Sample records for yeast malassezia pachydermatis

  1. Patch test responses to Malassezia pachydermatis in healthy basset hounds and in basset hounds with Malassezia dermatitis.

    PubMed

    Bond, R; Patterson-Kane, J C; Perrins, N; Lloyd, D H

    2006-08-01

    The effects of the patch test application of Malassezia pachydermatis extracts were evaluated in seven healthy basset hounds and in seven basset hounds with Malassezia dermatitis. Antigens (4 and 0.4 mg/ml) and saline controls were applied for 48 h using filter paper discs in Finn chambers. One healthy basset hound and five affected hounds showed positive patch test reactivity to the yeast antigens. Positive patch test reactions were characterized histologically by mild epidermal hyperplasia and mild to moderate perivascular, periadnexal and interstitial infiltrates of neutrophils and CD3+ lymphocytes. Immediate intradermal test reactivity to M. pachydermatis antigens was seen in one healthy and one affected hound, whereas delayed intradermal test reactivity was seen in six healthy hounds and five affected hounds. This study indicates that patch test reactivity to M. pachydermatis antigen may occur in healthy basset hounds, and in contrast to delayed intradermal test reactivity, is more frequent in basset hounds with Malassezia dermatitis.

  2. The role of drug efflux pumps in Malassezia pachydermatis and Malassezia furfur defence against azoles.

    PubMed

    Iatta, Roberta; Puttilli, Maria Rita; Immediato, Davide; Otranto, Domenico; Cafarchia, Claudia

    2017-03-01

    This study aims to evaluate the effect of efflux pump modulators (EPMs) on the minimal inhibitory concentration (MIC) of fluconazole (FLZ) and voriconazole (VOR) in Malassezia furfur and Malassezia pachydermatis. The in vitro efficacy of azoles, in combination with EPMs (ie haloperidol-HAL, promethazine-PTZ and cyclosporine A-CYS), against 21 M. furfur from bloodstream infection patients and 14 M. pachydermatis from the skin of dogs with dermatitis, was assessed using a broth microdilution chequerboard analysis. Data were analysed using the model-fractional inhibitory concentration index (FICI) method. The MIC of FLZ and VOR of Malassezia spp. decreased in the presence of sub-inhibitory concentrations of HAL and/or PTZ. The synergic effect was observed only in strains with FLZ MIC≥128 μg/mL for M. furfur, FLZ MIC≥64 μg/mL for M. pachydermatis and VOR MIC≥4 μg/mL in both Malassezia spp. These results suggest that the drug efflux pumps are involved as defence mechanisms to azole drugs in Malassezia yeast. The synergism might be related to an increased expression of efflux pump genes, eventually resulting in azole resistance phenomena. Finally, the above FLZ and VOR MIC values might be considered the cut-off to discriminate susceptible and resistant strains. © 2016 Blackwell Verlag GmbH.

  3. In vitro susceptibility testing of Malassezia pachydermatis to gentamicin.

    PubMed

    Silva, Freddy A; Ferrer, Otilia; Déniz, Soraya; Rosario, Inmaculada; Conde-Felipe, Magnolia; Díaz, Esther L; Acosta-Hernández, Begoña

    2017-08-01

    Two studies have observed that growth media containing gentamicin can inhibit the growth of the yeast organism Malassezia pachydermatis. The minimum inhibitory concentration (MIC) of this bactericidal antibiotic for this organism has not been previously determined. To evaluate the susceptibility of M. pachydermatis isolates to gentamicin. The MIC of gentamicin was determined using a modified version of the M27-A3 microdilution method following the guidelines of the Clinical and Laboratory Standards Institute. A modified Christensen's urea broth was used to enhance the growth of the M. pachydermatis isolates. Visual and spectrophotometric end-point readings were performed to detect the presence or absence of yeast growth. The MIC50 and MIC90 of gentamicin were 8.12 μg/mL and 32.5 μg/mL, respectively; M. pachydermatis strains were classified as susceptible (S), intermediate (I) and resistant (R). The susceptibility of these isolates to gentamicin in vitro, by visual and spectrophotometric end-point reading, was: S, 54-56%; I, 40-41%; and R, 3-6%. Prospective MICs for M. pachydermatis have been established for gentamicin. © 2017 ESVD and ACVD.

  4. In vitro combination of antifungal agents against Malassezia pachydermatis.

    PubMed

    Schlemmer, Karine B; de Jesus, Francielli P K; Loreto, Erico S; Farias, Julia B; Alves, Sydney H; Ferreiro, Laerte; Santurio, Janio M

    2018-06-19

    The yeast Malassezia pachydermatis is a common commensal and occasional opportunistic pathogen of theskin microbiota of animals and humans. In this study, the susceptibility of M. pachydermatis isolates to fluconazole (FLC), itraconazole (ITZ), ketoconazole (KTZ), clotrimazole (CLZ), and miconazole (MCZ) alone and in combination with terbinafine (TRB), nystatin (NYS), and caspofungin (CSP) was evaluated in vitro based on the M27-A3 technique and the checkerboard microdilution method using Sabouraud dextrose broth with 1% tween 80 (SDB). Based on the mean FICI values, the main synergies observed were combinations of ITZ+CSP and CLZ+CSP (55.17%). The most significant combinations deserve in vivo evaluations because might provide effective alternative treatments against M. pachydermatis due to their synergistic interactions.

  5. Azole susceptibility of Malassezia pachydermatis and Malassezia furfur and tentative epidemiological cut-off values.

    PubMed

    Cafarchia, Claudia; Iatta, Roberta; Immediato, Davide; Puttilli, Maria Rita; Otranto, Domenico

    2015-09-01

    This study aims to determine the minimal inhibitory concentration (MIC) distribution and the epidemiological cut-off values (ECVs) of Malassezia pachydermatis and Malassezia furfur isolates for fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS), and voriconazole (VOR). A total of 62 M. pachydermatis strains from dogs with dermatitis and 78 M. furfur strains from humans with bloodstream infections (BSI) were tested by a modified broth microdilution Clinical and Laboratory Standards Institute (CLSI) method. ITZ and POS displayed lower MICs than VOR and FLZ, regardless of the Malassezia species. The MIC data for azoles of M. pachydermatis were four two-fold dilutions lower than those of M. furfur. Based on the ECVs, about 94% of Malassezia strains might be categorized within susceptible population for all azoles, except for FLZ, and azole cross-resistance was detected in association with FLZ in M. pachydermatis but not in M. furfur.The study proposes, for the first time, tentative azole ECVs for M. pachydermatis and M. furfur for monitoring the emergence of isolates with decreased susceptibilities and shows that the azole MIC distribution varied according to the Malassezia species tested, thus suggesting the usefulness of determining the susceptibility profile for effective treatment of each species. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Characterization of the species Malassezia pachydermatis and re-evaluation of its lipid dependence using a synthetic agar medium.

    PubMed

    Puig, Laura; Bragulat, M Rosa; Castellá, Gemma; Cabañes, F Javier

    2017-01-01

    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.

  7. Methodological Issues in Antifungal Susceptibility Testing of Malassezia pachydermatis

    PubMed Central

    Peano, Andrea; Pasquetti, Mario; Tizzani, Paolo; Chiavassa, Elisa; Guillot, Jacques; Johnson, Elizabeth

    2017-01-01

    Reference methods for antifungal susceptibility testing of yeasts have been developed by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antibiotic Susceptibility Testing (EUCAST). These methods are intended to test the main pathogenic yeasts that cause invasive infections, namely Candida spp. and Cryptococcus neoformans, while testing other yeast species introduces several additional problems in standardization not addressed by these reference procedures. As a consequence, a number of procedures have been employed in the literature to test the antifungal susceptibility of Malassezia pachydermatis. This has resulted in conflicting results. The aim of the present study is to review the procedures and the technical parameters (growth media, inoculum preparation, temperature and length of incubation, method of reading) employed for susceptibility testing of M. pachydermatis, and when possible, to propose recommendations for or against their use. Such information may be useful for the future development of a reference assay. PMID:29371554

  8. Characterization of the species Malassezia pachydermatis and re-evaluation of its lipid dependence using a synthetic agar medium

    PubMed Central

    Puig, Laura; Castellá, Gemma

    2017-01-01

    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. PMID:28586389

  9. Malassezia pachydermatis and M nana predominate amongst the cutaneous mycobiota of Sphynx cats.

    PubMed

    Volk, Andrea V; Belyavin, Clare E; Varjonen, Katarina; Cadiergues, Marie-Christine; Stevens, Kim B; Bond, Ross

    2010-12-01

    Carriage of Malassezia species yeasts in healthy Sphynx cats was compared with that in Devon Rex cats (DRC), Cornish Rex cats (CRC) and domestic shorthair (DSH) cats. Swab samples from the external ear, anus and claw folds, and contact plate samples from the axillae and groins, were incubated on modified Dixon's agar at 32°C for 7 days. Malassezia species were isolated from all 18 Sphynx cats; M pachydermatis accounted for 118/140 isolates. Of 20 isolates of M nana, 16 were recovered from the ear canal. M slooffiae was isolated from the claw fold of one cat and the left groin of another. The high counts of M pachydermatis obtained from the axillae, groins and claw folds of the Sphynx cats exceeded those of healthy DSH, CRC and DRC; axillary populations were comparable to those of seborrhoeic DRC. These data support recent reports of high Malassezia species colonisation in Sphynx cats. Copyright © 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

  10. Species composition of Malassezia yeasts in dogs in Slovakia.

    PubMed

    Sihelská, Zuzana; Váczi, Peter; Conková, Eva

    2016-01-01

    Malassezia (M.) pachydermatis is the lipophilic yeast, which is normally present on the skin and in the ear canal of dogs but under certain conditions it may cause dermatitis and otitis. There is less known about the occurrence of lipid-dependent Malassezia species in dogs. The aim of this study was to detect whether lipid-dependent yeasts are part of the normal microflora in dogs. Two groups of animals were selected for comparison. The group of healthy dogs contained samples of 118 individuals and the group of dogs with cutaneous lesions or otitis externa comprised 328 dogs. The isolates of Malassezia were identified by using genotypic methods that allow the precise identification. M. pachydermatis was the most frequently isolated species in this study (121 isolates). Only four isolates were identified as M. furfur and one isolate was identified as M. nana.

  11. Malassezia pachydermatis fungemia in an adult with multibacillary leprosy.

    PubMed

    Roman, Jorge; Bagla, Prabhava; Ren, Ping; Blanton, Lucas S; Berman, Megan A

    2016-06-01

    Malassezia pachydermatis is a relatively rare agent of bloodstream infections. We describe an unusual case of Malassezia fungemia in an adult patient hospitalized for Staphylococcus aureus bacteremia who was also found to have multibacillary leprosy. Treatment of the patient required extensive medical management but resulted in a good outcome.

  12. Lipid Metabolic Versatility in Malassezia spp. Yeasts Studied through Metabolic Modeling

    PubMed Central

    Triana, Sergio; de Cock, Hans; Ohm, Robin A.; Danies, Giovanna; Wösten, Han A. B.; Restrepo, Silvia; González Barrios, Andrés F.; Celis, Adriana

    2017-01-01

    Malassezia species are lipophilic and lipid-dependent yeasts belonging to the human and animal microbiota. Typically, they are isolated from regions rich in sebaceous glands. They have been associated with dermatological diseases such as seborrheic dermatitis, pityriasis versicolor, atopic dermatitis, and folliculitis. The genomes of Malassezia globosa, Malassezia sympodialis, and Malassezia pachydermatis lack the genes related to fatty acid synthesis. Here, the lipid-synthesis pathways of these species, as well as of Malassezia furfur, and of an atypical M. furfur variant were reconstructed using genome data and Constraints Based Reconstruction and Analysis. To this end, the genomes of M. furfur CBS 1878 and the atypical M. furfur 4DS were sequenced and annotated. The resulting Enzyme Commission numbers and predicted reactions were similar to the other Malassezia strains despite the differences in their genome size. Proteomic profiling was utilized to validate flux distributions. Flux differences were observed in the production of steroids in M. furfur and in the metabolism of butanoate in M. pachydermatis. The predictions obtained via these metabolic reconstructions also suggested defects in the assimilation of palmitic acid in M. globosa, M. sympodialis, M. pachydermatis, and the atypical variant of M. furfur, but not in M. furfur. These predictions were validated via physiological characterization, showing the predictive power of metabolic network reconstructions to provide new clues about the metabolic versatility of Malassezia. PMID:28959251

  13. Lipid Metabolic Versatility in Malassezia spp. Yeasts Studied through Metabolic Modeling.

    PubMed

    Triana, Sergio; de Cock, Hans; Ohm, Robin A; Danies, Giovanna; Wösten, Han A B; Restrepo, Silvia; González Barrios, Andrés F; Celis, Adriana

    2017-01-01

    Malassezia species are lipophilic and lipid-dependent yeasts belonging to the human and animal microbiota. Typically, they are isolated from regions rich in sebaceous glands. They have been associated with dermatological diseases such as seborrheic dermatitis, pityriasis versicolor, atopic dermatitis, and folliculitis. The genomes of Malassezia globosa , Malassezia sympodialis , and Malassezia pachydermatis lack the genes related to fatty acid synthesis. Here, the lipid-synthesis pathways of these species, as well as of Malassezia furfur , and of an atypical M. furfur variant were reconstructed using genome data and Constraints Based Reconstruction and Analysis. To this end, the genomes of M. furfur CBS 1878 and the atypical M. furfur 4DS were sequenced and annotated. The resulting Enzyme Commission numbers and predicted reactions were similar to the other Malassezia strains despite the differences in their genome size. Proteomic profiling was utilized to validate flux distributions. Flux differences were observed in the production of steroids in M. furfur and in the metabolism of butanoate in M. pachydermatis . The predictions obtained via these metabolic reconstructions also suggested defects in the assimilation of palmitic acid in M. globosa , M. sympodialis , M. pachydermatis , and the atypical variant of M. furfur , but not in M. furfur. These predictions were validated via physiological characterization, showing the predictive power of metabolic network reconstructions to provide new clues about the metabolic versatility of Malassezia .

  14. A pilot study of the efficacy of wipes containing chlorhexidine 0.3%, climbazole 0.5% and Tris-EDTA to reduce Malassezia pachydermatis populations on canine skin.

    PubMed

    Cavana, Paola; Peano, Andrea; Petit, Jean-Yanique; Tizzani, Paolo; Perrot, Sébastien; Bensignor, Emmanuel; Guillot, Jacques

    2015-08-01

    Wipes containing chlorhexidine and azole derivates have been recommended for veterinary use. No study has been published about their activity against Malassezia pachydermatis. To evaluate the in vivo and in vitro activity of wipes soaked in a chlorhexidine, climbazole and Tris-EDTA solution against Malassezia pachydermatis. Five research colony shar-pei dogs. Wipes were applied once daily onto the left axilla, left groin and perianal area (protocol A), and twice daily on the right axilla, right groin and umbilical region (protocol B) for 3 days. In vivo activity was evaluated by quantifying Malassezia colonies through contact plates on the selected body areas before and after wipe application. The activity of the solution in which the wipes were soaked was assessed in vitro by contact tests following the European Standard UNI EN 1275 guidelines. Samples collected after wipe application showed a significant and rapid reduction of Malassezia yeast CFU. No significant difference in the Malassezia reduction was found between protocols A and B. In vitro assay showed 100% activity against Malassezia yeasts after a 15 min contact time with the wipe solution. Wipes containing chlorhexidine, climbazole and Tris-EDTA substantially reduced the M. pachydermatis population on the skin of dogs. The results, although this was an uncontrolled study performed on a small number of dogs, suggest that these wipes may be useful for topical therapy of Malassezia dermatitis involving the lips, paws, perianal area and skin folds. © 2015 ESVD and ACVD.

  15. In vitro antifungal susceptibility of Malassezia pachydermatis from dogs with and without skin lesions.

    PubMed

    Cafarchia, Claudia; Figueredo, Luciana A; Iatta, Roberta; Montagna, Maria Teresa; Otranto, Domenico

    2012-03-23

    Canine Malassezia dermatitis is frequently treated with systemic ketoconazole (KTZ) and itraconazole (ITZ). However, no information is available on the antifungal susceptibility to azoles and allilamine of Malassezia pachydermatis isolates from dogs with or without skin lesions. The present study was designed to evaluate the in vitro antifungal susceptibility of M. pachydermatis strains from dogs with or without skin lesions to KTZ, ITZ, miconazole (MICO), fluconazole (FLZ), posaconazole (POS), voriconazole (VOR) and terbinafine (TER) using the Clinical and Laboratory Standards Institute reference Broth Microdilution Method (CLSI M27-A2). The association between the susceptibility to antifungal compounds and the origin of M. pachydermatis, from skin with or without lesions has been also assessed. A total of 62 M. pachydermatis strains from healthy dogs (i.e., Group A=30) or with skin lesions (i.e., Group B=32) were tested. ITZ, KTZ and POS showed the highest activity against M. pachydermatis strains, whereas MICO TER and FLZ the lowest. A higher number of Malassezia resistant strains were registered among isolates from Group B than those from Group A. This study indicates that M. pachydermatis strains were susceptible to ITZ, KTZ, and POS. However, dogs with lesions may harbour strains with low susceptibility to antifungal agents and displaying cross-resistance phenomena to azole. The antifungal therapy in Malassezia infections requires careful appraisal of choice of drugs especially in cases of unresponsiveness to antifungal treatment or recurrent infections. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. In vitro and in vivo activity of a killer peptide against Malassezia pachydermatis causing otitis in dogs.

    PubMed

    Cafarchia, Claudia; Immediato, Davide; Paola, Giancarlo Di; Magliani, Walter; Ciociola, Tecla; Conti, Stefania; Otranto, Domenico; Polonelli, Luciano

    2014-05-01

    In order to overcome the limitations inherent in current pharmacological treatments for Malassezia pachydermatis, the cause of otitis externa in dogs, the efficacy of a killer decapeptide (KP) was evaluated in vitro and in vivo. Sixteen dogs with naturally occurring M. pachydermatis otitis externa were enrolled, and the in vitro fungicidal activity of KP was evaluated using yeasts recovered from these animals. The therapeutic activity was evaluated in four groups of four animals each. The dogs were topically treated with KP (150 μl, 2 mg/ml) three times per week (group A) or every day (group B), treated with a scramble peptide every day (group C), or left untreated (group D). Assessment of clinical signs (pruritus, erythema, and lichenification and/or hyperpigmentation), expressed as mean of the total clinical index score (mTCIS), the population size of M. pachydermatis at the cytological examination (mean number of yeast cells at 40× magnification [mYC]), and culture testing (mean number of log10 CFU/swab [mCFU]), were conducted daily from the first day of treatment (T0) until two consecutive negative cultures (mCFU ≤ 2). KP showed an in vitro fungicidal effect against M. pachydermatis isolates, with an MFC90 value of 1 μg/ml. The mTCIS, mYC and mCFU were negative only in animals in group B after T8. Daily administration of KP for 8 days was safe and effective in controlling both clinical signs and the population size of M. pachydermatis causing otitis externa, thus offering an alternative to the currently available therapeutic or prophylactic protocols for recurrent cases of Malassezia otitis in dogs.

  17. Highly efficient transformation system for Malassezia furfur and Malassezia pachydermatis using Agrobacterium tumefaciens-mediated transformation.

