Ngo Thi Minh Chau, Ton That Dong Duong, Ton Nu Phuong Anh, Chi Cao Le, Tran Thi Giang, Do Thi Bich Thao, Ha Thi Ngoc Thuy, Tiep Vo Minh, Nguyen Phuoc Vinh, Mai Ba Hoang Anh, Tra Nguyen Thi My, Nguyen Đac Hanh, Nguyen Thanh Huy
Department of Parasitology, Hue University of Medicine and Pharmacy, Hue University, 49000 Hue City, Vietnam.
Department of Dermatology, Hue University of Medicine and Pharmacy, Hue University, 49000 Hue City, Vietnam.
Med Mycol. 2025 Jul 2;63(7). doi: 10.1093/mmy/myaf064.
The Candida parapsilosis complex, consisting of C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis, is a major cause of Candida onychomycosis. Increasing reports of high levels of resistance to antifungal drugs, particularly fluconazole and echinocandin, have raised concerns about C. parapsilosis complex. This study investigates antifungal resistance and hydrolytic enzyme activity in these species. Species were identified using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and internal transcribed spacer (ITS) 1-4 sequencing. Antifungal susceptibility was assessed using Sensititre™ YeastOne™. Hydrolytic enzyme production was assessed by agar plate culture. Among 43 isolates, C. parapsilosis sensu stricto was most prevalent (48.8%, n = 21/43), followed by C. orthopsilosis (39.6%, n = 17/43) and C. metapsilosis (11.6%, n = 5/43). All C. parapsilosis sensu stricto isolates were susceptible to antifungal agents, except 4.8% (n = 1/21) showing dose-dependent susceptibility to fluconazole and 4.8% (n = 1/21) resistance to amphotericin B. Candida orthopsilosis showed significant resistance to fluconazole and voriconazole (52.9% each, n = 9/17), posaconazole (23.5%, n = 4/17), and low resistance to amphotericin B (5.9%, n = 1/17). One C. metapsilosis isolate (20%) showed cross-resistance to fluconazole and voriconazole, and another (20%) was resistant to 5-flucytosine. Enzymatic assays showed higher protease and lipase activity in C. parapsilosis sensu stricto and C. orthopsilosis compared to C. metapsilosis, with C. parapsilosis sensu stricto showing the highest protease activity. Comprehensive research into antifungal susceptibility and virulence factors of the C. parapsilosis species complex is essential to monitor the growing threat of antifungal resistance and to better understand its role in onychomycosis pathogenesis.
近平滑念珠菌复合体由狭义近平滑念珠菌、正平滑念珠菌和间平滑念珠菌组成，是念珠菌性甲真菌病的主要病因。越来越多关于对抗真菌药物，尤其是氟康唑和棘白菌素高度耐药的报道，引发了人们对近平滑念珠菌复合体的担忧。本研究调查了这些菌种的抗真菌耐药性和水解酶活性。使用聚合酶链反应（PCR）-限制性片段长度多态性（RFLP）和内转录间隔区（ITS）1-4测序来鉴定菌种。使用Sensititre™ YeastOne™评估抗真菌药敏性。通过琼脂平板培养评估水解酶的产生。在43株分离株中，狭义近平滑念珠菌最为常见（48.8%，n = 21/43），其次是正平滑念珠菌（39.6%，n = 17/43）和间平滑念珠菌（11.6%，n = 5/43）。所有狭义近平滑念珠菌分离株均对抗真菌药物敏感，但有4.8%（n = 1/21）对氟康唑呈剂量依赖性敏感，4.8%（n = 1/21）对两性霉素B耐药。正平滑念珠菌对氟康唑和伏立康唑显示出显著耐药性（各52.9%，n = 9/17），对泊沙康唑耐药率为23.5%（n = 4/17），对两性霉素B耐药率较低（5.9%，n = 1/17）。1株间平滑念珠菌分离株（20%）对氟康唑和伏立康唑呈现交叉耐药，另一株（20%）对5-氟胞嘧啶耐药。酶活性测定显示，与间平滑念珠菌相比，狭义近平滑念珠菌和正平滑念珠菌具有更高的蛋白酶和脂肪酶活性，狭义近平滑念珠菌的蛋白酶活性最高。对近平滑念珠菌菌种复合体的抗真菌药敏性和毒力因子进行全面研究，对于监测日益增长的抗真菌耐药性威胁以及更好地了解其在甲真菌病发病机制中的作用至关重要。
