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Posadas J, Velez P, Pajares S, Gasca-Pineda J, Espinosa-Asuar L. Fungal diversity in sediments of the eastern tropical Pacific oxygen minimum zone revealed by metabarcoding. PLoS One 2024; 19:e0301605. [PMID: 38739592 PMCID: PMC11090300 DOI: 10.1371/journal.pone.0301605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 03/19/2024] [Indexed: 05/16/2024] Open
Abstract
Oxygen minimum zones (OMZ) represent ~8% of the ocean, with the Pacific as the largest and top expanding area. These regions influence marine ecosystems, promoting anaerobic microbial communities. Nevertheless, only a fraction of microbial diversity has been studied, with fungi being the less explored component. So, herein we analyzed fungal diversity patterns in surface and subsurface sediments along a bathymetric transect using metabarcoding of the ITS1 region in the OMZ of the Mexican Pacific off Mazatlán. We identified 353 amplicon sequence variants (ASV), within the Ascomycota, Basidiomycota, and Rozellomycota. Spatial patterns evidenced higher alpha diversity in nearshore and subsurface subsamples, probably due to temporal fluctuations in organic matter inputs. Small-scale heterogeneity characterized the community with the majority of ASV (269 ASV) occurring in a single subsample, hinting at the influence of local biogeochemical conditions. This baseline data evidenced a remarkable fungal diversity presenting high variation along a bathymetric and vertical transects.
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Affiliation(s)
- Judith Posadas
- Posgrado en Ciencias del Mar y Limnología, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Patricia Velez
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Silvia Pajares
- Unidad Académica de Ecología y Biodiversidad Acuática, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Jaime Gasca-Pineda
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Laura Espinosa-Asuar
- Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Hobi S, Bęczkowski PM, Mueller R, Tse M, Barrs VR. Malassezia dermatitis in dogs and cats. Vet J 2024; 304:106084. [PMID: 38431127 DOI: 10.1016/j.tvjl.2024.106084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 02/16/2024] [Accepted: 02/18/2024] [Indexed: 03/05/2024]
Abstract
Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce a secondary Malassezia dermatitis, otitis externa or paronychia. Since allergic dermatitis is one of the most common underlying causes, diagnostic investigation for allergy is often indicated. Cats may suffer from various other underlying problems, especially where Malassezia dermatitis is generalised. Malassezia dermatitis in dogs and cats is chronic, relapsing and pruritic. Direct cytology from dermatological lesions and the ear canal, showing "peanut-shaped" budding yeasts, facilitates a rapid and reliable diagnosis. Topical treatment includes antiseptic and antifungal azole-based products. Systemic treatment with oral antifungals is indicated only in severe or refractory disease. Identification and treatment of the underlying cause is essential for an optimal response. In this evidence-based narrative review, we discuss the clinical presentation of Malassezia dermatitis in dogs and cats, underlying comorbidities, and diagnostic considerations. Treatment is discussed in light of emerging evidence of antifungal resistance and the authors' clinical experience.
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Affiliation(s)
- Stefan Hobi
- Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong Administrative Region of China.
