Department of Microbiology, SydPath, St. Vincent's Hospital, Victoria St., Darlinghurst, 2010 NSW, Australia.
Eur J Clin Microbiol Infect Dis. 2013 Mar;32(3):335-43. doi: 10.1007/s10096-012-1746-z. Epub 2012 Sep 21.
Blastocystis is one of the most common enteric parasites present in humans. There is still much uncertainty about the pathogenic potential of this parasite, and it was suggested that its pathogenicity could be subtype-related. This report aimed to study 98 Blastocystis isolates found in human stool specimens to identify the subtypes present and carry out phylogenetic analysis on these isolates. This study also aimed to show the relationship between subtype and symptoms. Five-hundred and thirteen stool samples were submitted to five different diagnostic techniques for the detection of Blastocystis. Polymerase chain reaction (PCR)-positive samples were then sequenced and the small subunit (SSU) rDNA sequences were aligned and submitted to phylogenetic analysis. Ninety-eight samples were positive by any of the diagnostic methods for Blastocystis and 96 were positive by PCR. There were seven different subtypes (1, 2, 3, 4, 6, 7 and 8) identified by PCR and sequencing. This is the first large-scale study to examine the occurrence of Blastocystis in Australia. This study reports the high incidence of subtype 3 (44 %) in this population and discusses the emerging idea of subtype-dependent pathogenicity.
芽囊原虫是存在于人类肠道中的最常见的寄生虫之一。关于这种寄生虫的致病潜力仍然存在很多不确定性，有人认为其致病性可能与亚型有关。本报告旨在研究从人类粪便标本中发现的 98 株芽囊原虫，以鉴定存在的亚型，并对这些分离株进行系统发育分析。本研究还旨在显示亚型与症状之间的关系。513 份粪便样本被提交给五种不同的诊断技术，以检测芽囊原虫。然后对聚合酶链反应（PCR）阳性样本进行测序，将小亚基（SSU）rDNA 序列进行比对，并进行系统发育分析。有 98 个样本通过任何一种芽囊原虫的诊断方法呈阳性，96 个样本通过 PCR 呈阳性。通过 PCR 和测序共鉴定出 7 种不同的亚型（1、2、3、4、6、7 和 8）。这是首次对澳大利亚芽囊原虫的发生情况进行大规模研究。本研究报告了该人群中 3 型（44%）的高发生率，并讨论了与亚型相关的致病性这一新兴观点。
