Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Eur J Clin Microbiol Infect Dis. 2017 Dec;36(12):2335-2342. doi: 10.1007/s10096-017-3065-x. Epub 2017 Jul 25.
Blastocystis is a single-celled intestinal parasite commonly found in humans and a broad range of animals all over the world. In humans, its role in health and disease remains unsettled. The aim of our study was to investigate the distribution of Blastocystis and Blastocystis subtypes (ST) in patients with inflammatory bowel disease (IBD) and control subjects. A total of 71 stool samples were collected from IBD patients, 69 and 2 of whom had ulcerative colitis (UC) and Crohn's Disease (CD), respectively. Moreover, 166 stool samples from healthy subjects were included as control samples. All stool samples were cultivated, and 550-bp fragments of the small subunit ribosomal RNA gene was amplified from Blastocystis-positive cultures. All PCR-positive samples were sequenced. Blastocystis was observed in 9 (12.67%) and 35 (21.1%) IBD patients and healthy controls, respectively. There was no statistically significant correlation between IBD and presence of Blastocystis (P = 0.147). There was a statistically significant correlation between age and Blastocystis colonization in the IBD group (P < 0.05), but not among healthy controls. No significant correlation between gender and colonization was observed. ST1 and ST3 were obtained from 1 (12.5%) and 7 (87.5%) IBD patients, respectively, while in the healthy control group, subtypes 1, 2, and 3 were found in 14 (40%), 12 (34.28%), and 9 (25.72%), respectively. Phylogenetic analysis showed no variation in the distribution of subtypes nor intra-subtype genetic diversity between samples acquired from IBD patients and healthy controls. This study showed a trend towards a lower prevalence of Blastocystis in IBD patients than in control subjects. ST3 sequences isolated from IBD patients and control individuals did not appear to differ genetically.
芽囊原虫是一种常见于人类和全球广泛动物的单细胞肠道寄生虫。在人类中，其在健康和疾病中的作用尚未确定。我们的研究旨在调查炎症性肠病（IBD）患者和对照人群中芽囊原虫及其亚型（ST）的分布。共收集了 71 份来自 IBD 患者的粪便样本，其中溃疡性结肠炎（UC）和克罗恩病（CD）患者分别为 69 例和 2 例。此外，还纳入了 166 份来自健康受试者的粪便样本作为对照样本。所有粪便样本均进行培养，从阳性培养物中扩增 550-bp 小亚基核糖体 RNA 基因片段。对所有 PCR 阳性样本进行测序。在 9（12.67%）和 35（21.1%）例 IBD 患者和健康对照者中观察到芽囊原虫。IBD 与芽囊原虫的存在之间无统计学显著相关性（P=0.147）。在 IBD 组中，年龄与芽囊原虫定植之间存在统计学显著相关性（P<0.05），但在健康对照组中则无相关性。未观察到性别与定植之间存在显著相关性。从 1（12.5%）例 IBD 患者和 7（87.5%）例健康对照者中分别获得 ST1 和 ST3，而在健康对照组中，分别在 14（40%）、12（34.28%）和 9（25.72%）例中发现亚型 1、2 和 3。系统进化分析显示，从 IBD 患者和健康对照者获得的样本中，亚类的分布和亚类内遗传多样性无差异。本研究显示 IBD 患者中芽囊原虫的流行率低于对照组。从 IBD 患者和对照个体中分离出的 ST3 序列在遗传上似乎没有差异。
