Laboratory of Medical and Molecular Mycology, Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Brazil.
Division of Infectious Disease, Department of Medicine, Duke University School of Medicine, Durham, NC, United States.
Front Cell Infect Microbiol. 2021 Jul 1;11:642658. doi: 10.3389/fcimb.2021.642658. eCollection 2021.
Cryptococcosis is an infectious disease of worldwide distribution, caused by encapsulated yeasts belonging to the phylum Basidiomycota. The genus includes several species distributed around the world. The / species complex is largely responsible for most cases of cryptococcosis. However, clinical series have been published of infections caused by () and (), among other related genera. Here, we examined the pathogenic potential and antifungal susceptibility of / species complex (clades I and II) and related genera ( and ) isolated from environmental and clinical samples. . (clade III), . (clade IV) and /. (clade V) strains produced higher levels of phospholipase and hemolysins, whereas the / species complex strains (clades I and II) had markedly thicker capsules, produced more biofilm biomass and melanin, which are known virulence attributes. Interestingly, 40% of . strains (clade II) had MICs above the ECV established for this species to amphotericin B. Several non-/ species complex (clades III to V) had MICs equal to or above the ECVs established for and for all the three antifungal drugs tested. Finally, all the non- clinical isolates (clades III to V) produced more melanin than the environmental isolates might reflect their particularly enhanced need for melanin during protection. It is very clear that / species complex (clades I and II) strains, in general, show more similar virulence phenotypes between each other when compared to non-/ species complex (clades III to V) isolates. These observations together with the fact that . and spp. (clades III to V) strains were collected from the outside of a University Hospital, identify features of these yeasts important for environmental and patient colonization and furthermore, define mechanisms for infections with these uncommon pathogens.
隐球菌病是一种分布于全球的传染病，由属于担子菌门的有包膜酵母引起。该属包含几个分布于世界各地的种。种复合体主要负责大多数隐球菌病病例。然而，已经发表了许多由种复合体（I 型和 II 型）和其他相关属（和）引起的感染的临床系列。在这里，我们研究了从环境和临床样本中分离出的种复合体（I 型和 II 型）和相关属（和）的致病潜力和抗真菌药敏性。种复合体（I 型和 II 型）的磷脂酶和溶血素产量较高，而种复合体（I 型和 II 型）的荚膜明显较厚，产生更多的生物膜生物量和黑色素，这是已知的毒力属性。有趣的是，40%的种复合体（II 型）菌株的 MIC 高于为该物种建立的 ECV 值。几种非种复合体（III 型至 V 型）的 MIC 值等于或高于为建立的 ECV 值和种的 MIC 值。最后，所有非临床分离株（III 型至 V 型）产生的黑色素量均高于环境分离株，这可能反映了它们在保护方面对黑色素的特殊需求增加。非常清楚的是，种复合体（I 型和 II 型）菌株通常彼此之间表现出更多相似的毒力表型，而与非种复合体（III 型至 V 型）分离株相比。这些观察结果加上种复合体（III 型至 V 型）菌株是从大学医院外采集的，这表明这些酵母具有重要的环境和患者定植特征，并且进一步定义了这些不常见病原体感染的机制。