    PubMed

    Celis, A M; Vos, A M; Triana, S; Medina, C A; Escobar, N; Restrepo, S; Wösten, H A B; de Cock, H

    2017-03-01

    Malassezia spp. are part of the normal human and animal mycobiota but are also associated with a variety of dermatological diseases. The absence of a transformation system hampered studies to reveal mechanisms underlying the switch from the non-pathogenic to pathogenic life style. Here we describe, a highly efficient Agrobacterium-mediated genetic transformation system for Malassezia furfur and M. pachydermatis. A binary T-DNA vector with the hygromycin B phosphotransferase (hpt) selection marker and the green fluorescent protein gene (gfp) was introduced in M. furfur and M. pachydermatis by combining the transformation protocols of Agaricus bisporus and Cryptococcus neoformans. Optimal temperature and co-cultivation time for transformation were 5 and 7days at 19°C and 24°C, respectively. Transformation efficiency was 0.75-1.5% for M. furfur and 0.6-7.5% for M. pachydermatis. Integration of the hpt resistance cassette and gfp was verified using PCR and fluorescence microscopy, respectively. The T-DNA was mitotically stable in approximately 80% of the transformants after 10 times sub-culturing in the absence of hygromycin. Improving transformation protocols contribute to study the biology and pathophysiology of Malassezia. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  18. An azole-resistant isolate of Malassezia pachydermatis.

    PubMed

    Nijima, Misako; Kano, Rui; Nagata, Masahiko; Hasegawa, Atsuhiko; Kamata, Hiroshi

    2011-04-21

    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. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Carriage of Malassezia spp. yeasts in Cornish Rex, Devon Rex and Domestic short-haired cats: a cross-sectional survey.

    PubMed

    Bond, R; Stevens, K; Perrins, N; Ahman, S

    2008-10-01

    Carriage of Malassezia spp. yeasts in healthy Cornish Rex cats (CRC) was compared with that in Devon Rex (DRC) and Domestic short-haired (DSH) cats. Samples obtained from the left external ear canal, anus and claw fold of digit III of the left fore foot by swabbing, and the axilla and groin using contact plates, were incubated for yeasts on modified Dixon's agar at 32 degrees C for 7 days. Malassezia species were isolated from 90% of the DRC, but from only 39% of the CRC and 50% of the DSH cats. M. pachydermatis accounted for 121 of 141 Malassezia spp. isolates. Five CRC were colonized by M. pachydermatis alone, one CRC yielded only M. nana, and one cat yielded only M. slooffiae, whereas five CRC were colonized by both M. pachydermatis and M. nana and another yielded M. pachydermatis, M. slooffiae and M. nana. M. nana was primarily isolated from the ear canal, whereas M. slooffiae was most often isolated from the claw. Both the frequencies of isolation and the population sizes of M. pachydermatis at all sites sampled in the CRC were comparable to those of 10 healthy DSH cats. Populations of M. pachydermatis in the left axilla and left and right groin in the CRC were significantly lower when compared with counts in a group of 21 healthy DRC, a breed with very similar coat characteristics but prone to seborrheic dermatitis caused by M. pachydermatis.

  20. Correlation between genetic variability and virulence factors in clinical strains of Malassezia pachydermatis of animal origin.

    PubMed

    Buommino, Elisabetta; Nocera, Francesca Paola; Parisi, Annamaria; Rizzo, Antonietta; Donnarumma, Giovanna; Mallardo, Karina; Fiorito, Filomena; Baroni, Adone; De Martino, Luisa

    2016-07-01

    Malassezia pachydermatis is a yeast belonging to the microbiota of the skin and mucous membranes of dog and cat, but it can also act as pathogen, causing dermatitis. The aim of this work was to evaluate the genetic variability of M. pachydermatis strains isolated from symptomatic dogs and cats and determine a correlation between genotype and phenotype. For this purpose eleven strains of M. pachydermatis were molecularly classified by nested-polymerase chain reaction (nested-PCR) based on ITS-1 and ITS-2 regions, specific for fungal rRNA genes. Furthermore, random amplification of polymorphic DNA (RAPD) was applied for genetic typing of M. pachydermatis isolates identifying four different genotypes. Strains belonging to genotype 1 produced the highest amount of biofilm and phospholipase activity. The inflammatory response induced by M. pachydermatis strains in immortalized human keratinocytes (HaCat cells) was significantly different when we compared the results obtained from each strain. In particular, HaCat cells infected with the strains belonging to genotypes 1 and 2 triggered the highest levels of increase in TLR-2, IL-1β, IL-6, IL-8, COX-2 and MMP-9 expression. By contrast, cells infected with the strains of genotype 3 and those of genotype 4 did not significantly induce TLR-2 and cytokines. The results obtained might suggest a possible association between genotype and virulence factors expressed by M. pachydermatis strains. This highlights the need for a more accurate identification of the yeast to improve the therapeutic approach and to monitor the onset of human infections caused by this emergent zoonotic pathogen.

  1. In Vitro Susceptibility of Malassezia pachydermatis Isolates from Canine Skin with Atopic Dermatitis to Ketoconazole and Itraconazole in East Asia

    PubMed Central

    WATANABE, Shion; KOIKE, Anna; KANO, Rui; NAGATA, Masahiko; CHEN, Charles; HWANG, Cheol-Yong; HASEGAWA, Atsuhiko; KAMATA, Hiroshi

    2013-01-01

    ABSTRACT Topical or oral azole antifungals are commonly used in canine atopic dermatitis (AD), as the lipophilic yeast Malassezia pachydermatis exacerbates canine AD. To examine whether canine AD lesions harbor azole-resistant M. pachydermatis isolates in East Asia, we investigated the in vitro susceptibility of M. pachydermatis isolates to ketoconazole (KTZ) and itraconazole (ITZ) obtained from AD lesions of canines in Japan, Korea and Taiwan. The minimum inhibitory concentrations (MICs) of KTZ and ITZ were measured by the E-test using Sabouraud dextrose agar with 0.5% Tween 40. The MICs of KTZ and ITZ for isolates from canines with AD were significantly higher than the MICs for isolates from healthy canines. Our findings suggested that the clinical isolates from canine AD skin lesions were less susceptible to azoles than those from normal canine skin in East Asia. PMID:24334863

  2. In vitro susceptibility of Malassezia pachydermatis isolates from canine skin with atopic dermatitis to ketoconazole and itraconazole in East Asia.

    PubMed

    Watanabe, Shion; Koike, Anna; Kano, Rui; Nagata, Masahiko; Chen, Charles; Hwang, Cheol-Yong; Hasegawa, Atsuhiko; Kamata, Hiroshi

    2014-04-01

    Topical or oral azole antifungals are commonly used in canine atopic dermatitis (AD), as the lipophilic yeast Malassezia pachydermatis exacerbates canine AD. To examine whether canine AD lesions harbor azole-resistant M. pachydermatis isolates in East Asia, we investigated the in vitro susceptibility of M. pachydermatis isolates to ketoconazole (KTZ) and itraconazole (ITZ) obtained from AD lesions of canines in Japan, Korea and Taiwan. The minimum inhibitory concentrations (MICs) of KTZ and ITZ were measured by the E-test using Sabouraud dextrose agar with 0.5% Tween 40. The MICs of KTZ and ITZ for isolates from canines with AD were significantly higher than the MICs for isolates from healthy canines. Our findings suggested that the clinical isolates from canine AD skin lesions were less susceptible to azoles than those from normal canine skin in East Asia.

  3. Antifungal agent susceptibilities and interpretation of Malassezia pachydermatis and Candida parapsilosis isolated from dogs with and without seborrheic dermatitis skin.

    PubMed

    Yurayart, Chompoonek; Nuchnoul, Noppawan; Moolkum, Pornsawan; Jirasuksiri, Supitcha; Niyomtham, Waree; Chindamporn, Ariya; Kajiwara, Susumu; Prapasarakul, Nuvee

    2013-10-01

    Malassezia pachydermatis and Candida parapsilosis are recognized as commensal yeasts on the skin of healthy dogs but also causative agents of eborrheic dermatitis, especially in atopic dogs. We determined and compared the susceptibility levels of yeasts isolated from dogs with and without seborrheic dermatitis (SD) using the disk diffusion method (DD) for itraconazole (ITZ), ketoconazole (KTZ), nystatin (NYS), terbinafine (TERB) and 5-fluorocytosine (5-FC) and the broth microdilution method (BMD) for ITZ and KTZ. The reliability between the methods was assessed using an agreement analysis and linear regression. Forty-five M. pachydermatis and 28 C. parapsilosis isolates were identified based on physiological characteristics and an approved molecular analysis. By DD, all tested M. pachydermatis isolates were susceptible to ITZ, KTZ, NYS and TERB but resistant to 5-FC. Only 46 - 60% of the tested C. parapsilosis isolates were susceptible to KTZ, TERB and 5-FC, but ITZ and NYS were effective against all. By BMD, over 95% of M. pachydermatis isolates were susceptible to KTZ and ITZ with an MIC90 < 0.03 and 0.12 μg/ml, respectively. The frequency of KTZ- and ITZ-resistant C. parapsilosis was 29% and 7%, and the MIC90 values were 1 μg/ml and 0.5-1 μg/ml, respectively. Regarding the agreement analysis, 2.2% of minor errors were observed in M. pachydermatis and 0.2-1% of very major errors occurred among C. parapsilosis. There were no significant differences in the yeast resistance rates between dogs with and without SD. KTZ and ITZ were still efficacious for M. pachydermatis but a high rate of KTZ resistant was reported in C. parapsilosis.

  4. Efficacy of Amitraz plus Metaflumizone for the treatment of canine demodicosis associated with Malassezia pachydermatis

    PubMed Central

    Tarallo, Viviana D; Lia, Riccardo P; Sasanelli, Mariateresa; Cafarchia, Claudia; Otranto, Domenico

    2009-01-01

    This case reports the efficacy of metaflumizone plus amitraz spot-on formulation (ProMeris Duo®; Fort Dodge) against generalized demodectic mange. A two year-old male dog presented at clinical examination with poor general condition, diffused alopecia, crusted lesions, pruritus, skin scales and pustules. Demodex mites, Malassezia pachydermatis yeasts and bacteria were diagnosed. The dog was treated with cephalexin and topically with metaflumizone plus amitraz spot on formulation at two weeks intervals until two consecutive skin scrapings resulted negative for mites. The number of adult mites statistically decreased at follow-up with a reduction of approximately 42 and 94% at +14 and +28 days post treatment (p.t.) respectively. Nymphs and larvae could not be detected from +28 day p.t. while eggs were no longer present +42 day p.t. The dog was negative for both bacteria and M. pachydermatis at 14 days p.t., coinciding with improved general clinical conditions, recovering skin lesions and no further signs of pruritus. These results show that metaflumizone plus amitraz associated with the antibiotic therapy is highly effective for treating generalized demodectic mange and could also be effective toward controlling M. pachydermatis opportunistic infections. PMID:19265536

  5. Susceptibility of Malassezia pachydermatis to aminoglycosides.

    PubMed

    Silva, Freddy Alejandro; Conde-Felipe, Magnolia; Rosario, Inmaculada; Ferrer, Otilia; Real, Fernando; Déniz, Soraya; Acosta, Félix; Padilla, Daniel; Acosta-Hernández, Begoña

    2017-12-01

    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. © 2017 Blackwell Verlag GmbH.

  6. Comparison of the results of intradermal test reactivity and serum allergen-specific IgE measurement for Malassezia pachydermatis in atopic dogs.

    PubMed

    Oldenhoff, Willam E; Frank, Glenn R; DeBoer, Douglas J

    2014-12-01

    Malassezia pachydermatis is part of the normal flora of canine skin. Malassezia hypersensitivity is recognized as a trigger for clinical signs of atopic dermatitis (AD) in some dogs. Determinations of Malassezia hypersensitivity are often made with intradermal testing (IDT), which may have limited availability in a first-opinion veterinary practice. The purpose of this study was to compare immediate IDT reactivity to M. pachydermatis with results of an enzyme-linked immunosorbent assay (ELISA) designed to detect anti-Malassezia IgE. Eighty-four dogs with a clinical diagnosis of AD. Multi-allergen IDT was performed on all dogs. Serum testing for allergen-specific IgE against a panel of common environmental allergens and M. pachydermatis was performed by ELISA using the FcεRIα receptor fragment as a detection reagent, with results reported as adjusted optical density (OD). A receiver operating characteristic (ROC) curve was used to analyse the results of the two tests. The median adjusted OD of the anti-Malassezia IgE ELISA for dogs reactive and nonreactive to M. pachydermatis on IDT was 0.137 and 0.024, respectively. Analysis of the ROC curve suggested a cut-off point for the anti-Malassezia ELISA that yielded a sensitivity of 77.0% and a specificity of 89% relative to IDT results. Substantial agreement was demonstrated between IDT reactivity and anti-Malassezia IgE as detected by the FcεRIα receptor reagent. Although correlation with a clinical diagnosis of Malassezia dermatitis was not attempted in this study, the results indicate that the ELISA may be used to demonstrate the presence of immediate-type Malassezia hypersensitivity in dogs with AD. © 2014 ESVD and ACVD.

  7. Cryptic Diversity of Malassezia pachydermatis from Healthy and Diseased Domestic Animals.

    PubMed

    Puig, Laura; Castellá, Gemma; Cabañes, F Javier

    2016-10-01

    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.

  8. Biofilm formation in Malassezia pachydermatis strains isolated from dogs decreases susceptibility to ketoconazole and itraconazole.

    PubMed

    Jerzsele, Akos; Gyetvai, Béla; Csere, István; Gálfi, Péter

    2014-12-01

    Malassezia pachydermatis is a commonly isolated yeast in veterinary dermatology that can produce biofilms in vitro and in vivo, lowering its susceptibility to antimicrobial drugs. The aim of this study was to determine and compare the in vitro susceptibility of planktonic cells and biofilms of M. pachydermatis isolates to ketoconazole and itraconazole. The presence of biofilm formation was confirmed by crystal violet staining and absorbance measurement at 595 nm wavelength, and by a scanning electron microscopy method. Cell viability was determined by the Celltiter 96 Aqueous One solution assay containing a water-soluble tetrazolium compound (MTS) with absorbance measurement at 490 nm. Planktonic cell minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of ketoconazole and itraconazole were very low: MIC90 and MFC90 were 0.032 and 0.125 μg/ml for ketoconazole, while 0.063 and 0.25 μg/ml for itraconazole, respectively. Also, the half maximal effective concentrations (EC50) of itraconazole were higher for planktonic cells and biofilms compared to ketoconazole. The EC50 values of ketoconazole were 18-169 times higher and those of itraconazole 13-124 times higher for biofilms than for planktonic cells. Biofilm EC50 levels exceeded MICs 103-2060 times for ketoconazole and 84-1400 times for itraconazole. No significant difference was found between these values of the two substances. In conclusion, biofilms of all examined M. pachydermatis strains were much less susceptible to ketoconazole and itraconazole than their planktonic forms.

  9. Intradermal test reactivity to Malassezia pachydermatis in healthy basset hounds and basset hounds with Malassezia dermatitis.

    PubMed

    Bond, R; Patterson-Kane, J C; Lloyd, D H

    2002-07-27

    Nineteen healthy beagles, eight healthy basset hounds and 17 basset hounds with Malassezia dermatitis were tested intradermally with two extracts of M pachydermatis. One healthy beagle and two affected basset hounds showed wheal and flare reactions 15 minutes after the injection. Delayed reactions, consisting of erythematous macules and plaques, were commonly observed 24 hours after the injection in both the healthy and affected basset hounds, but occurred infrequently in the beagles. At 24 hours the diameters of the lesions in the healthy and affected basset hounds were significantly (P<0.01) greater than those in the healthy beagles, but the diameters in the healthy and affected basset hounds did not vary significantly. Delayed reactions in six of the basset hounds with Malassezia dermatitis were characterised histologically by superficial perivascular and periadnexal infiltrates of neutrophils and lymphocytes.

  10. Biofilm production and antifungal susceptibility of co-cultured Malassezia pachydermatis and Candida parapsilosis isolated from canine seborrheic dermatitis.

    PubMed

    Bumroongthai, K; Chetanachan, P; Niyomtham, W; Yurayart, C; Prapasarakul, N

    2016-07-01

    The yeasts Malassezia (M.) pachydermatis and Candida (C.) parapsilosis are often co-isolated in case of canine seborrhea dermatitis (SD) and also are emerging as opportunistic pathogens of immunocompromised human beings. Increased information about how their relationship results in biofilm production and an antifungal response would be useful to inform treatment and control. This study was designed to investigate biofilm production derived from co-culture of M. pachydermatis and C. parapsilosis from dog skin and to determine their in vitro antifungal susceptibility. We demonstrated that regardless of yeast strain or origin all single and dual cultures produced biofilms within 24 hours, and the greatest amount was present after 72 hours. Biofilm production from mixed cultures was greater than for single strains (P < .05). All sessile forms of the single and dual cultures were resistant to the tested antifungals itraconazole and ketoconazole, whereas planktonic forms were susceptible. The study suggests that dual cultures produce stronger biofilms that are likely to enhance persistence in skin lesions in dogs and result in greater resistance to antifungal treatment. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Effects of beta-thujaplicin on anti-Malassezia pachydermatis remedy for canine otitis externa.

    PubMed

    Nakano, Yasuyuki; Wada, Makoto; Tani, Hiroyuki; Sasai, Kazumi; Baba, Eiichiroh

    2005-12-01

    The antifungal activity of beta-thujaplicin was evaluated against 51 Malassezia pachydermatis strains isolated from canine ear canals with or without otitis externa. For comparison, sensitivity tests were performed on M. pachydermatis isolates for nystatin, ketoconazole, and terbinafine HCl, all clinically available antifungal agents. The minimal inhibition concentrations over 50% of the tested isolates (MIC50) were 3.13 microg/ml for beta-thujaplicin and nystatin, 0.016 microg/ml for ketoconazole, and 1.56 microg/ml for terbinafine HCl. The antifungal effect for M. pachydermatis of beta-thujaplicin compared favorably with commercial antifungal agents. None of the 51 M. pachydermatis isolates showed resistance against any of the tested antibiotics investigated in this study. Ten representative isolates of M. pachydermatis were subcultured for 30 generations at concentrations close to the MIC levels of beta-thujaplicin, nystatin, ketoconazole, and terbinafine HCl, and examined to determine whether they had acquired resistance to each drug. As a result, M. pachydermatis was found to achieve resistance more easily for ketoconazole and terbinafine HCl than for beta-thujaplicin or nystatin. The MIC50 of beta-thujaplicin did not change during the course of subculture, and it is thought that the potential development of a resistant strain is low, even with continuous infusion for otitis externa therapy. beta-Thujaplicin is an inexpensive and safe treatment with anti-inflammatory and deodorant effects that can be recommended as an effective remedy for canine otitis externa.

