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Majocchi's granuloma: Autoinoculation and adaption of Trichophyton rubrum with molecular evidence
Author(s) -
Zhao Ying,
Gan Mingyu,
Li Li,
Su Huilin,
Zhang Qiangqiang,
Hoog Sybren,
Zhu Min
Publication year - 2021
Publication title -
mycoses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.13
H-Index - 69
eISSN - 1439-0507
pISSN - 0933-7407
DOI - 10.1111/myc.13337
Subject(s) - trichophyton rubrum , biology , dermatophyte , trichophyton , chin , microbiology and biotechnology , strain (injury) , genetics , anatomy , antifungal
Background Trichophyton rubrum , an important aetiological agent of superficial dermatophytosis, occasionally penetrates into deeper tissues, causing inflammation and a granulomatous response. Only few case reports of T. rubrum granuloma with molecular evidence for autoinoculation have been published. Objectives To find the genetic basis of adaptation to a different microhabitat following autoinoculation of Trichophyton rubrum . Methods A case of Majocchi's granuloma is reported, with isolation of T. rubrum strains from foot and chin, respectively. Whole‐genome sequencing of the two strains has been performed. Phylogenetic reconstruction and SIFT analysis were conducted. Results A phenotypic difference has been observed between the two isolates. 20 and 19 indels, 8 and 15 SNVs were found in foot and chin strains, respectively. Foot and chin strains formed a monophyletic group. Two non‐synonymous mutations of chin strains were observed in the TERG_06754 gene encoding cytochrome c peroxidase (CCP). The G293C amino acid change in TERG_03373 was predicted to affect protein function significantly. The mutated amino acid (cysteine) was only found in the chin strain in all dermatophyte non‐redundant sequences. Conclusions Non‐synonymous mutations located in TERG_06754 and TERG_03373 were predicted to affect protein functions, which may facilitate the adaption for invasion of the superficial cutaneous strain. As the different living environments of these two strains (oxygenous, lower‐temperature for the pedal strain; hypoxia, higher‐temperature for the chin strain), a stratum corneum‐to‐dermal adaption hypothesis of T. rubrum was proposed.