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Journal of Fungi (Basel, Switzerland) Nov 2018The aim of this study was to establish a ketoconazole susceptibility test for using modified Leeming⁻Notman agar (mLNA). The susceptibilities of 33 isolates obtained...
The aim of this study was to establish a ketoconazole susceptibility test for using modified Leeming⁻Notman agar (mLNA). The susceptibilities of 33 isolates obtained by modified CLSI M27-A3 method were compared with the results by disk diffusion method, which used different concentrations of ketoconazole on 6 mm diameter paper disks. Results showed that 93.9% (31/33) of the minimum inhibitory concentration (MIC) values obtained from both methods were similar (consistent with two methods within 2 dilutions). BCRC 21676 and ATCC 22019 were used to verify the results obtained from the disk diffusion and modified CLSI M27-A3 tests, and they were found to be consistent. Therefore, the current study concludes that this new novel test-using different concentrations of reagents on cartridge disks to detect MIC values against ketoconazole-can be a cost-effective, time-efficient, and less technically demanding alternative to existing methods.
PubMed: 30453525
DOI: 10.3390/jof4040126 -
Veterinary Medicine and Science Mar 2022The antifungal efficacy of cold atmospheric microwave plasma (CAMP) against Malassezia pachydermatis has not been to be evaluated.
BACKGROUND
The antifungal efficacy of cold atmospheric microwave plasma (CAMP) against Malassezia pachydermatis has not been to be evaluated.
OBJECTIVE
To examine the antifungal effects of CAMP against M. pachydermatis and its synergistic effects with chlorhexidine gluconate (CHX).
METHODS
A M. pachydermatis isolate was collected from a dog with otitis externa and Malassezia dermatitis at the Seoul National University Veterinary Medical Teaching Hospital. The antifungal effect was determined by applying CAMP to a M. pachydermatis isolate that was incubated for 3 days at 37°C. After 1, 2, 3 and 5 min of application, the efficacy of the plasma treatment was determined according to the number of colony forming units (CFUs). A mixture consisting of inoculum and CHX was applied to evaluate the synergistic effect of the plasma treatment in the same way.
RESULTS
The application of CAMP showed significant antifungal effects against M. pachydermatis. The antifungal effect of CAMP was enhanced by an increased exposure time and output power. The application of CAMP with 0.02% and 0.2% CHX resulted in lower survival rates against M. pachydermatis when compared with its sole application at 1 or 2 min.
CONCLUSIONS
The study findings demonstrate that CAMP has a potential as a new antifungal option for M. pachydermatis and has synergistic antifungal effects with CHX in vitro. Clinical applications for CAMP are necessary to assess the antifungal efficacy for patients.
Topics: Animals; Antifungal Agents; Chlorhexidine; Dog Diseases; Dogs; Humans; Malassezia; Microwaves; Plasma Gases
PubMed: 35089639
DOI: 10.1002/vms3.719 -
Veterinary Microbiology Apr 2011Canine Malassezia dermatitis (MD) is frequently treated with systemic ketoconazole (KTZ) and itaconazole (ITZ). However, the antifungal susceptibility of clinical...
Canine Malassezia dermatitis (MD) is frequently treated with systemic ketoconazole (KTZ) and itaconazole (ITZ). However, the antifungal susceptibility of clinical isolates of M. pachydermatis from dogs and cats to the azoles has not been well investigated. In the present study, the in vitro susceptibility of the standard strain (CBS1879: the neotype strain of M. pachydermatis) and 29 clinical isolates of M. pachydermatis to the azoles was measured by a modified CLSI M27-A2 test using modified Dixon medium as well as by the E-test. The minimum inhibitory concentrations (MICs) of the 30 isolates of M. pachydermatis (including the neotype strain) against KTZ and ITZ were <0.03 μg/ml by the two methods. The MICs of 1 clinical isolate (ASC-11) were 1 and 2 μg/ml against KTZ, and 2 and 8 μg/ml against ITZ, by the modified CLSI M27-A2 test and the E-test, respectively. Thus, isolate ASC-11 may be resistant to these azoles, making this the first report of a resistant isolate of M. pachydermatis to KTZ and ITZ.
