16,75%）、犬小孢子菌（2/16,12.5%）、石膏样小孢子菌（2/16,12.5%）;不同病原菌的5.8SrDNA序列高度保守,而ITS区的变异性则较高;对该区序列的聚类分析表明,不同种菌株ITS1比ITS2在碱基构成和序列长度上有更大变异;而种内各菌株的ITS1和ITS2在长度上均没有变异,碱基构成上存在微小的变异,可基于该区进行兔皮肤真菌的分类鉴定。该研究确定了兔皮肤病原PCR检测特异引物的靶序列,为兔皮肤真菌病病原的特异性分子鉴定提供了可靠的靶标,为兔皮肤真菌的科学分类提供了分子依据。     

Technical note: Specific PCR amplification of protozoal 18S rDNA sequences from DNA extracted from ruminal samples of cows

A protozoa-specific primer (P-SSU-342f) was designed and paired with a eukarya-specific primer to amplify a 1,360-bp fragment of DNA encoding protozoal small subunit (SSU) ribosomal RNA from ruminal fluid of cows fed a mixed forage:grain diet or alfalfa hay. Sequencing of clones showed that P-SSU-342f is specific to ruminal protozoa and, with slight modifications, the primer will be useful for ecological studies of ruminal protozoa.     

ITS1 rDNA序列用于瘤胃原虫研究可行性的探讨

文章主要探讨瘤胃原虫rDNA序列的ITS1区段用于其群体研究的可行性和有效性。试验1由3只瘘管山羊提供瘤胃液、以不同结构碳水化合物底物(可溶性淀粉/滤纸纤维:A,100:0、B,70:30、C,50:50、D,30:70、E,0:100)进行体外培养;试验2以4只瘘管山羊为试验动物,以A(鱼粉)、B(羽毛粉)、C(玉米蛋白粉)和D(豆粕)等蛋白质饲料配制的4种等氮日粮进行4×4拉丁方试验,采用ITS1rDNA序列的遗传指纹检测及细胞计数技术研究原虫群体组成的变化。遗传指纹检测结果表明,在试验1不同碳水化合物结构底物培养条件下或在试验2不同蛋白日粮条件下,原虫群体组成都发生了变化。细胞计数的研究结果与之一致。依据本研究结果可见,ITS1rDNA序列是原虫研究的良好素材。     

Application of polymerase chain reaction based on ITS1 rDNA to speciate Eimeria

A method was developed to recover Eimeria spp. oocysts directly from poultry litter and determine which species of Eimeria were present using polymerase chain reaction (PCR) based on the ITS1 rDNA sequence. The species composition of Eimeria oocysts was also compared before and after propagation in susceptible chickens to determine if the relative proportion of each species changed after expansion. In samples from two broiler operations, ITS1-PCR was able to detect Eimeria spp. oocysts recovered from litter, with Eimeria acervulina, Eimeria maxima, and Eimeria praecox being the predominant species present therein. Although Eimeria tenella was found in one sample, the other species--Eimeria brunetti, Eimeria necatrix, and Eimeria mitis-were not detected. The species composition as determined by ITS1-PCR did not appear to appreciably alter after expansion in susceptible chickens. The described method represents a rapid means for determining the major Eimeria species in a poultry operation and may be helpful in choosing a particular live oocyst vaccine formulation to protect chickens against coccidiosis.     

Coprodiagnosis of Hammondia heydorni in dogs by PCR based amplification of ITS 1 rRNA: differentiation from morphologically indistinguishable oocysts of Neospora caninum

Hammondia heydorni is thought to be a non-pathogenic coccidian parasite of dogs that is closely related to Neospora caninum, an important parasite of cattle and dogs. Oocysts of these two species are morphologically indistinguishable from each other. A population of 2240 dogs in the Czech Republic was screened for the presence of H. heydorni/N. caninum oocysts and five (0.22%), represented by five of 3135 faecal samples (0.16%), were positive. The internal transcribed spacer 1 region of the rRNA gene (ITS1) from two isolates were cloned and the DNA sequences were identical with those of the ITS1 of H. heydorni. Based on the rRNA sequences available for H. heydorni and related coccidia, the primer pair JS4-JS5 was designed to amplify the 3' end of the small subunit (SSU) rRNA gene and ITS1 of H. heydorni. When tested on DNA extracted from a variety of parasites, the primers amplified a specific 267 bp fragment in our isolates only. The presence of DNA equivalent to 10 oocysts was sufficient for the amplification of the ITS1. We present a PCR-based diagnostic method as the only fast and reliable method for the diagnosis of H. heydorni in dogs.     

