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1.
Mycoses ; 62(10): 932-936, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31278884

RESUMO

The immediate immune response developed by the keratinocytes against Malassezia yeasts has been addressed yielding conflicting results. This study aims the assessment of cytokines and antimicrobial peptides gene expression elicited by M. sympodialis and M. furfur once in contact with a reconstructed human epidermis. A yeast suspension was prepared in RPMI 1640 medium (Sigma-Aldrich, St. Louis, MO) supplemented with Tween 60 and oleic acid to obtain approximately 1 × 106 cells in a volume of 100 µL. Clinical isolates of M. sympodialis (from pityriasis versicolor) and M. furfur (from seborrhoeic dermatitis) were inoculated, separately, onto a reconstructed human epidermis. A distinct expression pattern was found between the two tested species, with a tendency for overexpression of pro-inflammatory cytokines very soon after infection, whereas no significant expression or gene downregulation was often noticed following 24 and 48 h of incubation. A possible Malassezia species-dependent immune response pattern is highlighted.


Assuntos
Epiderme/imunologia , Epiderme/microbiologia , Interações Hospedeiro-Patógeno , Queratinócitos/imunologia , Queratinócitos/microbiologia , Malassezia/crescimento & desenvolvimento , Malassezia/imunologia , Peptídeos Catiônicos Antimicrobianos/análise , Citocinas/análise , Dermatomicoses/microbiologia , Dermatomicoses/patologia , Humanos , Modelos Teóricos
3.
Cell Host Microbe ; 25(3): 377-388.e6, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30850233

RESUMO

Inflammatory bowel disease (IBD) is characterized by alterations in the intestinal microbiota and altered immune responses to gut microbiota. Evidence is accumulating that IBD is influenced by not only commensal bacteria but also commensal fungi. We characterized fungi directly associated with the intestinal mucosa in healthy people and Crohn's disease patients and identified fungi specifically abundant in patients. One of these, the common skin resident fungus Malassezia restricta, is also linked to the presence of an IBD-associated polymorphism in the gene for CARD9, a signaling adaptor important for anti-fungal defense. M. restricta elicits innate inflammatory responses largely through CARD9 and is recognized by Crohn's disease patient anti-fungal antibodies. This yeast elicits strong inflammatory cytokine production from innate cells harboring the IBD-linked polymorphism in CARD9 and exacerbates colitis via CARD9 in mouse models of disease. Collectively, these results suggest that targeting specific commensal fungi may be a therapeutic strategy for IBD.


Assuntos
Colite/patologia , Colite/fisiopatologia , Doença de Crohn/patologia , Doença de Crohn/fisiopatologia , Trato Gastrointestinal/microbiologia , Malassezia/crescimento & desenvolvimento , Malassezia/isolamento & purificação , Animais , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Camundongos
4.
Mycoses ; 62(7): 597-603, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30636018

RESUMO

BACKGROUND: Malassezia yeasts produce bioactive indolic substances when grown on L-tryptophan agar. A panel of these substances was tested against commensal and opportunistic fungi, the Minimum Inhibitory Concentration (MIC) was determined and the potential for in loco antifungal activity on the skin was assessed. MATERIALS AND METHODS: Eight indoles were included (malassezin, pityriacitrin, indirubin, indolo[3,2-b]carbazole, 6-formylindolo[3,2-b]carbazole, tryptanthrin, 6-hydroxymethylindolo[3,2-b]carbazole and 6-methylindolo[3,2-b]carbazole) and were tested against 40 fungal strains [yeasts: Malassezia spp.(N = 9); Cryptococcus spp.(N = 10); Candida spp.(N = 7); Yarrowia lipolytica(N = 1); Exophialla dermatitidis (N = 2); moulds: Aspergillus spp.(N = 7); Fusarium spp.(N = 2); Rhizopus oryzae(N = 2)]. The concentration of 5/8 of the tested indoles on diseased skin was calculated from published data. Kruskal-Wallis and Mann-Whitney U tests were employed for group susceptibility evaluation in 33 strains. RESULTS: The MIC range was 0.125-32 µg/mL, and the median log2 MIC was four. Indirubin was the most potent antifungal agent and differed significantly from the others. The highest median MIC was found for FICZ. Malassezia with Candida strains were more susceptible compared to Cryptococcus and Aspergillus, and this inhibitory activity was predicted to be valid also on human skin. CONCLUSIONS: Malassezia yeasts produce indolic species that inhibit an array of clinically significant yeasts and moulds.


Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Meios de Cultura/química , Fungos/efeitos dos fármacos , Indóis/isolamento & purificação , Indóis/farmacologia , Malassezia/crescimento & desenvolvimento , Humanos , Malassezia/metabolismo , Testes de Sensibilidade Microbiana
5.
Mycoses ; 61(12): 954-958, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30106183

RESUMO

We report a malasseziosis model in immunocompromised Swiss mice. For this model, the mice were immunosuppressed with a combination of cyclophosphamide at 150 mg/kg and hydrocortisone acetate at 250 mg/kg. Two groups were formed according to the site of inoculation. Dermatitis group received an intradermal injection of 5 × 106 cell/mouse at a shaved dorsal region, while the otitis group received the same inoculum in the middle ear. Five animals/group were euthanised at different times, and the skin and ear were histopathologically analysed. During the first euthanasia, which occurred after inoculation, microscopic examination showed that all mice presented budding yeast-like in a tissue sample. The presence of yeasts decreased over time being undetected on the 17th day (dermatitis group) and the 21st day (otitis group) after inoculation. This is the first murine model for malasseziosis that can be useful for evaluating new treatment approaches.


Assuntos
Dermatomicoses/microbiologia , Dermatomicoses/patologia , Modelos Animais de Doenças , Malassezia/crescimento & desenvolvimento , Otite Média/patologia , Animais , Ciclofosfamida/administração & dosagem , Feminino , Histocitoquímica , Hidrocortisona/administração & dosagem , Hospedeiro Imunocomprometido , Imunossupressores/administração & dosagem , Injeções Intradérmicas , Camundongos , Otite Média/microbiologia
6.
Lett Appl Microbiol ; 67(5): 497-505, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30099746

RESUMO

A healthy skin provides a protective barrier against pathogenic micro-organisms. Recent studies have shown that probiotics, as those of Bifidobacterium genus, could act beneficially in dermatology, both when ingested and by topical use. In the present study, we evaluated by in vitro antagonism assays and using two skin cell lines the potential of four strains of Bifidobacterium spp. Among the four bifidobacteria, Bifidobacterium longum 51A was the only one able to inhibit the growth of the eight pathogenic indicators tested. Production of some cytokines and extracellular matrix proteins was determined when ccc or inactivated cells of the bifidobacteria were incubated with keratinocyte and/or fibroblast cell cultures. Significant results were observed only for IL-6, IL-8 and IL-18 production, and inactivated Bifidobacterium pseudolongum 1191A was the only one which significantly stimulated collagen production, whereas lumican was stimulated by treatments with live Bifidobacterium bifidum 1622A , B. longum 51A and B. pseudolongum 1191A . Highest adhesion and internalization capabilities were observed with B. bifidum 1622A and Bifidobacterium breve 1101A . Concluding, B. longum 51A was highlighted for its antagonistic capacity and B. bifidum 1622A and B. pseudolongum 1191A for stimulating the production of cytokines and proteins of the extracellular matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: The skin is the first line of defence against invasive micro-organisms, and its local microbiota provides additional protective functions based on antagonism against pathogenic micro-organisms and immunomodulation. Based on in vitro assays using Bifidobacterium spp. we demonstrated the antagonistic potential, as well as capacity in stimulating the production of cytokines and proteins of the extracellular matrix that these bacteria may exert on skin cells. This positive influence suggests the use of a consortium of these bifidobacteria in a topical product for dermatological treatments.