  12. Real-Time PCR Identification of Six Malassezia Species.

    PubMed

    Ilahi, Amin; Hadrich, Inès; Neji, Sourour; Trabelsi, Houaida; Makni, Fattouma; Ayadi, Ali

    2017-06-01

    Lipophilic yeast Malassezia species is widely found on the skin surface of humans and other animals. This fungus can cause pityriasis versicolor, Malassezia folliculitis, and seborrheic dermatitis. Still now, there is a problem with species identification of Malassezia with conventional methods. We developed a real-time polymerase chain reaction (PCR) assay with multiple hybridization probes for detecting M. globosa, M. furfur, M. restricta, M. sympodialis, M. slooffiae, and M. pachydermatis. The amplification curves and specific melting peaks of the probes hybridized with real-time PCR product were used for species identifications. The assay was further evaluated on 120 samples which were performed by swabbing from 60 domestic animals (23 goats, 10 dogs, 15 cows, 3 cats, 8 rabbits, and 1 donkey) and in 70 human samples (28 patients with pityriasis versicolor, 17 breeders, and 25 control group). Fifteen M. pachydermatis were identified from animals. From human, 61 isolates were identified as M. globosa (28), M. furfur (15), M. restricta (6), M. sympodialis (8), M. slooffiae (2), and M. pachydermatis (2). Eight cases of co-detection from 6 patients and 2 breeders were revealed. Our findings show that the assay was highly effective in identifying Malassezia species. The application of multiplex real-time PCR provides a sensitive and rapid identification system for Malassezia species, which may be applied in further epidemiological surveys from clinical samples.

  13. Malassezia species in healthy skin and in dermatological conditions.

    PubMed

    Prohic, Asja; Jovovic Sadikovic, Tamara; Krupalija-Fazlic, Mersiha; Kuskunovic-Vlahovljak, Suada

    2016-05-01

    The genus Malassezia comprises lipophilic species, the natural habitat of which is the skin of humans and other warm-blooded animals. However, these species have been associated with a diversity of dermatological disorders and even systemic infections. Pityriasis versicolor is the only cutaneous disease etiologically connected to Malassezia yeasts. In the other dermatoses, such as Malassezia folliculitis, seborrheic dermatitis, atopic dermatitis, and psoriasis, these yeasts have been suggested to play pathogenic roles either as direct agents of infection or as trigger factors because there is no evidence that the organisms invade the skin. Malassezia yeasts have been classified into at least 14 species, of which eight have been isolated from human skin, including Malassezia furfur, Malassezia pachydermatis, Malassezia sympodialis, Malassezia slooffiae, Malassezia globosa, Malassezia obtusa, Malassezia restricta, Malassezia dermatis, Malassezia japonica, and Malassezia yamatoensis. Distributions of Malassezia species in the healthy body and in skin diseases have been investigated using culture-based and molecular techniques, and variable results have been reported from different geographical regions. This article reviews and discusses the latest available data on the pathogenicity of Malassezia spp., their distributions in dermatological conditions and in healthy skin, discrepancies in the two methods of identification, and the susceptibility of Malassezia spp. to antifungals. © 2015 The International Society of Dermatology.

  14. Granulomatous dermatitis due to Malassezia sympodialis.

    PubMed

    Desai, Harsha B; Perkins, Philip L; Procop, Gary W

    2011-09-01

    A 67-year-old man, with multiple skin lesions that appeared over 2 years, had biopsies that disclosed granulomatous dermatitis with associated small yeasts. The urinary antigen test results were negative for Histoplasma infection; cultures from the biopsies did not grow any fungi or other potential pathogens. The chest roentgenogram results were normal. Morphologic examination revealed features of a Malassezia species. Broad-range fungal polymerase chain reaction and DNA sequencing disclosed that the infecting fungus was Malassezia sympodialis , a lipid-dependent yeast. This report supports one other case report that Malassezia species may cause granulomatous dermatitis; in the previous case, the etiologic agent was Malassezia pachydermatis , a nonlipid-dependent species. We recommend the use of lipid-supplemented culture media for specimens from patients with granulomatous dermatitis because several Malassezia species are dependent on lipid; the absence of lipid supplementation in routine cultures likely explains the negative culture results for this patient. This, to our knowledge, is the first report of granulomatous dermatitis caused by M sympodialis.

  15. [Malassezia yeasts and their significance in dermatology].

    PubMed

    Hort, W; Nilles, M; Mayser, P

    2006-07-01

    Yeasts of the genus Malassezia belong to the normal microflora of the human skin. In addition they are known to cause a variety of skin diseases; the most frequent of which is pityriasis versicolor. Malassezia yeasts are also thought to be associated with seborrheic dermatitis, dandruff and Malassezia folliculitis. Recently the significance of Malassezia yeasts as a trigger factor for atopic dermatitis of the head and neck region has been pointed out. The role of the Malassezia yeasts in these different diseases has been controversial in the past and remains an issue because of difficulties in isolation, culture and differentiation of the organism. Thanks to molecular techniques, 10 species can actually be differentiated. The article presents the different Malassezia-associated diseases, their clinical picture, diagnosis and appropriate therapy. In addition the speciation of Malassezia is reviewed.

  16. Comparison of two shampoos for treatment of Malassezia pachydermatis-associated seborrhoeic dermatitis in basset hounds.

    PubMed

    Bond, R; Rose, J F; Ellis, J W; Lloyd, D H

    1995-03-01

    A randomised-double-blind parallel study compared the clinical and antimicrobial efficacies of a miconazole-chlorhexidine shampoo with a selenium sulphide shampoo for the treatment of seborrhoeic dermatitis associated with Malassezia pachydermatis in 33 basset hounds. All 16 miconazole-chlorhexidine treated hounds and 11 of 17 selenium sulphide treated hounds improved when shampooed at three-day intervals for three weeks. The miconazole-chlorhexidine treated hounds showed significantly greater reductions in pruritus (P < 0.01), erythema (P < 0.001), exudation (P < 0.01) and overall severity (P < 0.001), and in counts of M pachydermatis (P < 0.001), total bacteria (P < 0.001) and coagulase-positive staphylococci (P < 0.001), when compared to the selenium sulphide treated group. Improvements in scaling and coat condition did not vary significantly between the two groups. These results indicate that seborrhoeic dermatitis in basset hounds is often associated with elevated cutaneous populations of M pachydermatis and bacteria, and that the miconazole-chlorhexidine shampoo is more effective than the selenium sulphide product for the treatment for this disease.

  17. Cutaneous carriage of Malassezia species in healthy and seborrhoeic Sphynx cats and a comparison to carriage in Devon Rex cats.

    PubMed

    Ahman, Susanne E; Bergström, Karin E

    2009-12-01

    Cutaneous carriage of Malassezia species yeast was investigated in 32 Sphynx cats, and in 10 domestic shorthair (DSH) cats. Samples for mycological culture were taken using contact plates and swabs at seven sites in each cat (left and right axillae and groin, left ear, claw fold on left front paw and the interdigital palmar web of the left front paw). Malassezia species were isolated from 26/32 Sphynx cats (81%) and from 0/10 DSH control cats. In five cases Malassezia species yeasts were isolated at a single site, in the remaining 21 Sphynx cats at multiple sites. A total of 73 Malassezia species isolates were made, of which 68 were Malassezia pachydermatis and five were lipid-dependent Malassezia. Five out of the 32 Sphynx had greasy seborrhoea, and all seborrhoeic cats had M pachydermatis isolated from their skin, at multiple sites. None of the 32 Sphynx had Malassezia species isolated from the ears. The difference in population sizes between Sphynx and DSH cats was significant (PMalassezia species in Sphynx was similar to that previously reported for Devon Rex cats (DRC) [Ahman S, Perrins N, Bond R. Carriage of Malassezia species yeasts in healthy and seborrhoeic Devon Rex cats. Med Mycol 2007; 45: 449-455]. The poor recovery of Malassezia species from ears in both Sphynx and DRC, has clinical implications for dermatological sampling in these breeds.

  18. A pilot study of the efficacy of wipes containing chlorhexidine 0.3%, climbazole 0.5% and Tris-EDTA to reduce Malassezia pachydermatis populations on canine skin

    PubMed Central

    Cavana, Paola; Peano, Andrea; Petit, Jean-Yanique; Tizzani, Paolo; Perrot, Sébastien; Bensignor, Emmanuel; Guillot, Jacques

    2015-01-01

    Background Wipes containing chlorhexidine and azole derivates have been recommended for veterinary use. No study has been published about their activity against Malassezia pachydermatis. Hypothesis/Objectives To evaluate the in vivo and in vitro activity of wipes soaked in a chlorhexidine, climbazole and Tris-EDTA solution against Malassezia pachydermatis. Animals Five research colony shar-pei dogs. Methods Wipes were applied once daily onto the left axilla, left groin and perianal area (protocol A), and twice daily on the right axilla, right groin and umbilical region (protocol B) for 3 days. In vivo activity was evaluated by quantifying Malassezia colonies through contact plates on the selected body areas before and after wipe application. The activity of the solution in which the wipes were soaked was assessed in vitro by contact tests following the European Standard UNI EN 1275 guidelines. Results Samples collected after wipe application showed a significant and rapid reduction of Malassezia yeast CFU. No significant difference in the Malassezia reduction was found between protocols A and B. In vitro assay showed 100% activity against Malassezia yeasts after a 15 min contact time with the wipe solution. Conclusions and clinical importance Wipes containing chlorhexidine, climbazole and Tris-EDTA substantially reduced the M. pachydermatis population on the skin of dogs. The results, although this was an uncontrolled study performed on a small number of dogs, suggest that these wipes may be useful for topical therapy of Malassezia dermatitis involving the lips, paws, perianal area and skin folds. Résumé Contexte Des lingettes contenant de la chlorhexidine et des dérivésazolés ont été recommandés en médicine vétérinaire. Aucune étude n'a été publiée sur leur activité contre Malassezia pachydermatis. Hypothèses/Objectifs Evaluer l'activité in vivo et in vitro de lingettes imprégnées d'une solution de chlorhexidine, climbazole et Tris

  19. [Phospholipase and proteinase production by Malassezia pachydermatis isolated in dogs with and without otitis].

    PubMed

    Ortiz, Gustavo; Martín, M Carmen; Carrillo-Muñoz, Alfonso J; Payá, M Jesús

    2013-01-01

    Malassezia pachydermatis is part of the skin microbiota of dogs and cats. M. pachydermatis has been associated with external otitis and seborrhoeic dermatitis, reported more often in dogs than in cats. When the physical, chemical or immunological mechanisms of the skin are altered, M. pachydermatis could act as a pathogen. Thus, several virulence factors, such as the ability to produce esterase, lipase, lipoxygenase, protease, chondroitin sulphatase, and hyaluronidase, have been studied. In the present study, we aim to identify the phospholipase activity measured at pH 6.3, and the proteinase activity measured at pH 6.3 and pH 6.8 (pH from ears of dogs with external otitis) of M. pachydermatis strains isolated from dogs with and without external otitis. The phospholipase activity was measured using a semi-quantitative method with egg yolk, and the proteinase activity with a semi-quantitative method using bovine serum albumin agar. The study was performed on 96 isolates of M. pachydermatis, 43 isolated from dogs without clinical symptoms of otitis, and 52 isolated from dogs with otitis. In our study, 75.8% of the isolates showed phospholipase activity at pH 6.3, and 81 and 97.9% of them showed proteinase activity measured at pH 6.3 and 6.8, respectively. A higher phospholipase activity was detected in strains isolated from dogs with otitis. The proteinase activity was increased at a pH of 6.8 (97.9%) in comparison to a pH of 6.3 (81%). Our results suggest that the phospholipase activity may play an important role in the invasion of host tissues in chronic canine otitis cases. The proteinase activity results obtained in this study suggest that a reduction in the pH of the treatment may improve its efficacy in the resolution of M. pachydermatis otitis. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  20. Efficacy of medicinal essential oils against pathogenic Malassezia sp. isolates.

    PubMed

    Khosravi, A R; Shokri, H; Fahimirad, S

    2016-03-01

    The purposes of this study were to evaluate the distribution pattern and population size of Malassezia species in dogs with atopic dermatitis (AD) and the inhibitory efficacy of Zataria multiflora, Thymus kotschyanus, Mentha spicata, Artemisia sieberi, Rosmarinus officinalis and Heracleum persicum essential oils against pathogenic Malassezia isolates. The samples were collected from 5 different anatomical sites of 33 atopic dogs and cultured onto modified Dixon agar (MDA) and Sabouraud dextrose agar (SDA) media. The essential oil extraction was performed by steam distillation using Clevenger system. Anti-Malassezia efficacy of medicinal essential oils and standard drugs was evaluated using broth microdilution method. A total of 103 yeast colonies were isolated from dogs with AD. Eight different Malassezia species were identified as follows: Malassezia pachydermatis (81.4%), M. globosa (7.8%), M. restricta (3.9%), M. sloofiae (2.9%), M. furfur (1%), M. nana (1%), M. obtusa (1%) and M. sympodialis (1%). The most and least infected sites were: anal (21.2%) and ear (10.6%) respectively. M. pachydermatis was the most frequent Malassezia species isolated from both skin and mucosa of dogs with AD. Antifungal susceptibility test revealed the inhibitory efficacy of essential oils on pathogenic Malassezia isolates with minimum inhibitory concentration (MIC(90)) values ranging from 30 to 850 μg/mL. Among the tested oils, Z. multiflora and T. kotschyanus exhibited the highest inhibitory effects (P<0.05). The essential oils of Z. multiflora and T. kotschyanus showed strong antifungal activity against pathogenic Malassezia species tested. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. Serum Malassezia-specific IgE in dogs with recurrent Malassezia otitis externa without concurrent skin disease.

    PubMed

    Layne, Elizabeth A; DeBoer, Douglas J

    2016-08-01

    Immediate-type hypersensitivity (ITH), mediated by IgE, to Malassezia pachydermatis is recognized in atopic dogs with recurrent yeast dermatitis and otitis externa (OE). Malassezia-associated OE commonly occurs in dogs without other signs of atopic dermatitis (AD). The aim of this study was to detect Malassezia-specific IgE in the sera of dogs with recurrent Malassezia OE without concurrent skin disease. Sera from healthy dogs were used for comparison. An FcεRIα-based ELISA was used to measure Malassezia-specific IgE. There was no significant difference between number of positive affected dogs (6/21, 29%) and number of positive unaffected dogs (15/86, 17%) (P=0.36). There was also no significant difference in the concentrations of Malassezia-specific IgE between the two groups (P=0.97). Malassezia-specific IgE did not distinguish between patient groups so, as with other canine allergens, serum IgE reactivity for Malassezia could not be used to differentiate between diseased and healthy patients. The presence of Malassezia-specific IgE in some of the affected dogs might indicate ITH to Malassezia in those dogs. Evaluation of ITH via intradermal test reactivity and response to allergen-specific immunotherapy might clarify the role of Malassezia-associated ITH in similarly affected dogs. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Detection and identification of Malassezia species in domestic animals and aquatic birds by PCR-RFLP

    PubMed Central

    Zia, M.; Mirhendi, H.; Toghyani, M.

    2015-01-01

    The present study aimed at detection and species-level identification of the Malassezia yeasts in domestic animals and aquatic birds by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Samples were collected using tape strips and swabs from 471 animals including 97 horses, 102 cattle, 105 sheep, 20 camels, 60 dogs, 30 cats, 1 hamster, 1 squirrel, 50 aquatic birds and 5 turkeys. Tape-strip samples were examined by direct microscopy. All samples were inoculated on modified Leeming and Notman agar medium. DNA extracted from the yeast colonies was amplified by PCR using primers specific for 26S rDNA. RFLP of the PCR products was performed using Hin6I enzyme, and PCR and RFLP products were visualized by agarose gel electrophoresis. Malassezia yeasts were detected at the following frequencies: 15.46% in horses, 12.74% in cattle, 12.38% in sheep, 28.33% in dogs, 26.66% in cats and 26% in aquatic birds. Eighty colonies of 6 species were isolated: Malassezia globosa 41.25%, Malassezia furfur 22.5%, Malassezia restricta 15%, Malassezia sympodialis 15%, Malassezia pachydermatis 5% and Malassezia slooffiae 1.25%. Therefore different lipophilic Malassezia species are found in a wide diversity of animals and aquatic birds. PCR-RFLP is a suitable technique for identification of different Malassezia species. PMID:27175148

  3. Seborrheic dermatitis due to Malassezia species in Ahvaz, Iran

    PubMed Central

    Zarei-Mahmoudabadi, Ali; Zarrin, Majid; Mehdinezhad, Forough

    2013-01-01

    Background and Objective Seborrheic dermatitis (SD) is a frequent disorder of the skin that is distinguished by the development of erythematous patches and yellow-gray scales. It is a multifactor disease that requires predisposing factors for its progress. Presence of these factors leads to reproduction of opportunistic yeast Malassezia spp. The aim of the present study was to isolate and identify distribution of Malassezia species on the scalp of SD patients in Ahvaz using modified Dixons agar. Materials and Methods A total of 110 patients diagnosed with SD were sampled. The sampling was carried out by brushing the hair and collecting the dandruff in paper pockets. For identification of Malassezia species, the scalp scales were cultured in Dixons agar. A combination of different characteristics including yeast cell morphology, ability to grow on Sabouraud dextrose agar, catalase test and ability to utilize individual Tweens (20, 40, 60 & 80) were used for identification of species. Results Twenty-seven of 110 (24.5%) SD patients had positive cultures for Malassezia species of which 17 (63%) were male and 10 (37%) were female. The most commonly identified Malassezia species was M. globosa (40.7%) followed by M. pachydermatis (22.2%), M. furfur (11.1%) and M. restricta(7.4%) and Malassezia species (18.5%). Conclusion Malassezia globosa was considered to be the most important orgaism involved in cases with Seborrheic dermatitisin this study. PMID:24475335

  4. Seborrheic dermatitis due to Malassezia species in Ahvaz, Iran.

    PubMed

    Zarei-Mahmoudabadi, Ali; Zarrin, Majid; Mehdinezhad, Forough

    2013-09-01

    Seborrheic dermatitis (SD) is a frequent disorder of the skin that is distinguished by the development of erythematous patches and yellow-gray scales. It is a multifactor disease that requires predisposing factors for its progress. Presence of these factors leads to reproduction of opportunistic yeast Malassezia spp. The aim of the present study was to isolate and identify distribution of Malassezia species on the scalp of SD patients in Ahvaz using modified Dixons agar. A total of 110 patients diagnosed with SD were sampled. The sampling was carried out by brushing the hair and collecting the dandruff in paper pockets. For identification of Malassezia species, the scalp scales were cultured in Dixons agar. A combination of different characteristics including yeast cell morphology, ability to grow on Sabouraud dextrose agar, catalase test and ability to utilize individual Tweens (20, 40, 60 & 80) were used for identification of species. Twenty-seven of 110 (24.5%) SD patients had positive cultures for Malassezia species of which 17 (63%) were male and 10 (37%) were female. The most commonly identified Malassezia species was M. globosa (40.7%) followed by M. pachydermatis (22.2%), M. furfur (11.1%) and M. restricta(7.4%) and Malassezia species (18.5%). Malassezia globosa was considered to be the most important orgaism involved in cases with Seborrheic dermatitisin this study.

  5. Comparative analysis of the frequency, distribution and population sizes of yeasts associated with canine seborrheic dermatitis and healthy skin.

