Chrysosporium Anamorph Of Nannizziopsis Vriesii Research Articles

A Cross-Inoculation Experiment Reveals that Ophidiomyces ophiodiicola and Nannizziopsis guarroi Can Each Infect Both Snakes and Lizards.

Host range and specificity are key concepts in the study of infectious diseases. However, both concepts remain largely undefined for many influential pathogens, including many fungi within the Onygenales order. This order encompasses reptile-infecting genera (Nannizziopsis, Ophidiomyces, and Paranannizziopsis) formerly classified as the Chrysosporium anamorph of Nannizziopsis vriesii (CANV). The reported hosts of many of these fungi represent a narrow range of phylogenetically related animals, suggesting that many of these disease-causing fungi are host specific, but the true number of species affected by these pathogens is unknown. For example, to date, Nannizziopsis guarroi (the causative agent of yellow fungus disease) and Ophidiomyces ophiodiicola (the causative agent of snake fungal disease) have been documented only in lizards and snakes, respectively. In a 52-day reciprocal-infection experiment, we tested the ability of these two pathogens to infect currently unreported hosts, inoculating central bearded dragons (Pogona vitticeps) with O. ophiodiicola and corn snakes (Pantherophis guttatus) with N. guarroi. We confirmed infection by documenting both clinical signs and histopathological evidence of fungal infection. Our reciprocity experiment resulted in 100% of corn snakes and 60% of bearded dragons developing infections with N. guarroi and O. ophiodiicola, respectively, demonstrating that these fungal pathogens have a broader host range than previously thought and that hosts with cryptic infections may play a role in pathogen translocation and transmission. IMPORTANCE Our experiment using Ophidiomyces ophiodiicola and Nannizziopsis guarroi is the first to look more critically at these pathogens' host range. We are the first to identify that both fungal pathogens can infect both corn snakes and bearded dragons. Our findings illustrate that both fungal pathogens have a more general host range than previously known. Additionally, there are significant implications concerning the spread of snake fungal disease and yellow fungus disease in popular companion animals and the increased chance of disease spillover into other wild and naive populations.

P506 First case of cutaneous mycosis caused by Nannizziopsis sp. in Chelonia

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMThe present report characterized a case of severe superficial and deep mycoses in a yellow-bellied slider (Trachemys scripta scripta) caused by Nannizziopsis sp. detected by histopathology and fungal culture. A female, 4-year-old, yellow-bellied slider (Trachemys scripta scripta) was presented for ulcerative and proliferative, chronic, skin lesions. White to pink, slightly round, with fuzzy borders, 0.5-2.5 cm in diameter, multifocal, proliferative, and ulcerative lesions were evident mainly on the left forelimb, right forelimb, pericloacal, chin, and oral cavity. The left forelimb was severely affected by a nodular subcutaneous mass.Several courses of disinfectant therapy, antibiotic, and antifungal treatments were given with no clinical improvements.Cytological smears of the ulcerative skin lesion revealed macrophages, heterophils, and fragments of septate hyphae. To investigate the cause of the lesions, the left forelimb was excised, fixed in 10% neutral buffered formalin, and submitted for histopathological examination. Biopsies and swabs from left forelimb, right forelimb, chin, and oral lesions were submitted for microbiological analysis.Samples were cultured on Sabouraud Dextrose Agar (SDA) and incubated at 30°C for 10 days. Histopathological examination showed severe pyogranulomatous dermatitis and myositis. Numerous septate, irregularly branched hyphae were evident within the pyogranulomas. Grocott methenamine silver stain (GMS) and Periodic acid-Schiff (PAS) confirmed the presence of filamentous fungi in the examined sections.Pure cultures of the same fungal strain were obtained from all the samples. Mature colonies on SDA showed a powdery aspect and a white felted surface. Microscopically, the hyphae were straight and branched, and conidia were clavate, sessile, or on short stalks.Based on both macroscopic and microscopic features the fungal strain was identified as Nannizziopsis sp.Susceptibility profile of the fungal isolate was tested for griseofulvin, miconazole, fluconazole, voriconazole, itraconazole, clotrimazole, and ketoconazole. Amplification and sequencing of ITS, 18S, and SSU gene regions have been performed to identify the fungal isolate. The sequences were aligned with the most similar sequences of established species deposited in GenBank in order to define levels of relatedness. Sequences showed that the isolate clustered with Nannizziopsiaceae. The sequence similarities of the isolate were 99% to N. arthrosporioides in ITS (535/543 bps), 99% to N. vriesii in 18S, and SSU (1648/1649 and 970/973 bps, respectively).Based on the histopathological, microbiological, and molecular analysis, Nannizziopsis sp. was the primary cause of severe deep mycoses in the present turtle. Mycoses caused by Chrysosporium-related fungi are an emerging infectious disease affecting reptiles. The fungi of this group were collectively identified as Chrysosporium anamorph of Nannizziopsis vriesii (CAVN) complex by their morphological characteristics. Recent molecular taxonomy studies have now re-classified Chrysosporium-related fungi into three genera: Nannizziopsis, Paranannizziopsis, and Ophidiomyces.Until now, nine species have been isolated and identified from reptiles. Dermatomycosis associated with Nannizziopsis spp. is frequently reported in lizards, terrestrial, and aquatic snakes, and crocodiles, with classical cutaneous ulcerative lesions. Cutaneous mycosis is common in turtles, however, to our knowledge this is the first case of Nannizziopsis cutaneous mycosis in Chelonia.

