Table 3_First environmental survey of Scedosporium species in Lebanon.docx

BackgroundScedosporium species are filamentous fungi causing a wide spectrum of infections in healthy and debilitated individuals. Despite their clinical significance, the ecology of Scedosporium species remains understudied, particularly in the Middle East.
MethodsIn this context, we conducted an environmental study to elucidate the distribution and ecological preferences of Scedosporium species in the North of Lebanon. One hundred and fifty-five soil samples were collected from different environmental areas and analyzed for several chemical parameters. Scedosporium isolates were then selected for species identification and genotyping.
ResultsOverall, 39 (25.16%) were positive for Scedosporium species, with a predominance of S. apiospermum (80.56%). Soil analysis revealed associations between the fungal presence and pH, nitrogen, phosphorus, and organic matter content. Moreover, genotyping analysis using MultiLocus Sequence Typing identified five major clusters. Interestingly, a number of Lebanese isolates formed an Asian-specific cluster (V) with one clinical Chinese isolate, whereas two clusters (II and III) showed a close association with German isolates, and clusters (I and IV) contained isolates with a global distribution.
ConclusionThese findings provide new insights into the ecology of Scedosporium species, bridging a gap in our knowledge of their distribution on the Asian continent and laying the groundwork for future clinical investigations. Future international collaborations are essential to trace the origin of S. apiospermum.

背景 帚霉属（Scedosporium）为丝状真菌属，可在健康人群与衰弱个体中引发广谱感染。尽管该类真菌具有重要临床意义，但其生态学特征仍未得到充分研究，在中东地区尤为如此。
方法 基于上述研究背景，我们开展了一项环境调查，以阐明黎巴嫩北部地区帚霉属真菌的分布规律与生态偏好。本研究从不同环境区域采集了155份土壤样本，并对其多项化学参数进行了检测分析。随后，我们选取帚霉属分离株开展物种鉴定与基因分型工作。
结果 总体而言，39份样本（占比25.16%）的帚霉属检测结果呈阳性，其中优势菌种为尖端帚霉（S. apiospermum），占阳性样本的80.56%。土壤分析结果显示，该真菌的检出与土壤pH值、氮、磷及有机质含量存在显著关联。此外，通过多位点序列分型（MultiLocus Sequence Typing, MLST）进行的基因分型分析共鉴定出5个主要聚类簇。值得注意的是，部分黎巴嫩分离株与1株中国临床分离株共同构成了亚洲特异性聚类簇（V）；另有两个聚类簇（Ⅱ、Ⅲ）与德国分离株呈现紧密亲缘关系；而聚类簇Ⅰ、Ⅳ则包含了具有全球分布特征的分离株。
结论 本研究结果为帚霉属真菌的生态学研究提供了新的视角，填补了我们对该属真菌在亚洲大陆分布认知上的空白，并为后续临床研究奠定了基础。未来需开展国际合作，以明确尖端帚霉的起源路径。