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Microscopic features of this Mycoleptodiscus species. (A) Small aggregate of sporodochial cells, a conidiogenous cell, and a conidium being released. Slide culture preparation mounted in lacto-fuchsin. (B) Conidiogenous cells with collarettes, and single-celled conidia with very short appendages. (C) Two-celled conidium. (D) Cellophane tape preparation demonstrating single-celled conidia with both polar and lateral appendages.
Source publication
An 8-year-old dog presented with several dermal excoriations. Lesion cytology revealed pyogranulomatous inflammation with
branching, septate hyphae. A mold identified as Mycoleptodiscus indicus by morphology and sequencing was cultured from fine-needle aspirates. This is the first report of a Mycoleptodiscus species as an etiologic agent in a dog.
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Citations
... In 2019, an 8-month-old immunocompetent cat in Georgia, USA, was diagnosed with an infection on the front knee with M. indicus (Maboni et al., 2019). It also caused several dermal excoriations in an 8-year-old immunodeficient dog (Metry et al., 2010). ...
Background: Lotus, Nelumbo nucifera Gaertn is Vietnam’s symbol and Buddhism’s flower and plays an essential part in rural Vietnam’s economy as all aspects of lotus could bring benefits to farmers. But, unfortunately, lotus yield in Vietnam is seriously affected by various plant diseases. Among them, leaf blight is currently emerging as one of the primary diseases devastating lotus crops in Vietnam, in which there are large necrotic parts on lotus leaves, flowers and seeds. Methods: Aloe barbadensis extract was used for synthesizing silver nanoparticles. Leaf blight lotus leaves were collected to isolate pathogenic fungi-infection of isolated pathogenic fungi on the healthy lotus and then identify hidden mold by 28S rRNA sequencing. Determination of in vitro minimal inhibition concentration of nano-silver was conducted according to Azizi. The reduction of disease symptoms and biological characteristics of the treated lotus was observed. Result: Morphological analysis and molecular identification of 28S rRNA sequencing showed that the pathogenic microorganism was Mycoleptodiscus indicus (M. indicus). Both in vitro antifungal activity and in vivo treatment of leaf blight lotus using a nano-silver solution showed that 30 ppm of nano-silver was the minimal inhibition concentration (MIC) for totally eradicating M. indicus growth. This was the first time M. indicus was reported to infect and cause leaf blight on a lotus. Previously, M. indicus was a well-known plant pathogen that could cross-kingdom infect humans and animals. Thus, the fact that lotus is widely cultured in Vietnamese rural could increase the chance for M. indicus to spread; hence, this raised the alarm about its potential harm to plants, humans and animals. And, significantly, it revealed nano-silver as a possible approach to prevent M. indicus.
... [1][2][3] In the last 2 decades, there have been increasing reports of M. indicus causing opportunistic phaeohyphomycosis in human and veterinary medicine. [4][5][6][7][8] Typically, it causes local cutaneous or subcutaneous infections after traumatic tissue inoculation. Initially reported in immunocompromised patients, this opportunistic fungus also may affect immunocompetent patients. ...
Objective
Describe the diagnosis, clinical course, and management of a dog with systemic Mycoleptodiscus indicus infection.
Case Summary
A 5‐year‐old male neutered Giant Schnauzer presented with left eye anterior uveitis, peripheral lymphadenopathy, hyperglobulinemia, anemia, and thrombocytopenia. A diagnosis of M. indicus infection was made based on histopathology and PCR. Treatment with itraconazole and terbinafine resulted in resolution of the hyperglobulinemia, anemia, thrombocytopenia, and peripheral lymphadenopathy. No evidence of fungal organisms was identified on lymph node, liver, or ocular histopathology after 7 months of treatment.
New or Unique Information Provided
This case is the first report of a systemic M. indicus infection in an apparently immunocompetent dog. Clinical resolution was achieved with systemic itraconazole and terbinafine.
... Mycoleptodiscus indicus, a dematiaceous hyphomycete, is a common contaminant of tropical or subtropical soils and occurs on the leaves of different plants for which it is pathogenic, particularly but not exclusively monocotyledons [1]. It has only been sporadically described as a subcutaneous infection agent in immunocompetent animals [2][3][4] and in immunocompromised patients. Compared to the general population, this type of patient has an increased risk of developing opportunistic fungal infections with greater morbidity and mortality. ...
