Scanlan Pauline D, Stensvold Christen Rune, Cotter Paul D
Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork, Cork, Ireland
Laboratory of Parasitology, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
Appl Environ Microbiol. 2015 Jun 15;81(12):4071-6. doi: 10.1128/AEM.00520-15. Epub 2015 Apr 3.
The human gut is host to a diversity of microorganisms, including the single-celled microbial eukaryote Blastocystis. Research has shown that most carriers host a single Blastocystis subtype (ST), which is unusual given the considerable within-host species diversity observed for other microbial genera in this ecosystem. However, our limited knowledge of both the incidence and biological significance of Blastocystis diversity within hosts (i.e., so-called mixed infections) is likely due to problems with existing methodologies. Here, we developed and applied Blastocystis ST-specific PCRs for the investigation of the most common subtypes of Blastocystis (ST1 to ST4) to a healthy human cohort (n = 50). We detected mixed infections in 22% of the cases, all of which had been identified as single-ST infections in a previous study using state-of-the-art methods. Our results show that certain STs occur predominantly as either single (ST3 and 4) or mixed (ST1) infections, which may reflect inter alia transient colonization patterns and/or cooperative or competitive interactions between different STs. Comparative analyses with other primers that have been used extensively for ST-specific analysis found them unsuitable for detection of mixed- and, in some cases, single-ST infections. Collectively, our data shed new light on the diversity of Blastocystis within and between human hosts. Moreover, the development of these PCR assays will facilitate future work on the molecular epidemiology and significance of mixed infections in groups of interest, including health and disease cohorts, and also help identify sources of Blastocystis transmission to humans, including identifying potential animal and environmental reservoirs.
人类肠道是多种微生物的宿主，包括单细胞微生物真核生物芽囊原虫。研究表明，大多数携带者体内仅有一种芽囊原虫亚型（ST），鉴于在该生态系统中观察到的其他微生物属在宿主体内具有相当大的物种多样性，这种情况并不常见。然而，我们对芽囊原虫在宿主体内多样性（即所谓的混合感染）的发生率和生物学意义了解有限，这可能是由于现有方法存在问题。在此，我们开发并应用了针对芽囊原虫最常见亚型（ST1至ST4）的特异性PCR，对一个健康人类队列（n = 50）进行调查。我们在22%的病例中检测到混合感染，而在之前一项使用先进方法的研究中，所有这些病例都被鉴定为单一ST感染。我们的结果表明，某些ST主要以单一感染（ST3和4）或混合感染（ST1）的形式出现，这可能尤其反映了不同ST之间的短暂定植模式和/或合作或竞争相互作用。与其他广泛用于ST特异性分析的引物进行比较分析发现，它们不适用于检测混合感染，在某些情况下也不适用于检测单一ST感染。总体而言，我们的数据为人类宿主内外芽囊原虫的多样性提供了新的见解。此外，这些PCR检测方法的开发将有助于未来开展关于感兴趣群体中混合感染的分子流行病学及意义的研究，包括健康和疾病队列，还将有助于确定芽囊原虫传播给人类的来源，包括识别潜在的动物和环境宿主。