Topics: Animals; Antifungal Agents; Cats; Dogs; Drug Resistance, Fungal; Itraconazole; Ketoconazole; Malassezia; Microbial Sensitivity Tests
PubMed: 21074337
DOI: 10.1016/j.vetmic.2010.10.010 -
American Journal of Veterinary Research Mar 2002To investigate the potential cell-mediated immune response of atopic dogs to the yeast Malassezia pachydermatis and to correlate it with the type-1 hypersensitivity... (Comparative Study)
Comparative Study
OBJECTIVE
To investigate the potential cell-mediated immune response of atopic dogs to the yeast Malassezia pachydermatis and to correlate it with the type-1 hypersensitivity (humoral) response of the same population of dogs.
ANIMALS
16 clinically normal dogs, 15 atopic dogs with Malassezia dermatitis, 5 atopic dogs with Malassezia otitis, and 7 atopic control (ie, without Malassezia dermatitis or otitis) dogs.
PROCEDURE
A crude extract of M pachydermatis was extracted for use as an intradermal allergy testing reagent and for stimulation of isolated peripheral blood mononuclear cells in vitro. Flow cytometry was also used to assess cell surface antigenic determinants (CD3, CD4, CD8, CD14, CD21, CD45RA, surface immunoglobulin) on peripheral blood mononuclear cells.
RESULTS
Atopic dogs with cytologic evidence of Malassezia dermatitis had an increased lymphocyte blastogenic response to crude M pachydermatis extract, compared with clinically normal dogs and dogs with Malassezia otitis. Atopic control dogs did not differ significantly in their responses from atopic dogs with Malassezia dermatitis or otitis. A significant correlation was not found between the lymphocyte blastogenic response and the type-1 hypersensitivity response to M pachydermatis within any of the groups.
CONCLUSIONS AND CLINICAL RELEVANCE
Cell-mediated and humoral reactivities to M pachydermatis contribute to the pathogenesis of atopic dermatitis in dogs but are not directly correlated. Modification of the dysregulated immune response toward M pachydermatis may assist in the reduction of pathologic changes associated with an atopic dermatitis phenotype in dogs.
Topics: Animals; Antibody Formation; Dermatitis, Atopic; Dermatomycoses; Dog Diseases; Dogs; Flow Cytometry; Immunity, Cellular; Leukocytes, Mononuclear; Lymphocyte Subsets; Malassezia; Skin Tests; Statistics, Nonparametric
PubMed: 11911571
DOI: 10.2460/ajvr.2002.63.358 -
Clinics in Dermatology Mar 2010Dermatophytes are significant pathogens in animal health due to their zoonotic potential, the economic consequences of infection in farm animal and fur production... (Review)
Review
Dermatophytes are significant pathogens in animal health due to their zoonotic potential, the economic consequences of infection in farm animal and fur production systems, and the distressing lesions they cause in small domestic pets. Malassezia spp are normal commensal and occasional pathogens of the skin of many veterinary species. Malassezia pachydermatis is a very common cause of otitis and pruritic dermatitis in dogs but is of less importance in other veterinary species. Dermatophytosis, and Malassezia otitis and dermatitis, represent the superficial mycoses of greatest significance in companion and farm animal health. Although the dermatophytes and Malassezia spp both exist in the stratum corneum of mammalian skin, there are important differences in the epidemiology, pathogenesis, and clinical consequences of infection. Dermatophytes are significant due to their zoonotic potential, the economic consequences of infection in farm animal and fur production systems, and the concern for owners of pets with inflammatory skin disease that is sometimes severe. Malassezia spp are normal commensals and occasional pathogens of the skin for many veterinary species, and M pachydermatis is a very common cause of otitis and pruritic dermatitis in dogs. This chapter will focus on the epidemiologic, clinical, diagnostic, and therapeutic aspects of dermatophytosis and Malassezia dermatitis in veterinary species. There are generally only sporadic reports of other superficial mycoses, such as candidiasis, piedra, and Rhodotorula dermatitis in veterinary medicine, and these are not included here.
