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Veterinary Dermatology Apr 2020Elevated immunoglobulin E (IgE) levels to Malassezia or Staphylococcus species in human atopic dermatitis are related to the skin severity index; a similar association...
BACKGROUND
Elevated immunoglobulin E (IgE) levels to Malassezia or Staphylococcus species in human atopic dermatitis are related to the skin severity index; a similar association has not been reported in atopic dogs.
OBJECTIVES
To investigate serum levels of allergen-specific IgE, total specific IgG and IgG subclasses (IgG1 and IgG2) for M. pachydermatis and S. pseudintermedius, and to correlate them with the severity of dermatitis in dogs.
ANIMALS
Serum samples were collected from dogs categorized by age and disease status. Groups 1 and 2: <3-year-old healthy (n = 9) and atopic dogs (n = 9), respectively; and groups 3 and 4: ≥3-year-old healthy (n = 11) and atopic dogs (n = 14), respectively.
METHODS AND MATERIALS
Antibody levels were measured by ELISA. The Canine Atopic Dermatitis Lesion Index (CADLI) was analyzed in relation to antibody levels.
RESULTS
Specific IgE and total IgG against M. pachydermatis and S. pseudintermedius were significantly increased in atopic dogs of all ages. Although differences between atopic and healthy dogs, with regard to specific IgG1 and IgG2 levels to each microbe, varied in significance within age groups. No significant relationships were found between the CADLI and any specific immunoglobulin levels for both microbe types.
CONCLUSIONS AND CLINICAL IMPORTANCE
In dog skin, microbes may act as allergens triggering inflammatory responses via IgE- and IgG-dependent pathway(s). The affinity of the IgG subclass produced may vary according to antigen type. Specific IgE levels may be related to clinical disease in dogs and not to skin lesion severity.
Topics: Animals; Antibodies, Bacterial; Antibodies, Fungal; Dermatitis, Atopic; Dermatomycoses; Dog Diseases; Dogs; Immunoglobulin E; Immunoglobulin G; Malassezia; Skin; Skin Tests; Staphylococcal Skin Infections; Staphylococcus
PubMed: 31696563
DOI: 10.1111/vde.12802 -
The Journal of Small Animal Practice Jul 2023To culture Malassezia and other fungi from the duodenum of dogs with gastrointestinal signs undergoing routine endoscopic examination.
OBJECTIVES
To culture Malassezia and other fungi from the duodenum of dogs with gastrointestinal signs undergoing routine endoscopic examination.
MATERIALS AND METHODS
Quantitative microbial culture was performed on duodenal juice aspirated from dogs with suspected enteropathy during routine upper gastrointestinal endoscopy; samples were cultured on Sabouraud's dextrose agar (30, 32 and 37°C) and modified Dixon agar (32°C) for 14 days. Isolates were identified phenotypically and by matrix-assisted laser desorption ionisation-time of flight, and internal transcribed spacer sequencing. Yeast presence was also evaluated by cytological and histopathological examination of smears and biopsy specimens.
RESULTS
Forty-five dogs were recruited with chronic inflammatory enteropathy (n=38), granulomatous colitis (n=2), gastric adenocarcinoma (n=2), duodenal small cell lymphoma (n=1) and idiopathic severe gastrointestinal haemorrhage (n=2). Fungi were cultured from 14 dogs: Malassezia pachydermatis was isolated from eight [chronic inflammatory enteropathy (n=7) (along with Candida albicans n=1); granulomatous colitis (n=1)] and Malassezia sympodialis from another (gastric adenocarcinoma). Five dogs with chronic inflammatory enteropathy yielded other yeasts (C. albicans, Candida glabrata, Kazachstania slooffiae, Kazachstania telluris, Pichia kudriavzevii [syn. C. krusei]). Yeasts were never observed in histopathological specimens. Fluorescent microscopical examination of cytological specimens showed yeast in only one case, from which K. slooffiae was subsequently isolated.
CLINICAL SIGNIFICANCE
Based on a literature search, this is the first report of isolation of M. pachydermatis, M. sympodialis, K. slooffiae and K. telluris from the canine duodenum. Further studies are needed to determine whether these are resident or transient fungi in the canine duodenum and whether their presence has a pathogenic effect on the host.
PubMed: 37681754
DOI: 10.1111/jsap.13649 -
Veterinary Research Communications Jun 2024Extracellular phospholipase (EPL) plays an important role in the pathogenesis of the yeast Malassezia pachydermatis. Currently, the attention of researchers is focused...
