Australia is geographically isolated and possesses a remarkable diversity of wildlife species. Marsupials are highly susceptible to infection with the cosmopolitan parasite Toxoplasma gondii. Of 46 marsupials screened for T. gondii by multilocus PCR-DNA sequencing at polymorphic genes (B1, SAG3, GRA6, GRA7), 12 were PCR-positive; the majority (67%; 9/12) were infected by non-archetypal Type II-like or atypical strains. Six novel alleles were detected at B1, indicating greater diversity of genotypes than previously envisaged. Two isolates lethal to marsupials, were avirulent to mice. The data support the conclusion that Australia's isolation may have favoured the persistence of non-archetypal ancestral genotypes.

中文翻译：

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感染澳大利亚有袋动物的非原型 II 型和非典型弓形虫菌株。

澳大利亚在地理上与世隔绝，拥有丰富多样的野生动物物种。有袋动物极易感染世界性寄生虫弓形虫。在通过多态性基因（B1、SAG3、GRA6、GRA7）的多位点 PCR-DNA 测序筛选出的 46 只有袋动物中，有 12 只为 PCR 阳性；大多数（67%；9/12）被非原型II型样或非典型菌株感染。在 B1 检测到六个新的等位基因，表明基因型的多样性比以前设想的更大。两种对有袋动物致命的分离物对小鼠无毒。数据支持以下结论：澳大利亚的孤立可能有利于非原型祖先基因型的持续存在。