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Malassezia pachydermatis is an opportunistic yeast found in the ear canal of small animals; however, the current azole-based therapy applied to it has failed to achieve clinical success due to the antifungal resistance. This issue has encouraged the studies in natural products, such as Origanum vulgare (oregano), Origanum majorana (marjoram) and Rosmarinus officinalis (rosemary) essential oils, although their mechanism of action remains unclear. Malassezia pachydermatis specimens deriving from otitis cases in dogs (n = 22) and cats (n = 2) were subjected to CLSI M27-A3. Sorbitol protection and ergosterol effect were analyzed to investigate their mechanism of action. Fungistatic (MIC) and fungicidal (MFC) activities were observed for oregano (MIC90/MFC90: 0.625 mg/mL); marjoram (MIC90/MFC90: 2.5 mg/mL) and rosemary MIC90/MFC90 > 2.5 mg/mL). Oregano showed superior antifungal effect even at lower MIC and MFC values. All three oils acted on cell wall and at complexation to fungal ergosterol. By gas chromatography (GC-FID), carvacrol was the major compound found in oregano (73.9%); 1,8-cineole was for marjoram and rosemary (20.9% and 49.4%, respectively). These findings support the potential use of these essential oils to treat canine and feline otitis caused by Malassezia pachydermatis. [ABSTRACT FROM AUTHOR]

Summary: 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. [ABSTRACT FROM AUTHOR]

Malassezia pachydermatis is an important opportunistic agent of dermatitis and otitis in dogs. M. pachydermatis is generally treated with topical therapies using combinations of antifungal, antimicrobial and anti-inflammatory agents. We investigated the in vitro activities of carvacrol (CRV), cinnamaldehyde (CIN) and thymol (THY) alone and in combination with antifungal agents (fluconazole, itraconazole, ketoconazole, clotrimazole, miconazole, terbinafine and nystatin) against M. pachydermatis. The assays were performed according to the Clinical and Laboratory Standards Institute (CLSI), using Sabouraud dextrose broth and checkerboard microdilution. The mean fractional inhibitory concentration index (FICI) showed primary synergies for the combinations carvacrol + nystatin, thymol + nystatin, and carvacrol + miconazole (80%). In conclusion, the results obtained indicate that the phytochemicals tested showed relevant in vitro anti- M. pachydermatis activity. Future in vivo experiments are needed to elucidate the safety and therapeutic potential of these combinations. [ABSTRACT FROM AUTHOR]

Introduction: Acne is the most common skin disease that affects up to 85% of people between 12 and 25 years old and 11% of persons over the age of 25 years. Frequently the disease acquires a severe course, which significantly reduces the quality of life indicators. Etiopathogenesis of acne has a multifactorial nature, the leading role is given to shifts in the immune status. Aim of the research: To evaluate the state of the immune status in patients with acne and concomitant skin malasseziosis. Materials and methods: 120 patients with acne were observed: 35 (45.8%) men and 65 (54.2%) women, aged 16-27 years. Duration of the disease was mostly 3-8 years (80.8%). Papulopustular acne was diagnosed in 102 patients, nodulocystic – in 18 ones. Skin malasseziosis was found in 100 patients in the form of pityriasisversicolor, purulent folliculitis, Darier’s disease (keratosis follicularis), and scalp pityriasis. Study of leukocyte count, leukocyte phenotyping and the study of phagocytes function were carried out. Furthermore, levels of IgA, IgG, IgM and concentration of IL-10 and IL-12 were studied in the peripheral blood. Results: We observed the statistically significant decrease in Phagocytic Index and Phagocytic Number, more demonstrative in patients with concomitant malasseziosis. We also noted the decrease of NBT-test indicators, more demonstrative in patients with the infection. The most pronounced inhibition of phagocytic activity was observed in patients with more severe acne (stage IV). In the study of number of lymphocytes populations and subpopulations in patients with acne violations of immunoregulatory type were identified: dissociation of CD3+ and CD22+, CD4+, CD8+, and especially CD16+ level, which led to the depression of T-cell-mediated immunity, which were more pronounced in patients with acne and concomitamtmalasseziosis, especially in patients with stage IV dermatosis. In the study of immunoglobulin levels an increase of IgM and IgG was marked, especially in patients with concomitant malasseziosis, which depended on the stage and form of dermatosis. We consider this fact as the progredient progression of acne with the presence of immunopathological changes under the influence of concomitant Malassezia infection. We observed the significant increase in production of IL-10 and IL-12 in patients with acne, which indicates the hyperactivity of anti-inflammatory mechanisms and may be the background for the intensification of microorganisms’ colonization, which was confirmed by the significantly higher indicators of these cytokines levels in patients with acne and concomitant skin malasseziosis.