Mycoses are emerging in reptiles

In 1968, the Dutch mycologist de Vries isolated for the first time a fungus that affected the skin and lungs of a lizard (Ameiva sp.). This strain displayed both the sexual (teleomorph) and the asexual form (anamorph) of the species, which received the name Nannizziopsis vriesii (Apinis) Currah in honour of the discoverer. In recent scientific literature, there are numerous cases of mycoses in different species of reptiles in which the etiological agent is called CANV. This acronym is incorrectly used to abbreviate the species Chrysosporium anamorph of Nannizziopsis vriesii, now obsolete. This species is characterized for presenting exclusively an asexual form with mainly pyriform conidia that can be confused with the microconidia some species of Trichophyton have.

Snake fungal disease: an emerging threat to wild snakes.

Since 2006, there has been a marked increase in the number of reports of severe and often fatal fungal skin infections in wild snakes in the eastern USA. The emerging condition, referred to as snake fungal disease (SFD), was initially documented in rattlesnakes, where the infections were believed to pose a risk to the viability of affected populations. The disease is caused by Ophidiomyces ophiodiicola, a fungus recently split from a complex of fungi long referred to as the Chrysosporium anamorph of Nannizziopsis vriesii (CANV). Here we review the current state of knowledge about O. ophiodiicola and SFD. In addition, we provide original findings which demonstrate that O. ophiodiicola is widely distributed in eastern North America, has a broad host range, is the predominant cause of fungal skin infections in wild snakes and often causes mild infections in snakes emerging from hibernation. This new information, together with what is already available in the scientific literature, advances our knowledge of the cause, pathogenesis and ecology of SFD. However, additional research is necessary to elucidate the factors driving the emergence of this disease and develop strategies to mitigate its impacts.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'.

An Overview of Reptile Fungal Pathogens in the Genera Nannizziopsis, Paranannizziopsis, and Ophidiomyces

Abstract Two recent molecular analyses of morphologically similar fungal isolates formerly grouped under the appellation “Chrysosporium anamorph of Nannizziopsis vriesii (CANV) complex” led to major taxonomic revisions and revealed new insights into the biology of these reptile pathogens. All CANV-complex isolates differed from N. vriesii and were assigned to 16 species, either within Nannizziopsis or within the new genera Paranannizziopsis and Ophidiomyces, and 14 of these species were newly described. From these revisions, a trend in host specificity clearly emerged that was not previously apparent. Nannizziopsis now includes nine species associated with chamaeleonid, gekkonid, cordylid, teiid, agamid, and iguanid lizards; crocodiles; and human hosts. Paranannizziopsis includes four species that infect squamates and tuataras. Ophidiomyces, with the single species Ophidiomyces ophiodiicola (formerly Chrysosporium ophiodiicola), is only associated with terrestrial or semiaquatic snakes. Nannizziopsi guarr...