Topics: Animal Diseases; Animals; Animals, Domestic; Cat Diseases; Cats; Cattle; Cattle Diseases; Colony Count, Microbial; Dermatomycoses; Dog Diseases; Dogs; Goat Diseases; Goats; Malassezia; Sheep; Sheep Diseases; Tinea; Tinea Versicolor; Veterinary Medicine; Zoonoses
PubMed: 20347667
DOI: 10.1016/j.clindermatol.2009.12.012 -
Scientific Reports Mar 2020The opportunistic pathogen Malassezia pachydermatis causes bloodstream infections in preterm infants or individuals with immunodeficiency disorders and has been...
The opportunistic pathogen Malassezia pachydermatis causes bloodstream infections in preterm infants or individuals with immunodeficiency disorders and has been associated with a broad spectrum of diseases in animals such as seborrheic dermatitis, external otitis and fungemia. The current approaches to treat these infections are failing as a consequence of their adverse effects, changes in susceptibility and antifungal resistance. Thus, the identification of novel therapeutic targets against M. pachydermatis infections are highly relevant. Here, Gene Essentiality Analysis and Flux Variability Analysis was applied to a previously reported M. pachydermatis metabolic network to identify enzymes that, when absent, negatively affect biomass production. Three novel therapeutic targets (i.e., homoserine dehydrogenase (MpHSD), homocitrate synthase (MpHCS) and saccharopine dehydrogenase (MpSDH)) were identified that are absent in humans. Notably, L-lysine was shown to be an inhibitor of the enzymatic activity of MpHCS and MpSDH at concentrations of 1 mM and 75 mM, respectively, while L-threonine (1 mM) inhibited MpHSD. Interestingly, L- lysine was also shown to inhibit M. pachydermatis growth during in vitro assays with reference strains and canine isolates, while it had a negligible cytotoxic activity on HEKa cells. Together, our findings form the bases for the development of novel treatments against M. pachydermatis infections.
Topics: Animals; Cell Line; Dermatomycoses; Dose-Response Relationship, Drug; Fungal Proteins; Fungemia; Genes, Essential; Homoserine Dehydrogenase; Humans; Lysine; Malassezia; Oxo-Acid-Lyases; Saccharopine Dehydrogenases; Threonine
PubMed: 32184419
DOI: 10.1038/s41598-020-61729-1 -
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 -
American Journal of Veterinary Research Jun 2004To investigate the direct interaction between canine keratinocytes and live Malassezia pachydermatis and thereby determine the role of these organisms in the... (Comparative Study)
Comparative Study
OBJECTIVE
To investigate the direct interaction between canine keratinocytes and live Malassezia pachydermatis and thereby determine the role of these organisms in the pathogenesis of epidermal hyperplasia associated with Malassezia dermatitis in dogs.
SAMPLE POPULATION
Primary canine keratinocyte cultures established from skin samples obtained from clinically normal dogs.
PROCEDURE
The proliferative response of keratinocytes co-cultured with Malassezia organisms for 1, 2, or 3 days was assessed by use of direct manual counting (to determine the number of keratinocytes in both the monolayer and the medium) and immunohistochemical staining techniques involving antibodies against proliferating cell nuclear antigen (PCNA) and another cellular proliferation marker, Ki-67. The potential cytotoxic effect of Malassezia organisms was investigated by use of an apoptosis detection kit to label keratinocytes co-cultured with M. pachydermatis that underwent apoptosis.
RESULTS
No stimulatory effect of Malassezia organisms on canine keratinocyte proliferation was detected via cell counting and immunohistochemical techniques. However, there was a significant increase in dead keratinocytes in the medium with increasing numbers of Malassezia organisms in the co-culture. More apoptotic cells were observed in keratinocyte monolayers co-cultured with high numbers of M. pachydermatis than there were in monolayers cultured without Malassezia organisms, and the number increased after prolonged incubation.