    PubMed

    Yurayart, Chompoonek; Chindamporn, Ariya; Suradhat, Sanipa; Tummaruk, Padet; Kajiwara, Susumu; Prapasarakul, Nuvee

    2011-03-24

    The purpose of this study was to investigate the diversity of yeast associated with the degree of canine seborrheic dermatitis (SD) by anatomical sites. Fifty-seven samples were divided as 17 healthy skin, 20 with primary seborrheic dermatitis (PSD), and 20 with secondary seborrheic dermatitis (SSD). Yeast isolation and characterization were carried out based on microscopical features and biochemical properties. DNA analysis at the internal transcribed spacer I of 26S rDNA region was utilized for species confirmation. Four species of yeast consisting Malassezia pachydermatis, Malassezia furfur, Candida parapsilosis and Candida tropicalis recovered from examined dogs. M. pachydermatis and C. parapsilosis were isolated from all dogs, but C. tropicalis and M. furfur were recovered from 3 healthy dogs and one diseased dog, respectively. The number of M. pachydermatis and C. parapsilosis in diseased dogs was higher than that of healthy specimens (P<0.01). High frequency and population size of C. parapsilosis were closely associated to PSD, while those of M. pachydermatis were associated with both PSD and SSD (P<0.01). C. parapsilosis were predominant at the perianal area. This study demonstrated the co-colonization of M. pachydermatis and C. parapsilosis in large amounts and frequency associated with stage of disease and anatomical site. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Traditional Mediterranean plants: characterization and use of an essential oils mixture to treat Malassezia otitis externa in atopic dogs.

    PubMed

    Nardoni, Simona; Pistelli, Luisa; Baronti, Ilenia; Najar, Basma; Pisseri, Francesca; Bandeira Reidel, Rose Vanessa; Papini, Roberto; Perrucci, Stefania; Mancianti, Francesca

    2017-08-01

    Several plants extracts from Mediterranean countries are traditionally employed in skin troubles both in humans and in animals. Malassezia pachydermatis is a lipophylic yeast responsible for otitis externa and dermatitis in dogs and for cutaneous and systemic disease in humans. Five mixtures of essential oils obtained from Mediterranean plants (Citrus paradisi, Salvia sclarea, Ocimum basilicum, Rosmarinus officinalis, Citrus limon, Anthemis nobilis, Lavandula hybrida and Thymus vulgaris) provided with antifungal and/or anti-inflammatory action assayed in vitro, were tested in vivo versus M. pachydermatis to treat once daily for 2 weeks 25 atopic dogs with Malassezia otitis externa. Mixture composed by C. limon 1%, S. sclarea 0,5%, R. officinalis 1%, A. nobilis 0,5% yielded excellent results in all treated dogs. Despite of clinical resolution after all treatments the number of blastospores did not decrease. This study confirms recent findings suggesting a multifactorial alternative approach for the management of canine Malassezia otitis.

  7. Assessment of in vitro inhibitory activity of hydrogen peroxide on the growth of Malassezia pachydermatis and to compare its efficacy with commercial ear cleaners.

    PubMed

    Marrero, Edrei Javier; Silva, Freddy Alejandro; Rosario, Inmaculada; Déniz, Soraya; Real, Fernando; Padilla, Daniel; Díaz, Esther Licia; Acosta-Hernández, Begoña

    2017-10-01

    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 ® . © 2017 Blackwell Verlag GmbH.

  8. Genotyping and antifungal susceptibility testing of multiple Malassezia pachydermatis isolates from otitis and dermatitis cases in pets: is it really worth the effort?

    PubMed

    Álvarez-Pérez, Sergio; García, Marta E; Peláez, Teresa; Blanco, José L

    2016-01-01

    A total of 216 colonies of Malassezia pachydermatis from 28 cases of fungal otitis or dermatitis in pets were genotyped by M13 fingerprinting and tested for antifungal susceptibility. A huge genetic diversity was found (157 M13 types in total), with all animals having a polyclonal pattern of infection (5.4 ± 1.5 genotypes/sample). Furthermore, analysis of molecular variance (AMOVA) revealed that most genetic diversity (44%) was found at the within sample level. In contrast, variability in antifungal susceptibility among isolates from the same sample was less important, with different M13 types displaying in most cases identical or very similar MIC results. Most isolates displayed high in vitro susceptibility to amphotericin B, terbinafine and all azoles tested except fluconazole, for which MIC values were always ≥4 μg/ml and a 26.9% of isolates displayed values ≥32 μg/ml. We conclude that although characterization of multiple yeast isolates results in a considerable increase in laboratory workload and expenses, it may help to get a better understanding of the epidemiology of M. pachydermatis in a given patient population. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. In vitro efficacy of a honey-based gel against canine clinical isolates of Staphylococcus pseudintermedius and Malassezia pachydermatis.

    PubMed

    Oliveira, Ana M P; Devesa, Joana S P; Hill, Peter B

    2018-03-22

    Staphylococcus pseudintermedius and Malassezia pachydermatis are important agents in canine pyoderma and otitis. Determine the in vitro efficacy of a honey-based gel (HBO) against meticillin-susceptible S. pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP) and M. pachydermatis, by minimum bactericidal concentration (MBC), minimum fungicidal concentration (MFC) and time-kill assay (TKA). Efficacy of the product's honey component (HO) also was evaluated. Sixty S. pseudintermedius and 10 M. pachydermatis canine isolates were selected. All isolates were tested against serial dilutions of an HBO containing 40% HO (40%, 20%, 10%, 5% and 2.5% w/v) and HO alone (undiluted, 40%, 20%, 10%, 5% and 2.5% w/v). Microbroth assay followed by subculture was used to determine MBC and MFC. The same protocol was applied after product exposure to catalase. A well-diffusion assay for S. pseudintermedius was used to generate inhibition zones. A TKA for 10 isolates of S. pseudintermedius and 10 isolates of M. pachydermatis was performed. MBC was 20% w/v (5-20% w/v) for HBO and HO. HBO had lower MBC values when compared to HO (P = 0.003). No statistical difference was observed between MSSP/MRSP isolates (HBO P = 0.757, HO P = 0.743). Only HO was affected by catalase (P = 0.015). MFC for HBO was 10% w/v (5-10% w/v) and 40% w/v for HO (20-≥40% w/v). All isolates were killed after 4 h of exposure. Staphylococcus pseudintermedius and M. pachydermatis are susceptible to the HBO and these results can be used for future clinical trials. © 2018 ESVD and ACVD.

  10. Skin diseases associated with Malassezia yeasts: facts and controversies.

    PubMed

    Gaitanis, Georgios; Velegraki, Aristea; Mayser, Peter; Bassukas, Ioannis D

    2013-01-01

    The implication of the yeast genus Malassezia in skin diseases has been characterized by controversy, since the first description of the fungal nature of pityriasis versicolor in 1846 by Eichstedt. This is underscored by the existence of Malassezia yeasts as commensal but also by their implication in diseases with distinct absence of inflammation despite the heavy fungal load (pityriasis versicolor) or with characteristic inflammation (eg, seborrheic dermatitis, atopic dermatitis, folliculitis, or psoriasis). The description of 14 Malassezia species and subsequent worldwide epidemiologic studies did not reveal pathogenic species but rather disease-associated subtypes within species. Emerging evidence demonstrates that the interaction of Malassezia yeasts with the skin is multifaceted and entails constituents of the fungal wall (melanin, lipid cover), enzymes (lipases, phospholipases), and metabolic products (indoles), as well as the cellular components of the epidermis (keratinocytes, dendritic cells, and melanocytes). Understanding the complexity of their interactions will highlight the controversies on the clinical presentation of Malassezia-associated diseases and unravel the complexity of skin homeostatic mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Comparison of lipid profiles of Malassezia pachydermatis strains isolated from dogs with otitis externa and without clinical symptoms of disease.

    PubMed

    Czyzewska, Urszula; Siemieniuk, Magdalena; Pyrkowska, Aleksandra; Nowakiewicz, Aneta; Bieganska, Malgorzata; Dabrowska, Iwona; Bartoszewicz, Marek; Dobrzyn, Pawel; Tylicki, Adam

    2016-01-01

    Malassezia pachydermatis can cause infections of the skin and mucous membranes, especially in animals. It becomes a problem also in medicine. It is considered that metabolic disorders as well as hormonal and immunological status of the host promote diseases caused by M. pachydermatis. Here we consider whether specific features of fungi could also favour infections. We checked whether there are differences in lipid profiles between strains obtained from dogs with otitis externa and strains obtained from healthy dogs. Lipid profiles were determined using thin layer chromatography and gas chromatography-mass spectrometry. All analyses were carried out on 32 strains derived from dogs with otitis externa and 31 strains isolated from dogs without symptoms of disease. The results show that strains isolated from dogs without symptoms of otitis externa are characterised by a higher content of fatty acids. They contain significantly more behenic and lignoceric acids on medium without addition of lipids, and more oleic acid and total monounsaturated fatty acids on medium with lipids supplementation. These strains have also a higher content of esters of ergosterol and triglycerides. Data obtained show differences which may be specific features of M. pachydermatis-specific strains related to the ability of infection, which could be not directly related of the host condition. © 2015 Blackwell Verlag GmbH.

  12. Antifungal susceptibility testing of Malassezia yeast: comparison of two different methodologies.

    PubMed

    Rojas, Florencia D; Córdoba, Susana B; de Los Ángeles Sosa, María; Zalazar, Laura C; Fernández, Mariana S; Cattana, María E; Alegre, Liliana R; Carrillo-Muñoz, Alfonso J; Giusiano, Gustavo E

    2017-02-01

    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. © 2016 Blackwell Verlag GmbH.

  13. Efficacy of a 2% climbazole shampoo for reducing Malassezia population sizes on the skin of naturally infected dogs.

    PubMed

    Cavana, P; Petit, J-Y; Perrot, S; Guechi, R; Marignac, G; Reynaud, K; Guillot, J

    2015-12-01

    Shampoo therapy is often recommended for the control of Malassezia overgrowth in dogs. The aim of this study was to evaluate the in vivo activity of a 2% climbazole shampoo against Malassezia pachydermatis yeasts in naturally infected dogs. Eleven research colony Beagles were used. The dogs were distributed randomly into two groups: group A (n=6) and group B (n=5). Group A dogs were washed with a 2% climbazole shampoo, while group B dogs were treated with a physiological shampoo base. The shampoos were applied once weekly for two weeks. The population size of Malassezia yeasts on skin was determined by fungal culture through modified Dixon's medium contact plates pressed on left concave pinna, axillae, groins, perianal area before and after shampoo application. Samples collected were compared by Wilcoxon rank sum test. Samples collected after 2% climbazole shampoo application showed a significant and rapid reduction of Malassezia population sizes. One hour after the first climbazole shampoo application, Malassezia reduction was already statistically significant and 15 days after the second climbazole shampoo, Malassezia population sizes were still significantly decreased. No significant reduction of Malassezia population sizes was observed in group B dogs. The application of a 2% climbazole shampoo significantly reduced Malassezia population sizes on the skin of naturally infected dogs. Application of 2% climbazole shampoo may be useful for the control of Malassezia overgrowth and it may be also proposed as prevention when recurrences are frequent. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  14. The Malassezia genus in skin and systemic diseases.

    PubMed

    Gaitanis, Georgios; Magiatis, Prokopios; Hantschke, Markus; Bassukas, Ioannis D; Velegraki, Aristea

    2012-01-01

    In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa: M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, and M. slooffiae. In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted: M. dermatis, M. japonica, M. yamatoensis, M. nana, M. caprae, M. equina, and M. cuniculi. However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links between Malassezia yeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin and Malassezia IgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution of Malassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis.

  15. The Malassezia Genus in Skin and Systemic Diseases

    PubMed Central

    Magiatis, Prokopios; Hantschke, Markus; Bassukas, Ioannis D.; Velegraki, Aristea

    2012-01-01

    Summary: In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa: M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, and M. slooffiae. In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted: M. dermatis, M. japonica, M. yamatoensis, M. nana, M. caprae, M. equina, and M. cuniculi. However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links between Malassezia yeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin and Malassezia IgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution of Malassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis. PMID:22232373

  16. [Lipophilic yeasts of the genus Malassezia and skin diseases. I. Seborrhoeic dermatitis].

    PubMed

    Buchvald, D

    2010-08-01

    Recent technological advances have revived the interest in Malassezia yeasts and their clinical role, which has long been a matter of controversy because of their fastidious nature in vitro and relative difficulty in isolation, cultivation and identification. Lipophilic yeasts of the genus Malassezia form a part of normal microbial flora of healthy human (and animal) skin, but they also have been associated with several dermatological diseases, like seborrhoeic dermatitis and atopic dermatitis. Our understanding of the interactions between Malassezia and the host might provide new opportunities to better control these often chronically relapsing diseases.

  17. Performance of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Identifying Clinical Malassezia Isolates

    PubMed Central

    Machouart, Marie; Morio, Florent; Sabou, Marcela; Kauffmann-LaCroix, Catherine; Contet-Audonneau, Nelly; Candolfi, Ermanno; Letscher-Bru, Valérie

    2016-01-01

    ABSTRACT The genus Malassezia comprises commensal yeasts on human skin. These yeasts are involved in superficial infections but are also isolated in deeper infections, such as fungemia, particularly in certain at-risk patients, such as neonates or patients with parenteral nutrition catheters. Very little is known about Malassezia epidemiology and virulence. This is due mainly to the difficulty of distinguishing species. Currently, species identification is based on morphological and biochemical characteristics. Only molecular biology techniques identify species with certainty, but they are time-consuming and expensive. The aim of this study was to develop and evaluate a matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) database for identifying Malassezia species by mass spectrometry. Eighty-five Malassezia isolates from patients in three French university hospitals were investigated. Each strain was identified by internal transcribed spacer sequencing. Forty-five strains of the six species Malassezia furfur, M. sympodialis, M. slooffiae, M. globosa, M. restricta, and M. pachydermatis allowed the creation of a MALDI-TOF database. Forty other strains were used to test this database. All strains were identified by our Malassezia database with log scores of >2.0, according to the manufacturer's criteria. Repeatability and reproducibility tests showed a coefficient of variation of the log score values of <10%. In conclusion, our new Malassezia database allows easy, fast, and reliable identification of Malassezia species. Implementation of this database will contribute to a better, more rapid identification of Malassezia species and will be helpful in gaining a better understanding of their epidemiology. PMID:27795342

  18. Performance of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identifying Clinical Malassezia Isolates.

    PubMed

    Denis, Julie; Machouart, Marie; Morio, Florent; Sabou, Marcela; Kauffmann-LaCroix, Catherine; Contet-Audonneau, Nelly; Candolfi, Ermanno; Letscher-Bru, Valérie

    2017-01-01

    The genus Malassezia comprises commensal yeasts on human skin. These yeasts are involved in superficial infections but are also isolated in deeper infections, such as fungemia, particularly in certain at-risk patients, such as neonates or patients with parenteral nutrition catheters. Very little is known about Malassezia epidemiology and virulence. This is due mainly to the difficulty of distinguishing species. Currently, species identification is based on morphological and biochemical characteristics. Only molecular biology techniques identify species with certainty, but they are time-consuming and expensive. The aim of this study was to develop and evaluate a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) database for identifying Malassezia species by mass spectrometry. Eighty-five Malassezia isolates from patients in three French university hospitals were investigated. Each strain was identified by internal transcribed spacer sequencing. Forty-five strains of the six species Malassezia furfur, M. sympodialis, M. slooffiae, M. globosa, M. restricta, and M. pachydermatis allowed the creation of a MALDI-TOF database. Forty other strains were used to test this database. All strains were identified by our Malassezia database with log scores of >2.0, according to the manufacturer's criteria. Repeatability and reproducibility tests showed a coefficient of variation of the log score values of <10%. In conclusion, our new Malassezia database allows easy, fast, and reliable identification of Malassezia species. Implementation of this database will contribute to a better, more rapid identification of Malassezia species and will be helpful in gaining a better understanding of their epidemiology. Copyright © 2016 Denis et al.

  19. Comparison of Nested PCR and RFLP for Identification and Classification of Malassezia Yeasts from Healthy Human Skin

    PubMed Central

    Oh, Byung Ho; Song, Young Chan; Choe, Yong Beom; Ahn, Kyu Joong

    2009-01-01

    Background Malassezia yeasts are normal flora of the skin found in 75~98% of healthy subjects. The accurate identification of the Malassezia species is important for determining the pathogenesis of the Malassezia yeasts with regard to various skin diseases such as Malassezia folliculitis, seborrheic dermatitis, and atopic dermatitis. Objective This research was conducted to determine a more accurate and rapid molecular test for the identification and classification of Malassezia yeasts. Methods We compared the accuracy and efficacy of restriction fragment length polymorphism (RFLP) and the nested polymerase chain reaction (PCR) for the identification of Malassezia yeasts. Results Although both methods demonstrated rapid and reliable results with regard to identification, the nested PCR method was faster. However, 7 different Malassezia species (1.2%) were identified by the nested PCR compared to the RFLP method. Conclusion Our results show that RFLP method was relatively more accurate and reliable for the detection of various Malassezia species compared to the nested PCR. But, in the aspect of simplicity and time saving, the latter method has its own advantages. In addition, the 26S rDNA, which was targeted in this study, contains highly conserved base sequences and enough sequence variation for inter-species identification of Malassezia yeasts. PMID:20523823

  20. Malassezia Yeast and Cytokine Gene Polymorphism in Atopic Dermatitis

    PubMed Central

    Das, Shukla; Ramachandran, V.G.; Saha, Rumpa; Bhattacharya, S.N.; Dar, Sajad

    2017-01-01

    Introduction Atopic Dermatitis (AD) is a recurrent chronic condition associated with microorganism and their interaction with the susceptible host. Malassezia yeast is a known commensal which is thought to provoke the recurrent episodes of symptoms in atopic dermatitis patients. Malassezia immunomodulatory properties along with defective skin barrier in such host, results in disease manifestation. Here, we studied Single Nucleotide Polymorphism (SNP) in IL10 and IFN γ genes of the host and its relation with susceptibility to Malassezia infection. Aim To isolate Malassezia yeast from AD patients and compare the genetic susceptibility of the host by correlating the cytokine gene polymorphism with the control subjects. Materials and Methods Study was conducted from January 2012 to January 2013. It was a prospective observational study done in Department of Microbiology and Department of Dermatology and Venereology in University College of Medical Sciences and GTB Hospital, Delhi. Sample size comprised of 38 cases each of AD. Skin scrapings were used for fungal culture on Sabouraud Dextrose Agar (SDA) and Modified Dixon Agar (MDA) and isolated were identified as per conventional phenotypic methods. Genomic DNA was extracted from blood samples collected from all study subjects. Cytokine genotyping was carried out by Amplification Refractory Mutations System- Polymerase Chain Reaction (ARMS-PCR) with sequence specific primers. Three SNPs (IL10-1082A/G; IL10-819/592C/T; IFN-γ+874A/T) in two cytokine genes were assessed in all the patients and healthy controls. Statistical Analysis Chi-Square Test or Fisher’s-Exact Test and Bonferroni’s correction. Results In AD group, Malassezia yeasts were cultured in 24 out of 38 samples and thus the identification rate was 63.1 percent as compared to healthy group, 52.6 percent (20/38). Significant difference in allele, or genotype distribution were observed in IL10-819/592C/T and IFN-γ+874A/T gene polymorphism in AD group

  1. [Malassezia and its presumed association with skin diseases in dogs].