TaqMan real-time polymerase chain reaction for detection of Ophidiomyces ophiodiicola, the fungus associated with snake fungal disease.

BackgroundFungal skin infections associated with Ophidiomyces ophiodiicola, a member of the Chrysosporium anamorph of Nannizziopsis vriesii (CANV) complex, have been linked to an increasing number of cases of snake fungal disease (SFD) in captive snakes around the world and in wild snake populations in eastern North America. The emergence of SFD in both captive and wild situations has led to an increased need for tools to better diagnose and study the disease.ResultsWe developed two TaqMan real-time polymerase chain reaction (PCR) assays to rapidly detect O. ophiodiicola in clinical samples. One assay targets the internal transcribed spacer region (ITS) of the fungal genome while the other targets the more variable intergenic spacer region (IGS). The PCR assays were qualified using skin samples collected from 50 snakes for which O. ophiodiicola had been previously detected by culture, 20 snakes with gross skin lesions suggestive of SFD but which were culture-negative for O. ophiodiicola, and 16 snakes with no clinical signs of infection. Both assays performed equivalently and proved to be more sensitive than traditional culture methods, detecting O. ophiodiicola in 98% of the culture-positive samples and in 40% of the culture-negative snakes that had clinical signs of SFD. In addition, the assays did not cross-react with a panel of 28 fungal species that are closely related to O. ophiodiicola or that commonly occur on the skin of snakes. The assays did, however, indicate that some asymptomatic snakes (~6%) may harbor low levels of the fungus, and that PCR should be paired with histology when a definitive diagnosis is required.ConclusionsThese assays represent the first published methods to detect O. ophiodiicola by real-time PCR. The ITS assay has great utility for assisting with SFD diagnoses whereas the IGS assay offers a valuable tool for research-based applications.

Dermatitis and Cellulitis in Leopard Geckos (Eublepharis macularius) Caused by the Chrysosporium Anamorph of Nannizziopsis vriesii

An epizootic of ulcerative to nodular ventral dermatitis was observed in a large breeding colony of 8-month to 5-year-old leopard geckos (Eublepharis macularius) of both sexes. Two representative mature male geckos were euthanized for diagnostic necropsy. The Chrysosporium anamorph of Nannizziopsis vriesii (CANV) was isolated from the skin lesions, and identification was confirmed by sequencing of the internal transcribed spacer region of the rRNA gene. Histopathology revealed multifocal to coalescing dermal and subcutaneous heterophilic granulomas that contained septate fungal hyphae. There was also multifocal epidermal hyperplasia with hyperkeratosis, and similar hyphae were present within the stratum corneum, occasionally with terminal chains of arthroconidia consistent with the CANV. In one case, there was focal extension of granulomatous inflammation into the underlying masseter muscle. This is the first report of dermatitis and cellulitis due to the CANV in leopard geckos.

Deep fungal dermatitis caused by the Chrysosporium anamorph of Nannizziopsis vriesii in captive coastal bearded dragons (Pogona barbata)

Deep fungal dermatitis caused by the Chrysosporium anamorph of Nannizziopsis vriesii (CANV) was diagnosed in a group of coastal bearded dragons (Pogona barbata). The outbreak extended over a 6-month period, with four of six lizards from the same zoological outdoor enclosure succumbing to infection. A fifth case of dermatomycosis was identified in a pet lizard originally sourced from the wild. Diagnosis of infection with the CANV was based on similar clinical signs and histopathology in all animals and confirmed by culture and sequencing of the fungus from one animal. This is the first report of the CANV causing disease in a terrestrial reptile species in Australia and the first in the coastal bearded dragon.

