Hijjawi Nawal, Yang Rongchang, Hatmal Ma'mon, Yassin Yasmeen, Mharib Taghrid, Mukbel Rami, Mahmoud Sameer Alhaj, Al-Shudifat Abdel-Ellah, Ryan Una
Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, The Hashemite University, PO Box 150459, Zarqa, 13115, Jordan.
Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA, 6150, Australia.
Exp Parasitol. 2018 Feb;185:23-28. doi: 10.1016/j.exppara.2018.01.011. Epub 2018 Jan 6.
Little is known about the prevalence of Giardia duodenalis in human patients in Jordan and all previous studies have used direct microscopy, which lacks sensitivity. The present study developed a novel quantitative PCR (qPCR) assay at the β-giardin (bg) locus and evaluated its use as a frontline test for the diagnosis of giardiasis in comparison with a commercially available ELISA using nested PCR and sequencing of the glutamate dehydrogenase (gdh) locus (gdh nPCR) as the gold standard. A total of 96 human faecal samples were collected from 96 patients suffering from diarrhoea from 5 regions of Jordan and were screened using the ELISA and qPCR. The analytical specificity of the bg qPCR assay revealed no cross-reactions with other genera and detected all the Giardia isolates tested. Analytical sensitivity was 1 Giardia cyst per μl of DNA extract. The overall prevalence of Giardia was 64.6%. The clinical sensitivity and specificity of the bg qPCR was 89.9% and 82.9% respectively compared to 76.5 and 68.0% for the ELISA. This study is the first to compare three different methods (ELISA, bg qPCR, nested PCR and sequencing at the gdh locus) to diagnose Jordanian patients suffering from giardiasis and to analyze their demographic data.
关于约旦人类患者中十二指肠贾第鞭毛虫的流行情况，人们了解甚少，而且以往所有研究都采用直接显微镜检查法，这种方法缺乏敏感性。本研究在β-贾第虫蛋白（bg）基因座开发了一种新型定量聚合酶链反应（qPCR）检测方法，并与使用巢式PCR和谷氨酸脱氢酶（gdh）基因座测序（gdh nPCR）作为金标准的市售酶联免疫吸附测定（ELISA）相比，评估了其作为贾第虫病诊断一线检测方法的用途。从约旦5个地区的96名腹泻患者中收集了96份人类粪便样本，并使用ELISA和qPCR进行筛查。bg qPCR检测方法的分析特异性显示与其他属无交叉反应，并且检测到了所有测试的贾第虫分离株。分析灵敏度为每微升DNA提取物中有1个贾第虫包囊。贾第虫的总体流行率为64.6%。与ELISA的临床灵敏度和特异性分别为76.5%和68.0%相比，bg qPCR的临床灵敏度和特异性分别为89.9%和82.9%。本研究首次比较了三种不同方法（ELISA､bg qPCR､巢式PCR和gdh基因座测序）来诊断约旦的贾第虫病患者，并分析了他们的人口统计学数据。
