Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan.
Department of Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A & M University, College Station, TX, USA.
Yale J Biol Med. 2021 Jun 30;94(2):343-349. eCollection 2021 Jun.
In this perspectives paper, we discuss fertilization strategies for and as well as heterogeneity in , the causative agent of human cysticercosis. Two different genotypes of (Asian and Afro/American) were confirmed by mitochondrial DNA analysis approximately two decades ago. Since then, outcrossings of the two genotypes have been identified in Madagascar where the two genotypes are distributed sympatrically. Outcrossings were confirmed by the presence of discordance between mitochondrial and nuclear DNA. Since multiple tapeworm infections are common in endemic areas, outcrossing events likely occur quite frequently. Therefore, mitochondrial DNA from specimens collected from humans and pigs in endemic areas should be analyzed. If variations are found between specimens, nuclear DNA analysis should be performed to confirm the presence of discordance between mitochondrial and nuclear genes. Additional outcrossings likely add complexity to understanding the existing genetic diversity. Serological surveys are also recommended since serodiagnostic glycoprotein can also differentiate between the two genotypes. Viable eggs from different genotypes or from hybrids of two different genotypes should be used for experimental infection of pigs or dogs in order to observe any pathological heterogeneity in cysticercosis development. Although genetic diversity of is expected to result in clinical heterogeneity of cysticercosis in humans and pigs, there is currently no evidence showing that this occurs. There are also no comparative experimental studies on this topic. Therefore, studies evaluating the link between parasite heterogeneity and clinical outcome are warranted.
在这篇观点文章中，我们讨论了 和 的受精策略，以及 （引起人类囊尾蚴病的病原体）的异质性。大约二十年前，通过线粒体 DNA 分析证实了 （亚洲和非洲/美洲）有两种不同的基因型。从那时起，在马达加斯加已经发现了这两种基因型的杂交，在那里这两种基因型是共生分布的。通过线粒体和核 DNA 之间的不和谐存在，证实了杂交事件的发生。由于在流行地区经常发生多种带绦虫感染，因此杂交事件可能经常发生。因此，应该分析从流行地区的人和猪身上采集的 标本中的线粒体 DNA。如果在标本之间发现变异，应该进行核 DNA 分析，以确认线粒体和核基因之间的不和谐存在。额外的杂交可能会增加对现有遗传多样性的理解的复杂性。还建议进行血清学调查，因为血清诊断糖蛋白也可以区分两种基因型。为了观察囊尾蚴病发展中的任何病理异质性，应该使用来自不同基因型的或来自两种不同基因型的杂种的有活力的卵来对猪或狗进行实验性感染。尽管 的遗传多样性预计会导致人类和猪囊尾蚴病的临床异质性，但目前没有证据表明这一点。在这个主题上也没有比较实验研究。因此，有必要进行评估寄生虫异质性与临床结果之间联系的研究。
