agar and Dermatomycoses

Aim of this study was to verify whether Mueller-Hinton agar supplemented with 2 % glucose and methylene blue (MH-GM), which is used for disk diffusion susceptibility testing of Candida species by the Clinical and Laboratory Standards Institute, is suitable for testing Malassezia pachydermatis. A variant of the disk diffusion procedure utilizing a 9-mm tablet was used to test 31 isolates against clotrimazole and miconazole using MH-GM as test medium. The MH-GM agar optimally supported the growth of all M. pachydermatis isolates, provided that the yeast inoculum was prepared with a lipid source (Tween 40 and 80). Zone edges were frequently definite and clear, facilitating the measurement of zone size and minimizing subjectivity. The inhibition zones correlated with MIC values obtained in a broth dilution assay. The agar diffusion method with MH-GM as the test medium appears as a suitable procedure for testing the susceptibility of M. pachydermatis to CTZ and MCZ in clinical laboratories. This test format may allow processing a large number of isolates in epidemiological studies. This may in turn facilitate clarifying to what extent the problem "drug resistance" accounts for cases of treatment failure in dogs with Malassezia otitis and dermatitis.

Topics: Agar; Animals; Antifungal Agents; Clotrimazole; Culture Media; Dermatomycoses; Disk Diffusion Antimicrobial Tests; Dog Diseases; Dogs; Glucose; Malassezia; Methylene Blue; Miconazole; Polysorbates

Batrachochytrium dendrobatidis is a member of the phylum Chytridiomycota and the causative organism chytridiomycosis, a disease of amphibians associated with global population declines and mass mortality events. The organism targets keratin-forming epithelium in adult and larval amphibians, which suggests that keratinolytic activity may be required to infect amphibian hosts. To investigate this hypothesis, we tested 10 isolates of B. dendrobatidis for their ability to grow on a range of keratin-supplemented agars and measured keratolytic enzyme activity using a commercially available kit (bioMerieux API ZYM). The most dense and fastest growth of isolates were recorded on tryptone agar, followed by growth on frog skin agar and the slowest growth recorded on feather meal and boiled snake skin agar. Growth patterns were distinctive for each nutrient source. All 10 isolates were strongly positive for a range of proteolytic enzymes which may be keratinolytic, including trypsin and chymotrypsin. These findings support the predilection of B. dendrobatidis for amphibian skin.

Topics: Agar; Animals; Anura; Chytridiomycota; Culture Media; Dermatomycoses; Keratins; Peptide Hydrolases

The main aim of this study was to verify the efficacy of subculture on potato dextrose agar (PDA) as a complement to the in vitro susceptibility test for Malassezia pachydermatis strains by a broth microdilution method, as well as to determine the MIC and MFC of azole derivatives, amphotericin B and caspofungin. The microdilution assay was performed in 96-well plates using a modified RPMI 1640 medium. The M. pachydermatis strains were resistant to caspofungin. All strains (n=50) had shown MIC values of <0.03, <0.03, 2.0, 4.0 and 4.0 microg/ml for itraconazole, ketoconazole, voriconazole, fluconazole and amphotericin B, respectively. Thus, the subculture on PDA improved the analysis of the in vitro antifungal susceptibility of M. pachydermatis.

Topics: Agar; Amphotericin B; Animals; Antifungal Agents; Azoles; Caspofungin; Culture Media; Dermatomycoses; Dog Diseases; Dogs; Echinocandins; Glucose; Lipopeptides; Malassezia; Microbial Sensitivity Tests; Microbiological Techniques; Solanum tuberosum

We incubated Sabouraud dextrose agar plates to recover dermatophytes from skin swabs sent for bacterial culture. Dermatophytes were recovered from 66 (0.3%) of 22,613 cultures. Twenty-one patients received specific antifungal treatment when their dermatophyte was reported. Most clinicians thought recovering and reporting the dermatophyte contributed to patient management.