    PubMed

    Nagata, Masahiko

    2013-01-01

    Malassezia pachydermatis is the major species in Malassezia isolated from dogs, and there is a presumably Malassezia-associated skin disease,"Malassezia dermatitis" in the dog. The skin lesion is characterized by relatively demarcated erythema with some scaling at the sebum-rich areas, in which lichenification and hyperpigmentation could be involved in the chronic stage. The clinical features suggest that it corresponds to seborrheic dermatitis in humans. Hence, it might be possible to identify essential pathogenesis of the disease by clarifying its differences in humans and animals as a shared disease.

  2. Molecular and Phenotypic Identification and Speciation of Malassezia Yeasts Isolated from Egyptian Patients with Pityriasis Versicolor

    PubMed Central

    Elshabrawy, Walaa Othman; Sallam, Manar

    2017-01-01

    Introduction Pityriasis Versicolor (PV) is a common health problem caused by genus Malassezia, a lipophilic fungi found as a part of the normal flora of skin. Although PV is common in Egypt, there is little information regarding the Malassezia species distribution in PV patients to date. Aim To spot a light on the distribution and clinico-epidemiological features of the Malassezia species in PV patients and healthy individuals that were established by conventional phenotypic and molecular techniques. Materials and Methods A cross-sectional study including 167 individuals; 137 clinically suspected PV patients attending Mansoura University Hospitals, Egypt and 30 healthy control individuals, was carried out. Characterization of Malassezia species was performed phenotypically by conventional, culture-based methods and biochemical tests. Genomic DNA was extracted from isolated colonies for PCR amplification of the highly conserved 26S rDNA region with further species level identification by Restriction Fragment Length Polymorphism (RFLP) using Hha1 and BstC1 enzymes. The association of Malassezia species with epidemiological profile and clinical characteristics was studied. Results A 94.2% of PV samples and 13.3% of control samples were positive by Potassium Hydroxide (KOH) while 71.5% of PV samples and 16.7% of control samples yielded growth in culture with high statistically significant differences (p=0.0001, for both methods). By phenotypic methods, only 75.5% of isolates from patients were identified as: M. furfur (51.4%), M. globosa, (29.7%), M. restricta (13.5%) and M. pachydermatis (5.4%) while by RFLP technique, six species were revealed: M. furfur (44.9%), M. globosa (24.5%), M. sympodialis (12.2 %), M. restricta (10.2%), M. obtusa (4.1%) and M. pachydermatis (4.1%). Most species were isolated from hypopigmented lesions of PV patients aged between 20-29 years. Neck and back were the most common affected sites. Only M. furfur (10%) and M. globosa (6.7%) were

  3. Malassezia virulence determinants.

    PubMed

    Hort, Wiebke; Mayser, Peter

    2011-04-01

    Malassezia yeasts are associated with a number of dermatologic and systemic diseases in humans and animals. Pityriasis versicolor is amongst these diseases and represents one of the most common human skin diseases. Beyond that, the role of Malassezia yeasts in the pathogenesis of other skin diseases such as psoriasis, seborrheic dermatitis and confluent and reticulate papillomatosis is discussed but remains less clear. Clear pathogenetic mechanisms of the above-mentioned diseases are not known so far. The review presents new findings on virulence factors of Malassezia yeasts, shedding light on the pathogenesis of Malassezia-associated diseases. Several virulence factors in Malassezia yeasts are known, based on their enzymatic lipolytic activity resulting in the production of distinct metabolites and special cell wall features. Recently, a secondary metabolic pathway possibly implicated in the pathogenesis of pityriasis versicolor was described. The article presents virulence factors of Malassezia yeasts ranging from irritant metabolic byproducts to highly bioactive indole derivatives and attempts to clarify their pathogenic implications in the different diseases. Special emphasis is given to the pathogenesis of pityriasis versicolor, as it represents the disease wherein the causative relationship with Malassezia yeasts appears the most obvious.

  4. The anatomical distribution and antimicrobial susceptibility of yeast species isolated from healthy dogs.

    PubMed

    Brito, Erika H S; Fontenelle, Raquel O S; Brilhante, Raimunda S N; Cordeiro, Rossana A; Monteiro, André J; Sidrim, José J C; Rocha, Marcos F G

    2009-11-01

    The aim of this work was to identify the predominant yeast species present at different anatomical sites in healthy dogs and to determine their in vitro antimicrobial susceptibility using a broth microdilution assay. Samples were collected from the preputial, vaginal, oral and perianal mucosae and the isolates cultured were identified according to their morphological characteristics and biochemical profile. Malassezia pachydermatis was the most commonly isolated yeast, followed by Candida parapsilosis, Candida tropicalis, Candida albicans, Saccharomyces cerevisiae and Rhodotorula spp. Minimum inhibitory concentrations of the azole derivatives ketoconazole, itraconazole and fluconazole against Candida spp. were 0.03-16 microg/mL, 0.06 to >16 microg/mL and 0.5-64 microg/mL, respectively and Candida isolates were sensitive to caspofungin and amphotericin B. Although all isolates of M. pachydermatis were sensitive to itraconazole, fluconazole, ketoconazole and amphotericin B, they were found to be resistant to caspofungin. The study has highlighted that Candida spp., M. pachydermatis, S. cerevisiae and Rhodotorula spp. are part of the normal canine surface microbiota and some of these organisms exhibit in vitro resistance to commonly used antimicrobials.

  5. Effects of Malassezia yeasts on serum Th1 and Th2 cytokines in patients with guttate psoriasis.

    PubMed

    Aydogan, Kenan; Tore, Okan; Akcaglar, Sevim; Oral, Barbaros; Ener, Beyza; Tunalı, Sukran; Saricaoglu, Hayriye

    2013-01-01

    Systemic and focal infections caused by microorganisms have been known to induce or exacerbate psoriasis. Although the role of yeast species of the genus Malassezia in the pathogenesis of psoriasis is not fully understood, it is thought that these lipophilic yeasts may represent a triggering factor in the exacerbation of psoriatic lesions. This study investigated the effects of Malassezia yeasts on serum Th1 and Th2 cytokines in patients with guttate psoriasis (GP) in order to define their role in the pathogenesis of psoriasis. Fifty patients with GP and 29 clinically healthy individuals were included in the study. All samples consisted of scales and scrapings taken from the scalps, trunks, and upper limbs of both psoriasis patients and healthy subjects. Psoriasis patients and healthy subjects were grouped according to their positivity or negativity for Malassezia yeasts as ascertained by direct microscopy and/or culture. An enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of Th1 and Th2 cytokines in these groups. No significant differences in positivity for Malassezia yeasts were found between psoriatic skin and healthy skin in samples taken from different body sites. Serum interleukin-13 (IL-13) levels were significantly lower in the psoriasis group compared with the control group (P = 0.04). Levels of other cytokines did not differ significantly between the psoriasis and control groups. Mean levels of Th2 cytokines (IL-4, IL-10, IL-13), but not of Th1 cytokines (IL-2 and IFN-γ), were significantly lower in psoriasis patients positive for Malassezia yeasts compared with those negative for Malassezia yeasts and control subjects (P = 0.04, P < 0.001 and P = 0.01, respectively). The isolation of Malassezia yeasts from GP lesions does not necessarily mean that these species are pathogenic, but their downregulating effects on anti-inflammatory Th2 cytokines may contribute to the occurrence of GP. © 2012 The International Society of

  6. Occurrence and distribution of Malassezia species on skin and external ear canal of horses.

    PubMed

    Shokri, Hojjatollah

    2016-01-01

    The aim of this study was to investigate the prevalence of Malassezia species from the body skin and external ear canal of healthy horses. The samples were obtained by scraping the skin surface from the nose, groin and dorsum and swabbing from the external ear canal of 163 animals, and then incubated on sabouraud dextrose agar and modified Dixon agar. Malassezia species were isolated from 34.9% of horses. The percentages of Malassezia species were 64.3% for Arab, 35.7% for Persian, 35.4% for Thoroughbred and 27.1% for Turkmen breeds. The greatest abundance of Malassezia species was found in the external ear canal (47.7%, representing significant difference with other sites), followed by nose (26.3%), groin (15.8%) and dorsum (10.5%) (P < 0.05). A total of 57 strains from six Malassezia species were detected with a frequency rate as follows: M. pachydermatis (33.3%), M. globosa (26.3%), M. sympodialis (14.1%), M. restricta (10.5%), M. obtusa (8.8%) and M. furfur (7%). The most common age-group affected was 1-3 years (59.4%). This study confirmed that cutaneous Malassezia microbiota in healthy horses varies by body site and age but not by breed and gender, representing M. pachydermatis as the most prevalent species on horse skin. © 2015 Blackwell Verlag GmbH.

  7. Efficient identification of Malassezia yeasts by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

    PubMed

    Kolecka, A; Khayhan, K; Arabatzis, M; Velegraki, A; Kostrzewa, M; Andersson, A; Scheynius, A; Cafarchia, C; Iatta, R; Montagna, M T; Youngchim, S; Cabañes, F J; Hoopman, P; Kraak, B; Groenewald, M; Boekhout, T

    2014-02-01

    Infections caused by Malassezia yeasts are most likely underdiagnosed, because fatty acid supplementation is needed for growth. Rapid identification of Malassezia species is essential for appropriate treatment of Malassezia-related skin infections, fungaemia and nosocomial outbreaks in neonates, children and adults and can be life-saving for those patients. Ma-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported to be a rapid and reliable diagnostic tool to identify clinically important yeasts, but so far no data have been reported on identification of Malassezia isolates with this technique. To create an extensive database of main mass spectra (MSPs) that will allow quick identification of Malassezia species by MALDI-TOF MS. An in-house library of 113 MSPs was created from 48 reference strains from the CBS-KNAW yeast collection. The in-house library was challenged with two test sets of Malassezia strains, namely 165 reference strains from the CBS collection and 338 isolates collected in Greece, Italy, Sweden and Thailand. MALDI-TOF MS allowed correct identification of all 14 Malassezia spp. MALDI-TOF MS results were concordant with those of sequence analyses of the internal transcribed spacers (ITS1/ITS2) and the D1/D2 domains of the large subunit of the ribosomal DNA. Implementation of the MALDI-TOF MS system as a routine identification tool will contribute to correct identification of Malassezia yeasts with minimal effort and in a short turnaround time, which is especially important for the rapid identification of Malassezia in skin diseases and nosocomial outbreaks. © 2013 British Association of Dermatologists.

  8. Malassezia vespertilionis sp. nov.: a new cold-tolerant species of yeast isolated from bats

    Treesearch

    J.M. Lorch; J.M. Palmer; K.J. Vanderwolf; K.Z. Schmidt; M.L. Verant; T.J. Weller; D.S. Blehert

    2018-01-01

    Malassezia is a genus of medically-important, lipid-dependent yeasts that live on the skin of warmblooded animals. The 17 described species have been documented primarily on humans and domestic animals, but few studies have examined Malassezia species associated with more diverse host groups such as wildlife. While...

  9. Immunoglobulin G responses to Malassezia pachydermatis in healthy dogs and dogs with Malassezia dermatitis.

    PubMed

    Bond, R; Lloyd, D H

    2002-04-20

    Serum immunoglobulin G (IgG) responses of healthy dogs and dogs with Malasseziapachydermatis dermatitis were compared by Western immunoblotting. M pachydermatis CBS 1879 was disrupted mechanically and its proteins were separated and blotted on to nitrocellulose membranes before being incubated with sera from eight healthy beagles, eight Irish setters with gluten-sensitive enteropathy, 15 healthy basset hounds, and 30 dogs with Mpachydermatis-associated dermatitis, 20 of which were basset hounds. The mean (se) numbers of bands of immunoreactivity observed in the seborrhoeic basset hounds (10.7 [0.4]) and affected mixed-breed dogs (9.4 [0.9]) were significantly greater than in the beagles (3-0 [1.0]), Irish setters (5.5 [1.1]) and healthy basset hounds (5.6 [0.7]). The number of bands identified was correlated (r(s) = 0.76, P < 0.001) with the anti-M pachydermatis IgG values measured by ELISA in a previous study. Most of the dogs were immunoreactive towards the 132, 66 and 50 to 54 kDa proteins and the affected dogs were also usually reactive towards the 219, 110, 71 and 42 kDa proteins.

  10. Genomic insights into the atopic eczema-associated skin commensal yeast Malassezia sympodialis.

    PubMed

    Gioti, Anastasia; Nystedt, Björn; Li, Wenjun; Xu, Jun; Andersson, Anna; Averette, Anna F; Münch, Karin; Wang, Xuying; Kappauf, Catharine; Kingsbury, Joanne M; Kraak, Bart; Walker, Louise A; Johansson, Henrik J; Holm, Tina; Lehtiö, Janne; Stajich, Jason E; Mieczkowski, Piotr; Kahmann, Regine; Kennell, John C; Cardenas, Maria E; Lundeberg, Joakim; Saunders, Charles W; Boekhout, Teun; Dawson, Thomas L; Munro, Carol A; de Groot, Piet W J; Butler, Geraldine; Heitman, Joseph; Scheynius, Annika

    2013-01-22

    Malassezia commensal yeasts are associated with a number of skin disorders, such as atopic eczema/dermatitis and dandruff, and they also can cause systemic infections. Here we describe the 7.67-Mbp genome of Malassezia sympodialis, a species associated with atopic eczema, and contrast its genome repertoire with that of Malassezia globosa, associated with dandruff, as well as those of other closely related fungi. Ninety percent of the predicted M. sympodialis protein coding genes were experimentally verified by mass spectrometry at the protein level. We identified a relatively limited number of genes related to lipid biosynthesis, and both species lack the fatty acid synthase gene, in line with the known requirement of these yeasts to assimilate lipids from the host. Malassezia species do not appear to have many cell wall-localized glycosylphosphatidylinositol (GPI) proteins and lack other cell wall proteins previously identified in other fungi. This is surprising given that in other fungi these proteins have been shown to mediate interactions (e.g., adhesion and biofilm formation) with the host. The genome revealed a complex evolutionary history for an allergen of unknown function, Mala s 7, shown to be encoded by a member of an amplified gene family of secreted proteins. Based on genetic and biochemical studies with the basidiomycete human fungal pathogen Cryptococcus neoformans, we characterized the allergen Mala s 6 as the cytoplasmic cyclophilin A. We further present evidence that M. sympodialis may have the capacity to undergo sexual reproduction and present a model for a pseudobipolar mating system that allows limited recombination between two linked MAT loci. Malassezia commensal yeasts are associated with a number of skin disorders. The previously published genome of M. globosa provided some of the first insights into Malassezia biology and its involvement in dandruff. Here, we present the genome of M. sympodialis, frequently isolated from patients with

  11. β-Endorphin enhances the phospholipase activity of the dandruff causing fungi Malassezia globosa and Malassezia restricta.

    PubMed

    Honnavar, Prasanna; Chakrabarti, Arunaloke; Prasad, Ghandam S; Singh, Pankaj; Dogra, Sunil; Rudramurthy, Shivaprakash M

    2017-02-01

    β-Endorphin is known to stimulate phospholipase production by Malassezia pachydermatis during canine dermatoses. The role of β-endorphin in Malassezia infection in humans is not well studied. The present study compares the influence of β-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 β-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 β-endorphin (M. globosa, P = .04; M. restricta, P = .001), which did not occur in isolates from healthy controls. Moreover, after β-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. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. [Taxonomy of Malassezia furfur: state of the art].

    PubMed

    Aspíroz, M C; Moreno, L A; Rubio, M C

    1997-12-01

    Malassezia furfur is a lipophilic yeast considered as a normal component of the human skin flora. Apart from pityriasis versicolor, M. furfur has been linked to several skin diseases such as seborrheic dermatitis, folliculitis or atopic dermatitis. Moreover, these yeasts have been reported as agent of invasive human diseases including pneumonia, catheter-associated sepsis and peritonitis. The existence of morphological, serological, metabolical, biochemical and karyotipical differences has been described among isolates of these yeasts. These observations gave arguments for a possible intraspecific division, and this hypothesis has been confirmed by the existence of six species within the formerly called M. furfur (lipid-dependent Malassezia strains): M. furfur, Malassezia sympodialis, Malassezia globosa, Malassezia obtusa, Malassezia restricta and Malassezia slooffiae.

  13. Progress in Malassezia Research in Korea

    PubMed Central

    Kim, Soo Young; Lee, Yang Won; Choe, Yong Beom

    2015-01-01

    Yeasts of the genus Malassezia are part of the normal flora of human skin. However, they are also associated with various skin diseases. Since the introduction of Malassezia to the Korean Dermatologic Society two decades ago, remarkable progress has been made in our knowledge of this genus. In this paper, we review recent developments in Malassezia research, including taxonomy and methods for species identification, recent genome analyses, Malassezia species distribution in healthy conditions and in specific skin diseases, trials investigating the mechanisms underlying Malassezia-related diseases, as well as therapeutic options. This review will enhance our understanding of Malassezia yeasts and related skin diseases in Korea. PMID:26719632

  14. Progress in Malassezia Research in Korea.

    PubMed

    Kim, Soo Young; Lee, Yang Won; Choe, Yong Beom; Ahn, Kyu Joong

    2015-12-01

    Yeasts of the genus Malassezia are part of the normal flora of human skin. However, they are also associated with various skin diseases. Since the introduction of Malassezia to the Korean Dermatologic Society two decades ago, remarkable progress has been made in our knowledge of this genus. In this paper, we review recent developments in Malassezia research, including taxonomy and methods for species identification, recent genome analyses, Malassezia species distribution in healthy conditions and in specific skin diseases, trials investigating the mechanisms underlying Malassezia-related diseases, as well as therapeutic options. This review will enhance our understanding of Malassezia yeasts and related skin diseases in Korea.

  15. Yeasts as important agents of onychomycosis: in vitro activity of propolis against yeasts isolated from patients with nail infection.

    PubMed

    Khosravi, Ali Reza; Shokri, Hojjatollah; Nikaein, Donya; Mansouri, Parvin; Erfanmanesh, Ahmad; Chalangari, Reza; Katalin, Martis

    2013-01-01

    The purposes of this study were to determine the frequency of the yeast species obtained from patients with clinical features of onychomycosis and the in vitro antifungal susceptibility of the yeast species to propolis. A prospective study was carried out at the Mycology Research Center in Iran from 2010 to 2011. Clinical diagnosis was performed by direct microscopic examination and culture. Different yeast species were identified by morphological and biochemical tests. An antifungal susceptibility test to fluconazole (FLU) and propolis by the broth microdilution method was performed on each isolate. One hundred and twenty-eight fungal isolates were obtained. The most prevalent fungi were yeasts (81, 63.2%), dermatophytes (36, 28.1%), and nondermatophyte fungi (11, 8.6%). Fingernails were more affected than toenails (65.4% vs. 19.8%, respectively). The most frequently found species was Candida albicans (38.5%), followed by Candida spp. (23.1%), C. tropicalis (10.8%), C. kefyr (6.2%), C. krusei (3.1%), Malassezia globosa (4.6%), M. slooffiae (4.6%), and M. pachydermatis (1.5%). Of all yeast isolates (65), seven showed resistance to FLU. The average MIC of propolis for FLU-susceptible isolates was 5.8 μg/mL, whereas this value was 12.25 μg/mL for FLU-resistant isolates. Our results proved that the propolis inhibits the growth of pathogenic yeasts and confirmed the efficiency of propolis as an anti-Candida and anti-Malassezia agent.