Extracellular phospholipase (EPL) plays an important role in the pathogenesis of the yeast Malassezia pachydermatis. Currently, the attention of researchers is focused on studying the virulence factors involved in this process and searching solutions to reduce their activity. One of the options is the use of natural remedies as anti-virulence agents. This study is aimed at investigating the production of extracellular phospholipase in M. pachydermatis strains (18 samples) and followed by the time-dependent inhibitory effect of selected azole antifungals (itraconazole, posaconazole and voriconazole) and plant essential oil components (terpinen-4-ol, thymol, carvacrol, eugenol and geraniol), evaluated by Egg Yolk Agar plate method. Almost all strains (17 isolates, (94.4%) were found to be intense EPL producers. A significant, time-dependent inhibition of EPL was noted after 1-, 3- and 6-h exposure of Malassezia cells to itraconazole (26.4%, 47.2% and 50.9%, respectively) compared to exposure to posaconazole (26.4%, 28.3% and 28.3%, respectively) and voriconazole (18.8%, 20.8% and 35.8%, respectively). After one-hour exposure to plant essential oil components, the best inhibitory effect was recorded for eugenol (62.3%), followed by terpinen-4-ol and thymol (56.6%), geraniol (41.5%) and carvacrol (26.4%). A 3-h exposure revealed that thymol retained the best inhibitory effect (88.7%) on EPL production, followed by carvacrol (73.6%), eugenol (56.6%), terpinen-4-ol (52.8%) and geraniol (49.1%). After 6-h exposure, no growth of M. pachydermatis strains exposed to carvacrol was observed, and the inhibitory efficiency for the other tested essential oil (EO) components achieved 88.7%. The obtained results indicate the promising efficacy of plant essential oils components in the inhibition of virulence factors such as EPL production.
PubMed: 38922388
DOI: 10.1007/s11259-024-10446-5 -
Journal de Mycologie Medicale Mar 2023Phagocytic responses are critical for effective host defense against opportunistic fungal pathogens, such as Encephalitozoon cuniculi, an obligate intracellular fungus...
Phagocytic responses are critical for effective host defense against opportunistic fungal pathogens, such as Encephalitozoon cuniculi, an obligate intracellular fungus that causes emerging encephalitozoonosis in humans and other animals. Malassezia has immunomodulatory effects and can modulate the production of pro- and anti-inflammatory cytokines via keratinocytes and human monocytes. In this study, we evaluated the modulatory effects of heat-killed Malassezia pachydermatis suspension on macrophages challenged with Encephalitozoon cuniculi. Macrophages were treated with heat-killed M. pachydermatis suspension before being infected with spores of E. cuniculi. The cultures were stained with calcofluor, and the spores, internalized or not, were counted to determine their phagocytic capacity and index (PC and PI, respectively). Microbicidal and phagocytic activities were evaluated by transmission electron microscopy (TEM). The untreated macrophages had higher PC and PI and number of phagocytosed spores than treated macrophages. However, TEM revealed that treated macrophages had higher microbicidal activity because there were few spores in different degrees of degeneration and amorphous materials in the phagocytic vacuoles. Macrophages treated with heat-killed M. pachydermatis suspension had lower PC and PI and incipient presence of E. cuniculi in phagosomes. Treated macrophages had a mixed pattern of cytokine release with Th1, Th2, and Th17 profiles, with emphasis on interleukin (IL)-10, IL-4, IL-17, IL-6, and interferon (IFN)-γ secretion, and particularly high production of anti-inflammatory cytokines. Our results suggest that treatment with heat-killed M. pachydermatis suspension increases the release of cytokines and decreases the phagocytic activity of macrophages challenged with E. cuniculi.
Topics: Animals; Humans; Malassezia; Encephalitozoon cuniculi; Hot Temperature; Macrophages; Cytokines
PubMed: 36306561
DOI: 10.1016/j.mycmed.2022.101338 -
Frontiers in Cellular and Infection... 2020and are lipophilic and lipid dependent yeasts, associated with the skin microbiota in humans and domestic animals, respectively. Although they are commensals, under...