副鸡嗜血杆菌16 S rDNA PCR检测方法的建立

根据副鸡嗜血杆菌的16 S rDNA基因序列设计一对特异性引物XZIC1和XZIC2,对6株副鸡嗜血杆菌进行PCR扩增。结果显示,该对引物对6株副鸡嗜血杆菌均扩增出与预期大小相一致的282bp片段,而对鸡毒支原体、禽巴氏杆菌、鸡传染性支气管炎病毒、鸡新城疫病毒、大肠埃希菌、鸡白痢沙门菌、禽流感病毒(H9)、鸡喉气管炎病毒及葡萄球菌等9种病原体的扩增结果均为阴性。该PCR敏感性结果表明,本方法可以检测到10pg的副鸡嗜血杆菌DNA模板。采用引物XZIC1和XZIC2,对分别用副鸡嗜血杆菌ctcc253、ctcc255、ctcc257、ctcc269株感染SPF鸡的临床病料DNA进行PCR扩增,均可扩增出单一的282bp的片段。     

鹅蛔虫ITS rDNA的分子特征及种类分析

为探究从广东省清远的鹅体内采集的蛔虫(Ascaridia anseris)的种类,对临床采集的鹅蛔虫样品,在形态观察的基础上,用保守引物NC5和NC2扩增鹅蛔虫的ITS rDNA基因片段,将扩增产物经克隆测序后,获得大小为1 009bp的鹅蛔虫ITS rDNA基因序列(GenBank登录号为KC905082)。序列比对和系统进化分析表明,鹅蛔虫5.8SrRNA基因与GenBank收录的鸡蛔虫(登录号为AJ001508)同源性为96%,而与不同地理株的鸽蛔虫的同源性在91%~96%之间;禽蛔科的鸡蛔虫、鸽蛔虫和鹅蛔虫同一进化分支,鹅蛔虫、鸡蛔虫和鸽蛔虫处于各自的独立进化分支。上述证明,鹅蛔虫是不同于鸽蛔虫的一个独立有效种,在系统发生关系上与鸡蛔虫更亲近。     

Rapid diagnostic PCR assays for members of the Culicoides obsoletus and Culicoides pulicaris species complexes, implicated vectors of bluetongue virus in Europe

Biting midges of the Culicoides obsoletus Meigen and Culicoides pulicaris L. species complexes (Diptera: Ceratopogonidae) are increasingly implicated as vectors of bluetongue virus in Palearctic regions. However, predicting epidemiological risk and the spread of disease is hampered because whilst vector competence of Culicoides is expressed only in adult females, morphological identification of constituent species is only readily applicable to adult males and some species distinguishing traits have overlapping character states. Furthermore, adult males are typically rare in field collections, making characterisation of Culicoides communities impossible. Here we highlight the utility of mitochondrial cytochrome oxidase subunit I (COI) DNA sequences for taxonomic resolution and species identification of all species within C. obsoletus and C. pulicarus complexes. Culicoides were collected from 18 sites in the UK and Continental Europe, and identified to species level, or species complex level, based on morphological characters. The sample comprised four species from the C. obsoletus complex (n = 88) and five species from the C. pulicaris complex (n = 39). The DNA sequence of the 5' end of the COI gene was obtained from all individuals. Each member species formed a well-supported reciprocally monophyletic clade in a maximum likelihood phylogeny. Levels of DNA sequence divergence were sufficiently high between species to allow the design of species-specific PCR primers that can be used in PCR for identification of members of the C. pulicaris complex or in a multiplex PCR to identify members of the C. obsoletus complex. This approach provides a valuable diagnostic tool for monitoring species composition in mixed field collections of Culicoides.     

茶叶基因PCR扩增条件研究

本文对茶叶基因PCR扩增条件进行了研究，并对其结果进行了分析。