Assuntos
Antibiose/fisiologia , Bifidobacterium/metabolismo , Citocinas/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Probióticos/metabolismo , Pele/microbiologia , Bifidobacterium/classificação , Candida albicans/crescimento & desenvolvimento , Linhagem Celular , Humanos , Malassezia/crescimento & desenvolvimento , Propionibacterium acnes/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento
7.
Med Mycol J ; 59(2): E25-E30, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29848908

RESUMO

The use of embryonated egg as an alternative in the study of the pathogenesis of fungi is evolving. Although murine models are the "gold standard," embryonated egg models are also used to screen determinants of virulence among fungi species. This study was aimed at determining the virulence potential of Cryptococcus gattii strains R265, R272, and EJB18, and Malassezia sympodialis using chorioallantoic membrane (CAM) of embryonated egg. At a concentration of 107 cfu/ml, C. gattii R272 was more virulent than R265 in the egg model, while EJB18 had low virulence. The CAM model supported the growth of Malassezia sympodialis strain and induced the formation of hyphae. The formation of lesions by the organism and its re-isolation from CAM suggest that the model can be used for evaluating the virulence of C. gattii. Histopathology of CAM from both strains also revealed massive disruption of CAM. This study suggests that embryonated egg is a useful alternative tool to pre-screen Cryptococcus gattii strains to select strains for subsequent testing in murine models and could also be a potential medium for studying the hyphal growth in Malassezia species.


Assuntos
Membrana Corioalantoide/microbiologia , Cryptococcus gattii/patogenicidade , Animais , Embrião de Galinha , Galinhas , Cryptococcus gattii/crescimento & desenvolvimento , Malassezia/crescimento & desenvolvimento , Malassezia/patogenicidade , Camundongos , Virulência
8.
Mycopathologia ; 183(6): 893-903, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29946996

RESUMO

Dandruff is a common scalp condition causing both a discomfort and an undesired social image. Various studies dating from early 1900s have investigated the condition, but understanding of underlying mechanisms and etiology of the condition is still in its infancy. Formation of dandruff is a common but complex event which has been associated with numerous causal factors. Physiological conditions such as pH, water content, or sebum secretion are some of the host-related factors. An imbalance between these factors can disturb the physiological equilibrium of the scalp that can lead to dandruff formation. However, severity of the condition is strongly related to the lipophilic yeast of the skin microbiota, Malassezia spp. On the other hand, there are recent publications highlighting the role of other scalp microbiota members on dandruff formation. This review investigates the processes leading to the formation of dandruff to provide an etiological description of the condition, with a focus on Malassezia spp.


Assuntos
Caspa/etiologia , Caspa/patologia , Dermatomicoses/etiologia , Dermatomicoses/patologia , Malassezia/crescimento & desenvolvimento , Humanos
9.
J Mycol Med ; 28(3): 486-491, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29753721

RESUMO

BACKGROUND: Malassezia furfur is lipodependent yeast like fungus that causes superficial mycoses such as pityriasis versicolor and dandruff. Nevertheless, there are no standard reference methods to perform susceptibility test of Malassezia species yet. AIMS: Therefore, in this study, we evaluated the optimized culture medium for growth of this lipophilic yeast using modified leeming-Notman agar and colorimetric resazurin microtiter assay to assess antimycotic activity of fluconazole against M. furfur. RESULTS: The result showed that these assays were more adjustable for M. furfur with reliable and reproducible MIC end-point, by confirming antimycotic activity of fluconazole with MIC of 2µg/ml. CONCLUSION: We conclude that this method is considered as the rapid and effective susceptibility testing of M. furfur with fluconazole antifungal activity.


Assuntos
Antifúngicos/farmacologia , Fluconazol/farmacologia , Malassezia/efeitos dos fármacos , Oxazinas/química , Xantenos/química , Colorimetria/métodos , Meios de Cultura/química , Dermatomicoses/microbiologia , Humanos , Malassezia/crescimento & desenvolvimento , Malassezia/fisiologia , Testes de Sensibilidade Microbiana/métodos , Tinha Versicolor/microbiologia
10.
Med Mycol ; 56(8): 987-993, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29462476

RESUMO

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.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Citocromo P-450 CYP1A1/biossíntese , Queratinócitos/metabolismo , Queratinócitos/microbiologia , Malassezia/crescimento & desenvolvimento , Receptores de Hidrocarboneto Arílico/biossíntese , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem Celular , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1B1/biossíntese , Citocromo P-450 CYP1B1/genética , Perfilação da Expressão Gênica , Humanos , RNA Mensageiro/análise , RNA Mensageiro/genética , Receptores de Hidrocarboneto Arílico/genética , Transcrição Genética
11.
Acta Derm Venereol ; 98(2): 256-261, 2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-28815268

