Faculdade de Ciências Farmacêuticas de Ribeirao Preto, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil.
Faculdade de Medicina de Ribeirao Preto, Departamento de Clinica Medica, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil.
Mycoses. 2020 Dec;63(12):1341-1351. doi: 10.1111/myc.13174. Epub 2020 Sep 30.
Cryptococcus neoformans/ Cryptococcus gattii species complex is composed of encapsulated yeast species that are causative agents of cryptococcosis. The characterisation of pathogenic Cryptococcus species provides useful data for epidemiological studies as well as the clinical diagnosis and treatment of patients.
This study aimed to characterise the epidemiology, antifungal susceptibility and virulence of 72 clinical strains isolated from cryptococcosis cases between 2012 and 2017 in a tertiary reference hospital in south-eastern Brazil.
Species and molecular types were molecularly assessed by PCR and PCR-restriction fragment length polymorphism (RFLP) of the URA5 gene. Antifungal susceptibility testing was performed according to the CLSI protocols. The virulence was studied in a Galleria mellonella infection model.
The most frequently isolated strain was C. neoformans molecular type VNI (61/72; 84.7%), although C. neoformans molecular type VNII (3/72; 4.2%) was also isolated. Additionally, C. deuterogattii molecular type VGII (8/72; 11.1%) was present, but most frequently from non-HIV-infected patients. Non-wild-type phenotype to the antifungals was observed in 26.4% (19/72) of the C. neoformans and C. deuterogattii clinical isolates, and the latter demonstrated higher MIC to fluconazole and itraconazole than C. neoformans clinical isolates. Finally, the virulence of C. neoformans and C. deuterogattii clinical isolates was diverse in G mellonella larvae and uncorrelated with the virulence factors of melanin and capsule.
The assessment of the spread of cryptococcal species and molecular types as well as the pattern of corresponding antifungal susceptibility and virulence aids in surveil the emergence of resistant strains, ensuring more accurate management of the cryptococcal infection.
新生隐球菌/格特隐球菌种复合体由包被的酵母物种组成，是隐球菌病的病原体。致病性隐球菌种的特征为流行病学研究以及对患者的临床诊断和治疗提供了有用的数据。
本研究旨在对 2012 年至 2017 年间巴西东南部一家三级参考医院的 72 株隐球菌病分离株的流行病学、抗真菌药敏性和毒力进行特征分析。
通过 PCR 和 URA5 基因 PCR-限制性片段长度多态性（RFLP）对种和分子型进行分子评估。根据 CLSI 方案进行抗真菌药敏试验。在大蜡螟感染模型中研究了毒力。
最常分离到的菌株是新生隐球菌分子型 VN1（61/72；84.7%），但也分离到新生隐球菌分子型 VNII（3/72；4.2%）。此外，还存在德氏隐球菌分子型 VGII（8/72；11.1%），但主要来自非 HIV 感染患者。26.4%（19/72）的新生隐球菌和德氏隐球菌临床分离株表现出非野生型表型对抗真菌药物，且后者对氟康唑和伊曲康唑的 MIC 高于新生隐球菌临床分离株。最后，新生隐球菌和德氏隐球菌临床分离株在大蜡螟幼虫中的毒力存在差异，与黑色素和荚膜的毒力因子无关。
评估隐球菌种和分子型的传播以及相应的抗真菌药敏性和毒力模式有助于监测耐药株的出现，确保对隐球菌感染进行更准确的管理。