| | - Paweł M Bęczkowski
- Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong Administrative Region of China
| | - Ralf Mueller
- LMU Small Animal Clinic, University of Munich, Munich, Germany
| | - May Tse
- Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong Administrative Region of China
| | - Vanessa R Barrs
- Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong Administrative Region of China; Centre for Animal Health and Welfare, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong Administrative Region of China
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Garcia-Bustos V, Acosta-Hernández B, Cabañero-Navalón MD, Pemán J, Ruiz-Gaitán AC, Rosario Medina I. The Ecology of Non- Candida Yeasts and Dimorphic Fungi in Cetaceans: From Pathogenicity to Environmental and Global Health Implications. J Fungi (Basel) 2024; 10:111. [PMID: 38392783 PMCID: PMC10889755 DOI: 10.3390/jof10020111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/20/2024] [Accepted: 01/24/2024] [Indexed: 02/24/2024] Open
Abstract
Cetaceans, which are integral to marine ecosystems, face escalating anthropogenic threats, including climate change and pollution, positioning them as critical sentinel species for ocean and human health. This review explores the neglected realm of non-Candida yeasts in cetaceans, addressing the gaps in the understanding of their prevalence, pathogenicity, and environmental impacts. By examining identified species such as Cryptococcus spp., Paracoccidioides spp., and several dimorphic fungi, this review emphasizes global prevalence, epidemiology and ecology, pathogenicity, and potential zoonotic implications. It also discusses the fine line between yeast commensalism and pathogenicity by considering environmental influences such as pollution, climate shifts, and immune suppression. Environmental impact discussions delve into how rising ocean temperatures and pollution can modify yeast mycobiota, potentially affecting marine host health and broader ecosystem dynamics. The cetacean's unique physiology and ecological niches are considered, highlighting potential impacts on behaviors, reproductive success, and survival rates. Identifying crucial knowledge gaps, the review calls for intensified research efforts, employing advanced molecular techniques to unravel the cetacean mycobiome. Systematic studies on yeast diversity, antifungal susceptibility, and their influence on environmental and ecosystem health are proposed, and the balance between commensal and pathogenic species emphasizes the significance of the One Health approach. In conclusion, as marine mammals face unprecedented challenges, unveiling non-Candida yeasts in cetaceans emerges as a critical endeavor with far-reaching implications for the conservation of marine ecosystems and for both animal and human public health.
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Affiliation(s)
- Victor Garcia-Bustos
- Universitary Institute of Animal Health and Food Security (ULPGC-IUSA), University of Las Palmas de Gran Canaria, 35416 Arucas, Spain
- Severe Infection Research Group, Health Research Institute La Fe, 46026 Valencia, Spain
| | - Begoña Acosta-Hernández
- Universitary Institute of Animal Health and Food Security (ULPGC-IUSA), University of Las Palmas de Gran Canaria, 35416 Arucas, Spain
| | | | - Javier Pemán
- Severe Infection Research Group, Health Research Institute La Fe, 46026 Valencia, Spain
| | | | - Inmaculada Rosario Medina
- Universitary Institute of Animal Health and Food Security (ULPGC-IUSA), University of Las Palmas de Gran Canaria, 35416 Arucas, Spain
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Vanderwolf K, Kyle C, Davy C. A review of sebum in mammals in relation to skin diseases, skin function, and the skin microbiome. PeerJ 2023; 11:e16680. [PMID: 38144187 PMCID: PMC10740688 DOI: 10.7717/peerj.16680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 11/24/2023] [Indexed: 12/26/2023] Open
Abstract
Diseases vary among and within species but the causes of this variation can be unclear. Immune responses are an important driver of disease variation, but mechanisms on how the body resists pathogen establishment before activation of immune responses are understudied. Skin surfaces of mammals are the first line of defense against abiotic stressors and pathogens, and skin attributes such as pH, microbiomes, and lipids influence disease outcomes. Sebaceous glands produce sebum composed of multiple types of lipids with species-specific compositions. Sebum affects skin barrier function by contributing to minimizing water loss, supporting thermoregulation, protecting against pathogens, and preventing UV-induced damage. Sebum also affects skin microbiome composition both via its antimicrobial properties, and by providing potential nutrient sources. Intra- and interspecific variation in sebum composition influences skin disease outcomes in humans and domestic mammal species but is not well-characterized in wildlife. We synthesized knowledge on sebum function in mammals in relation to skin diseases and the skin microbiome. We found that sebum composition was described for only 29 live, wild mammalian species. Sebum is important in dermatophilosis, various forms of dermatitis, demodicosis, and potentially white-nose syndrome. Sebum composition likely affects disease susceptibility, as lipid components can have antimicrobial functions against specific pathogens. It is unclear why sebum composition is species-specific, but both phylogeny and environmental effects may drive differences. Our review illustrates the role of mammal sebum function and influence on skin microbes in the context of skin diseases, providing a baseline for future studies to elucidate mechanisms of disease resistance beyond immune responses.