RESUMO

Dead Sea climatotherapy (DSC) is a therapeutic modality for a variety of chronic skin conditions, yet there has been scarce research on the relationship between the cutaneous microbiota and disease states in response to DSC. We characterized the skin bacterial and fungal microbiome of healthy volunteers who underwent DSC. Bacterial community diversity remained similar before and after treatment, while fungal diversity was significantly reduced as a result of the treatment. Individuals showed greater inter-individual than temporal bacterial community variance, yet the opposite was true for fungal community composition. We further identified Malassezia as the genus driving temporal mycobiome variations. The results indicate that the microbiome remains stable throughout DSC, while the mycobiome undergoes dramatic community changes. The results of this study will serve as an important baseline for future investigations of microbiome and mycobiome temporal phenomena in diseased states.


Assuntos
Bactérias/crescimento & desenvolvimento , Balneologia/métodos , Climatoterapia/métodos , Fungos/crescimento & desenvolvimento , Helioterapia/métodos , Microbiota , Pele/microbiologia , Bactérias/classificação , Feminino , Fungos/classificação , Voluntários Saudáveis , Humanos , Israel , Malassezia/crescimento & desenvolvimento , Masculino , Micobioma , Fatores de Tempo
12.
Mycoses ; 61(2): 111-118, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28976036

RESUMO

The activation of NLRP3, NLRC4 and AIM2 inflammasomes is pivotal for innate immunity against some pathogenic fungi, but their role in the pathogenesis of Malassezia folliculitis (MF) remains unclear. The objective of the study was to determine the expression of 4 canonical inflammasomes (NLRP1, NLRP3, NLRC4 and AIM2) and their priming-associated molecules (TLR2, TLR4, Dectin-1, Dectin-2 and NFκB) in MF lesion. Expression of NLRP1, NLRP3, NLRC4, AIM2, caspase-1, IL-1ß, TLR2, TLR4, Dectin-1, Dectin-2 and NFκB was detected by immunohistochemistry in skin lesion of 23 MF patients and normal skin of 12 healthy subjects. Furthermore, NLRP1, NLRP3, NLRC4, AIM2, caspase-1 and IL-1ß mRNA was measured by quantitative real-time PCR (qRT-PCR) in 12 MF cases and 10 controls. Immunohistochemical analysis revealed that NLRP3, NLRC4, AIM2, Casp-1, IL-1ß, TLR2, TLR4, Dectin-1, Dectin-2 and NFκB expression was up-regulated in the epidermis and dermal inflammatory cells of MF lesion compared with control skin (P < .01-.05), but NLRP1 expression was not different between both groups (P > .05). qRT-PCR showed that levels of NLRP3, Casp-1 and IL-1ß mRNA were significantly increased (P < .01-.05), whereas those of NLRP1, NLRC4 and AIM2 mRNA were slightly augmented compared to control skin (P > .05). Our observation suggests that simultaneous activation of NLRP3, NLRC4 and AIM2 inflammasomes may play an important role in the pathogenesis of MF.


Assuntos
Dermatomicoses/patologia , Foliculite/patologia , Imunidade Inata , Fatores Imunológicos/biossíntese , Inflamassomos/biossíntese , Malassezia/crescimento & desenvolvimento , Adolescente , Adulto , Humanos , Imuno-Histoquímica , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
13.
Mycoses ; 60(12): 796-799, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28925032

RESUMO

Previous studies have evaluated the action of gentamicin against Malassezia pachydermatis. The aim of this study was to evaluate in vitro susceptibility of M. pachydermatis to the aminoglycosides- gentamicin, tobramycin, netilmicin and framycetin. The minimum inhibitory concentration (MIC) of gentamicin was determined following methods M27-A3 microdilution and Etest® . The Etest® was used to determine the minimum inhibitory concentration (MIC) of the tobramycin and netilmicin. The Kirby-Bauer test was used to determine the antibiotic susceptibility to the framycetin. The MIC50 and MIC90 were 8.12 µg/mL and 32.5 µg/mL by microdilution method for gentamicin. The MIC50, determined by the Etest® , was 8 µg/mL for gentamicin and netilmicin and 64 µg/mL for tobramycin. The MIC90 was 16 and 32 µg/mL for gentamicin and netilmicin respectively. The MIC90 was outside of the detectable limits for tobramycin. To framycetin, 28 strains (40%) of the 70 M. pachydermatis isolates tested showed a diameter of 22 mm, 22 strains (31.42%) showed a diameter of 20 mm, 16 strains showed a diameter of ≤ 18 mm, and only 5.71% of the isolates showed a diameter of ≥ 22 mm. This study provides evidence of high in vitro activity of the aminoglycosides-gentamicin, tobramycin, netilmicin and framycetin against M. pachydermatis. For gentamicin Etest® showed similar values of MIC50 y MIC90 that the obtained by microdilution method. We considered Etest® method could be a good method for these calculations with aminoglycosides.