and are lipophilic and lipid dependent yeasts, associated with the skin microbiota in humans and domestic animals, respectively. Although they are commensals, under specific conditions they become pathogens, causing skin conditions, such as pityriasis versicolor, dandruff/seborrheic dermatitis, folliculitis in humans, and dermatitis and otitis in dogs. Additionally, these species are associated with fungemia in immunocompromised patients and low-weight neonates in intensive care units with intravenous catheters or with parenteral nutrition and that are under-treatment of broad-spectrum antibiotics. The host-pathogen interaction mechanism in these yeasts is still unclear; for this reason, it is necessary to implement suitable new host systems, such as . This infection model has been widely used to assess virulence, host-pathogen interaction, and antimicrobial activity in bacteria and fungi. Some advantages of the model are: (1) the immune response has phagocytic cells and antimicrobial peptides that are similar to those in the innate immune response of human beings; (2) no ethical implications; (3) low cost; and (4) easy to handle and inoculate. This study aims to establish as an infection model for and . To achieve this objective, first, larvae were first inoculated with different inoculum concentrations of these two species, 1.5 × 10 CFU/mL, 1.5 × 10 CFU/mL, 1.5 × 10 CFU/mL, and 11.5 × 10 CFU/mL, and incubated at 33 and 37°C. Then, for 15 days, the mortality and melanization were evaluated daily. Finally, the characterization of hemocytes and fungal burden assessment were as carried out. It was found that at 33 and 37°C both and successfully established a systemic infection in . proved to be slightly more virulent than at a temperature of 37°C. The results suggest that larvae mortality and melanization is dependent on the specie of , the inoculum concentration and the temperature. According to the findings, can be used as an model of infection to conduct easy and reliable approaches to boost our knowledge of the genus.
Topics: Animals; Dandruff; Dogs; Host-Pathogen Interactions; Humans; Malassezia; Skin
PubMed: 32432057
DOI: 10.3389/fcimb.2020.00199 -
Medical Mycology Nov 2018Cytochrome P450 CYP1A1 and CYP1B1 enzymes are regulated by the aryl hydrocarbon receptor (AhR), a transcription factor activated by a variety of ligands among which...
Cytochrome P450 CYP1A1 and CYP1B1 enzymes are regulated by the aryl hydrocarbon receptor (AhR), a transcription factor activated by a variety of ligands among which Malassezia metabolites. In this study, we analyzed the modulation of CYP1A1, CYP1B1, and AhR in human keratinocytes infected with different strains of Malassezia pachydermatis, as well as the upregulation of some genes involved in the epidermal homeostasis. We demonstrated that all the strains induced AhR activation and its nuclear translocation in HaCaT cells infected for 24 h, compared to untreated cells. The expression of CYP1A1 and CYP1B1, prototypical markers of the AhR signaling pathway, were upregulated with the level of CYP1A1 mRNA approximately 100-fold greater than that for CYP1B1. Filaggrin, involucrin, and TGaseI, proteins involved in epidermal differentiation, were all modulated by Malassezia pachydermatis strains, with the strongest induction observed for filaggrin. By contrast, quinone oxidoreductase 1 (NQO1), which is part of the antioxidant defense system involved in detoxification, was not modulated in our experimental model. In conclusions, our findings suggest that Malassezia pachydermatis infection of human keratinocytes induces activation of the AhR, and increases the expression of its responsive genes and markers of epidermal differentiation, paving the way for occurrence/exacerbation of pathological skin conditions.
Topics: Basic Helix-Loop-Helix Transcription Factors; Cell Line; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP1B1; Filaggrin Proteins; Gene Expression Profiling; Humans; Keratinocytes; Malassezia; RNA, Messenger; Receptors, Aryl Hydrocarbon; Transcription, Genetic
PubMed: 29462476
DOI: 10.1093/mmy/myy004 -
Pathogens (Basel, Switzerland) Jan 2023Canine atopic dermatitis (CAD) is a common, chronic, inflammatory skin disease in dogs worldwide. This disease often predisposes for secondary organisms overgrowth and... (Review)
Review
Canine atopic dermatitis (CAD) is a common, chronic, inflammatory skin disease in dogs worldwide. This disease often predisposes for secondary organisms overgrowth and skin infections with pathogens, such as and . Unfortunately, the causes of this disease in both humans and animals are not fully understood; therefore, the only possible option is a lifelong, symptomatic treatment. The management of CAD is mainly based on limiting contact with allergens and antipruritic therapy, most often with glucocorticoids and antihistamines. A serious problem in this situation is the fact, that long-term administration of glucocorticoids leads to side effects like polyuria, alopecia, increased susceptibility to infection, muscle atrophy, and many others. For this reason, great emphasis is placed on the development of replacement and supportive therapies. It is a well-documented fact that reduced concentrations of serum vitamin D3 contribute to the severity of atopic dermatitis symptoms in humans. Moreover, unlike the most commonly used therapeutic methods, of which the main goal is to ameliorate inflammation and pruritus, namely the symptoms of AD, vitamin D3 supplementation affects some underlying factors of this disease. Therefore, in this review, we summarize the current state of knowledge regarding the role of vitamin D3 in CAD, its protective effect against secondary bacterial and fungal infections, and the potential of its supplementation in dogs.
