Molecular characterization of Cysticercus tenuicollis of slaughtered livestock in Upper Egypt governorates

Objective: To present the molecular characterization of Cysticercus tenuicollis(C. tenuicollis) of Taenia hydatigena(T. hydatigena) from livestock isolates in Egypt, and to introduce a detailed image of C. tenuicollis infection in ruminant animals in Upper Egypt.Methods: The prevalence rates of C. tenuicollis infections among the slaughtered animals from different organs were determined using the amplification of sequencing of the MT-CO1 gene.Results: In the present study the infection rates of C. tenuicollis were found to be 16%and 19% in sheep and goat samples respectively. Firstly we report one larval stage of T. hydatigena detected in the camel liver in Egypt. C. tenuicollis infection manifested a higher prevalence in females than in males. Those above two years of age manifested a higher infection rate than younger animals. The preferred site for the infection was the omentum: a 70% preference in sheep and a 68% preference in goats. The molecular characterization using the MT-CO1 gene of isolates from sheep, goats and camels corresponded to T. hydatigena. For this study, molecular characterizations of T. hydatigena were done for the first time in Egypt. Molecular tools are of great assistance in characterizing the C. tenuicollis parasite especially when the morphological character cannot be detected, because the metacestodes are frequently confused with infection by the hydatid cyst, especially when these occur in the visceral organs. In the present study,C. tenuicollis manifested high identity in the goat and sheep samples, while differences were found more frequently in the camel samples(10 base pair).Conclusions: Clearly molecular diagnosis for C. tenuicollis infection significantly helps to differentiate it from such other metacestodes as hydatidosis, which manifests a completely different pathogenicity and requires different control programs.

青海省隐孢子虫的分子特征

本研究中分别对来自西宁动物园的21种观赏动物,乌兰县的16头牦牛和42只山羊,用免疫荧光法(IFT)进行了隐孢子虫卵囊的调查。用套式PCR进行种和基因型的检测,并且用18SrRNA进行序列分析。用IFT分别在西宁动物园的17个观赏动物,乌兰县的2头牦牛和15只山羊中发现了隐孢子虫的卵囊。对IFT阳性样品进行PCR扩增,其中10份为PCR阳性。并且用黑豹(Panthera pardus)、黑颈鹤(Grus nigricollis),蛮羊(Ammotragus lervia),羚牛(Budorcastaxicolor),小熊猫(Ailurus fulgens)和白马鸡(Crossoptilon crossoptilon)等动物隐孢子虫卵囊的PCR序列分析结果跟与微小隐孢子虫鼠基因型进行了比较。本研究首次报道了青海省野生动物中隐孢子虫的感染情况,并且首次在北山羊上分离得到的隐孢子虫中发现了鹿源基因型,类似C.bovis基因型,以及在山羊和野牦牛上发现了新的Cryptosporidium spp。

不同动物源脑心肌炎病毒的分离、鉴定和全基因组序列分析

为研究脑心肌炎病毒（encephalomyocarditis virus,EMCV）对不同动物宿主的感染情况。本试验应用改进的＂细胞接种与RT-PCR方法相结合＂技术,成功分离到国内首株地方土猪源EMCV、首株家养野猪源EMCV、1株鼠源EMCV和3株良种猪源EMCV,并进行了全基因组序列测定和分析。结果显示,6株EMCV分离毒的基因组全长从7 724~7 735bp不等,ORF长度均为6 879bp,彼此间核苷酸同源性为99.3%~99.8%,与其他不同动物源EMCV参考毒株的同源性为79.9%~99.9%,与国内猪源、鼠源分离毒的同源性均在99.4%以上;各基因片段中,以VP1和2A变异幅度最大,VP2和3D最为保守;基于EMCV全基因组、ORF和VP1基因序列绘制的系统发育进化树显示,EMCV可分为G1、G2和G3 3个群,猪源EMCV主要分布在G1、G2群,鼠源EMCV在G1、G3群中均有分布;6株EMCV分离毒与其他国内参考毒株同属于G1群,但分布并不完全集中。结果表明,地方土猪和家养野猪可感染EMCV并引起发病,提醒在进行地方品种养殖和野生动物家养时要充分考虑人兽共患疫病传播的生态学;鼠在良种猪、家养野猪和地方土猪EMCV之间的交叉感染、传播与流行中起到重要媒介作用;不同EMCV地方流行株间存在较大的地域差异,其传播具有一定的区域限制性;EMCV在感染不同动物时可能会发生某些突变,以适应新的宿主。