Assuntos
Aminoglicosídeos/farmacologia , Antifúngicos/farmacologia , Malassezia/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Amicacina/análise , Amicacina/farmacologia , Aminoglicosídeos/análise , Gentamicinas/análise , Gentamicinas/farmacologia , Malassezia/crescimento & desenvolvimento , Netilmicina/análise , Netilmicina/farmacologia , Tobramicina/análise , Tobramicina/farmacologia
14.
Microb Pathog ; 110: 66-72, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28645774

RESUMO

The genus Malassezia comprises of extremely lipophilic yeasts secreting lipases as a vital factor for survival. They are emerging as opportunistic pathogens in medical microbiology and dermatology by causing recurring and recalcitrant infection. Combinatorial therapy is a constructive way to combat infectious diseases. In that prospect, totally 16 Indian medicinal plants were screened, among which a maximum degree of antimicrobial activity was ascertained in Embelia ribes. Subsequently embelin was identified as the bioactive principle with antagonistic potential by comparative antimicrobial assay and FTIR analysis. The MIC of embelin was determined as 400 µg/ml exhibiting ∼75% of growth inhibition. Further, a fungistatic activity based on anti-lipase potential (65-89%) of embelin has been clearly substantiated by XTT and lipase assay. In addition, embelin exhibited a synergistic effect with the antifungal drug ketoconazole (KTZ) against four different Malassezia spp. with FIC index of 0.5. Therefore, the combinations of embelin and KTZ may represent a promising therapeutic regimen to treat Malassezia infections with subjugated clinical and environmental toxicity. To the best of our knowledge, this is the first report delineating the anti-lipase activity of embelin and in vitro synergistic interaction between embelin and KTZ against Malassezia spp.


Assuntos
Antifúngicos/farmacologia , Benzoquinonas/farmacologia , Cetoconazol/farmacologia , Malassezia/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Benzoquinonas/química , Benzoquinonas/isolamento & purificação , Combinação de Medicamentos , Sinergismo Farmacológico , Embelia/química , Humanos , Índia , Lipase/efeitos dos fármacos , Malassezia/crescimento & desenvolvimento , Malassezia/patogenicidade , Testes de Sensibilidade Microbiana , Triazóis/farmacologia
15.
PLoS One ; 12(6): e0179148, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28586389

RESUMO

The genus Malassezia includes lipophilic yeasts, which are part of the skin microbiota of various mammals and birds. Unlike the rest of Malassezia species, M. pachydermatis is described as non-lipid-dependent, as it is able to grow on Sabouraud glucose agar (SGA) without lipid supplementation. In this study we have examined the phenotypic variability within M. pachydermatis and confirmed its lipid-dependent nature using a synthetic agar medium. We used a selection of representative non-lipid-dependent strains from different animal species and three atypical lipid-dependent strains of this species, which were not able to grow after multiple passages on SGA. More than 400 lipid-dependent Malassezia isolates from animals were studied in order to detect the three lipid-dependent strains of M. pachydermatis. The identity of the atypical strains was confirmed by DNA sequencing. On the other hand, we have modified the Tween diffusion test, which is widely used in the characterization of these yeasts, by using a synthetic agar-based medium instead of SGA. This modification has proved to be useful for differentiation of M. pachydermatis strains, providing reproducible results and a straightforward interpretation. The finding of these peculiar lipid-dependent strains exemplifies the large variability within the species M. pachydermatis, which involves rare atypical strains with particular growth requirements.


