Detection of Toxoplasma gondii oocysts in water: proposition of a strategy and evaluation in Champagne-Ardenne Region, France
Detection of Toxoplasma gondii oocysts in water: proposition of a strategy and evaluation in Champagne-Ardenne Region, France
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DOI：
10.1590/s0074-02762009000200023
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发表时间：
2009-03-01
期刊：
影响因子：
--
通讯作者：
Villena, I
中科院分区：
文献类型：
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作者：
Aubert, D;Villena, I
由于卵囊污染，水是传播人类和兽医弓形虫病的媒介。世界各地的几次弓形虫病爆发都与受污染的饮用水有关。我们已经开发了一种检测水中弓形虫卵囊的方法，我们提出了一种检测多种水生寄生虫的策略，包括隐孢子虫属。还有贾第虫过滤水样品以回收弓形虫卵囊，并且在通过免疫荧光检测隐孢子虫卵囊和贾第虫包囊之后，如法国标准程序NF T 90-455所推荐的，在蔗糖密度梯度上纯化样品。弓形虫的检测是基于PCR扩增和小鼠接种，以确定回收的卵囊的存在和感染性。在实验接种测定后，我们确定PCR测定比生物测定更灵敏。然后将该策略应用于自2001年以来收集的482个环境水样。我们在37个环境样品（7.7%）中检测到弓形虫DNA，包括公共饮用水，但没有一个是阳性的生物测定。该策略有效地检测水中的弓形虫卵囊，并可能适合作为公共卫生哨兵方法。替代方法可与此方法结合使用，以确定通过分子方法检测到的寄生虫的感染性。
Water is a vehicle for disseminating human and veterinary toxoplasmosis due to oocyst contamination. Several outbreaks of toxoplasmosis throughout the world have been related to contaminated drinking water. We have developed a method for the detection of Toxoplasma gondii oocysts in water and we propose a strategy for the detection of multiple waterborne parasites, including Cryptosporidium spp. and Giardia. Water samples were filtered to recover Toxoplasma oocysts and, after the detection of Cryptosporidium oocysts and Giardia cysts by immunofluorescence, as recommended by French norm procedure NF T 90-455, the samples were purified on a sucrose density gradient. Detection of Toxoplasma was based on PCR amplification and mouse inoculation to determine the presence and infectivity of recovered oocysts. After experimental seeding assays, we determined that the PCR assay was more sensitive than the bioassay. This strategy was then applied to 482 environmental water samples collected since 2001. We detected Toxoplasma DNA in 37 environmental samples ( 7.7%), including public drinking water; however, none of them were positive by bioassay. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method. Alternative methods can be used in conjunction with this one to determine the infectivity of parasites that were detected by molecular methods.