  16. Malassezia spp. overgrowth in allergic cats.

    PubMed

    Ordeix, Laura; Galeotti, Franca; Scarampella, Fabia; Dedola, Carla; Bardagí, Mar; Romano, Erica; Fondati, Alessandra

    2007-10-01

    A series of 18 allergic cats with multifocal Malassezia spp. overgrowth is reported: atopic dermatitis was diagnosed in 16, an adverse food reaction in another and one was euthanized 2 months after diagnosis of Malassezia overgrowth. All the cats were otherwise healthy and those tested (16 out of 18) for feline leukaemia or feline immunodeficiency virus infections were all negative. At dermatological examination, multifocal alopecia, erythema, crusting and greasy adherent brownish scales were variably distributed on all cats. Cytological examination revealed Malassezia spp. overgrowth with/without bacterial infection in facial skin (n = 11), ventral neck (n = 6), abdomen (n = 6), ear canal (n = 4), chin (n = 2), ear pinnae (n = 2), interdigital (n = 1) and claw folds skin (n = 1). Moreover, in two cats Malassezia pachydermatis was isolated in fungal cultures from lesional skin. Azoles therapy alone was prescribed in seven, azoles and antibacterial therapy in eight and azoles with both antibacterial and anti-inflammatory therapy in three of the cats. After 3-4 weeks of treatment, substantial reduction of pruritus and skin lesions was observed in all 11 cats treated with a combined therapy and in five of seven treated solely with azoles. Malassezia spp. overgrowth may represent a secondary cutaneous problem in allergic cats particularly in those presented for dermatological examination displaying greasy adherent brownish scales. The favourable response to treatment with antifungal treatments alone suggests that, as in dogs, Malassezia spp. may be partly responsible for both pruritus and cutaneous lesions in allergic cats.

  17. Malassezia skin diseases in humans.

    PubMed

    Difonzo, E M; Faggi, E; Bassi, A; Campisi, E; Arunachalam, M; Pini, G; Scarfì, F; Galeone, M

    2013-12-01

    Although Malassezia yeasts are a part of the normal microflora, under certain conditions they can cause superficial skin infection, such as pityriasis versicolor (PV) and Malassezia folliculitis. Moreover the yeasts of the genus Malassezia have been associated with seborrheic dermatitis and dandruff, atopic dermatitis, psoriasis, and, less commonly, with confluent and reticulated papillomatosis, onychomycosis, and transient acantholytic dermatosis. The study of the clinical role of Malassezia species has been surrounded by controversy due to the relative difficulty in isolation, cultivation, and identification. This review focuses on the clinical, mycologic, and immunologic aspects of the various skin diseases associated with Malassezia. Moreover, since there exists little information about the epidemiology and ecology of Malassezia species in the Italian population and the clinical significance of these species is not fully distinguished, we will report data about a study we carried out. The aim of our study was the isolation and the identification of Malassezia species in PV-affected skin and non-affected skin in patients with PV and in clinically healthy individuals without any Malassezia associated skin disease.

  18. Malassezia vespertilionis sp. nov.: A new cold-tolerant species of yeast isolated from bats

    USGS Publications Warehouse

    Lorch, Jeffrey M.; Palmer, Jonathan M.; Vanderwolf, Karen J.; Schmidt, Katie Z.; Verant, Michelle L.; Weller, Theodore J.; Blehert, David S.

    2018-01-01

    Malassezia is a genus of medically-important, lipid-dependent yeasts that live on the skin of warm-blooded animals. The 17 described species have been documented primarily on humans and domestic animals, but few studies have examined Malassezia species associated with more diverse host groups such as wildlife. While investigating the skin mycobiota of healthy bats, we isolated a Malassezia sp. that exhibited only up to 92 % identity with other known species in the genus for the portion of the DNA sequence of the internal transcribed spacer region that could be confidently aligned. The Malassezia sp. was cultured from the skin of nine species of bats in the subfamily Myotinae; isolates originated from bats sampled in both the eastern and western United States. Physiological features and molecular characterisation at seven additional loci (D1/D2 region of 26S rDNA, 18S rDNA, chitin synthase, second largest subunit of RNA polymerase II, β-tubulin, translation elongation factor EF-1α, and minichromosome maintenance complex component 7) indicated that all of the bat Malasseziaisolates likely represented a single species distinct from other named taxa. Of particular note was the ability of the Malassezia sp. to grow over a broad range of temperatures (7–40 °C), with optimal growth occurring at 24 °C. These thermal growth ranges, unique among the described Malassezia, may be an adaptation by the fungus to survive on bats during both the host's hibernation and active seasons. The combination of genetic and physiological differences provided compelling evidence that this lipid-dependent yeast represents a novel species described herein as Malassezia vespertilionis sp. nov. Whole genome sequencing placed the new species as a basal member of the clade containing the species M. furfur, M. japonica, M. obtusa, and M. yamatoensis. The genetic and physiological uniqueness of Malassezia vespertilionis among its closest relatives may make it

  19. Genomic Insights into the Atopic Eczema-Associated Skin Commensal Yeast Malassezia sympodialis

    PubMed Central

    Gioti, Anastasia; Nystedt, Björn; Li, Wenjun; Xu, Jun; Andersson, Anna; Averette, Anna F.; Münch, Karin; Wang, Xuying; Kappauf, Catharine; Kingsbury, Joanne M.; Kraak, Bart; Walker, Louise A.; Johansson, Henrik J.; Holm, Tina; Lehtiö, Janne; Stajich, Jason E.; Mieczkowski, Piotr; Kahmann, Regine; Kennell, John C.; Cardenas, Maria E.; Lundeberg, Joakim; Saunders, Charles W.; Boekhout, Teun; Dawson, Thomas L.; Munro, Carol A.; de Groot, Piet W. J.; Butler, Geraldine; Heitman, Joseph; Scheynius, Annika

    2013-01-01

    ABSTRACT Malassezia commensal yeasts are associated with a number of skin disorders, such as atopic eczema/dermatitis and dandruff, and they also can cause systemic infections. Here we describe the 7.67-Mbp genome of Malassezia sympodialis, a species associated with atopic eczema, and contrast its genome repertoire with that of Malassezia globosa, associated with dandruff, as well as those of other closely related fungi. Ninety percent of the predicted M. sympodialis protein coding genes were experimentally verified by mass spectrometry at the protein level. We identified a relatively limited number of genes related to lipid biosynthesis, and both species lack the fatty acid synthase gene, in line with the known requirement of these yeasts to assimilate lipids from the host. Malassezia species do not appear to have many cell wall-localized glycosylphosphatidylinositol (GPI) proteins and lack other cell wall proteins previously identified in other fungi. This is surprising given that in other fungi these proteins have been shown to mediate interactions (e.g., adhesion and biofilm formation) with the host. The genome revealed a complex evolutionary history for an allergen of unknown function, Mala s 7, shown to be encoded by a member of an amplified gene family of secreted proteins. Based on genetic and biochemical studies with the basidiomycete human fungal pathogen Cryptococcus neoformans, we characterized the allergen Mala s 6 as the cytoplasmic cyclophilin A. We further present evidence that M. sympodialis may have the capacity to undergo sexual reproduction and present a model for a pseudobipolar mating system that allows limited recombination between two linked MAT loci. PMID:23341551

  20. Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin

    PubMed Central

    Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S.; Bassukas, Ioannis D.

    2013-01-01

    Malassezia yeasts are commensal microorganisms which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia associated diseases demonstrated 10–1000 fold higher AhR activating capacity than control skin extracts. LC/MS/MS analysis of the patients’ extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9/12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture-extracts and pure metabolites in HaCaT cells by Reverse Transcriptase Real-Time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1 and AhRR. Indirubin and FICZ activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared to the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development. PMID:23448877

  1. Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin.

    PubMed

    Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S; Bassukas, Ioannis D

    2013-08-01

    Malassezia yeasts are commensal microorganisms, which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia-associated diseases demonstrated 10- to 1,000-fold higher AhR-activating capacity than control skin extracts. Liquid chromatography-tandem mass spectrometry analysis of the patients' extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9 out of 12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture extracts and pure metabolites in HaCaT cells by reverse transcriptase real-time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1, and AhRR. Indirubin- and FICZ-activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared with the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development.

  2. Malassezia species and seborrheic dermatitis.

    PubMed

    Zisova, Lilia G

    2009-01-01

    Malassezia spp. are medically important dimorphic, lipophilic yeasts that form part of the normal cutaneous microflora of human. Seborrheic dermatitis is a multifactor disease that needs endogenous and exogenous predisposing factors for its development. Presence of these factors leads to reproduction of the saprophytic opportunistic pathogen Malassezia spp. and development of a disease. The inflammatory reaction against the yeast Malassezia is considered basic in the etiology of the seborrheic dermatitis. The pathogenesis and exact mechanisms via which these yeasts cause inflammation are still not fully elucidated. They are rather complex and subject of controversy in literature. Most probably Malassezia spp. cause seborrheic dermatitis by involving and combining both nonummune and immune mechanisms (nonspecific and specific). Which of these mechanisms will dominate in any single case depends on the number and virulence of the yeasts as well as on the microorganism reactivity. In the recent years a great interest have been aroused by the epidemiological investigations. Depending on the geographical place of the countries different Malassezia species in seborrheic dermatitis dominate in the different countries. In view of the etiology and pathogenesis of the seborrheic dermatitis comprehensive antifungal preparations have been recently introduced and are nowadays the basic therapeutic resource in the treatment of this disease.

  3. Identification of the haemolytic activity of Malassezia species.

    PubMed

    Juntachai, Weerapong; Kummasook, Aksarakorn; Mekaprateep, Malee; Kajiwara, Susumu

    2014-03-01

    Malassezia species are part of the normal skin flora and are associated with a number of human and animal skin diseases. However, the mechanisms that mediate infection and host-fungal interactions are poorly understood. The haemolytic activity of several microorganisms is considered a factor that contributes to pathogenicity of the organism to humans and animals. This virulence factor was previously identified in several pathogenic fungi that cause systemic mycoses, such as Aspergillus and Candida. In this study, the haemolytic activity of six major Malassezia species, including M. furfur, M. globosa, M. pachydermatis, M. restricta, M. slooffiae and M. sympodialis, was investigated. The haemolytic activity of these species was tested on tryptone soya agar with 5% sheep blood. All the examined Malassezia species produced a halo zone of complete haemolysis. A quantitative analysis of the haemolytic activity was performed by incubating sheep erythrocytes with the extraction from culture of each Malassezia species. Interestingly, M. globosa and M. restricta showed significantly high haemolytic activity compared with the other Malassezia species. In addition, M. globosa also exhibited stable haemolytic activity after treatment at 100 °C and in the presence of some proteases, indicating that this haemolytic factor is different from those of other fungi. © 2013 Blackwell Verlag GmbH.

  4. Malassezia yeasts activate the NLRP3 inflammasome in antigen-presenting cells via Syk-kinase signalling.

    PubMed

    Kistowska, Magdalena; Fenini, Gabriele; Jankovic, Dragana; Feldmeyer, Laurence; Kerl, Katrin; Bosshard, Philipp; Contassot, Emmanuel; French, Lars E

    2014-12-01

    Although being a normal part of the skin flora, yeasts of the genus Malassezia are associated with several common dermatologic conditions including pityriasis versicolour, seborrhoeic dermatitis (SD), folliculitis, atopic eczema/dermatitis (AE/AD) and dandruff. While Malassezia spp. are aetiological agents of pityriasis versicolour, a causal role of Malassezia spp. in AE/AD and SD remains to be established. Previous reports have shown that fungi such as Candida albicans and Aspergillus fumigatus are able to efficiently activate the NLRP3 inflammasome leading to robust secretion of the pro-inflammatory cytokine IL-1β. To date, innate immune responses to Malassezia spp. are not well characterized. Here, we show that different Malassezia species could induce NLRP3 inflammasome activation and subsequent IL-1β secretion in human antigen-presenting cells. In contrast, keratinocytes were not able to secrete IL-1β when exposed to Malassezia spp. Moreover, we demonstrate that IL-1β secretion in antigen-presenting cells was dependent on Syk-kinase signalling. Our results identify Malassezia spp. as potential strong inducers of pro-inflammatory responses when taken up by antigen-presenting cells and identify C-type lectin receptors and the NLRP3 inflammasome as crucial actors in this process. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Comparison of two sampling techniques to assess quantity and distribution of Malassezia yeasts on the skin of Basset Hounds.

    PubMed

    Bensignor, E; Jankowski, F; Seewald, W; Touati, F; Deville, M; Guillot, J

    2002-10-01

    Cytological examination using the tape-strip technique and fungal culture using contact plates with modified Dixon's medium were compared to evaluate the carriage of Malassezia yeasts on four cutaneous sites (left pinna, umbilical region, axilla and perianal area) in adult Basset Hounds. Twenty animals were included in the study. High numbers of Malassezia were isolated from at least one area in 100% of the animals. The frequencies of isolation and population sizes differed significantly according to anatomical location. They were greater on the pinna, followed by the umbilical area, axilla and perianal area. Fungal culture was more sensitive than cytology for the isolation of Malassezia yeasts. Frequencies of isolation were greater using this method, but population sizes were constantly smaller than with cytology.

  6. Epidemiologic Study of Malassezia Yeasts in Seborrheic Dermatitis Patients by the Analysis of 26S rDNA PCR-RFLP.

    PubMed

    Oh, Byung Ho; Lee, Yang Won; Choe, Yong Beom; Ahn, Kyu Joong

    2010-05-01

    This case-control study concerns a molecular biological method based on the data gathered from a group of Korean subjects to examine the distribution of Malassezia yeasts in seborrheic dermatitis (SD) patients. Cultures for Malassezia yeasts were taken from the foreheads, cheeks and chests of 60 patients with SD and in 60 healthy controls of equivalent age. The purpose of this study is to identify the relationship between certain species of Malassezia and SD. This was done by analyzing the differences in the distribution of Malassezia species in terms of age and body parts of the host with healthy controls. 26S rDNA PCR-RFLP, a fast and accurate molecular biological method, was used to overcome the limits of morphological and biochemical methods. The positive Malassezia culture rate was 51.7% in patients with SD, which was lower than that of healthy adults (63.9%). M. restricta was dominant in patients with SD (19.5%). Likewise, M. restricta was identified as a common species (20.5%) in healthy controls. In the ages 31~40, M. restricta was found to be the most common species (31.6%) among SD patients. According to the results of the study, the most frequently isolated species was M. restricta (19.5%) in patients with SD. There was no statistically significant difference in the distribution of Malassezia species between the SD patients and healthy control groups.

  7. In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species.

    PubMed

    Carrillo-Muñoz, Alfonso Javier; Rojas, Florencia; Tur-Tur, Cristina; de Los Ángeles Sosa, María; Diez, Gustavo Ortiz; Espada, Carmen Martín; Payá, María Jesús; Giusiano, Gustavo

    2013-09-01

    The strict nutritional requirements of Malassezia species make it difficult to test the antifungal susceptibility. Treatments of the chronic and recurrent infections associated with Malassezia spp. are usually ineffective. The objective of this study was to obtain in vitro susceptibility profile of 76 clinical isolates of Malassezia species against 16 antifungal drugs used for topical or systemic treatment. Isolates were identified by restriction fragment length polymorphism. Minimal inhibitory concentrations (MIC) were obtained by a modified microdilution method based on the Clinical Laboratory Standards Institute reference document M27-A3. The modifications allowed a good growth of all tested species. High in vitro antifungal activity of most tested drugs was observed, especially triazole derivatives, except for fluconazole which presented the highest MICs and widest range of concentrations. Ketoconazole and itraconazole demonstrated a great activity. Higher MICs values were obtained with Malassezia furfur indicating a low susceptibility to most of the antifungal agents tested. Malassezia sympodialis and Malassezia pachydermatis were found to be more-susceptible species than M. furfur, Malassezia globosa, Malassezia slooffiae and Malassezia restricta. Topical substances were also active but provide higher MICs than the compounds for systemic use. The differences observed in the antifungals activity and interspecies variability demonstrated the importance to studying the susceptibility profile of each species to obtain reliable information for defining an effective treatment regimen. © 2013 Blackwell Verlag GmbH.

  8. [Cutaneous Malassezia infections and Malassezia associated dermatoses: An update].

    PubMed

    Nenoff, P; Krüger, C; Mayser, P

    2015-06-01

    The lipophilic yeast fungus Malassezia (M.) spp. is the only fungal genus or species which is part of the physiological human microbiome. Today, at least 14 different Malassezia species are known; most of them can only be identified using molecular biological techniques. As a facultative pathogenic microorganism, Malassezia represents the causative agent both of superficial cutaneous infections and of blood stream infections. Pityriasis versicolor is the probably most frequent infection caused by Malassezia. Less common, Malassezia folliculitis occurs. There is only an episodic report on Malassezia-induced onychomycosis. Seborrhoeic dermatitis represents a Malassezia-associated inflammatory dermatosis. In addition, Malassezia allergenes should be considered as the trigger of "Head-Neck"-type atopic dermatitis. Ketoconazole possesses the strongest in vitro activity against Malassezia, and represents the treatment of choice for topical therapy of pityriasis versicolor. Alternatives include other azole antifungals but also the allylamine terbinafine and the hydroxypyridone antifungal agent ciclopirox olamine. "Antiseborrhoeic" agents, e.g. zinc pyrithione, selenium disulfide, and salicylic acid, are also effective in pityriasis versicolor. The drug of choice for oral treatment of pityriasis versicolor is itraconazole; an effective alternative represents fluconazole. Seborrhoeic dermatitis is best treated with topical medication, including topical corticosteroids and antifungal agents like ketoconazole or sertaconazole. Calcineurin inhibitors, e.g. pimecrolimus and tacrolimus, are reliable in seborrhoeic dermatitis, however are used off-label.

  9. Identification of Malassezia species isolated from Iranian seborrhoeic dermatitis patients.

    PubMed

    Hedayati, M T; Hajheydari, Z; Hajjar, F; Ehsani, A; Shokohi, T; Mohammadpour, R

    2010-01-01

    In recent years, the genus Malassezia has come to be considered important in the etiology of seborrhoeic dermatitis (SED). The aim of present study was identification of Malassezia species on the lesions of Iranian SED patients. 100 patients with SED were enrolled in the study. The patients were evaluated both clinically for the severity of SED and microscopically for the presence of the yeast Malassezia. Diagnosis of Malassezia was made after the yeast Malassezia was microscopically observed on skin scales stained with methylene blue. All samples were also cultivated on Leeming and Notman and Sabouraud's dextrose agar culture media. The agar plates were incubated at 32 degrees C for 2 weeks and evaluated for the existence of growth every day for one week. Identification of isolated yeast was based on morphological and physiological characteristics. From 100 patients with SED, 60% were female. The age range was 12-65 years with median 27.3 years. The highest prevalence of SED was seen in 20-29 years age group. 59% and 41% of patients had local and generalized lesions, respectively. 58% of patients showed lesion on scalp. Microscopic examination of skin scales was positive in 100% of SED lesions. 96% of patients showed more than 1-3 yeasts in each microscopic field whereas only 4% patients showed 1-3 yeasts in whole slide. Totally, 77% of the specimens yielded Malassezia in culture. Malassezia globosa was the most commonly isolated Malassezia species (55.8%). Malassezia globosa had also most frequencies on scalp and face lesions. Malassezia furfur had most frequency on trunk lesions. The results of our study showed high recovery rate of Malassezia species on lesions of patients with SED. So it might be playing a causative role in the etiology of this disease.

