Nunes C M, Sinhorini I L, Ogassawara S
Department of Veterinary Medicine, São Paulo State University, Brazil.
Vet Parasitol. 1994 Jun;53(3-4):269-74. doi: 10.1016/0304-4017(94)90190-2.
In epidemiological surveys, the evaluation of soil contamination by Toxocara canis eggs requires a quick and easy method for the isolation of parasite eggs from soil samples. The efficiency of flotation methods is influenced by sample size, soil texture, degree of soil contamination, pretreatment, flotation solutions and time of flotation. This investigation was designed to evaluate the influence of soil texture in the recovery of T. canis eggs with the centrifugal flotation technique of Dada (Dada, B.J.O., 1979. A new technique for the recovery of Toxocara eggs from soil. J. Helminthol., 53: 141-144). Four types of soil (clay silt, sandy, silty clay and sand) were artificially contaminated with T. canis eggs (200 eggs per gram). Zinc sulphate (specific gravity 1.20) and sodium dichromate (specific gravity 1.35) were used as flotation solutions. Twenty replicated examinations were performed for each type of soil and flotation solution. There was a statistically significant difference in the results depending on soil type. The highest recovery percentages were observed in soils rich in sand (62.5% for sand and 38.0% for sandy soil). Differences were also observed with different flotation solutions. Sodium dichromate solution was more efficient for recovering T. canis eggs, regardless of the soil texture.
在流行病学调查中，评估犬弓首蛔虫卵对土壤的污染情况需要一种快速简便的方法，以便从土壤样本中分离出寄生虫卵。浮选法的效率受样本大小、土壤质地、土壤污染程度、预处理、浮选溶液和浮选时间的影响。本研究旨在利用达达的离心浮选技术（达达，B.J.O.，1979年。一种从土壤中回收弓首蛔虫卵的新技术。《寄生虫学杂志》，53: 141 - 144）评估土壤质地对犬弓首蛔虫卵回收率的影响。用犬弓首蛔虫卵（每克200个卵）对四种类型的土壤（粉质黏土、砂土、粉质黏土和砂）进行人工污染。使用硫酸锌（比重1.20）和重铬酸钠（比重1.35）作为浮选溶液。对每种类型的土壤和浮选溶液进行20次重复检测。结果表明，根据土壤类型不同存在统计学显著差异。在富含砂的土壤中观察到最高回收率（砂为62.5%，砂土为38.0%）。使用不同的浮选溶液也观察到差异。无论土壤质地如何，重铬酸钠溶液在回收犬弓首蛔虫卵方面效率更高。
