Department of Microbiology, Osaka City Institute of Public Health and Environmental Sciences, Tennoji-ku, Osaka 543-0026, Japan.
Parasitol Res. 2010 Feb;106(3):733-6. doi: 10.1007/s00436-009-1703-7.
Giardia duodenalis is a pathogen that has been found in a variety of mammals, including humans, and consists of host-specific (assemblages C, D, E, F, and G) and zoonotic (assemblages A, B) genetic groups. Ferrets are popular pets, and they, like humans, are hosts to this pathogen. The genetic characteristics of the Giardia population in ferrets are unclear because only one ferret isolate has been genotyped. To develop a more complete picture of the genetic characteristics of the Giardia population in domestic ferrets two additional Giardia isolates, recovered independently from two ferrets suffering from intestinal or hepatic giardiasis, were analyzed genetically. The sequences of both isolates at three loci, small subunit ribosomal RNA (SSUrDNA, 292 bp), beta-giardin (734 bp), and glutamate dehydrogenase (GDH, 713 bp) were identical to each other, but the sequences of triosephosphate isomerase locus (TPI, 512 bp) had five substitutions between isolates. Sequence homology and phylogenetic analyses at four loci identified both isolates as members of the assemblage A. Moreover, the sequences of SSUrDNA, beta-giardin, and GDH from both isolates were identical to those of the previous ferret isolate genotyped as assemblage A within the regions of overlap. The result obtained in the present study indicates that at least two genetically different types in assemblage A exist in domestic ferrets. In addition, there have been no reported human and animal isolates with the same sequence as those from ferret isolates at all four loci examined, suggesting that the present ferret isolates might be host-specific.
十二指肠贾第鞭毛虫是一种病原体，已在多种哺乳动物中发现，包括人类，包括宿主特异性（组合 C、D、E、F 和 G）和人畜共患（组合 A、B）遗传群。雪貂是受欢迎的宠物，它们和人类一样是这种病原体的宿主。由于仅对一种雪貂分离株进行了基因分型，因此雪貂中贾第鞭毛虫种群的遗传特征尚不清楚。为了更全面地了解雪貂中贾第鞭毛虫种群的遗传特征，对另外两个从患有肠或肝贾第虫病的两只雪貂中独立分离的贾第虫分离株进行了遗传分析。两个分离株在三个基因座（小亚基核糖体 RNA（SSUrDNA，292 bp），β-微管蛋白（734 bp）和谷氨酸脱氢酶（GDH，713 bp））的序列完全相同，但三磷酸异枸橼酸酶基因座（TPI，512 bp）的序列在分离株之间有五个替换。四个基因座的序列同源性和系统发育分析将两个分离株鉴定为 A 组合成员。此外，两个分离株的 SSUrDNA、β-微管蛋白和 GDH 序列与先前鉴定为 A 组合的雪貂分离株的序列在重叠区域内完全相同。本研究的结果表明，在雪貂中至少存在两种遗传上不同的 A 组合类型。此外，在所检查的四个基因座中，没有报道过与人或动物分离株具有与雪貂分离株相同序列的分离株，这表明目前的雪貂分离株可能是宿主特异性的。