... The patient was subjected to induction treatment with liposomal Amphotericin B, followed by long-term therapy with Itraconazole. The treatment, together with the drain of the abscess, allowed the complete resolution of the lesion [1][2][3][4][5][6][7][8][9]. ...
... In an immunocompetent healthy man, M. indicus was reported to cause septic arthritis [7]. Infections are presumably acquired by traumatic implantation [8], with plants implied as potential sources of infection [7]. In veterinary medicine, M. indicus has been reported in one case of an immunosuppressed dog, presenting with dermal excoriations and draining tract from a swollen leg [8]. ...
... Infections are presumably acquired by traumatic implantation [8], with plants implied as potential sources of infection [7]. In veterinary medicine, M. indicus has been reported in one case of an immunosuppressed dog, presenting with dermal excoriations and draining tract from a swollen leg [8]. To our knowledge, this is the first report in a cat to provide detailed identification of this microorganism via cytology, fungal culture, DNA sequencing, phylogenetic analysis, and to report treatment with a successful clinical outcome. ...
... M. indicus is a rare cause of human and animal infections, though it is a well-recognized plant pathogen [1]. There are few reports in the literature of M. indicus infection in humans and only one report in a dog [3,[5][6][7][8]. M. lateralis, a similar species to M. indicus, was reported to cause subcutaneous phaeohyphomycosis in a cat from Australia [16]. ...
Background:
Mycoleptodiscus indicus is a dematiaceous hyphomycete fungus found on plant leaves. It has been rarely reported as a cause of human or animal disease, possibly because it is difficult to culture and identify from clinical specimens. Infections are presumably acquired by traumatic implantation.
Case presentation:
An 8-year-old non-immunosuppressed cat from Georgia, USA, presented with a left front leg swelling without lameness. Cytology from a fine needle aspirate revealed pyogranulomatous inflammation with both cytoplasmic and extracellular fungal elements. There were septate hyphae with irregularly sized segments, non-staining uneven walls, and rounded yeast-like forms from which longer hyphae arose in a hub-and-spoke pattern. A mold was isolated on agar from a fine needle aspirate collected 1 week later and identified as M. indicus by morphology, DNA sequencing and phylogenetic analysis. The cat recovered completely and uneventfully with antifungal treatment.
Conclusions:
We report a previously undescribed presentation of M. indicus causing a subcutaneous infection in a cat with successful antifungal treatment. In this study we highlight the potential of M. indicus to infect immunocompetent animals, and the veterinary medical community should be aware of its unusual but characteristic clinical, microbiological and cytologic presentation.
... Furthermore, analyses of sequences deposited in the GenBank database as M. indicus or Myco leptodiscus sp. (Dewar & Sigler 2010, Metry et al. 2010, Koo et al. 2012 showed that they are related to Muyocopron (Muyocopronales). Muyocopron was proposed by Spegazzini (1881), re-described by Saccardo (1883), and its taxonomical placement treated initially in Microthyriaceae (Von Arx & Müller 1975, Lumbsch & Huhndorf 2007 and later in Muyo copronaceae , Pang et al. 2013, Mapook et al. 2016a. ...
... In New Zealand, Koo et al. (2012) reported an association with Mycoleptodiscus from progressive necrotizing fungal cellulitis and myositis in the leg of a patient with glioblastoma multiforme. Domesticated animals were also reported with infections associated with Mycoleptodiscus species, such as a subcutaneous infection in a cat in Australia (Hull et al. 1997), and in an immunosuppressed dog in the USA (Metry et al. 2010 The aim of the present study is to clarify the taxonomy and phylogeny of Mycoleptodiscus species within Ascomycota. For this purpose, we used a set of strains of Mycoleptodiscus species isolated from clinical and plant specimens, including the available ex-type strains, and performed the multi-locus analyses of ITS rDNA, LSU, rpb1, rpb2 and tef1 sequences. ...
... The first report of Muyocopron (as Mycoleptodis cus) as etiologic agent of phaeohyphomycosis was attributed to M. indicus (Padhye et al. 1995). Since then, several authors have reported clinical cases of M. indicus in human and other mammals (Garrison et al. 2008, Dewar & Sigler 2010, Metry et al. 2010. However, the LSU and ITS sequences data from those strains indicated close affinities with Mu. laterale. ...
