Esteban Violeta, Gilabert Pablo, Ferrer Consuelo, Gálvez Beatriz, Chiner Eusebi, Colom María Francisca
Department of Respiratory Medicine, San Juan de Alicante University Hospital, 03550, Alicante, Spain.
Medical Mycology Laboratory, Department of Plant Production and Microbiology, Institute for Healthcare and Biomedical Research of Alicante (ISABIAL), University Miguel Hernández, Campus of San Juan de Alicante, 03550, Alicante, Spain.
Mycopathologia. 2024 Dec 7;190(1):1. doi: 10.1007/s11046-024-00910-w.
Pulmonary surfactant, the primary substance lining the epithelium of the human Lower Respiratory Tract (LRT), is rich in lipids, with dipalmitoyl-phosphatidylcholine (DPPC) being the most abundant. Although surfactants are known to have antifungal activity against some yeast species, the significant presence of species like Malassezia restricta in the lung mycobiome suggests that these yeasts may exhibit some level of lipo-tolerance or even lipo-affinity for pulmonary lipids. This study explored the affinity and tolerance of yeasts, identified as significant members of the lung microbiome, to pulmonary lipids through culture-based methods. Eleven species from the genera Malassezia, Candida (including the new genera Nakaseomyces and Meyerozyma), and Cryptococcus were tested for their growth on media containing pulmonary lipids such as DPPC and commercial porcine surfactant and in other culture medium that contain non-pulmonary lipids such as glycerol monostearate and tweens. The yeasts' lipo-affinity or lipo-tolerance was assessed based on their growth on these lipids compared to standard media, specifically Modified Leeming Notman Agar (MLNA) for Malassezia species and Sabouraud Dextrose Agar (SDA) for the other genera. The addition of DPPC or surfactant to the media enhanced the growth of most Malassezia yeasts and some Cryptococcus species. C. parapsilosis, Meyerozyma guilliermondii and Cryptococcus neoformans s.s. showed similar growth to that on the standard media, while the other yeasts primarily demonstrated lipo-tolerance without lipo-affinity for these compounds. To our knowledge, this is the first report on the influence of pulmonary lipids on the in vitro growth of Malassezia spp. and other yeast members of the lung mycobiome. Some yeasts, such as Malassezia restricta, commonly found in the lower respiratory tract (LRT), exhibit specific affinity for lung lipids like DPPC and commercial porcine surfactant. This finding suggests that lung lipids may play a significant role in shaping the LRT mycobiome.
肺表面活性物质是人类下呼吸道（LRT）上皮的主要内衬物质，富含脂质，其中二棕榈酰磷脂酰胆碱（DPPC）含量最为丰富。尽管已知表面活性物质对某些酵母菌种具有抗真菌活性，但肺部真菌菌群中诸如限制马拉色菌等菌种的大量存在表明，这些酵母可能对肺部脂质表现出一定程度的脂耐受性甚至脂亲和力。本研究通过基于培养的方法，探究了被鉴定为肺部微生物群重要成员的酵母对肺部脂质的亲和力和耐受性。对马拉色菌属、念珠菌属（包括新属 Nakaseomyces 和 Meyerozyma）和隐球菌属的 11 个菌种进行了测试，观察它们在含有 DPPC 和商业猪表面活性物质等肺部脂质的培养基以及含有单硬脂酸甘油酯和吐温等非肺部脂质的其他培养基上的生长情况。根据这些酵母在这些脂质培养基上与标准培养基（马拉色菌属菌种用改良 Leeming Notman 琼脂（MLNA），其他属用沙氏葡萄糖琼脂（SDA））上的生长情况，评估其脂亲和力或脂耐受性。向培养基中添加 DPPC 或表面活性物质可促进大多数马拉色菌酵母和一些隐球菌菌种的生长。近平滑念珠菌、季也蒙毕赤酵母和新生隐球菌变种在这些培养基上的生长与在标准培养基上相似，而其他酵母主要表现出对这些化合物的脂耐受性，无脂亲和力。据我们所知，这是关于肺部脂质对马拉色菌属菌种及肺部真菌菌群其他酵母成员体外生长影响的首次报道。一些常见于下呼吸道（LRT）的酵母，如限制马拉色菌，对 DPPC 和商业猪表面活性物质等肺部脂质表现出特定亲和力。这一发现表明肺部脂质可能在塑造下呼吸道真菌菌群方面发挥重要作用。
