Emerging Microbes and Infections · Available online 6 Jul 2026 · In press · DOI 10.1080/22221751.2026.2695535
Yiying Zhao, Rongchen Dai, Feiyi Liu, Keyu Liu, Wei Kang, Ge Zhang, Jin Li, Jingjia Zhang, Tong Wang, Haotian Gao, Yuyan Huang, David S. Perlin, Meng Xiao, Yingchun Xu, Xin Fan
A notable increase in azole resistance among Candida tropicalis has been observed worldwide, particularly in the Asia-Pacific region, associated with the expansion of an emerging resistant population named cluster AZR. Here, we present up-to-date epidemiological, antifungal susceptibility and population genomic data from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) study. A total of 911 C. tropicalis isolates causing invasive candidiasis were collected in 2022–2023, representing 16.1% of all Candida isolates and ranking as the third most common species. High resistance rates to fluconazole (42.3%) were observed, with 87.5% showing cross-resistance to voriconazole. Candidemia isolates showed significantly higher azole resistance than non-candidemia isolates (46.1% vs 39.2%, p = 0.036). Fluconazole resistance rate was higher in medical departments (55.0%) but lower in ICUs (33.7%). Longitudinal analysis demonstrated an overall upward trend in fluconazole resistance from 5.7% since 2009. Although a transient decline was observed during 2020–2021, resistance rebounded thereafter and reached a historical peak of 43.1% in 2022. Population genomic analysis of 604 isolates identified cluster AZR as the predominant fluconazole-resistant population (58.6%), and its expansion was associated with the temporal increase in azole resistance. Of note, all cluster AZR isolates harboured the ERG11 A395 T key resistant mutation, and 98.2% had increased ERG11 copy number. Besides, genomic analysis identified strain replacement and dual-clade mixed infection in cluster AZR-associated clinical cases. In conclusion, the high prevalence of azole resistance in C. tropicalis and the expansion of cluster AZR represent a significant clinical challenge and underscore the need for effective interventions.
Abstract from DOAJ. Public domain (CC0 1.0).
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Zhao, Y., Dai, R., Liu, F., et al. (2026). Population genomics reveals a long-term increase in azole resistance associated with the emerging cluster AZR among Candida tropicalis causing invasive infections. Emerging Microbes and Infections. https://doi.org/10.1080/22221751.2026.2695535