Department of Biological Sciences, Faculty of Science, Nara Women's University, Nara 630-8605, Japan.
Parasitol Res. 2011 Oct;109(4):1045-50. doi: 10.1007/s00436-011-2342-3. Epub 2011 Apr 16.
Blastocystis sp. is now recognized as one of the most common intestinal parasite in human fecal examinations. Recently, PCR-based diagnostic methods of Blastocystis infection using direct DNA extraction from fresh fecal samples with commercially available kits are reported. Several kits have been developed, but little has been done in comparing the detective sensitivity between PCR methods using the commercial kits. In this study, we compared the detective sensitivity among five commercially available kits (MagNA Pure LC DNA Isolation Kit I, Roche; QuickGene SP Kit DNA, FujiFilm; NucleoSpin Plant II, Macherey-Nagel; QIAamp DNA Stool Mini Kit, Qiagen; ZR Fecal DNA Kit, Zymo Research) and fecal culture method. In a preliminary test, the DNA isolated with two kits (FujiFilm and Macherey-Nagel) showed negative PCR, while the other three kits showed positive PCR. Then, DNA from 50 clinical samples that was Blastocystis-positive in the examination of fecal culture method were isolated with the three kits and 1.1 kbp SSU rRNA gene was detected with PCR. The positive rates of the three kits (Roche, Qiagen, and Zymo Research) were 10, 48 and 94%, respectively. The present study indicated that there is different detective sensitivity among the commercial kits, and fecal culture method is superior in detection rate and cost performance than DNA-elution kits for diagnosis of Blastocystis sp. subtypes.
目前，芽囊原虫被认为是人类粪便检查中最常见的肠道寄生虫之一。最近，已有研究报道了基于 PCR 的芽囊原虫感染诊断方法，该方法可直接从新鲜粪便样本中提取 DNA，并使用市售试剂盒进行检测。已经开发出了几种试剂盒，但在比较使用商业试剂盒的 PCR 方法的检测灵敏度方面，研究工作做得还很少。在这项研究中，我们比较了五种市售试剂盒（罗氏 MagNA Pure LC DNA 提取试剂盒 I、富士胶片 QuickGene SP 试剂盒 DNA、马基那格尔 NucleoSpin 植物 II 试剂盒、凯杰 QIAamp DNA 粪便迷你试剂盒、泽鲁姆 Zymo Research ZR 粪便 DNA 试剂盒）和粪便培养方法的检测灵敏度。在初步测试中，两种试剂盒（富士胶片和马基那格尔）分离的 DNA 显示 PCR 阴性，而其他三种试剂盒显示 PCR 阳性。然后，用三种试剂盒从粪便培养方法检测为阳性的 50 份临床样本中分离 DNA，并通过 PCR 检测 1.1 kbp SSU rRNA 基因。这三种试剂盒（罗氏、凯杰和泽鲁姆）的阳性率分别为 10%、48%和 94%。本研究表明，商业试剂盒之间存在不同的检测灵敏度，粪便培养方法在检测率和性价比方面优于 DNA 洗脱试剂盒，可用于诊断芽囊原虫亚型。