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Affiliation(s)
- Karen Vanderwolf
- Department of Environmental and Life Sciences, Trent University, Peterborough, Ontario, Canada
| | - Christopher Kyle
- Forensic Science Department, Trent University, Peterborough, Ontario, Canada
- Natural Resources DNA Profiling and Forensics Center, Trent University, Peterborough, Ontario, Canada
| | - Christina Davy
- Department of Environmental and Life Sciences, Trent University, Peterborough, Ontario, Canada
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
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Hobi S, Cafarchia C, Romano V, Barrs VR. Malassezia: Zoonotic Implications, Parallels and Differences in Colonization and Disease in Humans and Animals. J Fungi (Basel) 2022; 8:jof8070708. [PMID: 35887463 PMCID: PMC9324274 DOI: 10.3390/jof8070708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 12/13/2022] Open
Abstract
Malassezia spp. are commensals of the skin, oral/sinonasal cavity, lower respiratory and gastrointestinal tract. Eighteen species have been recovered from humans, other mammals and birds. They can also be isolated from diverse environments, suggesting an evolutionary trajectory of adaption from an ecological niche in plants and soil to the mucocutaneous ecosystem of warm-blooded vertebrates. In humans, dogs and cats, Malassezia-associated dermatological conditions share some commonalities. Otomycosis is common in companion animals but is rare in humans. Systemic infections, which are increasingly reported in humans, have yet to be recognized in animals. Malassezia species have also been identified as pathogenetic contributors to some chronic human diseases. While Malassezia species are host-adapted, some species are zoophilic and can cause fungemia, with outbreaks in neonatal intensive care wards associated with temporary colonization of healthcare worker’s hands from contact with their pets. Although standardization is lacking, susceptibility testing is usually performed using a modified broth microdilution method. Antifungal susceptibility can vary depending on Malassezia species, body location, infection type, disease duration, presence of co-morbidities and immunosuppression. Antifungal resistance mechanisms include biofilm formation, mutations or overexpression of ERG11, overexpression of efflux pumps and gene rearrangements or overexpression in chromosome 4.
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Affiliation(s)
- Stefan Hobi
- Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University, Tat Chee Avenue, Kowloon, Hong Kong, China
- Correspondence: (S.H.); (V.R.B.)
| | - Claudia Cafarchia
- Department of Veterinary Medicine, University of Bari, Str. prov. per Casamassima Km 3, Valenzano, (Bari), 70010, Italy; (C.C.); (V.R.)
| | - Valentina Romano
- Department of Veterinary Medicine, University of Bari, Str. prov. per Casamassima Km 3, Valenzano, (Bari), 70010, Italy; (C.C.); (V.R.)
| | - Vanessa R. Barrs
- Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University, Tat Chee Avenue, Kowloon, Hong Kong, China
- Centre for Animal Health and Welfare, City University of Hong Kong, Kowloon Tong, Hong Kong, China
- Correspondence: (S.H.); (V.R.B.)
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High-throughput amplicon sequencing of fungi and microbial eukaryotes associated with the seagrass Halophila stipulacea (Forssk.) Asch. from Al-Leith mangroves, Saudi Arabia. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01744-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Fusariosis in a Captive South American Sea Lion (Otaria flavescens): A Case Report. Mycopathologia 2018; 184:187-192. [PMID: 29761326 DOI: 10.1007/s11046-018-0270-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/03/2018] [Indexed: 10/16/2022]
Abstract
Superficial mycoses are commonly reported in captive pinnipeds, usually maintained in wet and warm environments, favorable to fungal growth. Most superficial mycoses in pinnipeds have been described as difficult to treat; however, the majority of the reports come from past decades. Cutaneous lesions associated with opportunistic Fusarium sp. infections have been previously recognized in this taxon. We described the clinical signs, associated lesions and diagnosis (thermography, imprint cytology, histopathology, culture, electron microscopy, PCR) of a fusariosis case by Fusarium sp. in the nails and skin of an adult male captive South American sea lion (Otaria flavescens) recently transferred from another zoological institution, and its successful long-term treatment with Ketoconazole PO (60 days) and Miconazole solution spray TO, followed by Itraconazole PO (30 days). Herein we provide a successful approach to the diagnosis and treatment of fusariosis.
