The first case of onychomycosis in a koala (Phascolarctos cinereus) due to atypical isolates of Microsporum gypseum, a diagnostic challenge

Authors

1 Department of Medical Parasitology & Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Medical Parasitology & Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

3 Teikyo University Institute of Medical Mycology, Tokyo, Japan

4 Department of Medical Mycology, School of Medicine, Health Research Institute, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

5 General Medical Education and Research Center, Teikyo University, Tokyo, Japan

Abstract

Background and Purpose: Superficial mycotic infections have been only poorly described in koalas and there are no reliable mycologically confirmed data regarding clinical isolation of dermatophytes in this animal. We report an 11-yearold female koala, kept in a zoo in Tokyo, Japan, and presenting with hyperkeratotic lesions and scaly plaques on forepaw claws and pads reminiscent of fungal infection.
Case Report: Direct microscopy of the scrapings was indicative of a dermatophyte infection. By culture and subsequent repeated subculturing of clinical specimens on Sabouraud dextrose agar, Mycobiotic agar, and potato dextrose agar, two distinct strains with different colony morphotypes (designed as types I and II) were identified. Macroscopic 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 internal transcribed spacer (ITS) region of rDNA, translation elongation factor-1α (Tef-1α), and beta-tubulin (BT2) genes confirmed the identity of both isolates as M. gypseum. The animal was treated with a continuous terbinafine regimen (250 mg/kg) once daily for 12 weeks.
Conclusion: To the best of our knowledge, the present report is the first confirmed case of dermatophytosis in a koala. The genetics underlying a variety of phenotypic traits in most classical dermatophyte species are unknown, and further studies are needed to understand this phenomenon. 

Keywords


1. Weitzman I, Summerbell RC. The dermatophytes. Clin Microbiol Rev. 1995; 8(2):240-59.
2. Hay RJ, Merz WG. Topley & Wilson’s microbiology and microbial infections. Medical mycology. Arnold: Hodder Headline; 2005.
3. Chermette R, Ferreiro L, Guillot J. Dermatophytoses in animals. Mycopathologia. 2008; 166(5-6):385-405.
4. Ranganathan S, Balajee SA, Raja SM. A survey of dermatophytosis in animals in Madras, India. Mycopathologia. 1997; 140(3):137-40.
5. Rotstein DS, Thomas R, Helmick K, Citino SB, Taylor SK, Dunbar MR. Dermatophyte infections in free-ranging Florida panthers (Felis concolor coryi). J Zoo Wildl Med. 1999; 30(2):281-4.
6. Sherwin WB, Timms P, Wilcken J, Houlden B. Analysis and conservation implications of koala genetics. Conserv Biol. 2000; 14(3):639-49.
7. Wales NS. Threatened species conservation act 1995. Queensland, Australia: Government Printer; 1995.
8. Hrdina F, Gordon G. The koala and possum trade in Queensland, 1906-1936. Australian Zool 2004; 32(4):543-85.
9. Taguchi Y, Hasumi Y, Abe S, Nishiyama Y. The effect of cinnamaldehyde on the growth and the morphology of Candida albicans. Med Mol Morphol. 2013; 46(1):8-13.
10. White TJ, Bruns T, Lee S, Taylor J. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. PCR Protocols. 1990; 18(1):315-22.
11. Rezaei-Matehkolaei A, Makimura K, de Hoog GS, Shidfar MR, Satoh K, Najafzadeh MJ, et al. Multilocus differentiation of the related dermatophytes Microsporum canis, Microsporum ferrugineum and Microsporum audouinii. J Med Microbiol. 2012; 61(Pt 1):57-63.
12. O’Donnell K, Cigelnik E. Two divergent intragenomic rDNA ITS2 types within a monophyletic lineage of the fungusfusariumare nonorthologous. Mol Phylogenet Evol. 1997; 7(1):103-16.
13. Glass NL, Donaldson GC. Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. Appl Environ Microbiol. 1995; 61(4):1323-30.
14. Reference method for broth dilution antifungal susceptibility testing of filamentous fungi; approved standard, CLSI M38-A. 2nd ed. Wayne PA: Clinical and Laboratory Standards Institute; 2008.
15. Rabb GB. The changing roles of zoological parks in conserving biological diversity. Am Zool. 1994; 34(1):159-64.
16. Deem S. Role of the zoo veterinarian in the conservation of captive and free-ranging wildlife. Int Zoo Yearbook. 2007; 41(1):3-11.
17. Hundloe TJ, Hamilton C. Koalas and tourism: an economic evaluation. Australia: Australian Institute; 1997.
18. Cafarchia C, Weigl S, Figueredo LA, Otranto D. Molecular identification and phylogenesis of dermatophytes isolated from rabbit farms and rabbit farm workers. Vet Microbiol. 2012; 154(3-4):395-402.
19. Monga D, Mohapatra L. A compilation of published reports of mycoses in animals in India.Mycopathologia. 1980; 72(1):3-11.
20. de Hoog GS, Guarro J, Gené J, Figueras MJ. Atlas of clinical fungi. 2nd ed. Netherlands: Centraalbureau voor Schimmelcultures (CBS); 2000.
21. Canfield P, Spencer A, Hartley W, Spielman D, Vogelnest L, Hulst F. Disorders of keratinization in a group of related, captive koalas (Phascolarctos cinereus), with a review of other skin conditions in koalas. J Zoo Wildl Med. 1992; 23(4):414-21.
22. Binstock JM. Molecular biology techniques for identifying dermatophytes and their possible use in diagnosing onychomycosis in human toenail: a review. J Am Podiatr Med Assoc. 2007; 97(2):134-44.
23. Nouripour-Sisakht S, Rezaei-Matehkolaei A, Abastabar M, Najafzadeh MJ, Satoh K, Ahmadi B, et al. Microsporum fulvum, an ignored pathogenic dermatophyte: a new clinical isolation from Iran. Mycopathologia. 2013; 176(1-2):157-60.
24. Gräser Y, Scott J, Summerbell R. The new species concept in dermatophytes-a polyphasic approach. Mycopathologia. 2008; 166(5-6):239-56.
25. Ellis D, Davis S, Alexiou H, Handke R, Bartley R. Descriptions of medical fungi, mycology unit, women’s and children’s hospital, and school of molecular and biomedical science, university of Adelaide. Adlelaide: University of Adelaide; 2007.
26. Rezaei-Matehkolaei A, Makimura K, De Hoog GS, Shidfar MR, Satoh K, Najafzadeh MJ, et al. Discrimination of Trichophyton tonsurans and Trichophyton equinum by PCR-RFLP and by β-tubulin and translation elongation factor 1-α sequencing. Med Mycol. 2012; 50(7):760-4
Volume 2, Issue 2
June 2016
Pages 45-50
  • Receive Date: 09 July 2019
  • Revise Date: 08 October 2020
  • Accept Date: 09 July 2019
  • Publish Date: 01 June 2016