Madsen Anne Mette, Zervas Athanasios, Tendal Kira, Nielsen Jeppe Lund
The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark.
Section for Biotechnology, Department of Chemistry and Bioscience, Aalborg University, Sohngaardsholmsvej 49, 9000 Aalborg, Denmark.
Environ Res. 2015 Jul;140:255-67. doi: 10.1016/j.envres.2015.03.027. Epub 2015 Apr 13.
The importance of the microbial diversity of bioaerosols in relation to occupational exposure and work related health symptoms is not known. The aim of this paper is to gain knowledge on the bacterial and fungal communities in dust causing organic dust toxic syndrome (ODTS) and in reference dust not causing ODTS. Bacterial and fungal communities were described in personal exposure samples from grass seed workers developing ODTS, in dust generated from grass seeds causing ODTS and in dust generated from reference seeds not causing ODTS. Amplicon sequencing of the bacterial 16S rRNA gene and the fungal ITS region, as well as matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) were used for identification of fungi and bacteria in personal exposure samples and in dust samples from grass seeds causing ODTS and in dust from reference grass seeds. Furthermore, activities of enzymes were measured in the same samples. The sequencing data revealed more than 150 bacterial and 25 fungal genera present in each sample. Streptomyces spp., Aspergillus fumigatus and Rhizopus microsporus were dominating in the dust causing ODTS but not in the reference dust. The dustiness in terms of Mucor sp. and R. microsporus were 100-1000 times higher for problematic seeds compared to reference seeds. The bacterial species in the dust causing ODTS included pathogenic species such as Klebsiella pneumonia and Streptomyces pneumonia, and it contained increased concentrations of total protein, serine protease, chitinase, and β-glucosidase. Twenty-three bacterial genera covered more than 50% of the total reads in the personal and problematic seed dust. These 23 genera accounted for less than 7% of the total reads in the reference seed dust. The microbial community of the dust from the problematic seeds showed great similarities to that from the personal air samples from the workers. In conclusion, we have shown for the first time a shift in the microbial community in aerosol samples that caused ODTS compared to the reference samples that did not cause the ODTS. Furthermore, elevated enzyme activities were found in the dust causing ODTS.
生物气溶胶的微生物多样性与职业暴露及工作相关健康症状之间的关系尚不清楚。本文旨在了解导致有机粉尘毒性综合征（ODTS）的粉尘以及未导致ODTS的对照粉尘中的细菌和真菌群落。对出现ODTS的草籽工人的个人暴露样本、导致ODTS的草籽产生的粉尘以及未导致ODTS的对照草籽产生的粉尘中的细菌和真菌群落进行了描述。利用细菌16S rRNA基因和真菌ITS区域的扩增子测序，以及基质辅助激光解吸/电离飞行时间（MALDI-TOF）技术，对个人暴露样本、导致ODTS的草籽粉尘样本以及对照草籽粉尘中的真菌和细菌进行鉴定。此外，还对相同样本中的酶活性进行了测定。测序数据显示，每个样本中存在150多个细菌属和25个真菌属。链霉菌属、烟曲霉和微小根霉在导致ODTS的粉尘中占主导地位，但在对照粉尘中并非如此。与对照草籽相比，有问题草籽中毛霉属和微小根霉的含尘量高100 - 1000倍。导致ODTS的粉尘中的细菌种类包括肺炎克雷伯菌和肺炎链霉菌等病原菌，且其总蛋白、丝氨酸蛋白酶、几丁质酶和β-葡萄糖苷酶的浓度升高。23个细菌属在个人和有问题草籽粉尘中的读数占总读数的50%以上。这23个属在对照草籽粉尘中的读数占总读数的比例不到7%。有问题草籽粉尘的微生物群落与工人个人空气样本的微生物群落有很大相似性。总之，我们首次表明，与未导致ODTS的对照样本相比，导致ODTS的气溶胶样本中的微生物群落发生了变化。此外，在导致ODTS的粉尘中发现酶活性升高。