Voriconazole, a safe alternative for treating infections caused by theChrysosporiumanamorph ofNannizziopsis vriesiiin bearded dragons (Pogona vitticeps)

Dermal and systemic infections caused by the Chrysosporium anamorph of Nannizziopsis vriesii (CANV) are highly prevalent in reptiles and may result in severe disease and high mortality. Due to the high incidence of therapeutic failures, optimizing treatment is required. We first determined in this study the minimal inhibitory concentrations (MIC) of itraconazole, voriconazole, amphotericin B and terbinafine against 32 CANV isolates. For voriconazole, amphotericin B and terbinafine a monomodal MIC distribution was seen, whereas a bimodal MIC distribution was present for itraconazole, indicating acquired resistance in one isolate. Fourteen naturally-infected bearded dragons (Pogona vitticeps), from the same owner, were treated orally with either itraconazole (5 mg/kg q24h) or voriconazole (10 mg/kg q24h). The clinical condition, drug plasma concentrations and the presence of CANV in skin samples were followed. The animals were treated until complete clearance of the fungus. The plasma concentrations of voriconazole and itraconazole exceeded the minimal inhibitory concentrations of the CANV isolates. Elimination of CANV was achieved on average after 27 and 47 days of treatment with itraconazole and voriconazole, respectively. Whereas only 2 out of 7 survived after itraconazole treatment, only a single animal died in the voriconazole treated group. In conclusion, based on a limited number of animals, voriconazole applied at a regimen of 10 mg/kg bodyweight (BW) q24h seems to be a safe and effective antimycotic drug to eliminate CANV infections in bearded dragons.

Cutaneous hyalohyphomycosis in a girdled lizard (Cordylus giganteus) caused by the Chrysosporium anamorph of Nannizziopsis vriesii and successful treatment with voriconazole

The Chrysosporium anamorph of Nannizziopsis vriesii was associated with dermatomycosis and high mortality in a group of captive giant girdled lizards (Cordylus giganteus). Treatment of one of the infected girdled lizards with voriconazole, which was selected on the basis of in vitro sensitivity testing of the isolate, resulted in resolution of lesions and negative fungal cultures from the skin. Three hours after oral administration of 10 mg/kg, the plasma level of voriconazole exceeded the 0.25-μg/mL minimal inhibitory concentration tenfold. In conclusion, administration of voriconazole at 10 mg/kg of body weight once daily for 10 weeks resulted in clinical cure and was well tolerated. A longer follow-up time and larger studies will be necessary to determine the long-term efficacy and safety of this treatment in giant girdled lizards.

Dermatologische Erkrankungen bei Reptilien

Reptiles are presented in increasing numbers in the small animal practice. The most important cause for dermatopathies is inadequate management, especially species inappropriate temperature and humidity. This aspect has to be considered in the treatment. Infectious skin diseases in reptiles are frequently caused by mites, as well as by bacteria and fungi. The special importance of the fungal disease caused by Chrysosporium Anamorph of Nannizziopsis vriesii (CANV) in lizards is emphasized. Viral skin diseases are less frequently diagnosed. Shell necrosis in chelonians is an important bacterial disease. Frequent causes of non-infectious dermatopathies are dysecdysis and trauma. Hypovitaminosis A is the most common metabolic disease. Physical examination, diagnostic tests and therapy in reptile skin diseases are comparable to mammals, however, scientific data in reptiles are still scarce.

