Toledo Rafael, Espert Ana M, Muñoz-Antoli Carla, Marcilla Antonio, Fried Bernard, Esteban J Guillermo
Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Av. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain.
J Parasitol. 2003 Dec;89(6):1227-31. doi: 10.1645/GE-3191.
The present study reports on the development of a coproantigen capture enzyme-linked immunosorbent assay (ELISA) for detecting Echinostoma caproni in experimentally infected rats. The capture ELISA was based on polyclonal rabbit antibodies that recognize excretory-secretory (ES) antigens. The detection limit of pure ES was 3 ng/ml in sample buffer and 60 ng/ml in fecal samples. The test was evaluated using a follow-up of 10 rats experimentally infected with 100 metacercariae of E. caproni, and the results were compared with those of other diagnostic methods such as parasitological examination and antibody titers determined by indirect ELISA. Coproantigens were detected in all the infected rats from the first day postinfection (DPI). The period of maximal coproantigen excretion was between 7 and 21 DPI. The values remained positive until 49-56 DPI, coinciding with the disappearance of the eggs in the stool samples of the infected rats. The kinetics of coproantigen detection were correlated with those of egg output. The present assay provides an alternative tool for the diagnosis of the echinostome infections. The proposed capture ELISA makes possible an earlier diagnosis than that provided by parasitological examination and indirect ELISA and also allows for the differentiation of past and current infections. Our results show that this assay can also be used to monitor the course of echinostome infections.
本研究报告了一种用于检测实验感染大鼠体内卡氏棘口吸虫的粪便抗原捕获酶联免疫吸附测定（ELISA）的开发情况。该捕获ELISA基于识别排泄分泌（ES）抗原的兔多克隆抗体。纯ES在样品缓冲液中的检测限为3 ng/ml，在粪便样品中的检测限为60 ng/ml。使用10只实验感染100个卡氏棘口吸虫囊蚴的大鼠进行随访评估该试验，并将结果与其他诊断方法（如寄生虫学检查和间接ELISA测定的抗体滴度）的结果进行比较。从感染后第一天（DPI）起，在所有感染大鼠中均检测到粪便抗原。粪便抗原排泄的高峰期在7至21 DPI之间。这些值在49 - 56 DPI之前一直呈阳性，这与感染大鼠粪便样本中虫卵消失的时间一致。粪便抗原检测的动力学与产卵量的动力学相关。本测定为棘口吸虫感染的诊断提供了一种替代工具。所提出的捕获ELISA能够比寄生虫学检查和间接ELISA更早地进行诊断，并且还能够区分既往感染和当前感染。我们的结果表明，该测定还可用于监测棘口吸虫感染的进程。