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Malassezia vespertilionis sp. nov.: a new cold-tolerant species of yeast isolated from bats. Persoonia - Molecular Phylogeny and Evolution of Fungi 2018; 41:56-70. [PMID: 30728599 PMCID: PMC6344816 DOI: 10.3767/persoonia.2018.41.04] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 11/28/2017] [Indexed: 11/30/2022]
Abstract
Malassezia is a genus of medically-important, lipid-dependent yeasts that live on the skin of warm-blooded animals. The 17 described species have been documented primarily on humans and domestic animals, but few studies have examined Malassezia species associated with more diverse host groups such as wildlife. While investigating the skin mycobiota of healthy bats, we isolated a Malassezia sp. that exhibited only up to 92% identity with other known species in the genus for the portion of the DNA sequence of the internal transcribed spacer region that could be confidently aligned. The Malassezia sp. was cultured from the skin of nine species of bats in the subfamily Myotinae; isolates originated from bats sampled in both the eastern and western United States. Physiological features and molecular characterisation at seven additional loci (D1/D2 region of 26S rDNA, 18S rDNA, chitin synthase, second largest subunit of RNA polymerase II, β-tubulin, translation elongation factor EF-1α, and minichromosome maintenance complex component 7) indicated that all of the bat Malassezia isolates likely represented a single species distinct from other named taxa. Of particular note was the ability of the Malassezia sp. to grow over a broad range of temperatures (7–40 °C), with optimal growth occurring at 24 °C. These thermal growth ranges, unique among the described Malassezia, may be an adaptation by the fungus to survive on bats during both the host's hibernation and active seasons. The combination of genetic and physiological differences provided compelling evidence that this lipid-dependent yeast represents a novel species described herein as Malassezia vespertilionis sp. nov. Whole genome sequencing placed the new species as a basal member of the clade containing the species M. furfur, M. japonica, M. obtusa, and M. yamatoensis. The genetic and physiological uniqueness of Malassezia vespertilionis among its closest relatives may make it important in future research to better understand the evolution, life history, and pathogenicity of the Malassezia yeasts.
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Nagahama T, Nagano Y. Cultured and uncultured fungal diversity in deep-sea environments. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2016; 53:173-87. [PMID: 22222832 DOI: 10.1007/978-3-642-23342-5_9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The importance of fungi found in deep-sea extreme environments is becoming increasingly recognized. In this chapter, current scientific findings on the fungal diversity in several deep-sea environments by conventional culture and culture-independent methods are reviewed and discussed, primarily focused on culture-independent approaches. Fungal species detected by conventional culture methods mostly belonged to Ascomycota and Basidiomycota phyla. Culture-independent approaches have revealed the presence of highly novel fungal phylotypes, including new taxonomic groups placed in deep branches within the phylum Chytridiomycota and unknown ancient fungal groups. Future attempts to culture these unknown fungal groups may provide key insights into the early evolution of fungi and their ecological and physiological significance in deep-sea environments.
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Affiliation(s)
- Takahiko Nagahama
- Department of Food and Nutrition, Higashi-Chikushi Junior College, 5-1-1 Shimoitozu, Kokurakita-ku, Kitakyusyu, Fukuoka, 800-0351, Japan,
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A CASE OF TRYCHOPHYTON RUBRUM DERMATOPHYTOSIS IN A PATAGONIAN SEA LION (OTARIA BYRONIA). J Zoo Wildl Med 2015; 46:621-3. [PMID: 26352974 DOI: 10.1638/2014-0214.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A 23-yr old female Patagonian sea lion (Otaria byronia) presented multifocal to coalescing and ulcerative skin lesions on the lumbar region. Skin scrapings were collected and a microscopic examination was conducted followed by a fungal culture that revealed a Trychophyton rubrum infection, an anthropophilic dermatophytosis agent. Oral terbinafine and topical eniconazole were used as a treatment for a period of 75 days and complete recovery was achieved. Epidemiological analysis revealed a dermatophytosis case in one of the carnivore section keepers a few weeks before the lesions were diagnosed in the sea lion.