Deep fungal dermatitis in three inland bearded dragons (Pogona vitticeps) caused by theChrysosporiumanamorph ofNannizziopsis vriesii

The Chrysosporium anamorph of Nannizziopsis vriesii (CANV), a keratinophilic fungus that naturally and experimentally causes severe and often fatal dermatitis in multiple reptile species, was isolated in pure culture from skin samples of three inland bearded dragons (Pogona vitticeps) with deep granulomatous dermatomycosis. The first animal presented with a focal maxillary swelling involving the skin and gingiva. This lizard died while undergoing itraconazole and topical miconazole therapy. The second presented with focally extensive discoloration and thickening of the skin of the ventrum and was euthanized after 10 weeks of itraconazole therapy. A third lizard presented with hyperkeratotic exudative dermatitis on a markedly swollen forelimb. Amputation and itraconazole therapy resulted in a clinical cure. Histopathology of tissue biopsies in all cases demonstrated granulomatous dermatitis with intralesional hyphae morphologically consistent with those produced by the CANV. The second lizard also had granulomatous hepatitis with intralesional hyphae. Evidence in this report suggests that the CANV is the etiologic agent of an emerging condition in captive bearded dragons that has been called 'yellow fungus disease'.

Pathogenicity of theChrysosporiumAnamorph ofNannizziopsis vriesiifor veiled chameleons (Chamaeleo calyptratus)

Veiled chameleons (Chamaeleo calyptratus) were experimentally challenged with the fungus Chrysosporium anamorph of Nannizziopsis vriesii (CANV). Chameleons were exposed to conidia in their captive environment, or were inoculated by direct application of a conidial suspension inoculum on intact and on abraded skin. The CANV induced lesions in all experimental groups and was recovered from infected animals, fulfilling Koch's postulates and confirming that it may act as a primary fungal pathogen in this species of reptile. A breach in cutaneous integrity, as simulated by mild scarification, increased the risk of infection but was not required for the CANV to express pathogenicity. Initial hyphae proliferation occurred in the outer epidermal stratum corneum, with subsequent invasion of the deeper epidermal strata and dermis. A spectrum of lesions was observed ranging from liquefactive necrosis of the epidermis to granulomatous inflammation in the dermis. CANV dermatomycosis appears to be contagious and can readily spread within a reptile collection, either directly through contact with infective arthroconidia or indirectly via fomites. Dense tufts of arthroconidiating hyphae were demonstrated histologically on the skin surface of many animals that developed dermatomycosis, and these arthroconidia may act as infective propagules involved in the transfer of disease between reptiles.

FATAL CUTANEOUS MYCOSIS IN TENTACLED SNAKES (ERPETON TENTACULATUM) CAUSED BY THE CHRYSOSPORIUM ANAMORPH OF NANNIZZIOPSIS VRIESII

The fungus Chrysosporium anamorph of Nannizziopsis vriesii was identified as the cause of fatal, multifocal, heterophilic dermatitis in four freshwater aquatic captive-bred tentacled snakes (Erpeton tentaculatum). Pale, 1- to 4-mm focal lesions involving individual scales, occurred primarily on the head and dorsum. Histology showed multifocal coagulation necrosis of the epidermis, with marked heterophilic infiltration without involvement of the underlying dermis. Septate, irregularly branched hyphae, and clusters of 4- to 8- by 2- to 3-microm rod-shaped cells (arthroconidia) were present within the lesions and in a superficial crust. Failure to maintain an acidic environment was likely a predisposing factor in the development of these lesions.

