Dhib I, Khammari I, Yaacoub A, Hadj Slama F, Ben Saïd M, Zemni R, Fathallah A
Parasitology-Mycology Laboratory, Faculty of Medicine, Farhat Hached University Hospital, Mohamed El Karoui Street, 4002, Sousse, Tunisia.
Immunology and Genetic Laboratory, Faculty of Medicine, Sousse, Tunisia.
Mycopathologia. 2017 Jun;182(5-6):487-493. doi: 10.1007/s11046-017-0110-3. Epub 2017 Jan 18.
According to epidemiological, clinical and mycological criteria, it has long been admitted that the Trichophyton mentagrophytes species includes two varieties: a zoophilic variety (var. mentagrophytes) and an anthropophilic variety (var. interdigitale) that involve the upper and the lower part of the body, respectively. The further application of molecular techniques to the characterization of dermatophyte strains showed that this classification is unreliable. The aim of our study was to assess the usefulness of PCR-RFLP (restriction fragment length polymorphism) and sequencing in the characterization of T. mentagrophytes strains taken from Tunisian patients. The study was carried out in 2008 in the laboratory of Parasitology-Mycology of Farhat Hached University Hospital, Sousse, Tunisia. A total of 133 strains were isolated from 133 patients addressed to the laboratory for dermatological lesions very evocative of dermatomycosis. Eighty strains were isolated from lesions located on the lower part of the body (onychomycosis, tinea pedis) and 53 strains from the upper part of the body (tinea capitis, tinea corporis). All strains were submitted to mycological examination (direct microscopic examination and culture on Sabouraud medium) and further investigated by using RFLP analysis of the PCR-amplified ITS1-5.8 s-ITS2 region of the ribosomal DNA and the MvaI restriction enzyme. In addition, 62 strains were further submitted to a sequencing of the ITS1-5.8 s-ITS2 region. On the basis of mycological criteria, all strains were diagnosed as T. mentagrophytes. All strains produced the same RFLP pattern and were identified as T. mentagrophytes interdigitale regardless of the location of lesions. Out of the 62 sequenced strains, 16 were found anthropophilic and 46 were zoophilic. In conclusion, all strains provisionally diagnosed as T. mentagrophytes on the basis of mycological criteria were shown to belong to T. interdigitale by using PCR-RFLP and sequencing irrespective of the site of lesions. The predominance of zoophilic strains needs further investigation.
根据流行病学、临床和真菌学标准，长期以来人们一直认为须癣毛癣菌物种包括两个变种：亲动物性变种（须癣毛癣菌变种）和亲人性变种（指间毛癣菌变种），分别累及身体的上部和下部。分子技术在皮肤癣菌菌株鉴定中的进一步应用表明这种分类是不可靠的。我们研究的目的是评估聚合酶链反应-限制性片段长度多态性（PCR-RFLP）和测序在鉴定从突尼斯患者分离出的须癣毛癣菌菌株中的作用。该研究于2008年在突尼斯苏塞法哈特·哈谢德大学医院寄生虫学-真菌学实验室进行。从133名因疑似皮肤癣菌病的皮肤病损前来实验室就诊的患者中分离出133株菌株。80株从身体下部的病损（甲癣、足癣）中分离得到，53株从身体上部的病损（头癣、体癣）中分离得到。所有菌株都进行了真菌学检查（直接显微镜检查和在沙氏培养基上培养），并通过对核糖体DNA的PCR扩增ITS1-5.8s-ITS2区域进行RFLP分析以及使用MvaI限制性内切酶进行进一步研究。此外，62株菌株进一步进行了ITS1-5.8s-ITS2区域的测序。根据真菌学标准，所有菌株均被诊断为须癣毛癣菌。所有菌株产生相同的RFLP模式，且无论病损位置如何均被鉴定为指间须癣毛癣菌。在62株测序菌株中，发现16株为亲人性，46株为亲动物性。总之，通过PCR-RFLP和测序表明，所有基于真菌学标准初步诊断为须癣毛癣菌的菌株均属于指间毛癣菌，而与病损部位无关。亲动物性菌株的优势地位需要进一步研究。