A three and a half months old male Pug was presented with a complaint of severe itching and hair loss since one month. Clinical examination of the skin revealed generalized alopecia with erythema and pustules all over the body with lichenification, hyperpigmentation and greasy exudations. Laboratory evaluation revealed numerous Demodex canis mites in skin scrapping, blue - purple peanut shaped yeast organisms of Malassezia genus in tape impression smear and Gram positive cocci sensitive to Cephalexin in antibiotic sensitivity test (ABST). The case was diagnosed as concurrent demodicosis and Malasseziosis with associated pyoderma and treated successfully. [ABSTRACT FROM AUTHOR]

External otitis is a common auditory meatus infirmity diagnosed in dogs and cats sent to veterinarian clinics. The etiology varies according to combinations of predisposing, primary and perpetuating factors, responsible for the disease. Malassezia pachydermatis is considered a normal inhabitant of the skin and can occasionally become an opportunistic pathogen of the external canal of dogs and cats. This study aimed to investigate the presence of M. pachydermatis in canine external otitis. The presence of yeast in external otitis of dogs sent to 168 veterinary hospitals in the Federal Universities of Rio Grande do Sul and Pelotas, as well as to clinics and private kennels was investigated. The sampling was performed with a sterile swab moistened with saline solution, rubbing it in the ear canal. Direct examination was performed from swabs of the collected material, stained by Gram method and examined under optical microscopy (1000X). It was seeded on Sabouraud Dextrose Agar with chloramphenicol and incubated at 32°C for up to ten days when the yeasts were identified. From the 168 cases of external otitis, M. pachydermatis was isolated in 139 (82.7%) cases. In this study, there was no difference regarding gender and age of the animals. The frequency of isolation in samples with positive scores on direct examination was significantly higher (p

Highlights • Malassezia pachydermatis is a common cause of skin and ear infection in dogs. • We injected Drosophila melanogaster flies with M. pachydermatis yeast cells. • Wild-type flies were resistant whereas Toll-deficient flies succumbed to the infection. • Toll-deficient flies are a promising model for studying systemic malasseziosis. Abstract Malassezia pachydermatis is a yeast that is commonly found in the skin of most animals. Changes in the physical, chemical or immunological processes of the skin may render the host more susceptible to the yeast, which then may cause otitis, dermatitis or, less often, systemic infection. We tested the pathogenicity of M. pachydermatis in wild-type (WT) and Toll -deficient Drosophila melanogaster. Flies were inoculated in the thorax with a needle previously dipped in inoculum concentrations ranging from 103 and 107 yeast cells/mL. After infection, flies were housed at 29 °C and mortality was evaluated daily until day seven. WT flies were resistant to the infection, whereas Toll -deficient flies showed inoculum-dependent mortality rates. Fungal burden, assessed by histopathological analysis and by counting the number of colony-forming units of dead flies, corroborated the results. The D. melanogaster model is a promising minihost model for future large-scale studies of virulence mechanisms and antifungal drug activity in malasseziosis. [ABSTRACT FROM AUTHOR]