PubMed: 36678493
DOI: 10.3390/pathogens12010145 -
Medical Mycology Case Reports Dec 2015A 13-year-old female Lhasa Apso was presented for blepharospasm and conjunctival hyperemia of the right eye. Ophthalmic examination revealed an anterior stromal ulcer...
A 13-year-old female Lhasa Apso was presented for blepharospasm and conjunctival hyperemia of the right eye. Ophthalmic examination revealed an anterior stromal ulcer associated with a raised yellow corneal plaque. In vivo confocal microscopy and cytology of the cornea identified neutrophilic inflammation and yeast cells. Malassezia pachydermatis was isolated from a corneal scraping. Treatment with topical voriconazole ophthalmic solution resolved the keratitis.
PubMed: 26909245
DOI: 10.1016/j.mmcr.2016.01.001 -
Veterinary Research Communications Jun 2023The yeast Malassezia pachydermatis is a common inhabitant of the skin and mucosae of dogs. However, under certain circumstances this yeast can overgrow and act as an...
The yeast Malassezia pachydermatis is a common inhabitant of the skin and mucosae of dogs. However, under certain circumstances this yeast can overgrow and act as an opportunistic pathogen causing otitis and dermatitis in dogs. Canine pododermatitis is a common disorder in dogs in which M. pachydermatis acts as an opportunistic pathogen. In the present study, the presence of Malassezia yeasts was assessed and quantified in samples collected from the interdigital space of dogs with pododermatitis before and after treatment, and from healthy dogs. The samples were subjected to two different cytological examinations, culture on Sabouraud glucose agar and modified Dixon's agar and a quantitative PCR targeting the internal transcribed spacer (ITS) genomic region. A selection of samples was analyzed by next generation sequencing (NGS) using the D1D2 domain of the large subunit of the ribosomal DNA as target. The pododermatitis samples before treatment showed higher cell counts, colony-forming units and ITS copies than the rest of samples. The NGS analysis revealed that Ascomycota was the main phylum in the healthy and post-treatment samples. However, Basidiomycota and M. pachydermatis was more abundant in the pododermatitis samples before treatment. These results support M. pachydermatis as an opportunistic agent in canine pododermatitis by a variety of methods, and demonstrate the correlation between cytologic and molecular methods for quantification.
Topics: Animals; Dogs; Malassezia; Saccharomyces cerevisiae; Agar; Dog Diseases; Dermatitis
PubMed: 35704160
DOI: 10.1007/s11259-022-09951-2 -
Mycologia 2019causes infections of the skin and mucous membranes, especially in individuals with metabolic, hormonal, and immunological disorders. The search for properties that...
causes infections of the skin and mucous membranes, especially in individuals with metabolic, hormonal, and immunological disorders. The search for properties that differentiate isolates from healthy and infected animals may result in the identification of typically commensal and potentially pathogenic strains within the entire species. We aimed to determine and compare protein profiles of strains isolated from 30 dogs with clinical symptoms of otitis externa and 34 dogs without symptoms of any disease. Two-dimensional gel electrophoresis was applied, and proteins distinguishing the two groups of strains were identified by liquid chromatography coupled with tandem mass spectrometry. Significant differences were found between potentially pathogenic and commensal isolates. The most significant finding was the presence of nicotinamide adenine dinucleotide phosphate (NADP)-dependent mannitol dehydrogenase and ketol-acid reductoisomerase among strains obtained from dogs with otitis externa. Nevertheless, it is not clear whether they are associated directly with the pathogenicity or they play the role of fungal allergen. On the basis of these findings, we can conclude that there may be two distinct groups of strains-one typically commensal and the other with properties that enhance the infection process. These results may be used for more precise diagnosis and identification of potentially pathogenic strains in the future.
Topics: Animals; Dermatomycoses; Dog Diseases; Dogs; Electrophoresis, Gel, Two-Dimensional; Fungal Proteins; Malassezia; Otitis Externa
PubMed: 31322986
DOI: 10.1080/00275514.2019.1630244