  10. Epidemiologic Study of Malassezia Yeasts in Seborrheic Dermatitis Patients by the Analysis of 26S rDNA PCR-RFLP

    PubMed Central

    Oh, Byung Ho; Choe, Yong Beom; Ahn, Kyu Joong

    2010-01-01

    Background This case-control study concerns a molecular biological method based on the data gathered from a group of Korean subjects to examine the distribution of Malassezia yeasts in seborrheic dermatitis (SD) patients. Cultures for Malassezia yeasts were taken from the foreheads, cheeks and chests of 60 patients with SD and in 60 healthy controls of equivalent age. Objective The purpose of this study is to identify the relationship between certain species of Malassezia and SD. This was done by analyzing the differences in the distribution of Malassezia species in terms of age and body parts of the host with healthy controls. Methods 26S rDNA PCR-RFLP, a fast and accurate molecular biological method, was used to overcome the limits of morphological and biochemical methods. Results The positive Malassezia culture rate was 51.7% in patients with SD, which was lower than that of healthy adults (63.9%). M. restricta was dominant in patients with SD (19.5%). Likewise, M. restricta was identified as a common species (20.5%) in healthy controls. In the ages 31~40, M. restricta was found to be the most common species (31.6%) among SD patients. Conclusion According to the results of the study, the most frequently isolated species was M. restricta (19.5%) in patients with SD. There was no statistically significant difference in the distribution of Malassezia species between the SD patients and healthy control groups. PMID:20548904

  11. Presence, species distribution, and density of Malassezia yeast in patients with seborrhoeic dermatitis - a community-based case-control study and review of literature.

    PubMed

    Barac, Aleksandra; Pekmezovic, Marina; Milobratovic, Danica; Otasevic-Tasic, Suzana; Radunovic, Milena; Arsic Arsenijevic, Valentina

    2015-02-01

    Malassezia yeast belongs to the normal cutaneous flora and under certain conditions it causes seborrhoeic dermatitis (SD). There is no culture-based study about the presence and density of the Malassezia in SD patients in Serbia. Aim was to show the presence, species distribution and density of Malassezia in patients with SD on lesional skin (LS) and non-lesional skin (NLS) and healthy controls (HC) and to compare data between Serbia and other countries. The study included 70 HC and 60 patients with SD in the study group (SG). Isolation, identification and examination of density of Malassezia colony-forming units from LS and NLS were performed. Malassezia was found more frequently in the SG than in HC, 90% and 60%, respectively (P < 0.01). The most frequent isolates in SG on LS were M. slooffiae (26%), followed by M. globosa (17%) and M. sympodialis (17%). The yeast density was much higher on LS of SG than on NLS of SG or in the HC group (P < 0.05). Higher density of Malassezia was shown on LS of SG than on NLS of SG and HC. M. slooffiae is the most prevalent species in SD patients in Serbia. This study demonstrated a positive relationship between severity of SD and presence of Malassezia spp. © 2015 Blackwell Verlag GmbH.

  12. Molecular Identification of Malassezia Species in Patients with Malassezia folliculitis in Sfax, Tunisia.

    PubMed

    Cheikhrouhou, F; Guidara, R; Masmoudi, A; Trabelsi, H; Neji, S; Sellami, H; Makni, F; Ayadi, A

    2017-06-01

    Malassezia folliculitis is caused by the invasion of hair follicles by large numbers of Malassezia cells. Several Malassezia researches still use cultures, morphology and biochemical techniques. The aim of this study was to identify Malassezia species isolated from patients diagnosed with folliculitis, at the Parasitology and Mycology Laboratory of Sfax University Hospital, and to explore the genetic diversity of Malassezia by using PCR-RFLP and PCR-sequencing targeting the rDNA region of the Malassezia genome. Specimens were taken from 27 patients with Malassezia folliculitis. For the molecular identification, PCR amplification of the 26S rDNAD1/D2 region was carried out using the Malup and Maldown primers and three restriction enzymes (BanI, MspI and HeaII) for RFLP analysis. The nucleotide sequences of each isolate were compared to those in the NCBI GenBank by using BLASTIN algorithm. Three species of Malassezia yeasts were identified among the 31 Malassezia strains isolated: M. globosa (83.9%), M. sympodialis (12. 9%) and M. furfur (3.2%). The sequence analysis of M. globosa showed six genotypes. There is a high genotypic variability of M. globosa colonizing patients with folliculitis.

  13. Molecular epidemiology of Malassezia globosa and Malassezia restricta in Sudanese patients with pityriasis versicolor.

    PubMed

    Saad, M; Sugita, T; Saeed, H; Ahmed, A

    2013-02-01

    Pityriasis versicolor is a superficial infection of the stratum corneum caused by Malassezia yeasts. The cutaneous Malassezia globosa and Malassezia restricta in Sudanese patients with pityriasis versicolor were elucidated using a molecular-based, culture-independent method and compared with that in healthy individuals. Scale samples were collected by applying an Opsite™ transparent dressing to lesional and non-lesional sites on 29 Sudanese patients with pityriasis versicolor and 54 healthy individuals. Malassezia DNA was extracted directly from the samples. The overall level of colonization by Malassezia globosa and Malassezia restricta was analyzed by real-time PCR using a TaqMan probe. The overall level of colonization by Malassezia at the lesional sites was higher than that at the non-lesional sites for all body sites, including the face, neck, cheeks, and trunk (2.7- to 6.0-fold increase). Both M. globosa and M. restricta were detected in patients and healthy individuals. However, M. globosa predominated at lesional sites, whereas the level of colonization by both species was similar in healthy individuals.

  14. [Prevalence of Malassezia species associated with seborrheic dermatitis lesions in patients in Argentina].

    PubMed

    Sosa, María de los Angeles; Rojas, Florencia; Mangiaterra, Magdalena; Giusiano, Gustavo

    2013-01-01

    Seborrheic dermatitis (SD) is considered the second most frequently dermatosis associated with the genus Malassezia but little is the knowledge about the epidemiology of this association. To determinate the prevalence of Malassezia species associated with SD and to analyse their distribution according to the location of the lesion on the body. This study was performed in Resistencia city, located in a subtropical area in northeast Argentina. In this study, 226 skin samples from patients with lesions compatible with SD were studied. Age, gender and body sites lesion were recorded. Strains were identified by PCR-RFLP. One hundred and thirty-one positive cultures were obtained. Association of 2 species was detected in 10 cases; therefore, 141 strains were isolated. Malasezzia globosa (43.3%) was the most frequent species isolated, followed by Malasezzia furfur (20.6%), Malasezzia sympodialis (17%) and Malasezzia restricta (16.3%). Three isolates of Malasezzia slooffiae (2.1%) and one of Malasezzia pachydermatis (0.7%) were obtained. Statistical significance (P<0.05) was found between M. globosa and scalp. Malasezzia restricta was isolated only in head areas. This study suggests M. globosa is the most related species to SD. The prevalence of other species is different from that reported by other authors. Only M. globosa and M. restricta presented a pattern of relationship with the body sites of the lesions. It is noteworthy is the isolation of the zoophylic species M. pachydermatis. The Malassezia genus ecology and the pathogenic role of its species are still under study. This work is a contribution to this knowledge. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  15. New lipid-dependent Malassezia species from parrots.

    PubMed

    Cabañes, F Javier; Coutinho, S Dall' Acqua; Puig, Laura; Bragulat, M Rosa; Castellá, Gemma

    2016-01-01

    All the currently recognized Malassezia species have been isolated from mammals. However, only a few of them have been isolated from birds. In fact, birds have been less frequently studied as carriers of Malassezia yeasts than mammals. In this study we describe two new taxa, Malassezia brasiliensis sp. nov. and Malassezia psittaci sp. nov. The isolates studied in this publication were isolated from pet parrots from Brazil. They were characterized using the current morphological and physiological identification scheme. DNA sequencing and analysis of the D1/D2 regions of the 26S rRNA gene, the ITS-5.8S rRNA gene sequences and the β-tubulin gene were also performed. The strains proposed as new species did not completely fit the phenotypic profiles of any the described species. The validation of these new species was supported by analysis of the genes studied. The multilocus sequence analysis of the three loci provides robust support to delineate these species. These studies confirm the separation of these two new species from the other species of the genus Malassezia, as well as the presence of lipid-dependent Malassezia yeasts on parrots. Copyright © 2016 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.

  16. Malassezia folliculitis in an infant

    PubMed Central

    Anane, S.; Chtourou, O.; Bodemer, C.; Kharfi, M.

    2013-01-01

    Malassezia folliculitis commonly affects the adolescents and the young adults. We describe an unusual case of Malassezia folliculitis which is particular in age of patient and scare evolution of lesions. The patient was a three-month-old immuno-competent boy. On clinical examination, 1- to 2-mm superficial follicular pustules were observed on his face, neck and upper trunk. Direct microscopy of pustule scrapings and hair follicles showed numerous Malassezia yeast cells. Based on the clinical and mycological data, the diagnosis of Malassezia folliculitis was made. The possible predisposing factors in our patient were heat and sweating, caused by the excessive heat of the summer season in Tunisia. Treatment with topical ketoconazole promoted cure with depressed varioliform scars. PMID:24432221

  17. Putative Malassezia dermatitis in six goats.

    PubMed

    Eguchi-Coe, Yuko; Valentine, Beth A; Gorman, Elena; Villarroel, Aurora

    2011-12-01

    Histopathology submissions from 28 goats with dermatological disease were identified in an archival search of pathology files. Microscopic sections of skin biopsy specimens were examined for the presence of Malassezia spp. organisms. Six cases with many Malassezia yeasts were identified histopathologically. Based on the extent of clinical disease, three cases were regarded as localized and three were generalized infections. Clinical findings included alopecia with dry seborrhoea (four cases), greasy seborrhoea (one case), and no clinical findings specific to localized Malassezia infection when concurrent bacterial infection was present (one case). Mild pruritus was reported in two cases of generalized infection. No breed predilection was apparent. Three cases were male and three were female. Malassezia dermatitis occurred in goats from 10 months to 13 years of age. Three of six cases had concurrent bacterial infection. Skin lesions resolved following topical antifungal therapy in the two goats that were treated. Histopathological findings in all cases were severe follicular and epidermal orthokeratotic hyperkeratosis with minimal epithelial change and mild superficial perivascular to interstitial nonsuppurative inflammation. Numerous budding yeasts were visible within the stratum corneum of all cases; however, Malassezia was not isolated in the three cases in which culture was attempted. Based upon these findings, the authors suggest that the diagnosis Malassezia dermatitis in goats is most likely to be made by cytological examination of skin impressions or by examination of skin biopsy samples. © 2011 The Authors. Veterinary Dermatology. © 2011 ESVD and ACVD.

  18. Malassezia species and their associated skin diseases.

    PubMed

    Harada, Kazutoshi; Saito, Mami; Sugita, Takashi; Tsuboi, Ryoji

    2015-03-01

    Malassezia spp. are lipophilic fungi that occur on all skin surfaces of humans and animals as commensal and pathogenic organisms. In the 2000s, several new species were added to the Malassezia genus by Japanese researchers. The genus Malassezia now includes 14 species of basidiomycetous yeast. Culture-independent molecular analysis clearly demonstrated that the DNA of Malassezia spp. was predominantly detected in core body and arm sites, suggesting that they are the dominant fungal flora of the human body. Malassezia spp. have been implicated in skin diseases including pityriasis versicolor (PV), Malassezia folliculitis (MF), seborrheic dermatitis (SD) and atopic dermatitis (AD). While Malassezia spp. are directly responsible for the infectious diseases, PV and MF, they act as an exacerbating factor in AD and SD. The fatty acids generated by Malassezia lipase can induce inflammation of the skin, resulting in development of SD. Patch and serum immunoglobulin E tests revealed that AD patients were hypersensitive to Malassezia. However, these findings only partially elucidated the mechanism by which Malassezia spp. induce inflammation in the skin; understanding of the pathogenetic role of Malassezia spp. in SD or AD remains incomplete. In this article, the latest findings of Malassezia research are reviewed with special attention to skin diseases. © 2015 Japanese Dermatological Association.

  19. Malassezia arunalokei sp. nov., a Novel Yeast Species Isolated from Seborrheic Dermatitis Patients and Healthy Individuals from India

    PubMed Central

    Honnavar, Prasanna; Prasad, Gandham S.; Ghosh, Anup; Dogra, Sunil; Handa, Sanjeev

    2016-01-01

    The majority of species within the genus Malassezia are lipophilic yeasts that colonize the skin of warm-blooded animals. Two species, Malassezia globosa and Malassezia restricta, are implicated in the causation of seborrheic dermatitis/dandruff (SD/D). During our survey of SD/D cases, we isolated several species of Malassezia and noticed vast variations within a few lipid-dependent species. Variations observed in the phenotypic characteristics (colony morphology, absence of catalase activity, growth at 37°C, and precipitation surrounding wells containing Tween 20 or Cremophor EL) suggested the possible presence of a novel species. Sequence divergence observed in the internal transcribed spacer (ITS) region, the D1/D2 domain, and the intergenic spacer 1 (IGS1) region of rDNA and the TEF1 gene, PCR-restriction fragment length polymorphism (RFLP) analysis of the ITS2 region, and fluorescent amplified fragment length polymorphism analysis support the existence of a novel species. Based on phenotypic and molecular characterization of these strains, we propose a new species, namely, M. arunalokei sp. nov., and we designate NCCPF 127130 (= MTCC 12054 = CBS 13387) as the type strain. PMID:27147721

  20. Malassezia arunalokei sp. nov., a Novel Yeast Species Isolated from Seborrheic Dermatitis Patients and Healthy Individuals from India.

    PubMed

    Honnavar, Prasanna; Prasad, Gandham S; Ghosh, Anup; Dogra, Sunil; Handa, Sanjeev; Rudramurthy, Shivaprakash M

    2016-07-01

    The majority of species within the genus Malassezia are lipophilic yeasts that colonize the skin of warm-blooded animals. Two species, Malassezia globosa and Malassezia restricta, are implicated in the causation of seborrheic dermatitis/dandruff (SD/D). During our survey of SD/D cases, we isolated several species of Malassezia and noticed vast variations within a few lipid-dependent species. Variations observed in the phenotypic characteristics (colony morphology, absence of catalase activity, growth at 37°C, and precipitation surrounding wells containing Tween 20 or Cremophor EL) suggested the possible presence of a novel species. Sequence divergence observed in the internal transcribed spacer (ITS) region, the D1/D2 domain, and the intergenic spacer 1 (IGS1) region of rDNA and the TEF1 gene, PCR-restriction fragment length polymorphism (RFLP) analysis of the ITS2 region, and fluorescent amplified fragment length polymorphism analysis support the existence of a novel species. Based on phenotypic and molecular characterization of these strains, we propose a new species, namely, M. arunalokei sp. nov., and we designate NCCPF 127130 (= MTCC 12054 = CBS 13387) as the type strain. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  1. Malassezia infections: a medical conundrum.

    PubMed

    Pedrosa, Ana Filipa; Lisboa, Carmen; Gonçalves Rodrigues, Acácio

    2014-07-01

    Malassezia yeasts have long been considered commensal fungi, unable to elicit significant damage. However, they have been associated with a diversity of cutaneous diseases, namely pityriasis versicolor, Malassezia folliculitis, seborrheic dermatitis, atopic dermatitis, psoriasis, and confluent and reticulate papillomatosis. Several hypotheses have been proposed to explain the pathogenic mechanisms of these fungi, but none have been confirmed. More recently, such organisms have been increasingly isolated from bloodstream infections raising serious concern about these fungi. Given the difficulty to culture these yeasts to proceed with speciation and antimicrobial susceptibility tests, such procedures are most often not performed and the cutaneous infections are treated empirically. The recurring nature of superficial skin infections and the potential threat of systemic infections raise the need of faster and more sensitive techniques to achieve isolation, identification, and antimicrobial susceptibility profile. This article reviews and discusses the latest available data concerning Malassezia infections and recent developments about diagnostic methods, virulence mechanisms, and susceptibility testing. Copyright © 2014 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  2. Association of Malassezia species with dandruff.

    PubMed

    Rudramurthy, Shivaprakash M; Honnavar, Prasanna; Dogra, Sunil; Yegneswaran, Prakash P; Handa, Sanjeev; Chakrabarti, Arunaloke

    2014-03-01

    Malassezia species implicated with dandruff vary at different geographical locations. The present study was conducted to determine the spectrum and distribution of Malassezia species in dandruff patients and healthy individuals. Patients with dandruff from northern (Chandigarh) and southern (Manipal, Karnataka) parts of India (50 each) and healthy individuals (20) were included in the study. Dandruff severity was graded as mild, moderate and severe. Malassezia spp. isolated were quantified and identified by phenotypic characters and molecular methods including PCR-RFLP and DNA sequencing. Number of Malassezia spp. retrieved was significantly higher (P<0.001) in dandruff cases (84%) as compared to healthy individuals (30%). Isolation of Malassezia spp. was significantly higher (P<0.01) in patients from southern India. In moderately severe cases M. restricta was single most predominant (37.8%) isolate from patients of northern part of India and M. furfur (46.4%) from patients of southern part of India. Malassezia density was significantly associated with the severity of dandruff (P<0.001). Our results on a limited number of individuals show that Malassezia spp. associated with dandruff varies in different regions of the country and the density of yeasts increases with severity of disease.

  3. The Role of Malassezia spp. in Atopic Dermatitis

    PubMed Central

    Glatz, Martin; Bosshard, Philipp P.; Hoetzenecker, Wolfram; Schmid-Grendelmeier, Peter

    2015-01-01

    Malassezia spp. is a genus of lipophilic yeasts and comprises the most common fungi on healthy human skin. Despite its role as a commensal on healthy human skin, Malassezia spp. is attributed a pathogenic role in atopic dermatitis. The mechanisms by which Malassezia spp. may contribute to the pathogenesis of atopic dermatitis are not fully understood. Here, we review the latest findings on the pathogenetic role of Malassezia spp. in atopic dermatitis (AD). For example, Malassezia spp. produces a variety of immunogenic proteins that elicit the production of specific IgE antibodies and may induce the release of pro-inflammatory cytokines. In addition, Malassezia spp. induces auto-reactive T cells that cross-react between fungal proteins and their human counterparts. These mechanisms contribute to skin inflammation in atopic dermatitis and therefore influence the course of this disorder. Finally, we discuss the possible benefit of an anti-Malassezia spp. treatment in patients with atopic dermatitis. PMID:26239555

  4. [Characterization of species of the gender Malassezia in patients with seborrheic dermatitis and subjects without skin lesions].