Mycoleptodiscus includes plant pathogens, animal opportunists, saprobic and endophytic fungi. The present study presents the first molecular phylogeny and revision of the genus based on four loci, including ITS, LSU, rpb2, and tef1. An extensive collection of Mycoleptodiscus cultures, including ex-type strains from the CBS, IMI, MUCL, BRIP, clinical isolates from the USA, and fresh isolates from Brazil and Spain, was studied morphologically and phylogenetically to resolve their taxonomy. The study showed that Mycoleptodiscus sensu lato is polyphyletic. Phylogenetic analysis places Mycoleptodiscus in Muyocopronales (Dothideomycetes), together with Arxiella, Leptodiscella, Muyocopron, Neocochlearomyces, and Paramycoleptodiscus. Mycoleptodiscus terrestris, the type species, and M. sphaericus are reduced to synonyms, and one new species is introduced, M. suttonii. Mycoleptodiscus atromaculans, M. coloratus, M. freycinetiae, M. geniculatus, M. indicus, M. lateralis (including M. unilateralis and M. variabilis as its synonyms) and M. taiwanensis belong to Muyocopron (Muyocopronales, Dothideomycetes), and M. affinis, and M. lunatus to Omnidemptus (Magnaporthales, Sordariomycetes). Based on phylogenetic analyses we propose Muyocopron alcornii sp. nov., a fungus associated with leaf spots on Epidendrum sp. (Orchidaceae) in Australia, Muyocopron zamiae sp. nov. associated with leaf spots on Zamia (Zamiaceae) in the USA, and Omnidemptus graminis sp. nov. isolated from a grass (Poaceae) in Spain. Furthermore, Neomycoleptodiscus venezuelense gen. & sp. nov. is introduced for a genus similar to Mycoleptodiscus in Muyocopronaceae.
... and Mucor spp., are found in soil and on the skin of dogs (Aho 1983). Localised cutaneous infections usually develop at wound sites, and both infection and dissemination are typically associated with immunosuppression (Waurzyniak et al. 1992, Herraez et al. 2001, Singh et al. 2006, Swift et al. 2006, Sutton et al. 2008, Metry et al. 2010, Armstrong et al. 2012, Burrough et al. 2012, Atencia et al. 2014. B. spicifera, the saprophytic organism isolated from dog 3 in the present series, is an uncommon opportunistic pathogen, with only one report of systemic disease in a dog treated with glucocorticoids (Waurzyniak et al. 1992). ...
... There have been two case reports of dogs diagnosed with opportunistic fungal infections during treatment with ciclosporin and glucocorticoids. The first dog received 2·1 mg/kg/ day prednisone and 10·4 mg/kg/day ciclosporin for treatment of IMHA (Metry et al. 2010). This dog presented with pitting oedema and draining skin lesions after 2 months of treatment and was ultimately diagnosed with subcutaneous Mycoleptodiscus indicus. ...
Glucocorticoids are the standard of care for the treatment of immune-mediated disorders, and ciclosporin is increasingly being used off-label as an adjunct immunosuppressive drug in dogs. However, opportunistic infections can develop during combination immunosuppressive regimens. This case series describes atypical fungal infections in eight dogs treated with immunosuppressive dosages of glucocorticoids and ciclosporin. The median duration of combined treatment prior to the identification of fungal infection was 31 (range, 13 to 201) days, although two dogs received glucocorticoids for prolonged periods prior to the addition of ciclosporin. The estimated prevalence of serious fungal infections with this drug combination appears to be low (approximately 1 · 67%), but these infections led directly or indirectly to death or euthanasia in five of eight (63%) dogs. These cases highlight the need for frequent clinical monitoring of dogs receiving immunosuppressive dosages of glucocorticoids and ciclosporin.
© 2015 British Small Animal Veterinary Association.
... In addition to be an agent of leaf necrosis, M. indicus have been described as a human pathogen causing subcutaneous phaeohyphomycosis [25]. The sequence of UM24 M. indicus was phylogenetically close to sequences of M. indicus (GU980694, GU980696, and GU980698) described as agent of subcutaneous infection in a dog [26]. Although few studies have indicated that endophytic fungi might be quiescent saprobes or latent pathogens, specific examples detailing these hypotheses remain scant. ...
