Lin Weihong, Yang Qianyue, Lin Zhiwei, Liu Shuang, Zhang Liangyan, Jiang Yueting, Fang Jingchun, Peng Yaqin, Guo Penghao
Department of Clinical Laboratory, The First Affiliated Hospital of Guangzhou Medical University, National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Disease, Guangzhou, 510120, China.
Department of Clinical Laboratory, People's Hospital of Yuxi City & The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, 653100, China.
Mycopathologia. 2025 Jul 18;190(4):65. doi: 10.1007/s11046-025-00972-4.
This study aims to investigate the clinical and molecular epidemiological characteristics of bloodstream infections caused by Candida tropicalis.
This retrospective study analyzed the clinical data of patients diagnosed with C. tropicalis bloodstream infections from January 2020 to December 2022. Antifungal susceptibility testing was performed. Multilocus sequence typing (MLST) was used to analyze strain homology, and mutation analysis of the ERG11 (azole resistance-associated) and FKS1 (echinocandin resistance-associated) genes was conducted.
Among the 26 cases of C. tropicalis bloodstream infections, hematologic malignancies were the most common underlying condition, with an overall mortality rate of 38.5%. Resistance rates to voriconazole and fluconazole were 30.8%, while the isolates exhibited high susceptibility to echinocandin drugs and amphotericin B. All fluconazole-resistant strains contained mutations in the ERG11 gene, with Y132F and S154F being the most frequent mutation sites. The mortality rate in fluconazole-resistant patients (37.5%) was similar to that of susceptible or dose-dependently susceptible patients (38.8%). A total of 20 distinct sequence types (DSTs) were identified among the 26 strains, all of which were previously known, indicating significant genetic diversity. The most abundant type was DST376.
Hematologic malignancies are the most common underlying disease of C. tropicalis bloodstream infections. The isolated strains demonstrate significant genetic diversity and a high level resistance to fluconazole.
本研究旨在调查热带念珠菌引起的血流感染的临床和分子流行病学特征。
这项回顾性研究分析了2020年1月至2022年12月期间被诊断为热带念珠菌血流感染患者的临床资料。进行了抗真菌药敏试验。采用多位点序列分型（MLST）分析菌株同源性，并对ERG11（与唑类耐药相关）和FKS1（与棘白菌素耐药相关）基因进行突变分析。
在26例热带念珠菌血流感染病例中，血液系统恶性肿瘤是最常见的基础疾病，总死亡率为38.5%。对伏立康唑和氟康唑的耐药率为30.8%，而分离株对棘白菌素类药物和两性霉素B表现出高敏感性。所有氟康唑耐药菌株的ERG11基因均存在突变，Y132F和S154F是最常见的突变位点。氟康唑耐药患者的死亡率（37.5%）与敏感或剂量依赖性敏感患者的死亡率（38.8%）相似。在26株菌株中总共鉴定出20种不同的序列类型（DSTs），所有这些类型之前均已被发现，表明存在显著的遗传多样性。最常见的类型是DST376。
血液系统恶性肿瘤是热带念珠菌血流感染最常见的基础疾病。分离出的菌株表现出显著的遗传多样性和对氟康唑的高度耐药性。