Topics: Adolescent; Adult; Agar; Aged; Aged, 80 and over; Antifungal Agents; Arthrodermataceae; Child; Child, Preschool; Culture Media; Dermatomycoses; Female; Humans; Male; Microbiological Techniques; Middle Aged; Skin; Specimen Handling; Time Factors

In recent years, the genus Malassezia has been expanded based on molecular data; in addition to M. furfur and M. pachydermatis, five new species (M. sympodialis, M. globosa, M. obtusa, M. restricta, M. slooffiae) have been described. Apart from their lipid dependence, little is known about the metabolism and nutritional requirements of these new species. Defined inocula of Malassezia reference strains were cultured on selective agar for pathogenic fungi which was overlaid with olive oil. Samples of the olive oil overlay were taken at regular intervals and the lipid fractions were analysed by high performance thin layer chromatography. Depending on the time of incubation and the number of cells, M. sympodialis and the other recently described species produced a significant increase in free fatty acids. In addition, a band of an apolar substance was identified as a mixture of fatty acid ethyl esters. While showing growth, strains of M. furfur produced only small amounts of ethyl esters and free fatty acids. The growth kinetics of M. furfur and M. sympodialis were also different: for M. sympodialis, a clear lag phase was observed, possibly indicating the necessity of extracellular hydrolysis of the triglycerides. The significance of the synthesis of ethyl esters could not be clarified. For routine differentiation, this metabolic difference is only of limited usefulness because slight contamination of M. furfur strains with other lipophilic Malassezia species may lead to misinterpretation due to the high metabolic activity. These metabolic differences might be important in the pathogenesis of Malassezia infections.

Topics: Agar; Animals; Chromatography, High Pressure Liquid; Culture Media; Dermatomycoses; Fatty Acids, Nonesterified; Gas Chromatography-Mass Spectrometry; Lipid Metabolism; Malassezia; Olive Oil; Plant Oils; Reference Values; Skin; Species Specificity; Swine

Topics: Agar; Animals; Cell Culture Techniques; Culture Media; Dermatomycoses; Dog Diseases; Dogs; Malassezia; Skin

Two plant products, Euphorbia hirta leaves and fruits of Musa sapientum, were evaluated as principal ingredients for selective cultivation of fungi. Sapientum glucose agar supported the growth of both dermatophytic, yeast-like, and saprophytic fungi; growth on this medium compared favourably with growth on Sabouraud glucose agar, a standard mycological medium. Sporulation and pigment formation were stronger on sapientum glucose agar than on Sabouraud glucose agar, although fungal growth on the latter was more luxuriant. Addition of Euphorbia extract to mycological media remarkably enhanced fungal growth on the media, and concomitantly suppressed bacterial growth to a similar extent as did antibiotics. The results of this study suggest that Euphorbia sapientum glucose agar can safely be recommended as a cheap and efficient medium for routine isolation of fungi in both clinical and general mycological studies.

Topics: Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Dermatomycoses; Euphorbiaceae; Female; Fungi; Humans; Mycology; Plant Extracts; Plant Leaves; Zingiberales

Topics: Agar; Dermatomycoses; Epidermophyton; Humans; Microscopy, Electron, Scanning; Trichophyton

Topics: Agar; Arthrodermataceae; Clone Cells; Culture Media; Dermatomycoses; Genetic Variation; Histidine; Melanins; Pigments, Biological; Spores, Fungal; Trichophyton; Urease

Topics: Adrenal Cortex Hormones; Agar; Agranulocytosis; Bone Marrow Diseases; Culture Media; Culture Techniques; Dermatomycoses; Finger Joint; Humans; Joint Diseases; Knee Joint; Male; Middle Aged; Radiography; Sporothrix; Sporotrichosis

Topics: Agar; Arthrodermataceae; Colorimetry; Culture Media; Dermatomycoses; Humans; Indicators and Reagents; Male; Methylene Blue; Military Medicine; United States; Vietnam

Topics: Agar; Arthrodermataceae; Culture Media; Dermatomycoses; Drug Resistance, Microbial; Europe; Griseofulvin; Humans; Methods; Trichophyton

Topics: Administration, Topical; Aerosols; Agar; Animals; Anti-Inflammatory Agents; Antifungal Agents; Aspergillus; Candida; Dermatomycoses; Guinea Pigs; Humans; Hydrocortisone; Mice; Microsporum; Prednisolone; Trichophyton

Topics: Agar; Animals; Antifungal Agents; Candida; Culture Media; Dermatomycoses; Epidermophyton; Guinea Pigs; Humans; Photometry; Tinea; Trichophyton

Topics: Agar; Arthrodermataceae; Coloring Agents; Culture Media; Dermatomycoses; Fungi; Humans; Indicators and Reagents; Ink; Methods; Mitosporic Fungi

Topics: Adaptation, Biological; Agar; Arthrodermataceae; Dermatomycoses; Glucose; Hair; Humans; Pigmentation; Soil Microbiology; Species Specificity

Topics: Agar; Amebicides; Antifungal Agents; Aspergillosis; Candidiasis; Dermatomycoses; Drug Synergism; Humans; Microsporum; Quinolines; Resorcinols; Tinea