Jackson Katrina M, Pelletier Keith C, Scheftel Joni, Kerkaert Joshua D, Robinson Serina L, McDonald Tami, Bender Jeff B, Knight Joseph F, Ireland Malia, Nielsen Kirsten
Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, USA.
Department of Forest Resources, University of Minnesota, St Paul, Minnesota, USA.
Appl Environ Microbiol. 2021 Mar 1;87(5). doi: 10.1128/AEM.01922-20. Epub 2020 Dec 18.
Outbreaks of blastomycosis, caused by the fungus , occur in endemic areas of the United States and Canada but the geographic range of blastomycosis is expanding. Previous studies inferred the location of through epidemiologic data associated with outbreaks because culture of from the environment is often unsuccessful. In this study, we used a culture-independent, PCR-based method to identify DNA in environmental samples using the BAD1 promoter region. We tested 250 environmental samples collected in Minnesota, either associated with blastomycosis outbreaks or environmental samples collected from high- and low-endemic regions to determine basal prevalence of in the environment. We identified a fifth BAD1 promoter haplotype of prevalent in Minnesota. Ecological niche analysis identified latitude, longitude, elevation, and site classification as environmental parameters associated with the presence of Using this analysis, a Random Forest model predicted presence in basal environmental samples with 75% accuracy. These data support use of culture-independent, PCR-based environmental sampling to track spread into new regions and to characterize the unknown environmental niche. Upon inhalation of spores from the fungus from the environment, humans and animals can develop the disease blastomycosis. Based on disease epidemiology, is known to be endemic in the United States and Canada around the Great Lakes and in the Ohio and Mississippi River Valleys but is starting to emerge in other areas. is extremely difficult to culture from the environment so little is known about the environmental reservoirs for this pathogen. We used a culture-independent PCR-based assay to identify the presence of DNA in soil samples from Minnesota. By combining molecular data with ecological niche modeling, we were able to predict the presence of in environmental samples with 75% accuracy and to define characteristics of the environmental niche. Importantly, we showed the effectiveness of using a PCR-based assay to identify in environmental samples.
由真菌引起的芽生菌病在美国和加拿大的流行地区爆发，但芽生菌病的地理范围正在扩大。以前的研究通过与疫情相关的流行病学数据推断其位置，因为从环境中培养往往不成功。在本研究中，我们使用了一种基于PCR的非培养方法，利用BAD1启动子区域鉴定环境样本中的DNA。我们测试了在明尼苏达州收集的250个环境样本，这些样本要么与芽生菌病爆发有关，要么是从高流行和低流行地区收集的环境样本，以确定环境中的基础流行率。我们在明尼苏达州发现了一种第五种流行的BAD1启动子单倍型。生态位分析确定纬度、经度、海拔和地点分类为与存在相关的环境参数。利用该分析，随机森林模型预测基础环境样本中存在的准确率为75%。这些数据支持使用基于PCR的非培养环境采样来追踪其向新区域的传播，并表征未知的环境生态位。吸入环境中真菌的孢子后，人和动物会患上芽生菌病。根据疾病流行病学，已知在美国和加拿大的五大湖周围以及俄亥俄河和密西西比河流域流行，但开始在其他地区出现。从环境中培养极其困难，因此对该病原体的环境储存库了解甚少。我们使用基于PCR的非培养检测方法来鉴定明尼苏达州土壤样本中DNA的存在。通过将分子数据与生态位建模相结合，我们能够以75%的准确率预测环境样本中是否存在，并定义其环境生态位的特征。重要的是，我们展示了使用基于PCR的检测方法鉴定环境样本中的有效性。
