Institute of Biotechnology, University of Helsinki, Viikinkaari 4, 00790 Helsinki, Finland.
BMC Microbiol. 2011 Oct 21;11:235. doi: 10.1186/1471-2180-11-235.
Indoor microbial contamination due to excess moisture is an important contributor to human illness in both residential and occupational settings. However, the census of microorganisms in the indoor environment is limited by the use of selective, culture-based detection techniques. By using clone library sequencing of full-length internal transcribed spacer region combined with quantitative polymerase chain reaction (qPCR) for 69 fungal species or assay groups and cultivation, we have been able to generate a more comprehensive description of the total indoor mycoflora. Using this suite of methods, we assessed the impact of moisture damage on the fungal community composition of settled dust and building material samples (n = 8 and 16, correspondingly). Water-damaged buildings (n = 2) were examined pre- and post- remediation, and compared with undamaged reference buildings (n = 2).
Culture-dependent and independent methods were consistent in the dominant fungal taxa in dust, but sequencing revealed a five to ten times higher diversity at the genus level than culture or qPCR. Previously unknown, verified fungal phylotypes were detected in dust, accounting for 12% of all diversity. Fungal diversity, especially within classes Dothideomycetes and Agaricomycetes tended to be higher in the water damaged buildings. Fungal phylotypes detected in building materials were present in dust samples, but their proportion of total fungi was similar for damaged and reference buildings. The quantitative correlation between clone library phylotype frequencies and qPCR counts was moderate (r = 0.59, p < 0.01).
We examined a small number of target buildings and found indications of elevated fungal diversity associated with water damage. Some of the fungi in dust were attributable to building growth, but more information on the material-associated communities is needed in order to understand the dynamics of microbial communities between building structures and dust. The sequencing-based method proved indispensable for describing the true fungal diversity in indoor environments. However, making conclusions concerning the effect of building conditions on building mycobiota using this methodology was complicated by the wide natural diversity in the dust samples, the incomplete knowledge of material-associated fungi fungi and the semiquantitative nature of sequencing based methods.
室内由于过度潮湿导致的微生物污染是住宅和工作场所中导致人类疾病的一个重要因素。然而，由于使用选择性的、基于培养的检测技术，室内环境中的微生物的普查受到限制。通过使用全长内部转录间隔区的克隆文库测序，结合 69 种真菌或检测组的定量聚合酶链反应（qPCR）和培养，我们能够更全面地描述室内真菌菌群。使用这套方法，我们评估了水分损坏对沉降灰尘和建筑材料样本中真菌群落组成的影响（分别为 n = 8 和 n = 16）。对受损建筑（n = 2）进行了修复前后的检查，并与未受损的参考建筑（n = 2）进行了比较。
依赖于培养和不依赖于培养的方法在灰尘中的主要真菌类群方面是一致的，但测序结果显示，在属的水平上，其多样性比培养或 qPCR 高五到十倍。在灰尘中检测到了以前未知的、经过验证的真菌类群，占所有多样性的 12%。在水损坏的建筑物中，真菌多样性，尤其是在无性菌类和伞菌类中，趋于更高。在建筑材料中检测到的真菌类群存在于灰尘样本中，但在受损和参考建筑中，它们占真菌总数的比例相似。克隆文库类群频率和 qPCR 计数之间的定量相关性中等（r = 0.59，p < 0.01）。
我们检查了一小部分目标建筑，发现与水损坏相关的真菌多样性升高的迹象。灰尘中的一些真菌是由于建筑物的生长，但为了了解建筑物结构和灰尘之间微生物群落的动态，需要更多关于与材料相关的群落的信息。基于测序的方法对于描述室内环境中的真实真菌多样性是不可或缺的。然而，由于灰尘样本中存在广泛的天然多样性、对材料相关真菌的不完全了解以及基于测序的方法的半定量性质，使用这种方法得出关于建筑物条件对建筑物真菌群的影响的结论变得复杂。
