Aix-Marseille Université, UMR MD3 Relations Hôte-Parasites, Pharmacologie et Thérapeutique, Faculté de Pharmacie, Marseille, France.
Appl Environ Microbiol. 2012 Feb;78(4):905-12. doi: 10.1128/AEM.06488-11. Epub 2011 Dec 9.
The protozoan parasites Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii are pathogens that are resistant to a number of environmental factors and pose significant risks to public health worldwide. Their environmental transmission is closely governed by the physicochemical properties of their cysts (Giardia) and oocysts (Cryptosporidium and Toxoplasma), allowing their transport, retention, and survival for months in water, soil, vegetables, and mollusks, which are the main reservoirs for human infection. Importantly, the cyst/oocyst wall plays a key role in that regard by exhibiting a complex polymeric coverage that determines the charge and hydrophobic characteristics of parasites' surfaces. Interaction forces between parasites and other environmental particles may be, in a first approximation, evaluated following the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability. However, due to the molecular topography and nano- to microstructure of the cyst/oocyst surface, non-DVLO hydrophobic forces together with additional steric attractive and/or repulsive forces may play a pivotal role in controlling the parasite behavior when the organism is subjected to various external conditions. Here, we review several parameters that enhance or hinder the adhesion of parasites to other particles and surfaces and address the role of fast-emerging techniques for mapping the cyst/oocyst surface, e.g., by measuring its topology and the generated interaction forces at the nano- to microscale. We discuss why characterizing these interactions could be a crucial step for managing the environmental matrices at risk of microbial pollution.
原虫寄生虫贾第鞭毛虫、隐孢子虫和刚地弓形虫是对许多环境因素具有抗性的病原体，它们对全球公共卫生构成重大威胁。它们的环境传播受其孢囊（贾第鞭毛虫）和卵囊（隐孢子虫和刚地弓形虫）的理化特性的严格控制，允许它们在水中、土壤、蔬菜和贝类中运输、保留和存活数月，这些是人类感染的主要宿主。重要的是，囊/卵囊壁在这方面起着关键作用，因为它具有复杂的聚合覆盖物，决定了寄生虫表面的电荷和疏水性特征。寄生虫与其他环境颗粒之间的相互作用力可以根据胶体稳定性的 Derjaguin-Landau-Verwey-Overbeek（DLVO）理论进行初步评估。然而，由于囊/卵囊表面的分子地形和纳米到微观结构，非 DLVO 疏水力以及额外的空间吸引力和/或排斥力可能在控制寄生虫行为方面发挥关键作用，当生物体受到各种外部条件时。在这里，我们回顾了几个增强或阻碍寄生虫与其他颗粒和表面粘附的参数，并讨论了新兴技术在绘制囊/卵囊表面方面的作用，例如，通过测量其拓扑结构和在纳米到微尺度上产生的相互作用力。我们讨论了为什么表征这些相互作用可能是管理存在微生物污染风险的环境基质的关键步骤。
