Munprom Kanyalak, Bunyaratavej Sumanas, Pattanaprichakul Penvadee, Jirawattanadon Pattriya, Matthapan Lalita, Prasong Waranyoo, Panyawong Chatisa, Plengpanich Akkarapong, Leeyaphan Charussri
Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Mycoses. 2025 Jan;68(1):e70019. doi: 10.1111/myc.70019.
Few ex vivo studies have investigated the virulence factors of fungi causing onychomycosis. The effect of nail polish in predisposing or protecting against onychomycosis remains debatable.
This ex vivo study aimed to identify the nail invasion ability of dermatophytes, non-dermatophytes and yeast, with and without nail polishing, in the nails of young and elderly individuals.
Six fungal species were tested: dermatophytes (Trichophyton rubrum, T. mentagrophytes, Microsporum canis), non-dermatophytes (Neoscytalidium dimidiatum, Fusarium spp.) and Candida albicans. Nail plates from eight volunteers (four aged ≥ 70 years; four aged < 70 years) were divided into polished and non-polished groups, incubated with each fungus and evaluated at 2, 4 and 8 weeks. Positive results were determined the presence of fungal hyphae or pseudohyphae penetrating the nail plate, with the enlargement of invasive fungal elements confirmed by histology.
At 2 weeks, N. dimidiatum exhibited the highest nail invasion rate (15/16, 93.75%), whereas C. albicans showed the lowest (1/16, 6.25%). Fungal penetration into nail plates increased with longer incubation durations. At 8 weeks, C. albicans did not invade any polished nail plates; however, the difference in invasion rates between polished and unpolished nail plates was not statistically significant. Additionally, age did not significantly affect the invasion of most fungi in this ex vivo study.
This ex vivo study supported the concept that fungal virulence is the main determining factor for nail invasion. N. dimidiatum caused the most and fastest nail plate penetration. Nail polishing may slow the penetration of low-virulence organisms.
很少有体外研究调查引起甲癣的真菌的毒力因子。指甲油在诱发或预防甲癣方面的作用仍存在争议。
本体外研究旨在确定皮肤癣菌、非皮肤癣菌和酵母菌在有或没有涂指甲油的情况下，对年轻和老年个体指甲的侵袭能力。
测试了六种真菌：皮肤癣菌（红色毛癣菌、须癣毛癣菌、犬小孢子菌）、非皮肤癣菌（二色新暗色孢霉、镰刀菌属）和白色念珠菌。将八名志愿者（四名年龄≥70岁；四名年龄<70岁）的指甲板分为涂指甲油组和未涂指甲油组，与每种真菌一起孵育，并在2、4和8周时进行评估。阳性结果通过真菌菌丝或假菌丝穿透指甲板来确定，侵袭性真菌成分的扩大通过组织学证实。
在2周时，二色新暗色孢霉表现出最高的指甲侵袭率（15/16，93.75%），而白色念珠菌表现出最低的侵袭率（1/16，6.25%）。随着孵育时间延长，真菌对指甲板的穿透增加。在8周时，白色念珠菌没有侵袭任何涂指甲油的指甲板；然而，涂指甲油和未涂指甲油的指甲板之间的侵袭率差异无统计学意义。此外，在本体外研究中，年龄对大多数真菌的侵袭没有显著影响。
本体外研究支持真菌毒力是指甲侵袭的主要决定因素这一概念。二色新暗色孢霉导致指甲板穿透最多且最快。涂指甲油可能会减缓低毒力生物体的穿透。
