P Chakraborty, Lyngdoh Valarie, Gogoi Neeta, Gandhi Sony, Lyngdoh Denzel L, Lanong Sheryl, Shah Kunjjal
Microbiology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, IND.
Clinical Microbiology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, IND.
Cureus. 2024 Nov 30;16(11):e74815. doi: 10.7759/cureus.74815. eCollection 2024 Nov.
Introduction Dermatophytes are the most common cause of superficial fungal infection. They are mostly diagnosed using phenotypic methods, but recently the molecular methods seem to be gaining ground. The objective of the present study was to compare the phenotypic and genotypic methods of identification of dermatophytes and understand the feasibility of using molecular methods for routine diagnosis of dermatophytosis. Methods Eight repertoire isolates of species identified using conventional phenotypic methods were sequenced using a target of the internal transcribed spacer (ITS1 & ITS2) flanking the DNA sequence 5.8S rDNA. The FASTA sequences obtained were put under the Basic Local Alignment Search Tool - Nucleotide (BLASTn) in the National Center for Biotechnology Information (NCBI) blast portal and compared with existing sequences. Results The comparison between the phenotypic and molecular methods was established in 7/8 (87.5%) of the isolates. The ITS-based sequencing was able to speciate but failed to differentiate between the species complexes of and Conclusion ITS-based molecular identification is unable to correctly compare phenotypic and molecular methods of identification. Moreover, due to the high polymorphism inherent in dermatophyte species complexes, ITS was unable to delineate the dermatophyte species correctly.
引言 皮肤癣菌是浅表真菌感染最常见的病因。它们大多通过表型方法进行诊断,但最近分子方法似乎越来越受到认可。本研究的目的是比较皮肤癣菌鉴定的表型和基因型方法,并了解使用分子方法进行皮肤癣菌病常规诊断的可行性。方法 使用常规表型方法鉴定的8个菌种的馆藏菌株,采用DNA序列5.8S rDNA侧翼的内部转录间隔区(ITS1和ITS2)作为靶点进行测序。将获得的FASTA序列置于美国国立生物技术信息中心(NCBI)BLAST门户的基本局部比对搜索工具-核苷酸(BLASTn)下,并与现有序列进行比较。结果 在8个分离株中的7个(87.5%)中建立了表型和分子方法之间的比较。基于ITS的测序能够鉴定菌种,但无法区分和的菌种复合体。结论 基于ITS的分子鉴定无法正确比较表型和分子鉴定方法。此外,由于皮肤癣菌菌种复合体固有的高度多态性,ITS无法正确区分皮肤癣菌菌种。