贾第虫谷氨酸脱氢酶基因座分离株的分子遗传学分析

Molecular genetic analysis of Giardia intestinalis isolates at the glutamate dehydrogenase locus.

作者信息

Monis P T, Mayrhofer G, Andrews R H, Homan W L, Limper L, Ey P L

机构信息

Department of Microbiology and Immunology, University of Adelaide, Australia.

出版信息

Parasitology. 1996 Jan;112 ( Pt 1):1-12. doi: 10.1017/s0031182000065021.

DOI:10.1017/s0031182000065021

PMID:8587793

Abstract

Samples of DNA from a panel of Giardia isolated from humans and animals in Europe and shown previously to consist of 2 major genotypes--'Polish' and 'Belgian'--have been compared with human-derived Australian isolates chosen to represent distinct genotypes (genetic groups I-IV) defined previously by allozymic analysis. Homologous 0.52 kilobase (kb) segments of 2 trophozoite surface protein genes (tsa417 and tsp11, both present in isolates belonging to genetic groups I and II) and a 1.2 kb segment of the glutamate dehydrogenase (gdh) gene were amplified by the polymerase chain reaction (PCR) and examined for restriction fragment length polymorphisms (RFLPs). Of 21 'Polish' isolates that were tested, all yielded tsa417-like and tsp11-like PCR products that are characteristic of genetic groups I or II (15 and 6 isolates respectively) in a distinct assemblage of G. intestinalis from Australia (Assemblage A). Conversely, most of the 19 'Belgian' isolates resembled a second assemblage of genotypes defined in Australia (Assemblage B) which contains genetic groups III and IV. RFLP analysis of gdh amplification products showed also that 'Polish' isolates were equivalent to Australian Assemblage A isolates (this analysis does not distinguish between genetic groups I and II) and that 'Belgian' isolates were equivalent to Australian Assemblage B isolates. Comparison of nucleotide sequences determined for a 690 base-pair portion of the gdh PCR products revealed > or = 99.0% identity between group I and group II (Assemblage A/'Polish') genotypes, 88.3-89.7% identity between Assemblage A and Assemblage B genotypes, and > or = 98.4% identity between various Assemblage B/'Belgian' genotypes. The results confirm that the G. duodenalis isolates examined in this study (inclusive of G. intestinalis from humans) can be divided into 2 major genetic clusters: Assemblage A (= 'Polish' genotype) containing allozymically defined groups I and II, and Assemblage B (= 'Belgian' genotype) containing allozymically defined groups III and IV and other related genotypes.

摘要

从欧洲人和动物身上分离出的一组贾第虫的DNA样本，之前已显示其由两种主要基因型组成——“波兰型”和“比利时型”——已与从澳大利亚人身上分离出的、被选来代表先前通过等位酶分析定义的不同基因型（遗传组I-IV）的分离株进行了比较。通过聚合酶链反应（PCR）扩增了两个滋养体表面蛋白基因（tsa417和tsp11，两者都存在于属于遗传组I和II的分离株中）的同源0.52千碱基（kb）片段以及谷氨酸脱氢酶（gdh）基因的1.2 kb片段，并检测了限制性片段长度多态性（RFLP）。在测试的21株“波兰型”分离株中，所有分离株均产生了tsa417样和tsp11样PCR产物，这些产物是澳大利亚肠道贾第虫一个独特组合（组合A）中遗传组I或II（分别为15株和6株）的特征。相反，19株“比利时型”分离株中的大多数类似于在澳大利亚定义的第二种基因型组合（组合B），该组合包含遗传组III和IV。对gdh扩增产物的RFLP分析还表明，“波兰型”分离株等同于澳大利亚组合A分离株（该分析无法区分遗传组I和II），“比利时型”分离株等同于澳大利亚组合B分离株。对gdh PCR产物690个碱基对部分测定的核苷酸序列进行比较，结果显示遗传组I和组II（组合A/“波兰型”）基因型之间的同一性≥99.0%，组合A和组合B基因型之间的同一性为88.3 - 89.7%，各种组合B/“比利时型”基因型之间的同一性≥98.4%。结果证实，本研究中检测的十二指肠贾第虫分离株（包括来自人类的肠道贾第虫）可分为两个主要遗传簇：组合A（=“波兰型”基因型），包含等位酶定义的组I和组II；组合B（=“比利时型”基因型），包含等位酶定义的组III和组IV以及其他相关基因型。