Chair of Bacteriology and Mycology, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Veterinärstraße 13, 80539, Munich, Germany.
Chair of Technical Microbiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Gregor-Mendel-Str. 4, 85354, Freising, Germany.
Mycotoxin Res. 2020 Feb;36(1):83-91. doi: 10.1007/s12550-019-00371-x. Epub 2019 Aug 21.
The fungus Stachybotrys (S.) chartarum was isolated from culinary herbs, damp building materials, and improperly stored animal forage. Two distinct chemotypes of the fungus were described that produced either high-cytotoxic macrocyclic trichothecenes (S type) or low-cytotoxic atranones (A type). Recently, two distinct gene clusters were described that were found to be necessary for the biosynthesis of either macrocyclic trichothecenes (21 SAT (Satratoxin) genes) or atranones (14 ATR (Atranone) genes). In the current study, PCR primers were designed to detect SAT and ATR genes in 19 S. chartarum chemotype S and eight S. chartarum chemotype A strains. Our analysis revealed the existence of three different genotypes: satratoxin-producing strains that harbored all SAT genes but lacked the ATR gene cluster (genotype S), non-satratoxin-producing strains that possessed the ATR genes but lacked SAT genes (genotype A), and a hitherto undescribed hybrid genotype among non-satratoxin-producing strains that harbored all ATR genes and an incomplete set of SAT genes (genotype H). In order to improve the discrimination of genotypes, a triplex PCR assay was developed and applied for the analysis of S. chartarum and S. chlorohalonata cultures. The results show that genes for macrocyclic trichothecenes and atranones are not mutually exclusive in S. chartarum. Correlation of the new genotype-based concept with mycotoxin production data shows also that macrocyclic trichothecenes are exclusively produced by S. chartarum genotype S strains.
真菌串珠镰孢（S.）chartarum 从烹饪草药、潮湿的建筑材料和储存不当的动物饲料中分离出来。描述了两种不同的真菌化学型，它们分别产生高细胞毒性的大环三萜（S 型）或低细胞毒性的异戊二烯酮（A 型）。最近，描述了两种不同的基因簇，发现它们对于大环三萜（21 SAT（Satratoxin）基因）或异戊二烯酮（14 ATR（Atranone）基因）的生物合成是必要的。在当前的研究中，设计了 PCR 引物来检测 19 种 S. chartarum 化学型 S 和 8 种 S. chartarum 化学型 A 菌株中的 SAT 和 ATR 基因。我们的分析揭示了三种不同基因型的存在：产 satratoxin 的菌株，它们拥有所有的 SAT 基因但缺乏 ATR 基因簇（基因型 S），不产 satratoxin 的菌株，它们拥有 ATR 基因但缺乏 SAT 基因（基因型 A），以及一种以前未描述的非产 satratoxin 菌株中的杂交基因型，它拥有所有的 ATR 基因和一组不完整的 SAT 基因（基因型 H）。为了提高基因型的区分能力，开发了一种三重 PCR 检测方法，并应用于 S. chartarum 和 S. chlorohalonata 培养物的分析。结果表明，在 S. chartarum 中，大环三萜和异戊二烯酮基因不是相互排斥的。基于新基因型的概念与真菌毒素产生数据的相关性也表明，只有 S. chartarum 基因型 S 菌株才能产生大环三萜。
