Dermatophytosis due to Microsporum incurvatum: Notification and Identification of a Neglected Pathogenic Species
- 203 Downloads
A 4-year-old Iranian boy developed erythematous, itchy and annular lesion on his face. Microscopic examination of the scraped samples with 10 % potassium hydroxide (KOH) revealed fungal septate hyphae and arthroconidia. The etiological agent was found to be Microsporum gypseum in mycological examinations. Amplification and restriction digestion of the internal transcribed spacers (ITS) of rDNA was not helpful for identification, but in ITS sequencing the isolate showed 98 % homology to Microsporum incurvatum strain CBS 172.64. Empirical treatment of the patient with griseofulvin for 4 weeks was successful. Other than our isolate, the ITS1 sequences of 38 strains from related species were retrieved from GenBank and phylogenetic tree using maximum likelihood method was constructed. The case isolate clustered apart from other strains of M. incurvatum. Pairwise comparison of ITS1 showed intraspecies variations of 0–13 nucleotides among M. incurvatum strains and an extensive interspecies variation of 33–80 bp and remarkable interspecies size polymorphism between the three sister species in the M. gypseum complex. The high level of ITS1 intraspecific variation is suitable for species identification rather than phylogeographic analysis of M. gypseum complex.
KeywordsMicrosporum incurvatum Microsporum gypseum ITS Phylogeny
This work was financially supported by grant number 91116 from Vice-Chancellor for Research Affairs of Ahvaz Jundishapur University of Medical Sciences.
Compliance with ethical standards
Conflict of interest
- 9.Abastabar M, Rezaei-Matehkolaei A, Shidfar MR, et al. Molecular epidemiological survey of clinically important dermatophytes in Iran based on specific RFLP profiles of beta-tubulin gene. H Iran J Public Health. 2013;42:1049–57.Google Scholar
- 10.Clinical and Laboratory Standards Institute. Reference method for broth dilution antifungal susceptibility testing of filamentous Fungi. In: Wayne PA, editor. Approved standard, CLSI document M38-A2, 2nd ed. Wayne: Clinical and Laboratory Standards Institute, 2008.Google Scholar
- 11.White TJ, Bruns T, Taylor J. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, editor. PCR protocols: a guide to methods and applications. London: Academic Press; 1990. p. 315–22.Google Scholar
- 14.Hall TA. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. In: Nucleic acids symposium series, vol. 41, pp. 95–98.Google Scholar
- 15.Lysková P, Hubka V, Bodnárová J. Případ tinea corporis vyvolaný Microsporum incurvatum, geofilním druhem příbuzným M. gypseum. Čes.-slov. Derm. 2014;89:187–91.Google Scholar
- 16.Yarita K, Sano A. EMBL/GenBank/DDBJ databases. http://www.ddbj.nig.ac.jp/index-j.html. Accessed 26 Oct 2004.
- 19.Makimura K, Tamura Y, Murakami A, et al. Cluster analysis of human and animal pathogenic Microsporum species and their teleomorphic states, Arthroderma species, based on the DNA sequences of nuclear ribosomal internal transcribed spacer 1. Microbiol Immunol. 2001;45:209–16.CrossRefPubMedGoogle Scholar