Laboratoire de Parasitologie-Mycologie, Institut de Biologie, CHU Nantes, France.
Laboratoire de Parasitologie-Mycologie, CHU de Dijon, France.
Clin Microbiol Infect. 2018 Nov;24(11):1205-1209. doi: 10.1016/j.cmi.2018.02.007. Epub 2018 Feb 15.
Besides the potential to identify a wide variety of gastrointestinal parasites, microscopy remains the reference standard in clinical microbiology for amoeba species identification and, especially when coupled with adhesin detection, to discriminate the pathogenic Entamoeba histolytica from its sister but non-pathogenic species Entamoeba dispar/Entamoeba moshkovskii. However, this approach is time-consuming, requires a high-level of expertise that can be jeopardized considering the low prevalence of gastrointestinal parasites in non-endemic countries. Here, we evaluated the CE-IVD-marked multiplex PCR (ParaGENIE G-Amoeba, Ademtech) targeting E. histolytica and E. dispar/E. moshkovskii and Giardia intestinalis.
This evaluation was performed blindly on a reference panel of 172 clinical stool samples collected prospectively from 12 laboratories and analysed using a standardized protocol relying on microscopy (and adhesin detection by ELISA for the detection of E. histolytica) including G. intestinalis (n = 37), various amoeba species (n = 55) including E. dispar (n = 15), E. histolytica (n = 5), as well as 17 other gastrointestinal parasites (n = 80), and negative samples (n = 37).
This new multiplex PCR assay offers fast and reliable results with appropriate sensitivity and specificity for the detection of G. intestinalis and E. dispar/E. moshkovskii from stools (89.7%/96.9% and 95%/100%, respectively). Detection rate and specificity were greatly improved by the PCR assay, highlighting several samples misidentified by microscopy, including false-negative and false-positive results for both E. dispar/E. moshkovskii and E. histolytica.
Given the clinical relevance of amoeba species identification, microbiologists should be aware of the limitations of using an algorithm relying on microscopy coupled with adhesin detection by ELISA.
除了能够鉴定各种胃肠道寄生虫外，显微镜仍然是临床微生物学中鉴定变形虫物种的参考标准，特别是当与黏附素检测结合使用时，可以区分致病性溶组织内阿米巴和其非致病性姐妹种迪斯帕内阿米巴/莫氏内阿米巴。然而，这种方法耗时，需要高水平的专业知识，考虑到非流行地区胃肠道寄生虫的低流行率，这种知识可能会受到影响。在此，我们评估了针对溶组织内阿米巴、迪斯帕内阿米巴/莫氏内阿米巴和贾第虫的经 CE-IVD 标记的多重 PCR（ParaGENIE G-Amoeba，Ademtech）。
该评估是在一个由 12 个实验室前瞻性收集的 172 份临床粪便参考样本的盲法参考面板上进行的，该参考样本使用标准化协议进行分析，该协议依赖于显微镜（和通过 ELISA 检测黏附素来检测溶组织内阿米巴），包括贾第虫（n=37）、各种变形虫物种（n=55），包括迪斯帕内阿米巴（n=15）、溶组织内阿米巴（n=5），以及其他 17 种胃肠道寄生虫（n=80）和阴性样本（n=37）。
这种新的多重 PCR 检测法提供了快速可靠的结果，具有适当的灵敏度和特异性，可用于检测粪便中的贾第虫和迪斯帕内阿米巴/莫氏内阿米巴（分别为 89.7%/96.9%和 95%/100%）。PCR 检测法极大地提高了检测率和特异性，突出了显微镜鉴定中的几个错误样本，包括迪斯帕内阿米巴/莫氏内阿米巴和溶组织内阿米巴的假阴性和假阳性结果。
鉴于变形虫物种鉴定的临床相关性，微生物学家应该意识到使用依赖于显微镜结合 ELISA 检测黏附素的算法的局限性。
