Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Bâtiment Mendel, 43 Bd du 11 novembre 1918, 69622 Villeurbanne, France.
Vet Parasitol. 2011 Dec 29;183(1-2):59-67. doi: 10.1016/j.vetpar.2011.06.018. Epub 2011 Jun 25.
Toxoplasmosis is a world-wide infection caused by Toxoplasma gondii. Oocysts disseminated in the environment by infected cats provide a major source of infection for humans and intermediate hosts. The level of soil contamination and the dynamics of this contamination are mostly unknown due to the lack of sensitivity of detection method. Our aim was to improve the detection of T. gondii oocysts in soil samples by comparing three extraction protocols (A, B and C) on unsporulated and sporulated oocysts of different strains and ages, and by testing the effect of sporulation and soil characteristics on oocyst recovery using the most efficient method. The oocyst recovery obtained using protocol C, in which the flotation solution was placed under the sample solution after the dispersion step, was at least ten-fold higher than protocols A and B, in which the sample was just filtered before flotation. The efficiency of protocol C, tested on five artificial soil matrices and four natural soils inoculated with oocysts, was lowest in soils with high proportions of sand. We recommend the protocol C for field investigations, and we advise that results should be interpreted with caution, considering the effect of soil characteristics, especially sand content, on oocyst recovery.
弓形虫病是一种全球性感染，由刚地弓形虫引起。感染猫通过粪便散布在环境中的卵囊为人类和中间宿主提供了主要的感染源。由于缺乏检测方法的灵敏度，土壤污染的程度和这种污染的动态大多是未知的。我们的目的是通过比较三种提取方案（A、B 和 C）对未孢子化和不同菌株和年龄的孢子化卵囊的检测，以及通过使用最有效的方法测试孢子化和土壤特性对卵囊回收的影响，来提高土壤样本中刚地弓形虫卵囊的检测。在分散步骤后将浮选溶液置于样品溶液下方的方案 C 中获得的卵囊回收率至少比方案 A 和 B 高十倍，在方案 A 和 B 中，在浮选之前只是对样品进行过滤。在接种卵囊的五个人工土壤基质和四个天然土壤上测试的方案 C 的效率在沙含量较高的土壤中最低。我们建议在现场调查中使用方案 C，并建议考虑土壤特性（尤其是沙含量）对卵囊回收的影响，谨慎解释结果。