Assuntos
Meios de Cultura/química , Doenças do Cão/microbiologia , Lipídeos/química , Malassezia/efeitos dos fármacos , Ágar/química , Animais , Gatos , Bovinos , Doenças do Cão/patologia , Cães , Orelha/microbiologia , Orelha/patologia , Glucose/metabolismo , Cavalos/microbiologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Malassezia/crescimento & desenvolvimento , Malassezia/patogenicidade , Filogenia , RNA Ribossômico/genética , Pele/microbiologia , Pele/patologia
16.
Mycoses ; 60(10): 645-650, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28557001

RESUMO

Otitis caused by Malassezia pachydermatis is generally a common and recurrent disease in canine clinical pathology. The increased incidence of fungal resistant to antifungal in both humans and pets is a cause for concern and is associated with the indiscriminate use of antifungals. Finding the most effective disinfectants and antifungals has become essential. To evaluate the in vitro inhibitory activity of hydrogen peroxide on the growth of M. pachydermatis and compare its efficacy with commercial ear cleaners. The test for sensitivity to antimicrobials was carried out following the indications of the CLSI document M44-A2. The comparative results demonstrated that hydrogen peroxide 1.5% showed excellent results for growth inhibition of M. pachydermatis, followed by Epiotic® and MalAcetic® , the lowest result was for Otoclean® .


Assuntos
Antifúngicos/farmacologia , Peróxido de Hidrogênio/farmacologia , Malassezia/efeitos dos fármacos , Animais , Dermatomicoses/microbiologia , Dermatomicoses/veterinária , Doenças do Cão/microbiologia , Cães , Malassezia/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Otite Externa/microbiologia , Otite Externa/veterinária
17.
Med Mycol ; 55(2): 150-154, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27497434

RESUMO

ß-Endorphin is known to stimulate phospholipase production by Malassezia pachydermatis during canine dermatoses. The role of ß-endorphin in Malassezia infection in humans is not well studied. The present study compares the influence of ß-endorphin on Malassezia globosa and Malassezia restricta isolated from patients with seborrhoeic dermatitis/dandruff (SD/D) and healthy controls. Malassezia isolates (five each of the two species from patients and healthy controls) were grown on modified Dixon's agar with or without 100 nmol/L ß-endorphin. Phospholipase activity was quantified based on its ability to hydrolyze L-α-phosphatidylcholine dimyristoyl (phospholipid substrate). Free fatty acid was measured by a colorimetry method. In isolates from patients, the phospholipase activity significantly increased after exposure to ß-endorphin (M. globosa, P = .04; M. restricta, P = .001), which did not occur in isolates from healthy controls. Moreover, after ß-endorphin exposure the patient isolates had significantly higher (P = .0004) phospholipase activity compared to the healthy control isolates. The results suggest that isolates of M. globosa and M. restricta from patients may differ from those of healthy humans.


Assuntos
Caspa/microbiologia , Voluntários Saudáveis , Malassezia/efeitos dos fármacos , Malassezia/enzimologia , Fosfolipases/análise , beta-Endorfina/metabolismo , Colorimetria , Meios de Cultura/química , Ácidos Graxos/análise , Humanos , Malassezia/crescimento & desenvolvimento , Malassezia/isolamento & purificação
18.
Mycoses ; 60(2): 104-111, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27625339

RESUMO

All Malassezia species are lipophilic; thus, modifications are required in susceptibility testing methods to ensure their growth. Antifungal susceptibility of Malassezia species using agar and broth dilution methods has been studied. Currently, few tests using disc diffusion methods are being performed. The aim was to evaluate the in vitro susceptibility of Malassezia yeast against antifungal agents using broth microdilution and disc diffusion methods, then to compare both methodologies. Fifty Malassezia isolates were studied. Microdilution method was performed as described in reference document and agar diffusion test was performed using antifungal tablets and discs. To support growth, culture media were supplemented. To correlate methods, linear regression analysis and categorical agreement was determined. The strongest linear association was observed for fluconazole and miconazole. The highest agreement between both methods was observed for itraconazole and voriconazole and the lowest for amphotericin B and fluconazole. Although modifications made to disc diffusion method allowed to obtain susceptibility data for Malassezia yeast, variables cannot be associated through a linear correlation model, indicating that inhibition zone values cannot predict MIC value. According to the results, disc diffusion assay may not represent an alternative to determine antifungal susceptibility of Malassezia yeast.


