Intraerythrocytic gamonts of at least 2 named Hepatozoon species have been reported to infect the erythrocytes of ranid frogs in Ontario, Canada. Although gamonts of both species are morphometrically similar, the cytopathological changes that 1 of these species, Hepatozoon clamatae, causes to host erythrocytes, manifested by nuclear fragmentation, was used historically to distinguish this parasite from Hepatozoon catesbianae. Molecular characterization of these 2 Hepatozoon species has been equivocal in correlating genotype with gamont morphotype. Amplification and sequencing of multiple potential genotyping loci within the nuclear (18S ribosomal deoxyribonucleic acid [rDNA]; internal transcribed spacer 1), apicoplast (23S rDNA), and mitochondrial genomes (complete genomes, cytochrome c oxidase subunits I and III [COI and COIII], and cytochrome b) were conducted on Hepatozoon species that infect ranid frogs in Ontario. Sequence data were then used to evaluate the diversity of parasites present in these amphibian hosts and to assign genotypes to gamont morphotypes, if possible. Three distinct genotypes were identified at all loci; the data permitted the discovery of a third, formerly unrecognized Hepatozoon species in ranid frogs from Ontario. Although all genetic loci demonstrated differences between Hepatozoon species, mitochondrial COIII sequences were most suitable for genotypic differentiation of these parasites of frogs. Linking genotypes to gamont morphotypes proved impossible; genotypes identified as H. catesbianae and H. clamatae were found in infections with or without nuclear fragmentation of their host erythrocytes. This suggests that differentiating these species must rely on suitable genotyping methods for identification in the blood of their amphibian intermediate hosts.

据报道，在加拿大安大略省，至少有2种命名为Hepatozoon物种的红细胞内gamonts感染了红鼻蛙的红细胞。尽管这两个物种的gamonts在形态上相似，但这些物种中的1个（导致幽门螺杆菌）导致宿主红细胞的细胞病理学变化以核碎裂为特征，在历史上曾被用来将该寄生虫与Catesbianae肝炎区分开来。这2个Hepatozoon的分子表征物种在将基因型与gamont形态型相关联方面一直是模棱两可的。核内多个潜在基因分型基因座的扩增和测序（18S核糖体脱氧核糖核酸[rDNA]；内部转录间隔子1），无顶质体（23S rDNA）和线粒体基因组（完整基因组，细胞色素C氧化酶亚基I和III [ COI和COIII ]，并在Hepatozoon上进行细胞色素b）在安大略省感染蛙类的物种。然后，将序列数据用于评估这些两栖动物宿主中存在的寄生虫的多样性，并在可能的情况下将基因型分配给gamont形态型。在所有基因座上都鉴定出三种不同的基因型。数据允许在安大略省的黑蛙中发现第三种以前未被发现的Hepatozoon物种。尽管所有的遗传位点均显示出肝臭虫物种之间的差异，但线粒体COIII序列最适合这些青蛙寄生虫的基因型分化。将基因型与gamont形态型联系起来是不可能的。基因型鉴定为H. catesbianae和H. clamatae在有或没有其宿主红细胞核碎裂的感染中发现。这表明区分这些物种必须依靠合适的基因分型方法来鉴定其两栖动物中间宿主的血液。