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Successfully treated dermatomycosis in California sea lions (Zalophus californianus). J Zoo Wildl Med 2013; 44:462-5. [PMID: 23805567 DOI: 10.1638/2011-0275r1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We describe clinical cases caused by Microsporum gypseum in two subadult male California sea lions (Zalophus californianus). Dermatomycosis is uncommonly reported in pinnipeds, including this species. In these cases, skin lesions were multifocal to coalescing, involved all flippers, and were most pronounced on the ventral surfaces of flippers. They were well-demarcated, depigmented, and covered with crusts. The definitive diagnosis was obtained through microscopic examination and fungal culture of skin scrapings. Oral terbinafine and topical enilconazole were used as treatments for 65 days, and complete recovery was subsequently achieved. California sea lion, dermatomycosis, Microsporum gypseum, terbinafine, enilconazole
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Systemic mycosis in a California sea lion (Zalophus californianus) with detection of cystofilobasidiales DNA. J Zoo Wildl Med 2012; 43:144-52. [PMID: 22448522 DOI: 10.1638/2011-0187.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A 6-yr-old, intact male California sea lion (Zalophus californianus) with a systemic mycosis died after 5 wk of antifungal drug therapy. Antemortem clinical findings included hind flipper swelling, ring-lesions on skin of the flippers, and dermal nodules that increased in size and number spreading from the hind flippers and ventral abdomen to the foreflippers and muzzle. Lesions were accompanied by severe lymphadenopathy and development of systemic clinical signs despite therapy using itraconazole and later voriconazole. Histopathologic evaluation of biopsies revealed granulomatous dermatitis due to infection by fungus-producing yeast cells in tissue. Isolation attempts, using biopsied skin and tissue samples collected at necropsy, failed to yield growth of a fungus producing yeast cells like those in histologic section. Consensus polymerase chain reaction (PCR) tests of biopsied skin for fungal DNA produced an amplicon having significant sequence identity with a Cystofilobasidiales, a fungus belonging to a subclade that includes several Cryptococcus spp. Histopathologic evaluation of necropsy tissues revealed a systemic mycosis with yeast cells disseminated throughout subcutis, lymph nodes, and viscera. Hepatic necrosis was identified associated with acute liver failure, possibly from the voriconazole administration. This is the first report documenting the clinical presentation, treatment, and pathologic findings of infection associated with Cystofilobasidiales in a marine mammal and serves to expand the understanding of mycoses in pinnipeds.
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Nagahama T, Takahashi E, Nagano Y, Abdel-Wahab MA, Miyazaki M. Molecular evidence that deep-branching fungi are major fungal components in deep-sea methane cold-seep sediments. Environ Microbiol 2011; 13:2359-70. [PMID: 21605311 DOI: 10.1111/j.1462-2920.2011.02507.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The motile cells of chytrids were once believed to be relics from the time before the colonization of land by fungi. However, the majority of chytrids had not been found in marine but freshwater environments. We investigated fungal diversity by a fungal-specific PCR-based analysis of environmental DNA in deep-sea methane cold-seep sediments, identifying a total of 35 phylotypes, 12 of which were early diverging fungi (basal fungi, ex 'lower fungi'). The basal fungi occupied a major portion of fungal clones. These were phylogenetically placed into a deep-branching clade of fungi and the LKM11 clade that was a divergent group comprised of only environmental clones from aquatic environments. As suggested by Lara and colleagues, species of the endoparasitic genus Rozella, being recently considered of the earliest branching taxa of fungi, were nested within the LKM11 clade. In the remaining 23 phylotypes identified as the Dikarya, the majority of which were similar to those which appeared in previously deep-sea studies, but also highly novel lineages associated with Soil Clone Group I (SCGI), Entorrhiza sp. and the agaricomycetous fungi were recorded. The fungi of the Dikarya may play a role in the biodegradation of lignin and lignin-derived materials in deep-sea, because the characterized fungal species related to the frequent phylotypes within the Dikarya have been reported to possess an ability to degrade lignin.
