Giardia duodenalis is a flagellated unicellular eukaryotic microorganism that usually parasitizes the small intestine of humans and many other vertebrates causing diarrheal disease throughout the world. Notably, Giardia despite minimization of most cellular systems shows different strategies to adapt to environmental conditions, evade the immune system and resist exposure to antimicrobial agents. Over the past years, epigenetic regulation of gene expression has been shown to have a relevant role in the parasite's biology. Interestingly, analysis of the Giardia genome revealed the presence of enzymes responsible for post-translational modification in histones, therefore suggesting that epigenetic mechanisms may regulate gene expression in this parasite. Thus, the purpose of this review is to summarize how epigenetic mechanisms play relevant roles in the pathogenicity of Giardia, with a particular emphasis on the molecular mechanisms associated with parasite differentiation, antigenic variation and antimicrobial resistance.

贾第鞭毛虫（Giardia duodenalis）是一种鞭毛单细胞真核微生物，通常寄生于人类的小肠和世界各地引起腹泻病的许多其他脊椎动物。值得注意的是，尽管大多数细胞系统都已最小化，贾第鞭毛虫仍显示出不同的策略来适应环境条件，逃避免疫系统并抵抗暴露于抗菌剂。在过去的几年中，已证明基因表达的表观遗传学调控在寄生虫的生物学中具有重要作用。有趣的是，对贾第虫的分析基因组揭示了组蛋白中负责翻译后修饰的酶的存在，因此表明表观遗传机制可能调节该寄生虫中的基因表达。因此，本综述的目的是总结表观遗传机制如何在贾第虫的致病性中发挥相关作用，特别着重于与寄生虫分化，抗原变异和抗菌素耐药性相关的分子机制。