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犬贾第虫dsRNA病毒的鉴定及特性 总被引：12，自引：0，他引：12
对分离到的6株犬贾第虫（Giardia cnais)包囊进行核酸分析，在其中1株犬贾第虫核酸的琼脂糖凝胶电泳图谱上观察到1条长度约7.0kb的片段。经鉴定，该核酸不能被DNA酶（100mg/L）降解，对质量浓度低的RNA酶（0.1mg/L)不敏感，但可被质量浓度高的RNA酶（10mg/L）降解。纯化包囊经流氮冻融后，磷钨酸负染，电镜观察发现有球形、直径约为33nm的病毒样粒子存在，包囊超薄切片在胞质中也观察到该病毒样粒子存在。RNA依赖RNA聚合酶活性测定结果表明，该病毒具有RNA依赖RNA聚合酶的活性。犬贾第虫dsRNA病毒核经RT-PCR扩增后得到1条预计扩增大小的片段，将其回收后连接到pMD18-T载体上进行克隆并测序，所得序列仅与蓝氏贾第虫病毒具有较高同源性。 相似文献
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Isabel Guadano Procesi Azzurra Carnio Federica Berrilli Margherita Montalbano Di Filippo Alessia Scarito Cristina Amoruso Marco Barni Marco Ruffini Giulia Barlozzari Manuela Scarpulla Claudio De Liberato 《Zoonoses and public health》2022,69(1):46-54
Giardia duodenalis is the most common intestinal protozoan in humans and animals worldwide, including eight morphologically identical assemblages, infecting pets, livestock, wildlife and human beings. Assemblages A and B are those with the higher zoonotic potential, and they have been detected in several mammals other than humans; the others (C to H) show a higher host specificity. Cats can harbour both the specific Assemblage F and the zoonotic ones A and B. Several studies have been carried out on G. duodenalis genotypes in cats; however, the role of this species in the epidemiology of giardiasis is still poorly understood. In this scenario, the present study carried out the detection and genetic characterization at sub-assemblage level of G. duodenalis from colony stray cats in central Italy. In the period 2018–2019, 133 cat faecal samples were analysed for the presence of G. duodenalis cysts by a direct immunofluorescence assay. Positive samples were subsequently subjected to molecular analyses for assemblage/sub-assemblage identification. Forty-seven samples (35.3%) were positive for G. duodenalis cysts by immunofluorescence. G. duodenalis DNA was amplified at SSU-rDNA locus from 39 isolates: 37 were positive for zoonotic Assemblage A and 2 showed a mixed infection (A + B). Positive results for the β-giardin gene were achieved for 25 isolates. Sequence analysis revealed 16 isolates belonging to Sub-assemblage AII and 8 to Sub-assemblage AIII. One isolate resulted as ambiguous AI/AIII. Large sequence variability at the sub-assemblage level was detected, with several double peaks and mutations, making complex a proper isolate allocation. When compared with previous studies, the 35.3% prevalence of G. duodenalis in cats reported in the present article was surprisingly high. Moreover, all positive cats resulted to be infected with zoonotic assemblages/sub-assemblages, thus indicating stray cats as a possible source of human giardiasis and highlighting the sanitary relevance of cat colonies in the study area. 相似文献
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Giardia isolates from eight horses from New York State (NY), USA and two horses from Western Australia (WA) were genetically characterized at the SSU-rDNA and triose-phosphate isomerase (TPI) genes. Phylogenetic analysis of the TPI gene provided strong support for the placement of both isolates of Giardia from horses in WA and a single isolate from a horse in NY within the assemblage AI genotype of G. duodenalis. Another two isolates from horses in NY placed within the assemblage AII genotype of G. duodenalis. Phylogenetic analysis of the TPI gene also provided strong bootstrap support for the placement of four G. duodenalis isolates from horses in NY into a potentially host-specific sub-assemblage of assemblage BIV. The results of this study are consistent with previous studies showing that assemblages AI and AII of G. duodenalis provide the greatest potential zoonotic risk to humans. Horses may therefore constitute a potential source for human infection of Giardia either directly or via watersheds. 相似文献
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贾第虫是一种人兽共患肠道寄生原虫,在全世界范围内传播,其感染率与地区和环境有非常大的关系。为了解中国南海周边国家和地区犬类贾第虫感染情况,判断海洋隔离是否是影响贾第虫传播的重要因素,自2018年6月至2019年7月,从中国广州、越南胡志明市、马来西亚吉隆坡、新加坡和菲律宾马尼拉分别采集犬类粪便样本616份。提取每个地区犬类粪便样本的DNA,以贾第虫磷酸丙糖异构酶(triose phosphate isomerase)基因TPI和BG(genotyping at the beta giardin)基因制作巢式PCR引物。提取的犬粪基因组DNA为模板进行巢式PCR扩增,确定其阳性感染率,PCR阳性产物经测序并将结果与GenBank中的贾第虫序列比对,判断其分型。结果发现,616份样品中,有48份样品检验结果为贾第虫感染阳性,阳性率为7.79%(48/616)。不同地区感染率分别是:中国广州4.81%、越南胡志明市6.90%、马来西亚吉隆坡9.09%、新加坡2.86%和菲律宾马尼拉11.52%。其中48份样品在TPI和BG位点分别检测到条带,阳性率分别为7.63%和5.19%。阳性样品再经过对于BG及TPI基因位点的测序比对,得知BG位点有集聚体B型(3.33%)、集聚体C型(86.67%)、集聚体D型(10%),TPI位点有集聚体B型(2.12%)、集聚体C型(85.1%)和集聚体D型(12.76%)。综上,中国南海周边地区存在贾第虫感染,公共卫生相对较好地区感染率较低,犬源贾第虫基因分型分布未明显受到海洋地域隔离影响。 相似文献