Mycotic Brain Abscess Caused by Opportunistic Reptile Pathogen

To the Editor: A 38-year-old, HIV-seropositive Nigerian man sought treatment with an 8-month history of severe parietal headache, impaired memory, fatigue, paresthesia of the left arm, and left-sided focal seizures. He had no history of neurologic disorders, including epilepsy. On physical examination, the patient appeared well, alert, and oriented, with slurred speech. Evaluation of the visual fields showed left homonymous hemianopsia. All other neurologic assessments were unremarkable. The patient had a blood pressure of 120/80, a pulse of 88 beats per minute, and a body temperature of 37.3°C. Leukocyte count was 8,600/µL, total lymphocyte count was 1,981/µL, CD4+ cell count was 102/µL, and CD4/CD8 ratio was 0.07. HIV RNA-load was <50 copies/mL; all other laboratory parameters were normal. The patient had received antiretroviral therapy (stavudine, lamivudine, nevirapine) for 5 months before admission, but no prophylaxis for opportunistic infections. Magnetic resonance imaging (MRI) of the brain disclosed 2 masses, 3.3 and 4.8 cm in diameter, respectively (Figure A), and signs of chronic sinusitis. A computed tomographic chest scan showed infiltration of both lower segments with multiple, small nodules (Figure B). Blood cultures were repeatedly negative. A computer-guided needle-aspiration of the brain lesions yielded yellow-brown, creamy fluid in which abundant septated fungal hyphae were detected microscopically (Figure C). Cytologic investigation was consistent with a necrotic abscess. The cycloheximide-resistant isolate was strongly keratinolytic and identified as a Chrysosporium anamorph of Nannizziopsis vriesii (1,2). High-dose antimicrobial treatment with voriconazole (200 mg twice daily, subsequently reduced to 200 mg daily) was added to the antiretroviral (ritonavir, amprenavir, trizivir), anticonvulsive, and adjuvant corticosteroid treatment. The isolate was highly susceptible to voriconazole in vitro (MIC, <16µg/mL [Etest, AB-Biodisk Solna, Sweden]). Recovery was complicated by a generalized seizure and severe, acute psychosis associated with rapid refilling of the 2 lesions with mycotic abscess fluid. After re-aspiration, the patient's psychosis improved gradually, and no further seizures occurred. When last seen 4 months later, the patient was healthy and without neurologic deficits. His CD4+ cell count was 233/µL, HIV-load was <50 copies/mL, and a MRI scan of the brain showed partial regression of the 2 brain lesions (Figure D). Figure Chrysosporium sp. brain abscess in an HIV-seropositive patient. A) T2-weighted magnetic resonance imaging (MRI) scan of the brain showing 2 large masses (triangles) surrounded by a ring of signal intensity and extensive perifocal edema (open arrows), ... Chrysosporium spp. are common soil saprobes, occasionally isolated from human skin. Invasive infection is very rare in humans, and most were observed in immunocompromised patients, manifesting as osteomyelitis (3,4) or diffuse vascular brain invasion (5). Here, we report the first case of brain abscesses by the Chrysosporium anamorph of N. vriesii. This fungus has been associated with fatal mycosis in reptiles (6,7) and cutaneous mycosis in chameleons originating from Africa (2). In our patient, we were unable to determine the portal of entry and the sequence of fungal dissemination; no skin lesions were present at the time of admission. However, the multifocal nature, lung infiltration, and involvement of the middle cerebral artery distribution suggest hematogenous dissemination (8,9) after replication of airborne conidia within the respiratory tract. Fungi cause >90% of brain abscesses in immunocompromised transplant patients with an associated mortality rate of 97% (10), despite aggressive surgery and antifungal therapy (9). Our patient was treated successfully with abscess drainage, antiretroviral therapy, and oral voriconazole, a novel antifungal triazole drug. Despite limited data available on voriconazole penetration into brain abscess cavities (9), this drug was clinically and radiologically effective in our patient.

Cutaneous Mycobiota of Captive Squamate Reptiles with Notes on the Scarcity of Chrysosporium Anamorph of Nannizziopsis vriesii

ABSTRACT The Chrysosporium anamorph of Nannizziopsis vriesii (CANV) is a fungus that has been implicated in several recent cases of reptile dermatomycoses. A survey was conducted to investigate whether this fungus was present on the skins of healthy squamate reptiles. Skin was collected as aseptically as possible from actively shedding lizards (n = 36) or from freshly shed snake exuvia (n = 91) and placed on fungal culture media for selective recovery of cycloheximide-tolerant fungi. The CANV was cultured from only one animal, an African rock python, Python sebae. Fungi belonging to 50 genera were identified from 127 reptiles: Aspergillus spp., Penicillium spp., and Paecilomyces lilacinus were most frequently isolated. Keratinophilic fungi isolated from reptiles did not belong to zoophilic or anthropophilic species, inferring that the potential for acquisition of dermatophytosis from handling squamate reptiles is low.