Assuntos
Antifúngicos/farmacologia , Malassezia/efeitos dos fármacos , Ágar , Anfotericina B/farmacologia , Meios de Cultura , Fluconazol/farmacologia , Itraconazol/farmacologia , Malassezia/crescimento & desenvolvimento , Miconazol/farmacologia , Testes de Sensibilidade Microbiana/métodos , Voriconazol/farmacologia
19.
Arch Dermatol Res ; 309(1): 47-53, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27885419

RESUMO

Malassezia furfur, a constituent of the normal human skin flora, is an etiological agent of pityriasis versicolor, which represents one of the most common human skin diseases. Under certain conditions, both exogenous and endogenous, the fungus can transition from a yeast form to a pathogenic mycelial form. To develop a standardized medium for reproducible production of the mycelial form of M. furfur to develop and optimize susceptibility testing for this pathogen, we examined and characterized variables, including kojic acid and glycine concentration, agar percentage, and pH, to generate a chemically defined minimal medium on which specific inoculums of M. furfur generated the most robust filamentation. Next, we examined the capacity of ketoconazole to inhibit the formation of M. furfur mycelial form. Both low and high, 0.01, 0.05 and 0.1 µg/ml concentrations of ketoconazole significantly inhibited filamentation at 11.9, 54.5 and 86.7%, respectively. Although ketoconazole can have a direct antifungal effect on both M. furfur yeast and mycelial cells, ketoconazole also has a dramatic impact on suppressing morphogenesis. Since mycelia typified the pathogenic form of Malassezia infection, the capacity of ketoconazole to block morphogenesis may represent an additional important effect of the antifungal.


Assuntos
Antifúngicos/farmacologia , Cetoconazol/farmacologia , Malassezia/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Morfogênese/efeitos dos fármacos , Relação Dose-Resposta a Droga , Malassezia/crescimento & desenvolvimento , Malassezia/patogenicidade , Reprodutibilidade dos Testes
20.
Mycoses ; 59(2): 108-16, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26691773

RESUMO

Severe skin diseases and systemic fungaemia are caused by Malassezia pachydermatis and Candida albicans respectively. Antifungal therapies are less effective because of chronic character of infections and high percentage of relapses. Therefore, there is a great need to develop new strategies of antifungal therapies. We previously found that oxythiamine decreases proliferation of yeast (Saccharomyces cerevisiae), therefore we suggest that thiamine antivitamins can be considered as antifungal agents. The aim of this study was the comparison of thiamine antivitamins (oxythiamine, amprolium, thiochrome, tetrahydrothiamine and tetrahydrooxythiamine) inhibitory effect on the growth rate and energetic metabolism efficiency in non-pathogenic S. cerevisiae and two potentially pathogenic species M. pachydermatis and C. albicans. Investigated species were cultured on a Sabouraud medium supplemented with trace elements in the presence (40 mg l(-1)) or absence of each tested antivitamins to estimate their influence on growth rate, enzyme activity and kinetic parameters of pyruvate decarboxylase and malate dehydrogenase of each tested species. Oxythiamine was the only antivitamin with antifungal potential. M. pachydermatis and S. cerevisiae were the most sensitive, whereas C. albicans was the least sensitive to oxythiamine action. Oxythiamine can be considered as supportive agent in superficial mycoses treatment, especially those caused by species from the genus Malassezia.


Assuntos
Antifúngicos/farmacologia , Antimetabólitos/farmacologia , Candida albicans/efeitos dos fármacos , Candidíase Cutânea/tratamento farmacológico , Dermatomicoses/tratamento farmacológico , Malassezia/efeitos dos fármacos , Tiamina/antagonistas & inibidores , Antifúngicos/uso terapêutico , Antimetabólitos/uso terapêutico , Candida albicans/crescimento & desenvolvimento , Candidíase Cutânea/microbiologia , Dermatomicoses/microbiologia , Fungemia/tratamento farmacológico , Fungemia/microbiologia , Humanos , Malassezia/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Oxitiamina/farmacologia , Oxitiamina/uso terapêutico , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento
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