Glucuronoxylomannan (GXM) participates in several immunoregulatory mechanisms, which makes it an important Cryptococcus virulence factor that is essential for the disease. Trichosporon asahii and Trichosporon mucoides share with Cryptococcus species the ability to produce GXM. To check whether other opportunistic species in the Trichosporonaceae family produce GXM-like polysaccharides, extracts from 28 strains were produced from solid cultures and their carbohydrate content evaluated by the sulfuric acid / phenol method. Moreover, extracts were assessed for cryptococcal GXM cross-reactivity through latex agglutination and lateral flow assay methods. Cryptococcus neoformans and Saccharomyces cerevisiae were used as positive and negative controls, respectively. In addition to T. asahii, the species Trichosporon inkin, Apiotrichum montevideense, Trichosporon japonicum, Trichosporon faecale, Trichosporon ovoides, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis are also producers of a polysaccharide immunologically similar to the GXM produced by human pathogenic Cryptococcus species. The carbohydrate concentration of the extracts presented a positive correlation with the GXM contents determined by titration of both methodologies. These results add several species to the list of fungal pathogens that produce glycans of the GXM type and bring information about the origin of potential false-positive results on immunological tests for diagnosis of cryptococcosis based on GXM detection.

葡糖醛酸木甘露聚糖 (GXM) 参与多种免疫调节机制，使其成为一种重要的隐球菌毒力因子，对疾病至关重要。Trichosporon asahii和Trichosporon mucoides与Cryptococcus物种具有产生 GXM 的能力。为了检查 Trichosporonaceae 家族中的其他机会性物种是否产生 GXM 样多糖，从 28 个菌株中提取了固体培养物，并通过硫酸/苯酚方法评估了它们的碳水化合物含量。此外，通过乳胶凝集和侧流测定方法评估了提取物的隐球菌 GXM 交叉反应性。新型隐球菌和酿酒酵母分别用作阳性和阴性对照。除了T. asahii 之外，Trichosporon inkin、Apiotrichum montevideense、Trichosporon japonicum、Trichosporon faecale、Trichosporon ovoides、Cutaneotrichosporon debeurmannianum和Cutaneotrichosporon arboriformis也是由非人形隐球菌产生的类似多糖的免疫致病菌。物种。提取物的碳水化合物浓度与通过两种方法滴定确定的 GXM 含量呈正相关。这些结果将几个物种添加到产生 GXM 类型聚糖的真菌病原体列表中，并提供了有关基于 GXM 检测诊断隐球菌病的免疫学测试潜在假阳性结果来源的信息。