Nouripour-Sisakht S, Mirhendi H, Shidfar M R, Ahmadi B, Rezaei-Matehkolaei A, Geramishoar M, Zarei F, Jalalizand N
Department of Medical Parasitology and Mycology, School of Public Health, National Institute of Health Research, Tehran University of Medical Sciences, Tehran, Iran.
Department of Medical Parasitology and Mycology, School of Public Health, National Institute of Health Research, Tehran University of Medical Sciences, Tehran, Iran.
J Mycol Med. 2015 Jun;25(2):101-7. doi: 10.1016/j.mycmed.2014.12.001. Epub 2015 Feb 2.
Onychomycosis is a common nail infection caused by dermatophytes, non-dermatophyte molds (NDM), and yeasts. Aspergillus species are emerging as increasing causes of toenail onychomycosis. The purpose of this study was species delineation of Aspergillus spp. isolated from patients with onychomycosis.
During a period of one year (2012-2013), nail samples were collected from patients clinically suspected of onychomycosis and subjected to microscopic examination and culture. Species identification was performed based on macro- and micro-morphology of colonies. For precise species identification, PCR-amplification and sequencing of the beta-tubulin gene followed by BLAST queries were performed where required.
A total of 463/2,292 (20.2%) tested nails were diagnosed with onychomycosis. Among the positive specimens, 154 cases (33.2%) were identified as saprophytic NDM onychomycosis, 135 (29.2%) of which were attributable to Aspergillus. Aspergillus species isolated from the infected nails included Aspergillus flavus (77.3%, n=119), Aspergillus niger (n=4), Aspergillus tubingensis (n=4), Aspergillus terreus (n=3), Aspergillus sydowii (n=2), Aspergillus spp. (n=2), and Aspergillus candidus (n=1). Among the patients diagnosed with onychomycosis due to Aspergillus (average patient age, 47.4 years), 40 had fingernail and 95 toenail involvement. The large toenails were most commonly affected.
This study identified a markedly high occurrence of A. flavus, and this fungus appears to be an emerging cause of saprophytic onychomycosis in Iran. The study moreover highlights the necessity of differentiating between dermatophytic and non-dermatophytic nail infections for informed decisions on appropriate therapy.
甲真菌病是一种常见的指甲感染，由皮肤癣菌、非皮肤癣菌霉菌（NDM）和酵母菌引起。曲霉属正逐渐成为趾甲甲真菌病日益增多的病因。本研究的目的是对从甲真菌病患者中分离出的曲霉属菌种进行鉴定。
在一年时间（2012 - 2013年）内，从临床怀疑患有甲真菌病的患者处采集指甲样本，进行显微镜检查和培养。根据菌落的宏观和微观形态进行菌种鉴定。如需精确鉴定菌种，则进行β-微管蛋白基因的PCR扩增和测序，随后进行BLAST查询。
在2292份检测指甲中，共有463份（20.2%）被诊断为甲真菌病。在阳性标本中，154例（33.2%）被鉴定为腐生性NDM甲真菌病，其中135例（29.2%）归因于曲霉。从感染指甲中分离出的曲霉属菌种包括黄曲霉（77.3%，n = 119）、黑曲霉（n = 4）、土曲霉（n = 4）、土曲霉（n = 3）、烟曲霉（n = 2）、曲霉属（n = 2）和白曲霉（n = 1）。在因曲霉导致甲真菌病的患者中（患者平均年龄47.4岁），40例累及手指甲，95例累及脚趾甲。大脚趾甲最常受累。
本研究发现黄曲霉的发生率显著较高，这种真菌似乎是伊朗腐生性甲真菌病的一个新兴病因。此外，该研究强调了区分皮肤癣菌性和非皮肤癣菌性指甲感染对于做出合适治疗决策的必要性。
