Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449, USA.
J Appl Microbiol. 2009 Oct;107(4):1089-97. doi: 10.1111/j.1365-2672.2009.04316.x. Epub 2009 Apr 18.
To evaluate the effectiveness of continuous separation channel centrifugation for concentrating Toxoplasma gondii and Cyclospora cayetanensis from drinking water and environmental waters.
Ready-to-seed vials with known quantities of T. gondii and C. cayetanensis oocysts were prepared by flow cytometry. Oocysts were seeded at densities ranging from 1 to 1000 oocysts l(-1) into 10 to 100 l test volumes of finished drinking water, water with manipulated turbidity, and the source waters from nine drinking water utilities. Oocysts were recovered using continuous separation channel centrifugation and counted on membrane filters using epifluorescent microscopy. Recovery efficiencies of both parasites were > or =84% in 10 l volumes of drinking water. In source waters, recoveries ranged from 64% to 100%, with the lowest recoveries in the most turbid waters. Method precision was between 10% and 20% coefficient of variation.
Toxoplasma gondii and C. cayetanensis are effectively concentrated from various water matrices by continuous separation channel centrifugation.
Waterborne transmission of T. gondii and C. cayetanensis presents another challenge in producing clean drinking water and protecting public health. Detection of these parasites relies on effectively concentrating oocysts from ambient water, otherwise false negatives may result. Validation data specific to T. gondii and C. cayetanensis concentration methods are limited. Continuous separation channel centrifugation recovers oocysts with high efficiency and precision, the method attributes required to accurately assess the risk of waterborne transmission.
评估连续分离通道离心法浓缩饮用水和环境水中弓形虫和环孢子虫的效果。
通过流式细胞术制备了含有已知数量弓形虫和环孢子虫卵囊的即用型接种瓶。将卵囊以 1 至 1000 个卵囊/L 的密度接种到 10 至 100 L 已处理饮用水、人为增加浊度的水以及来自九个饮用水处理厂的水源水中。使用连续分离通道离心法回收卵囊，并在膜过滤器上使用荧光显微镜进行计数。在 10 L 体积的饮用水中，两种寄生虫的回收率均大于等于 84%。在水源水中，回收率范围为 64%至 100%，浊度最高的水中回收率最低。方法精密度在 10%至 20%之间，变异系数。
连续分离通道离心法可有效浓缩各种水基质中的弓形虫和环孢子虫。
弓形虫和环孢子虫经水传播对生产清洁饮用水和保护公众健康构成了另一挑战。这些寄生虫的检测依赖于从环境水中有效浓缩卵囊，否则可能导致假阴性结果。针对弓形虫和环孢子虫浓缩方法的验证数据有限。连续分离通道离心法具有高效和高精度回收卵囊的特点，这是准确评估水传播风险所需的方法属性。