44 dogs with pruritic localized or generalized skin diseases were examined along with 118 healthy dogs. A patient's history, clinical signs, response to previous therapy and cytologic examination findings were all used in diagnosing Malassezia dermatitis. Skin swabs were collected from 8 anatomical sites for cytological examination. In healthy dogs, Malassezia yeasts were most frequently isolated in the perianal and perioral areas. The frequency of isolation Malassezia were higher in dogs with localized dermatitis, especially in affected areas, indicating role of Malassezia in occurrence of skin lesions. German shepherd and Labrador predominated in present study owing to large population of these breeds. It is important to diagnose and treat any underlying predisposing factors. Topical treatment with Miconazole nitrate (2%) and Chlorhexidine (2%), twice weekly for 3 weeks and systemic treatments with azole derivatives (Ketoconazole, 10 mg/ kg/ day and Itraconazole, 5 mg /kg/ day) for 3 weeks were effective in controlling Malassezia dermatitis. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The first aim of this study was to evaluate the in vitro efficacies of fluconazole, ketoconazole, itraconazole and voriconazole on M. pachydermatis growth inhibition. This study also evaluated M. pachydermatis azole cross-resistance, comparing wild clinical isolates and the same isolates with in vitro-induced fluconazole resistance. Methods: Two techniques were used: (1) a broth microdilution method based on protocol M27-A3 from the Clinical and Laboratory Standards Institute to determine the minimum inhibitory concentration (MIC) and (2) the Fekete-Forgács method to induce fluconazole resistance in vitro. The isolates were divided into two groups: group 1 included fluconazole-susceptible clinical isolates (n =30) and group 2 contained the same isolates with in vitro-induced fluconazole resistance (n =30). Results: The two groups exhibited differences in susceptibility (p <0.001). Group 1 isolates were susceptible to azoles: ketoconazole (MIC 0.01–1.0μg/mL), itraconazole (MIC 0.01–1.0μg/mL), voriconazole (MIC 0.01–4.0μg/mL), and fluconazole (MIC 0.01–4.0μg/mL). Group 2 isolates demonstrated a wider range of MICs to azoles: ITZ (MIC 0.06–64.0μg/mL), KTZ (MIC 0.25–32.0μg/mL), VRZ (MIC 2.0–128.0μg/mL), and FLZ (MIC 64.0–128.0μg/mL). Conclusions: It was shown that FLZ-resistant M. pachydermatis isolates exhibit cross-resistance to other azoles, reinforcing the importance of susceptibility tests as a guide for the therapeutic prescription of antifungals in medical and veterinary mycology. [Copyright &y& Elsevier]

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A male German shepherd dog was brought with poor general condition, alopecia, crusted lesions, pruritus, skin scales and pustules. Clinical and laboratory examinations, diagnosed it as combined infection of Malassezia and Demodex canis. The treatment was started with oral Ketoconazole @ 10mg/kg body weight for 20 days and Amitraz external application once in a week and Ivermectin 10mg tablet on weekly interval. The animal was reviewed on 20th day and there was slight improvement in condition. Ivermectin was advised for another 30 days at one week interval and advised to apply sulphur in neem oil (2.5% solution) for 30 days. The animal was reviewed after 30 days and drastic improvement was noticed. The animal was advised to continue the external application of sulphur in neem oil combination for another 30 days. After 90 days of treatment, the animal was perfectly normal with no signs of skin infection. We conclude that Ketoconazole followed by sulphur in neem oil can be used effectively for the control of malassezia and Amitraz external application and ivermectin oral tablets can be effectively used for treatment of canine demodicosis. [ABSTRACT FROM AUTHOR]

A 10 month old female Labrador retriever dog was presented with history of recurrent skin disease with loss of hair, severe pruritus, dandruff and oily skin. Malasseziosis was diagnosed by examination of stained impression smears from lesions, cutlural isolation and identification. Thyroid function test revealed significantly lower levels of T4 level. Animal was successfuly treated with Ketaconazole and Levothyroxine. [ABSTRACT FROM AUTHOR]

Malassezia pachydermatis is an important opportunistic agent of dermatitis and otitis in dogs. M. pachydermatis is generally treated with topical therapies using combinations of antifungal, antimicrobial and anti-inflammatory agents. We investigated the in vitro activities of carvacrol (CRV), cinnamaldehyde (CIN) and thymol (THY) alone and in combination with antifungal agents (fluconazole, itraconazole, ketoconazole, clotrimazole, miconazole, terbinafine and nystatin) against M. pachydermatis. The assays were performed according to the Clinical and Laboratory Standards Institute (CLSI), using Sabouraud dextrose broth and checkerboard microdilution. The mean fractional inhibitory concentration index (FICI) showed primary synergies for the combinations carvacrol+nystatin, thymol+nystatin, and carvacrol+miconazole (80%). In conclusion, the results obtained indicate that the phytochemicals tested showed relevant in vitro anti-M. pachydermatis activity. Future in vivo experiments are needed to elucidate the safety and therapeutic potential of these combinations., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)