Crop Research Institute, Drnovska 507/73, CZ-16106 Prague 6-Ruzyne, Czechia.
Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlarska 2, CZ-611 37 Brno, Czechia.
FEMS Microbiol Ecol. 2021 Mar 31;97(4). doi: 10.1093/femsec/fiab039.
In culture, the house dust mite, Dermatophagoides pteronyssinus, shows different growth patterns, but the composition and changes in the associated microbial community during mite culture growth are poorly known. In this study, we analyzed temporal changes in microbial communities including 'internal' communities (inside mites, ingested) and 'environmental' communities (from culture environment). Microbial community structure was correlated with guanine content (a nitrogenous waste product of mites) and mite population density. Both internal and environmental microbial communities were remarkably consistent between biological replicates from the same culture age group and were composed of relatively few dominant taxa-11 bacterial and 3 fungal operational taxonomic units (OTUs). Significant changes over time in microbial community structure in the bulk culture environment and in internal mite samples were observed. The yeast, Saccharomyces cerevisiae, a main component of the mite diet, gradually disappeared during mite culture growth and was replaced by fungi from the genera Aspergillus and Candida in both 'internal' and 'environmental' samples. In environmental samples, bacteria from the genus Lactobacillus and S. cerevisiae were negatively correlated, and Aspergillus and Candida positively correlated, with guanine content. The relative abundance of bacteria from the genus Kocuria increased with mite density but declined with increasing guanine content. The relative abundance of bacteria from the genus Virgibacillus was negatively correlated with mite density in 'internal' samples. Gram-positive bacteria dominated bacterial microbiomes at all time points in our experiments, indicating a more limited possibility for vaccine contamination by bacterial endotoxins (heat-stable lipopolysaccharides produced mostly by Gram-negative bacteria) in our experimental cultures.
在文化中，屋尘螨（Dermatophagoides pteronyssinus）表现出不同的生长模式，但有关螨培养生长过程中相关微生物群落的组成和变化尚不清楚。在这项研究中，我们分析了微生物群落的时间变化，包括“内部”群落（螨体内，摄入）和“环境”群落（来自培养环境）。微生物群落结构与鸟嘌呤含量（螨的含氮废物）和螨种群密度相关。内部和环境微生物群落都与来自同一培养年龄组的生物重复之间非常一致，并且由相对较少的优势分类群组成-11 个细菌和 3 个真菌操作分类单元（OTU）。在大块培养环境和内部螨样本中，观察到微生物群落结构随时间的显著变化。酵母，酿酒酵母（Saccharomyces cerevisiae），是螨饮食的主要成分，在螨培养生长过程中逐渐消失，而代之以曲霉和假丝酵母属的真菌，在“内部”和“环境”样本中均如此。在环境样本中，与鸟嘌呤含量呈负相关的是乳杆菌属和酿酒酵母属的细菌，而与鸟嘌呤含量呈正相关的是曲霉和假丝酵母属的真菌。与螨密度呈正相关的是节杆菌属的细菌相对丰度增加，但与鸟嘌呤含量呈负相关。与螨密度呈负相关的是海洋杆菌属的细菌在“内部”样本中的相对丰度。在我们的实验中，所有时间点都以革兰氏阳性菌为主导的细菌微生物组，这表明我们的实验培养中，细菌内毒素（主要由革兰氏阴性菌产生的热稳定脂多糖）污染疫苗的可能性较小。