... In addition to be an agent of leaf necrosis, M. indicus have been described as a human pathogen causing subcutaneous phaeohyphomycosis [25]. The sequence of UM24 M. indicus was phylogenetically close to sequences of M. indicus (GU980694, GU980696, and GU980698) described as agent of subcutaneous infection in a dog [26]. Although few studies have indicated that endophytic fungi might be quiescent saprobes or latent pathogens, specific examples detailing these hypotheses remain scant. ...
Echinacea is one of the top ten selling medicinal herbs in Europe and United States. Commercially available formulations may contain different plant parts of three species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with healthy E. purpurea clones and their ability to produce defense compounds. We recovered and identified thirty-nine fungal endophytes through the molecular methods in 15 distinct phylotypes, which were closely related to species of the following genera Ceratobasidium, Cladosporium Colletotrichum, Fusarium, Glomerella, and Mycoleptodiscus. These taxa were previously reported as decomposer and phytopathogenic fungi. The fungal community associated with two E. purpurea clones showed high richness and dominance indices with different distribution among plant organs. Crude extracts of fungal isolates were tested for antifungal and insecticidal biological activities. A total of 16 extracts (41%) showed antifungal properties; while just the extract of M. indicus exhibited larvicidal activity against A. aegypti. These results suggest that the symbiosis between the endophytic fungal community and micropropagated clones of E. purpurea was re-established after acclimatization to soil and the endophytic fungi produced compounds against phytopathogenic fungi.
... In addition to be an agent of leaf necrosis, M. indicus have been described as a human pathogen causing subcutaneous phaeohyphomycosis [25]. The sequence of UM24 M. indicus was phylogenetically close to sequences of M. indicus (GU980694, GU980696, and GU980698) described as agent of subcutaneous infection in a dog [26]. Although few studies have indicated that endophytic fungi might be quiescent saprobes or latent pathogens, specific examples detailing these hypotheses remain scant. ...
Echinacea is one of the top ten selling medicinal herbs in Europe and United States. Commercially available formulations may contain different plant parts of three species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with healthy E. purpurea clones and their ability to produce defense compounds. We recovered and identified thirty-nine fungal endophytes through the molecular methods in 15 distinct phylotypes, which were closely related to species of the following genera Ceratobasidium, Cladosporium Col-letotrichum, Fusarium, Glomerella, and Mycoleptodiscus. These taxa were previously reported as decomposer and phytopathogenic fungi. The fungal community associated with two E. purpurea clones showed high richness and dominance indices with different distribution among plant organs. Crude extracts of fungal isolates were tested for an-tifungal and insecticidal biological activities. A total of 16 extracts (41%) showed antifungal properties; while just the extract of M. indicus exhibited larvicidal activity against A. aegypti. These results suggest that the symbiosis between the endophytic fungal community and micropropagated clones of E. purpurea was re-established after acclimatization to soil and the endophytic fungi produced compounds against phytopathogenic fungi.
Fungi are among the most common infectious agents affecting the skin of animals. The skin can serve as a port of entry for fungal infections, which can eventually become disseminated. In some regions of the world, oomycetes, such as Pythium and Lagenidium, are also responsible for a significant number of severe cutaneous infections. Histologic evaluation of fungal morphology, including size, shape, septation, branching, and budding characteristics, combined with the distribution of inflammatory infiltrates within different skin layers can potentially identify etiologic agents, guiding selection of antifungals and additional diagnostics. Fungal infections of the skin surface are typically caused by Malassezia and rarely Candida, with opportunistic fungi also capable of colonizing the skin surface, especially when the barrier is broken. Folliculocentric infections, caused by dermatophytes, result in mild to severe inflammation and can occasionally penetrate deep into the skin. A wide range of fungi, including agents of hyalohyphomycosis, phaeohyphomycosis, and dimorphic fungal infections, as well as oomycetes, result in nodular cutaneous and subcutaneous lesions. With the occasional exception of dimorphic fungi, fungal speciation often requires cultures performed on fresh tissues. However, molecular techniques such as pan-fungal polymerase chain reaction on paraffin blocks is becoming an increasingly useful tool to distinguish between cutaneous fungal pathogens. This review focuses on describing the clinical and histologic features of the most common fungal and oomycete infections affecting the skin of animals, divided according to distribution patterns of lesions and fungal or oomycete morphology.
