The first established microsatellite markers to distinguish Candida orthopsilosis isolates and detection of a nosocomial outbreak in China

作者：Zhengyu Luo, Yating Ning, Shu-Ying Yu, Meng Xiao, Rongchen Dai, Xinfei Chen, Yao Wang, Wei Kang, Yan Jiang, Hua Yu, Hongjie Liang, Yingchun Xu, Tianshu Sun, Li Zhang · 发表于：Journal of Clinical Microbiology · 年份：2023 · DOI：10.1128/jcm.00806-23 · 被引用次数：5 · 研究领域：Antifungal resistance and susceptibility、Fungal Infections and Studies、Infectious Diseases and Mycology

ABSTRACT The infection proportion of Candida orthopsilosis , a member of the C. parapsilosis complex, has increased globally in recent years, and nosocomial outbreaks have been reported in several countries. This study aimed to establish microsatellite loci-based typing method that was able to effectively distinguish among C. orthopsilosis isolates. Three reference C. orthopsilosis genome sequences were analyzed to identify repeat loci. DNA sequences containing over eight bi- or more nucleotide repeats were selected. A total of 51 loci were initially identified, and locus-specific primers were designed and tested with 20 epidemiologically unrelated isolates. Four loci with excellent reproducibility, specificity, and resolution for molecular typing purposes were identified, and the combined discriminatory power (DP, based on 20 epidemiologically unrelated isolates) of these four loci was 1.0. Reproducibility was demonstrated by consistently testing three strains each in triplicate, and stability, demonstrated by testing 10 successive passages. Then, we collected 48 C . orthopsilosis non-duplicate clinical isolates from the China Hospital Invasive Fungal Surveillance Net study to compare the DP of the microsatellite-based typing with internal transcribed spacer (ITS) and amplified fragment length polymorphism (AFLP) typing analyses, using ATCC 96139 as a reference strain. These 49 isolates were subdivided into 12 microsatellite types (COMT1–12), six AFLP types, and three ITS ty...