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硝唑尼特治疗犬贾第虫病的研究 总被引：1，自引：0，他引：1
选择试验犬8只,将其随机分为4个小组,每组2只.连续6 d对8只试验犬分剐进行粪检,确定无贾第虫感染后,用体外纯培养的犬贾第虫滋养体接种试验犬,然后每天采集试验犬新鲜粪便40 g,用硫酸锌漂浮法进行粪检,当检测犬贾第虫感染呈阳性时,分别用1、2、4 mg/kg体质量剂量的硝唑尼特时1、2、3组试验犬进行灌服治疗,第4组试验犬不用药作为对照.用药后,每天以同样的方法检测贾第虫包囊,并计数.结果表明,以2、4 mg/kg体质量给药的试验犬1 d后粪检结果转为阴性,以1 mg/kg体质量给药的试验犬4 d后粪检结果转为阴性.结果表明以2、4 mg/kg体质量剂量的硝唑尼特对犬贾第虫痛有很好的疗效. 相似文献
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A study was undertaken to determine the prevalences of Cryptosporidium and Giardia in dairy calves less than 6 months of age in Norway. Faecal samples were collected from a total of 1386 calves, between 3 and 183 days of age, in 136 dairy farms from three different areas of Norway. Faecal samples were examined for Cryptosporidium oocysts and Giardia cysts after concentration and immunofluorescent staining.
Giardia was found in 93% (127 out of 136) of the farms and in 49% (679 out of 1386) of the calves. Cryptosporidium was found in 53% (72 out of 136) of the farms and in 12% (167 out of 1386) of the calves. The level of Giardia and/or Cryptosporidium was low in the majority of the infected calves.
Infection peaked in the age group 2–3 months for both Cryptosporidium and Giardia. The prevalences of both parasites were higher in samples taken during winter than in samples taken during summer, and statistically significant differences were found when prevalences in different age groups of calves were compared between the three areas. A significantly lower prevalence of Cryptosporidium was found in calves housed in shared pens that were thoroughly washed more than three times a year than in calves from pens washed less often. For Giardia there was a trend for decreasing intensity of infection with increasing age in the sampled calves. For Cryptosporidium there was a trend for increasing herd prevalence with increasing number of calves in the herd, but this trend was not statistically significant. Other parameters which were investigated such as housing, feeding or management routines were not associated with prevalence or intensity of infection with either parasite. 相似文献
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Sina Rehbein Christian Klotz Ralf Ignatius Elisabeth Müller Anton Aebischer Barbara Kohn 《Zoonoses and public health》2019,66(1):117-124
Giardia duodenalis is a relevant gastrointestinal protozoan pathogen of humans and animals. This species complex consists of eight genetically different assemblages. Assemblages A and B are pathogenic to humans and pets, thus confer zoonotic potential. The risk of zoonotic transmission has been controversially discussed. The aim of this monocentric cross‐sectional pilot study was to investigate G. duodenalis assemblages in humans and pets living in common households in Berlin/Brandenburg (Germany). Samples from dogs, cats and humans sharing the same households were screened for Giardia infection by antigen‐detecting assays. All human samples were additionally analysed by a Giardia‐specific qPCR. Cyst quantification and sequences of different gene loci (triosephosphate isomerase (tpi), glutamate dehydrogenase (gdh), β‐giardin (bg) and for dogs SSUrDNA) were analysed. A total of 38 households (31 households with dogs and seven with cats) with 69 human individuals participated in the study. Initial antigen‐detecting assays revealed Giardia‐positive results for 13 (39%) canine, one (14%) feline and one human sample. Reanalysis of the human samples by qPCR revealed two more positive specimens (4%). Two of these three samples were identified as assemblage B at all tested loci. Success rate of assemblage typing for pet samples was generally low and comprised mainly the SSUrDNA locus only. Overall, six of 13 Giardia‐positive canine samples were typable (2× A, 1× co‐infection: A and B, 1× C; 2× D). One pair of samples (dog and human) from the same household had a similar but not identical assemblage B sequence at tpi locus. Assemblage A was also detected in the dog specimen, which hampered sequence analysis. In conclusion, although exhibiting limitations due to the sample size, our study highlights the need for better and standardized typing tools to distinguish G. duodenalis strains with higher resolution in order to perform proper case–control studies for a realistic estimation of zoonotic risk. 相似文献