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Abstract(Please copy/paste the abstract send to the congress) : |
The first case of onychomycosis in a koala due to atypical isolates of Microsporum gypseum, a diagnostic challenge
Gholam Reza Shokoohi, Koichi Makimura, Hossein Mirhendi, Ali Rezaei-Matehkolaei, Kazuo Satoh
Department of Medical Parasitology & Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,
Emali;:mirhendi@tums.ac.ir
Introduction: Dermatophytosis is one of the most familiar conditions to veterinary and medical dermatologists. It represents a spectrum of cosmopolitan zoonotic infections, affecting keratinized tissues in humans and other animals caused by a large group of keratinophilic fungi in the genera of Trichophyton, Microsporum and Epidermophyton. The koala is an iconic Australian animal that there are limited numbers of the animal in aboriginal countries zoos. Superficial mycoses have been poorly studied in koalas and as far as we know there are no reliable mycological or molecular data regarding the isolation and identification of dermatophytes in this animal. Here, we report the isolation, phenotypic and genotypic identification-process of a dermatophytosis agent in a captivated koala.
Case report
Inspection of an 11-year-old female Queensland koala, kept in a Zoological Park, Tokyo, Japan, revealed hyperkeratotic lesions on the claws of right forepaw, along with white-yellowish, and scaly plaques on forepaw pads (Figs. 1A and 1B). On direct microscopy of a KOH wet-mount preparation from scrapings irregular, narrow and hyaline hyphae suggested a dermatophytic infection. Culture of clinical specimens onto Sabouraud dextrose agar (SDA) was positive for two distinct colonies (designed as types I and II) with different macro-morphology (Figs. 2A to 2H). In repeated subculturing on Mycobiotic agar and Potato dextrose agar (PDA), Macro- and microscopic characteristics of the strains were suggestive of three different species, i.e. Microsporum canis, M. gypseum, and M. fulvum, however, partial sequencing of ITS-rRNA, translation elongation factor 1-α (Tef-1α), and beta tubulin (BT2) genes confirmed the identity of both isolates as M. gypseum. The animal was treated using a continuous terbinafine regimen, 250 mg/kg once daily for 12 weeks.
Conclusion: As far as we know this is the first proven case of dermatophytosis in a koala. the discrepancy observed between gross- and micro-morphometrics of two strains isolated from the same clinical specimen, with each other and with a typical M. gypseum highlights again the popular contests; the multiformity of phenotypic traits in dermatophytes, inefficiency of morphological characters and efficacy of genomic information for reliable species delineation. |