CONCLUSIONS AND CLINICAL RELEVANCE
M. pachydermatis did not stimulate canine keratinocyte proliferation in vitro. The results suggested that the epidermal hyperplasia observed in dogs with Malassezia dermatitis is unlikely to be caused by a direct effect of the organism on the keratinocyte cell cycle, but is likely to involve other mechanisms.
Topics: Analysis of Variance; Animals; Apoptosis; Cell Count; Cells, Cultured; Dermatomycoses; Dog Diseases; Dogs; Immunohistochemistry; In Vitro Techniques; Keratinocytes; Ki-67 Antigen; Malassezia; Proliferating Cell Nuclear Antigen; Time Factors
PubMed: 15198219
DOI: 10.2460/ajvr.2004.65.787 -
Mycopathologia Oct 2016Malassezia pachydermatis is part of the normal cutaneous microbiota of wild and domestic carnivores. However, under certain conditions this yeast can overproliferate and...
Malassezia pachydermatis is part of the normal cutaneous microbiota of wild and domestic carnivores. However, under certain conditions this yeast can overproliferate and cause several diseases in its host, mainly otitis and dermatitis in dogs. The aim of this study was to conduct a molecular characterization of M. pachydermatis isolates from healthy and diseased domestic animals, in order to assess the molecular diversity and phylogenetic relationship within this species. The large subunit (LSU) and the internal transcribed spacer (ITS) of ribosomal RNA, chitin synthase 2 (CHS2) and β-tubulin genes from sixteen strains isolated from dogs, cats, a goat, a pig and a horse were sequenced. A different number of types of sequences were identified for each target gene, including some types described for the first time. Five sequence types were characterized for the LSU, eleven for the ITS region, nine for CHS2 and eight for β-tubulin. A multilocus analysis was performed including the four genes, and the resulting phylogenetic tree revealed fifteen genotypes. Genotypes were distributed in two well-supported clades. One clade comprised strains isolated from different domestic animals and a strongly supported cluster constituted by strains isolated from cats. The second clade included strains isolated mainly from dogs and an outlier strain isolated from a horse. No apparent association could be observed between the health status of the animal hosts and concrete strains. The multilocus phylogenetic analysis is a useful tool to assess the intraspecific variation within this species and could help understand the ecology, epidemiology and speciation process of M. pachydermatis.
Topics: Animals; Animals, Domestic; Cats; Chitin Synthase; Cluster Analysis; DNA, Fungal; DNA, Ribosomal; DNA, Ribosomal Spacer; Dermatomycoses; Dogs; Genetic Variation; Genotype; Goats; Horses; Malassezia; Multilocus Sequence Typing; Phylogeny; RNA, Ribosomal; Swine; Tubulin
PubMed: 27283291
DOI: 10.1007/s11046-016-0026-3 -
Animals : An Open Access Journal From... Apr 2023Chronic otitis externa of dogs is a significant problem due to the prevalence and complexity of the treatment of such animals. There is evidence that in 60-80% of cases...
Chronic otitis externa of dogs is a significant problem due to the prevalence and complexity of the treatment of such animals. There is evidence that in 60-80% of cases of infectious diseases microorganisms located in the biofilm phenotype play the main role. Microorganisms in the biofilm phenotype have a number of advantages, the most significant of which is considered to be increased resistance to various external factors. Among them, a special place is occupied by resistance to antibiotics. In recent decades, research has been conducted at an increasing scale on the role of biofilm infections in various pathologies in veterinary medicine. The etiology and therapy of dog otitis externa caused by biofilm has not been fully studied. This is why we consider relevant the scientific and practical aspects of research on the etiology and therapy of dog otitis externa from the position of biofilm infection. In this work, it has been statistically proven that there is a relationship between the optical density of biofilms and their sensitivity to drugs, and this relationship is statistically significant. In addition, we have demonstrated that Farnesol has a good antibiofilm effect at a concentration of more 1.6 μM/mL (24% OD decrease of biofilm), and its highest antibiofilm effect (71-55%-more than a half) was observed at a concentration of 200-12.5 μM/mL.
PubMed: 37048514
DOI: 10.3390/ani13071259