Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran.
Mycoses. 2021 Aug;64(8):918-925. doi: 10.1111/myc.13306. Epub 2021 Jun 1.
Trichosporonosis is an emerging fungal infection caused by Trichosporon species, a genus of yeast-like fungi, which are frequently encountered in human infections ranging from mild cutaneous lesions to fungemia in immunocompromised patients. The incidence of trichosporonosis has increased in recent years, owing to higher numbers of individuals at risk for this infection. Although amphotericin B, posaconazole and isavuconazole are generally effective against Trichosporon species, some isolates may have variable susceptibility to these antifungals.
Herein, we evaluated the species distribution, genetic diversity and antifungal susceptibility profiles of Trichosporon isolates in Iran.
The yeasts were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Phylogenetic analysis was performed based on amplified fragment length polymorphism (AFLP). The in vitro susceptibilities of eight antifungal agents were analysed using the Clinical and Laboratory Standards Institute broth microdilution methods.
The isolates belonged to the species T asahii (n = 20), T japonicum (n = 4) and T faecale (n = 3). A dendrogram of the AFLP analysis demonstrated that T asahii and non-asahii Trichosporon strains (T japonicum and T faecale) are phylogenetically distinct. While voriconazole was the most active agent (GM MIC = 0.075 μg/ml), high fluconazole MICs (8 μg/ml) were observed for a quarter of Trichosporon isolates. The GM MIC value of amphotericin B for T asahii and non-asahii Trichosporon species was 0.9 μg/ml.
The distribution and antifungal susceptibility patterns of the identified Trichosporon species could inform therapeutic choices for treating these emerging life-threatening fungi.
芽生菌病是一种由芽生菌属（一种酵母样真菌）引起的新兴真菌感染，在免疫功能低下患者的轻度皮肤损伤至真菌血症等各种人类感染中均有发现。近年来，由于感染风险增加，芽生菌病的发病率有所上升。两性霉素 B、泊沙康唑和伊曲康唑通常对芽生菌属有效，但一些分离株对这些抗真菌药物的敏感性可能存在差异。
本研究评估了伊朗芽生菌属分离株的种分布、遗传多样性和抗真菌药敏谱。
通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）鉴定酵母。基于扩增片段长度多态性（AFLP）进行系统发育分析。采用临床和实验室标准协会肉汤微量稀释法分析 8 种抗真菌药物的体外药敏情况。
分离株分别属于白念珠菌（n=20）、日本芽生菌（n=4）和 T 粪球（n=3）。AFLP 分析的聚类分析表明，白念珠菌和非白念珠菌芽生菌（日本芽生菌和 T 粪球）在系统发育上是不同的。伏立康唑是最有效的药物（GM MIC=0.075μg/ml），四分之一的芽生菌属分离株对氟康唑的 MIC 值较高（8μg/ml）。白念珠菌和非白念珠菌芽生菌属的两性霉素 B GM MIC 值为 0.9μg/ml。
所鉴定的芽生菌属的分布和抗真菌药敏模式可为治疗这些新出现的危及生命的真菌提供治疗选择。
