van der Giessen J W B, de Vries A, Roos M, Wielinga Peter, Kortbeek L M, Mank T G
National Institute for Public Health and the Environment (RIVM), Microbiological Laboratory for Health Protection, Antonie van Leeuwenhoeklaan 9, P.O. Box 1, Bilthoven, The Netherlands.
Int J Parasitol. 2006 Jun;36(7):849-58. doi: 10.1016/j.ijpara.2006.03.001. Epub 2006 Mar 29.
Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is a protozoan organism that can infect the intestinal tract of many animal species including mammals. Genetic heterogeneity of G. duodenalis is well described but the zoonotic potential is still not clear. In this study, we analysed 100 Giardia DNA samples directly isolated from human stool specimens, to get more insight in the different G. duodenalis assemblages present in the Dutch human population. Results showed that these human isolates could be divided into two main Assemblages A and B within the G. duodenalis group on the basis of PCR assays specific for the Assemblages A and B and the DNA sequences of 18S ribosomal RNA and the glutamate dehydrogenase (gdh) genes. Genotyping results showed that G. duodenalis isolates originating from Dutch human patients belonged in 35% of the cases to Assemblage A (34/98) and in 65% of the cases to Assemblage B (64/98) whereas two human cases remained negative in all assays tested. In addition, we compared these human samples with animal samples from the Netherlands and human and animal samples from other countries. A phylogenetic analysis was carried out on the DNA sequences obtained from these Giardia and those available in GenBank. Using gdh DNA sequence analysis, human and animal Assemblage A and B Giardia isolates could be identified. However, phylogenetic analysis revealed different sub-clustering for human and animal isolates where host-species-specific assemblages (C, D, E, F and G) could be identified. The geographic origin of the human and animal samples was not a discriminating factor.
十二指肠贾第虫（同义词：兰氏贾第虫、肠贾第虫）是一种原生动物，可感染包括哺乳动物在内的许多动物物种的肠道。十二指肠贾第虫的基因异质性已有充分描述，但其人畜共患病潜力仍不明确。在本研究中，我们直接分析了从人类粪便标本中分离出的100份贾第虫DNA样本，以更深入了解荷兰人群中存在的不同十二指肠贾第虫组合。结果表明，根据针对组合A和B的PCR检测以及18S核糖体RNA和谷氨酸脱氢酶（gdh）基因的DNA序列，这些人类分离株可在十二指肠贾第虫组内分为两个主要组合A和B。基因分型结果显示，来自荷兰人类患者的十二指肠贾第虫分离株在35%的病例中属于组合A（34/98），在65%的病例中属于组合B（64/98），而两例人类病例在所有检测中均为阴性。此外，我们将这些人类样本与来自荷兰的动物样本以及来自其他国家的人类和动物样本进行了比较。对从这些贾第虫获得的DNA序列以及GenBank中可用的序列进行了系统发育分析。使用gdh DNA序列分析，可以鉴定人类和动物的组合A和B贾第虫分离株。然而，系统发育分析揭示了人类和动物分离株的不同亚聚类，其中可以鉴定出宿主物种特异性组合（C、D、E、F和G）。人类和动物样本的地理来源不是一个区分因素。
