Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland.
Environmental Health Unit, Finnish Institute for Health and Welfare, Kuopio, Finland.
Microbiol Spectr. 2024 Mar 5;12(3):e0359623. doi: 10.1128/spectrum.03596-23. Epub 2024 Feb 1.
Actinobacteria are abundant in soil and other environmental ecosystems and are also an important part of the human microbiota. Hence, they can also be detected in indoor environments and on building materials, where actinobacterial proliferation on damp materials can indicate moisture damage. The aim of this study was to evaluate the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of 28 environmental strains of Actinobacteria isolated from building materials and indoor and outdoor air samples, mainly collected in the context of moisture damage investigations in buildings in Finland. The 16S rRNA gene sequencing and chemotaxonomic analyses were performed, and results were compared with the MALDI-TOF MS Biotyper identification. Using 16S rRNA gene sequencing, all isolates were identified on the species or genus level and were representatives of and genera. Based on MALDI-TOF MS analysis, initially, 11 isolates were identified as spp. and 1 as with a high identification score. After an upgrade in the MALDI-TOF MS database and re-evaluation of mass spectra, 13 additional isolates were identified as , and . MALDI-TOF MS has the potential in environmental strain identification; however, the standard database needs to be considerably enriched by environmental Actinobacteria representatives.
The manuscript addresses the challenges in identifying environmental bacteria using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) Biotyper-based protein profiling. The matter of the studies-actinobacterial strains-has been isolated mostly from building materials that originated from a confirmed moisture-damaged situation. Polyphasic taxonomy, 16S RNA gene sequencing, and MALDI-TOF mass spectrometry were applied for identification purposes. In this experimental paper, a few important facts are highlighted. First, Actinobacteria are abundant in the natural as well as built environment, and their identification on the species and genus levels is difficult and time-consuming. Second, MALDI-TOF MS is an effective tool for identifying bacterial environmental strains, and in parallel, continuous enrichment of the proteomics mass spectral databases is necessary for proper identification. Third, the chemical approach aids in the taxonomical inquiry of Actinobacteria environmental strains.
放线菌在土壤和其他环境生态系统中大量存在，也是人类微生物组的重要组成部分。因此，它们也可以在室内环境和建筑材料中检测到，放线菌在潮湿材料上的增殖可以表明水分损坏。本研究的目的是评估基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）对从建筑材料以及室内和室外空气样本中分离的 28 株环境放线菌的鉴定，这些样本主要是在芬兰建筑物水分损坏调查的背景下收集的。进行了 16S rRNA 基因测序和化学生态分类分析，并将结果与 MALDI-TOF MS Biotyper 鉴定进行比较。使用 16S rRNA 基因测序，所有分离株都在种或属水平上得到鉴定，代表 和 属。基于 MALDI-TOF MS 分析，最初有 11 株分离株被鉴定为 种，1 株被鉴定为 ，具有较高的鉴定得分。在 MALDI-TOF MS 数据库升级并重新评估质谱后，又鉴定出 13 株额外的分离株为 、 和 。MALDI-TOF MS 具有鉴定环境菌株的潜力；然而，标准数据库需要通过环境放线菌代表进行大量补充。
本文讨论了使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）基于蛋白质谱的生物鉴定技术鉴定环境细菌时所面临的挑战。研究的主题-放线菌菌株-主要是从已经确认的水分损坏情况下的建筑材料中分离出来的。多相分类学、16S RNA 基因测序和 MALDI-TOF 质谱分析都被应用于鉴定目的。在这篇实验论文中，强调了几个重要的事实。首先，放线菌在自然和建筑环境中大量存在，对其进行种和属水平的鉴定既困难又耗时。其次，MALDI-TOF MS 是一种有效的鉴定细菌环境菌株的工具，同时，为了正确鉴定，需要不断丰富蛋白质组质谱数据库。第三，化学方法有助于放线菌环境菌株的分类学研究。
