Sundar N, Cole R A, Thomas N J, Majumdar D, Dubey J P, Su C
United States Department of Agriculture, Agricultural Research Service, Animal Natural Resources Institute, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD 20705-2350, USA.
Vet Parasitol. 2008 Feb 14;151(2-4):125-32. doi: 10.1016/j.vetpar.2007.11.012. Epub 2007 Nov 17.
Sea otters (Enhydra lutris) have been reported to become infected with Toxoplasma gondii and at times succumb to clinical disease. Here, we determined genotypes of 39 T. gondii isolates from 37 sea otters in two geographically distant locations (25 from California and 12 from Washington). Six genotypes were identified using 10 PCR-RFLP genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico, and by DNA sequencing of loci SAG1 and GRA6 in 13 isolates. Of these 39 isolates, 13 (33%) were clonal Type II which can be further divided into two groups at the locus Apico. Two of the 39 isolates had Type II alleles at all loci except a Type I allele at locus L358. One isolate had Type II alleles at all loci except the Type I alleles at loci L358 and Apico. One isolate had Type III alleles at all loci except Type II alleles at SAG2 and Apico. Two sea otter isolates had a mixed infection. Twenty-one (54%) isolates had an unique allele at SAG1 locus. Further genotyping or DNA sequence analysis for 18 of these 21 isolates at loci SAG1 and GRA6 revealed that there were two different genotypes, including the previously identified Type X (four isolates) and a new genotype named Type A (14 isolates). The results from this study suggest that the sea otter isolates are genetically diverse.
据报道，海獭（Enhydra lutris）会感染刚地弓形虫，有时会死于临床疾病。在此，我们确定了来自两个地理上相距遥远地点的37只海獭的39株刚地弓形虫分离株的基因型（25株来自加利福尼亚，12株来自华盛顿）。使用包括SAG1、SAG2、SAG3、BTUB、GRA6、c22 - 8、c29 - 2、L358、PK1和Apico在内的10个PCR - RFLP遗传标记，并通过对13株分离株的SAG1和GRA6基因座进行DNA测序，鉴定出了6种基因型。在这39株分离株中，13株（33%）为克隆II型，在Apico基因座可进一步分为两组。39株分离株中有2株在所有基因座上均为II型等位基因，但在L358基因座上为I型等位基因。1株在所有基因座上均为II型等位基因，但在L358和Apico基因座上为I型等位基因。1株在所有基因座上均为III型等位基因，但在SAG2和Apico基因座上为II型等位基因。两株海獭分离株存在混合感染。21株（54%）分离株在SAG1基因座上有独特的等位基因。对这21株分离株中的18株在SAG1和GRA6基因座进行进一步的基因分型或DNA序列分析，发现有两种不同的基因型，包括先前鉴定的X型（4株）和一种名为A型的新基因型（14株）。本研究结果表明，海獭分离株在遗传上具有多样性。
