Histopathology, Molecular Identification and Antifungal Susceptibility Testing of Nannizziopsis arthrosporioides from a Captive Cuban Rock Iguana ( Cyclura nubila )

Chrysosporium -related fungi, the cause of superficial and deep mycoses, are an emerging infectious disease affecting not only reptiles but also immunocompromized humans. However, the information on Nannizziopsis arthrosporioides is extremely scarce. We herein characterized N. arthrosporioides isolated from a Cuban rock iguana ( Cyclura nubila ). Three skin ulcers were found in a Cuban rock iguana after captivity for 8 years. Microscopic examination revealed hyperplastic, hyperkeratotic, and ulcerative dermatitis coupled with numerous branched, septate fungal hyphae. The fungal culture yielded growth of zonate, felted cottony-powdery colonies with lobate margins on medium. Maximum-likelihood phylogeny tree based on the combined partial actin and partial β-tubulin genes demonstrated that current isolates were mostly close to N. arthrosporioides . Furthermore, antifungal susceptibility test demonstrated that N. arthrosporioides had lowest minimal inhibitory concentration (MIC) values to isavuconazole, efinaconazole, and luliconazole, which may be the potential treatment of choice for N. arthrosporioides infection. The current study describes the first confirmed case of dermatomycosis caused by N. arthrosporioides of a captive reptile in Asia with detailed descriptions of the clinical, histopathological, and mycological features. The current findings provide new information on global distribution and host range of N. arthrosporioides and can raise the concern on the transboundary or emerging disease of N. arthrosporioides in Asian region.