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Affiliation(s)
- Takahiko Nagahama
- Department of Foods and Human Nutrition, Higashi-Chikushi Junior College, 5-1-1 Shimoitozu, Kokurakita-ku, Kitakyusyu, 803-8511, Japan.
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Chen TA, Hill PB. The biology of Malassezia organisms and their ability to induce immune responses and skin disease. Vet Dermatol 2005; 16:4-26. [PMID: 15725101 DOI: 10.1111/j.1365-3164.2005.00424.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tai-An Chen
- Division of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, UK
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Prado MR, Brito EHS, Girão MD, Monteiro AJ, Sidrim JJC, Rocha MFG. Higher incidence of Malassezia pachydermatis in the eyes of dogs with corneal ulcer than in healthy dogs. Vet Microbiol 2004; 100:115-20. [PMID: 15135519 DOI: 10.1016/j.vetmic.2003.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Revised: 12/03/2003] [Accepted: 12/19/2003] [Indexed: 11/17/2022]
Abstract
Malassezia pachydermatis is usually associated with otitis and dermatitis in dogs but it can also cause diseases in other species, including humans. In a human neonatal intensive care unit, M. pachydermatis was isolated from an infant's ocular discharge. Therefore, the aim of this study was to ascertain the presence of Malassezia spp. and its possible consequences in dogs' eyes. This research included 19 dogs with unilateral or bilateral corneal ulcers and 60 healthy dogs. A total of 158 clinical specimens from both the groups were obtained from the conjunctival sac of each eye by a calibrated platinum loop. The samples were placed on Dixon and blood agar, incubated at 35 degrees C, and examined daily for 15 days. Then, the strains were subcultured on Sabouraud agar. Of 22 clinical specimens collected from the eyes with corneal ulcers, five cultures (23%) were positive for M. pachydermatis. Of 16 samples collected from the contralateral healthy eye, cultures were positive in three samples (19%). Three animals had unilateral corneal ulcer and positive cultures for M. pachydermatis in both the eyes. Two dogs had unilateral corneal ulcer and positive cultures for M. pachydermatis in the same eye. However, from the 120 samples of 60 healthy dogs, only four clinical specimens (3%) had positive cultures for M. pachydermatis. The findings of M. pachydermatis, in a considerable percentage of clinical specimens from dogs with corneal ulcer, suggest its possible role at least as an aggravating factor in the pathophysiology of this disease.
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Affiliation(s)
- M R Prado
- School of Veterinary Medicine, Post-Graduation Program in Veterinary Science, State University of Ceará, Rua Maria Tomasia 1031, Aldeota; CEP 60.150-170 Fortaleza, Ceará, Brazil.
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Baker GC, Tow LA, Cowan DA. PCR-based detection of non-indigenous microorganisms in 'pristine' environments. J Microbiol Methods 2003; 53:157-64. [PMID: 12654487 DOI: 10.1016/s0167-7012(03)00021-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PCR-based technologies are widely employed for the detection of specific microorganisms, and may be applied to the identification of non-indigenous microorganisms in 'pristine' environments. For 'pristine' environments such as those found on the Antarctic continent, the application of these methods to the assessment of environmental contamination from human activities must be treated with caution. Issues such as the possibility of non-human dispersal of organisms, stability and survival of non-indigenous organisms in vivo, the sensitivity, reproducibility and specificity of the PCR process (and particularly primer design) and the sampling regime employed must all be considered in detail. We conclude that despite these limitations, PCR and related technologies offer enormous scope for assessment of both natural and non-indigenous microbial distributions.
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Affiliation(s)
- Gillian C Baker
- Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville, Cape Town, South Africa.
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