    PubMed

    Rendic, Elizabeth; Díaz, Cristina; Fich, Félix

    2003-11-01

    The yeast Malassezia spp has an established etiological role in pityriasis versicolor, folliculitis, systemic infections and onychomycosis. To assess the presence of Malassezia spp in patients with seborrheic dermatitis (SD), to find a correlation between Malassezia spp count and the severity of the disease and to compare the prevalence of the different Malassezia species in SD patients and subjects without skin lesions. Scrapings of the face from 81 patients with SD (69 males) and 79 subjects (54 males) without skin lesions were obtained for a direct microscope examination and yeast culture. The yeast Malassezia was found in 76% of SD patients and in 82% of subjects without skin lesions. There was a positive correlation between the number of yeasts found on direct examination and the clinical severity of lesions in SD patients. Although this correlation was statistically significant (P = 0.046), the degree of association (rho = 0.22) was weak. Fifty Malassezia species were identified. M globosa was found in 67% of SD patients, followed by M furfur and M sympodialis, each present in 16.5% of the SD patients. In subjects without skin lesions, the most prevalent species were M globosa (77%), followed by M sympodialis (12%), M slooffiae (7%) and M furfur (4%). The presence of the yeast Malassezia is not associated with the presence of skin lesions.

  5. Antifungal Susceptibility Testing of Malassezia spp. with an Optimized Colorimetric Broth Microdilution Method.

    PubMed

    Leong, Cheryl; Buttafuoco, Antonino; Glatz, Martin; Bosshard, Philipp P

    2017-06-01

    Malassezia is a genus of lipid-dependent yeasts. It is associated with common skin diseases such as pityriasis versicolor and atopic dermatitis and can cause systemic infections in immunocompromised individuals. Owing to the slow growth and lipid requirements of these fastidious yeasts, convenient and reliable antifungal drug susceptibility testing assays for Malassezia spp. are not widely available. Therefore, we optimized a broth microdilution assay for the testing of Malassezia that is based on the CLSI and EUCAST assays for Candida and other yeasts. The addition of ingredients such as lipids and esculin provided a broth medium formulation that enabled the growth of all Malassezia spp. and could be read, with the colorimetric indicator resazurin, by visual and fluorescence readings. We tested the susceptibility of 52 strains of 13 Malassezia species to 11 commonly used antifungals. MIC values determined by visual readings were in good agreement with MIC values determined by fluorescence readings. The lowest MICs were found for the azoles itraconazole, posaconazole, and voriconazole, with MIC 90 values of 0.03 to 1.0 μg/ml, 0.06 to 0.5 μg/ml, and 0.03 to 2.0 μg/ml, respectively. All Malassezia spp. were resistant to echinocandins and griseofulvin. Some Malassezia spp. also showed high MIC values for ketoconazole, which is the most widely recommended topical antifungal to treat Malassezia skin infections. In summary, our assay enables the fast and reliable susceptibility testing of Malassezia spp. with a large panel of different antifungals. Copyright © 2017 American Society for Microbiology.

  6. Antifungal Susceptibility Testing of Malassezia spp. with an Optimized Colorimetric Broth Microdilution Method

    PubMed Central

    Leong, Cheryl; Buttafuoco, Antonino

    2017-01-01

    ABSTRACT Malassezia is a genus of lipid-dependent yeasts. It is associated with common skin diseases such as pityriasis versicolor and atopic dermatitis and can cause systemic infections in immunocompromised individuals. Owing to the slow growth and lipid requirements of these fastidious yeasts, convenient and reliable antifungal drug susceptibility testing assays for Malassezia spp. are not widely available. Therefore, we optimized a broth microdilution assay for the testing of Malassezia that is based on the CLSI and EUCAST assays for Candida and other yeasts. The addition of ingredients such as lipids and esculin provided a broth medium formulation that enabled the growth of all Malassezia spp. and could be read, with the colorimetric indicator resazurin, by visual and fluorescence readings. We tested the susceptibility of 52 strains of 13 Malassezia species to 11 commonly used antifungals. MIC values determined by visual readings were in good agreement with MIC values determined by fluorescence readings. The lowest MICs were found for the azoles itraconazole, posaconazole, and voriconazole, with MIC90 values of 0.03 to 1.0 μg/ml, 0.06 to 0.5 μg/ml, and 0.03 to 2.0 μg/ml, respectively. All Malassezia spp. were resistant to echinocandins and griseofulvin. Some Malassezia spp. also showed high MIC values for ketoconazole, which is the most widely recommended topical antifungal to treat Malassezia skin infections. In summary, our assay enables the fast and reliable susceptibility testing of Malassezia spp. with a large panel of different antifungals. PMID:28381607

  7. Phospholipase activity after β-endorphin exposure discriminates Malassezia strains isolated from healthy and seborrhoeic dermatitis skin.

    PubMed

    Vlachos, Ch; Gaitanis, G; Alexopoulos, E C; Papadopoulou, C; Bassukas, I D

    2013-12-01

    Phospholipase activity and its induction by β-endorphin have been associated with pathogenic Malassezia pachydermatis animal isolates. To evaluate Malassezia phosholipase activity in human isolates from seborrhoeic dermatitis (SD) and healthy controls before and after β-endorphin exposure. Eighty-four volunteers with or without SD (N = 41) were sampled. Isolated Malassezia strains were incubated in Dixon's medium with and without 100 nmol/L β-endorphin. Subsequently, phospholipase activity was assessed in egg-yolk agar and the results were compared employing Wilcoxon sign test for paired data, chi-squared test and multinomial logistic regression analysis. A total of 64 Malassezia strains were isolated. SD strains tended to have decreased phospholipase activity before (P = 0.057) and increased after exposure to β-endorphin (P = 0.061) compared to isolates from healthy skin. Phospholipase activity after β-endorphin exposure related to basal enzyme activity as a measure of per strain phospholipase inducibility by β-endorphin did not depend on Malassezia species (P = 0.652). However, this latter biochemical trait discriminates strains isolated from SD lesional and healthy skin (P = 0.036). β-endorphin exposure modifies the in vitro phosholipase activity in Malassezia species isolated from SD lesional skin. This is in accordance with emerging evidence that enhanced local lipase activity is involved in the pathogenesis of SD. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

  8. [Recent advances in research on Malassezia microbiota in humans].

    PubMed

    Sugita, Takashi; Zhang, Enshi; Tanaka, Takafumi; Nishikawa, Akemi; Tajima, Mami; Tsuboi, Ryoji

    2013-01-01

    Malassezia species of lipophilic yeasts account for most fungal microbiota. Although they colonize healthy skin, they are also associated with several skin diseases, including pityriasis versicolor, seborrheic dermatitis, Malassezia folliculitis, and atopic dermatitis. To date, 14 members of the Malassezia genus have been identified. Of these, both M. globosa and M. restricta predominate, regardless of skin-disease type. Comprehensive analysis of fungal microbiota in the skin of patients with atopic dermatitis using an rRNA clone library method revealed that fungal microbiota cluster according to disease severity. The external ear canal and sole of the foot are colonized by specific Malassezia microbiota.

  9. Epidemiologic Study of Malassezia Yeasts in Patients with Malassezia Folliculitis by 26S rDNA PCR-RFLP Analysis

    PubMed Central

    Ko, Jong Hyun; Choe, Yong Beom; Ahn, Kyu Joong

    2011-01-01

    Background So far, studies on the inter-relationship between Malassezia and Malassezia folliculitis have been rather scarce. Objective We sought to analyze the differences in body sites, gender and age groups, and to determine whether there is a relationship between certain types of Malassezia species and Malassezia folliculitis. Methods Specimens were taken from the forehead, cheek and chest of 60 patients with Malassezia folliculitis and from the normal skin of 60 age- and gender-matched healthy controls by 26S rDNA PCR-RFLP. Results M. restricta was dominant in the patients with Malassezia folliculitis (20.6%), while M. globosa was the most common species (26.7%) in the controls. The rate of identification was the highest in the teens for the patient group, whereas it was the highest in the thirties for the control group. M. globosa was the most predominant species on the chest with 13 cases (21.7%), and M. restricta was the most commonly identified species, with 17 (28.3%) and 12 (20%) cases on the forehead and cheek, respectively, for the patient group. Conclusion Statistically significant differences were observed between the patient and control groups for the people in their teens and twenties, and in terms of the body site, on the forehead only. PMID:21747616

  10. Identification of Malassezia species in patients with seborrheic dermatitis in China.

    PubMed

    Zhang, Hao; Ran, Yuping; Xie, Zhen; Zhang, Ruifeng

    2013-02-01

    The causes of seborrheic dermatitis (SD) are complex and incompletely understood. Among the factors, Malassezia yeasts have been reported to play a major etiological role in SD. Many previous studies adopted conventional culture methods that were disadvantaged to detect Malassezia microflora in SD patients, resulting in a low detection rate for each species and high variance in types of microflora observed. This study analyzed Malassezia microflora in SD patients by applying a transparent dressing to the lesional skin and using direct detection of fungal DNA using nested PCR. We collected samples from the lesional skin of 146 SD patients in China and extracted fungal DNA directly from the lesional samples without culture. Specific primers for each Malassezia species were designed to amplify existing yeasts in each sample. Some samples were randomly selected to culture and identified by morphological and physiologic criteria. M. globosa and M. restricta were found in 87.0 and 81.5% of seborrheic dermatitis patients, respectively, which together accounted for more than 50% of Malassezia spp. recovered in these Chinese patients. The majority of SD patients (82.9%) showed co-colonization of two or more Malassezia species. M. globosa and M. restricta predominated in Malassezia colonization in Chinese SD patients. Compared with conventional culture, non-culture-based methods may more accurately reflect Malassezia microflora constitution.

  11. Association of Malassezia species with dandruff

    PubMed Central

    Rudramurthy, Shivaprakash M.; Honnavar, Prasanna; Dogra, Sunil; Yegneswaran, Prakash P.; Handa, Sanjeev; Chakrabarti, Arunaloke

    2014-01-01

    Background & objectives: Malassezia species implicated with dandruff vary at different geographical locations. The present study was conducted to determine the spectrum and distribution of Malassezia species in dandruff patients and healthy individuals. Methods: Patients with dandruff from northern (Chandigarh) and southern (Manipal, Karnataka) parts of India (50 each) and healthy individuals (20) were included in the study. Dandruff severity was graded as mild, moderate and severe. Malassezia spp. isolated were quantified and identified by phenotypic characters and molecular methods including PCR-RFLP and DNA sequencing. Results: Number of Malassezia spp. retrieved was significantly higher (P<0.001) in dandruff cases (84%) as compared to healthy individuals (30%). Isolation of Malassezia spp. was significantly higher (P<0.01) in patients from southern India. In moderately severe cases M. restricta was single most predominant (37.8%) isolate from patients of northern part of India and M. furfur (46.4%) from patients of southern part of India. Malassezia density was significantly associated with the severity of dandruff (P<0.001). Interpretation & conclusions: Our results on a limited number of individuals show that Malassezia spp. associated with dandruff varies in different regions of the country and the density of yeasts increases with severity of disease. PMID:24820838

  12. Pityriazepin and other potent AhR ligands isolated from Malassezia furfur yeast

    PubMed Central

    Mexia, Nikitia; Gaitanis, George; Velegraki, Aristea; Soshilov, Anatoly; Denison, Michael S.; Magiatis, Prokopios

    2015-01-01

    Malassezia furfur yeast strains isolated from diseased human skin preferentially biosynthesize indole alkaloids which can be detected in human skin and are highly potent activators of the aryl hydrocarbon receptor (AhR) and AhR-dependent gene expression. Chemical analysis of an EtOAc extract of a M. furfur strain obtained from diseased human skin and grown on L-tryptophan agar revealed several known AhR active tryptophan metabolites along with a previously unidentified compound, pityriazepin. While its structure resembled that of the known alkaloid pityriacitrin, the comprised pyridine ring had been transformed into an azepinone. The indoloazepinone scaffold of pityriazepin is extremely rare in nature and has only been reported once previously. Pityriazepin, like the other isolated compounds, was found to be a potent activator of the AhR-dependent reporter gene assays in recombinant cell lines derived from four different species, although significant species differences in relative potency was observed. The ability of pityriazepin to competitively bind to the AhR and directly stimulate AhR DNA binding classified it as a new naturally-occurring potent AhR agonist. Malassezia furfur produces an expanded collection of extremely potent naturally occurring AhR agonists, which produce their biological effects in a species-specific manner.1 PMID:25721496

  13. The Role of L-DOPA on Melanization and Mycelial Production in Malassezia Furfur

    PubMed Central

    Youngchim, Sirida; Nosanchuk, Joshua D.; Pornsuwan, Soraya; Kajiwara, Susumu; Vanittanakom, Nongnuch

    2013-01-01

    Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization. PMID:23762233

  14. The role of L-DOPA on melanization and mycelial production in Malassezia furfur.

    PubMed

    Youngchim, Sirida; Nosanchuk, Joshua D; Pornsuwan, Soraya; Kajiwara, Susumu; Vanittanakom, Nongnuch

    2013-01-01

    Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization.

  15. Beyond spaghetti and meatballs: skin diseases associated with the Malassezia yeasts.

    PubMed

    Levin, Nikki A

    2009-01-01

    Malassezia are common lipid-dependent fungi that grow on the sebaceous areas of human skin, including the face, scalp, and upper trunk. Although Malassezia are a part of the normal human skin flora, they may also cause or exacerbate several skin diseases, including tinea versicolor, Pityrosporum folliculitis, and seborrheic dermatitis. Topical antifungals are the mainstay of treating Malassezia-related diseases. Chronic prophylaxis is often required to prevent recurrences.

  16. A laboratory-based study on patients with Parkinson's disease and seborrheic dermatitis: the presence and density of Malassezia yeasts, their different species and enzymes production.

    PubMed

    Arsic Arsenijevic, Valentina S; Milobratovic, Danica; Barac, Aleksandra M; Vekic, Berislav; Marinkovic, Jelena; Kostic, Vladimir S

    2014-03-14

    Seborrheic dermatitis (SD) and Parkinson's disease (PD) are frequently associated conditions. Aims of this study were: to determine severity of SD, presence of different species and density of Malassezia yeasts; to assess yeast lipases and phosphatases production in vitro and to compare these results between SD patients with and without PD. This case-control prospective study was conducted at the Dermatology and Neurology Units, Clinical Centre of Serbia and at the National Medical Mycology Reference Laboratory, University of Belgrade Medical School, Serbia. A total of 90 patients and 70 healthy controls (HC) were investigated: 60 patients with SD (SDN) and 30 patients with SD and PD (SDP). Culture-based mycological examination was carried out on lesional skin (LS) and non-lesional skin (NLS). A yeasts density was determined by counting the Malassezia colony forming units per tape (CFU/tape). Enzymes production by isolated Malassezia was investigated. The most patients with SD were male (76.7%; SDP and 63.3%; SDN) and the intensity of SD was dominantly severe or moderate (76.7%; SDP and 75%; SDN). The presence of Malasseziа was high on LS in both groups (87.3%; SDP and 86.7%; SDN) (p=0.667).The highest yeasts density (mean CFU/tape=67.8) was detected on LS in 53% of SDP group and in 21.7% of SDN group (mean CFU/tape=31.9) (p < 0.01). The presence of negative cultures was lower in SDP group (13.3%) in comparison to HC and SDN groups (37% and 31.7%, respectively). Malassezia density on NLS in SDP group (mean CFU/tape=44.3) was significantly higher in comparison to SDN and HC (p=0.018). M. globosa was the most abundant species identified amongst isolates from the SDP group (42.3%) and exhibited high production of phosphatase and lipase in vitro. From this laboratory-based study a positive correlation between SD, PD, M. globosa incidence, high yeast density and high phosphatase and lipase activity was established. Our data lead to conclusion that local skin

  17. Molecular identification of Malassezia species isolated from dermatitis affections.

    PubMed

    Affes, M; Ben Salah, S; Makni, F; Sellami, H; Ayadi, A

    2009-05-01

    The lipophilic yeast of the genus Malassezia are opportunistic microorganisms of the skin microflora but they can be agents of various dermatomycoses. The aim of this study was to perform molecular identification of the commonly isolated Malassezia species from various dermatomycoses in our region. Thirty strains of Malassezia were isolated from different dermatologic affections: pityriasis versicolor (17), dandruff (5), seborrheic dermatitis (4), onyxis (2), folliculitis (1) and blepharitis (1). These species were identified by their morphological features and biochemical characterisation. The molecular identification was achieved by amplification of the internal transcribed spacer region by simple PCR. PCR technique was used for molecular characterisation of four Malassezia species: Malassezia globosa (270 bp), Malassezia furfur (230 bp), Malassezia sympodialis (190 bp) and Malassezia restricta (320 bp). We have detected the association between M. furfur and M. sympodialis in 16% and confirmed presumptive identification in 70% of the cases. The phenotypic identification based on microscopic and physiological method is difficult and time consuming. The application of a simple PCR method provides a sensitive and rapid identification system for Malassezia species, which may be applied in epidemiological surveys and routine practice.

  18. [A study of culture-based easy identification system for Malassezia].

    PubMed

    Kaneko, Takamasa

    2011-01-01

    Most species of this genus are lipid-dependent yeasts, which colonize the seborrheic part of the skin, and they have been reported to be associated with pityriasis versicolor, Malassezia folliculitis, seborrheic dermatitis, and atopic dermatitis. Malassezia have been re-classified into 7 species based on molecular biological analysis of nuclear ribosomal DNA/RNA and new Malassezia species were reported. As members of the genus Malassezia share similar morphological and biochemical characteristics, it was thought to be difficult to differentiate between them based on phenotypic features. While molecular biological techniques are the most reliable methods for identification of Malassezia, they are not available in most clinical laboratories. We studied ( i ) development of an efficient isolation media and culture based easy identification system, ( ii ) the incidence of atypical biochemical features in Malassezia species and propose a culture-based easy identification system for clinically important Malassezia species, M. globosa, M. restricta, and M. furfur.

  19. Malassezia (Pityrosporum) Folliculitis

    PubMed Central

    Rubenstein, Richard M.

    2014-01-01

    Malassezia (Pityrosporum) folliculitis is a fungal acneiform condition commonly misdiagnosed as acne vulgaris. Although often associated with common acne, this condition may persist for years without complete resolution with typical acne medications. Malassezia folliculitis results from overgrowth of yeast present in the normal cutaneous flora. Eruptions may be associated with conditions altering this flora, such as immunosuppression and antibiotic use. The most common presentation is monomorphic papules and pustules, often on the chest, back, posterior arms, and face. Oral antifungals are the most effective treatment and result in rapid improvement. The association with acne vulgaris may require combinations of both antifungal and acne medications. This article reviews and updates readers on this not uncommon, but easily missed, condition. PMID:24688625

  20. A laboratory-based study on patients with Parkinson’s disease and seborrheic dermatitis: the presence and density of Malassezia yeasts, their different species and enzymes production

    PubMed Central

    2014-01-01

    Background Seborrheic dermatitis (SD) and Parkinson’s disease (PD) are frequently associated conditions. Aims of this study were: to determine severity of SD, presence of different species and density of Malassezia yeasts; to assess yeast lipases and phosphatases production in vitro and to compare these results between SD patients with and without PD. Methods This case–control prospective study was conducted at the Dermatology and Neurology Units, Clinical Centre of Serbia and at the National Medical Mycology Reference Laboratory, University of Belgrade Medical School, Serbia. A total of 90 patients and 70 healthy controls (HC) were investigated: 60 patients with SD (SDN) and 30 patients with SD and PD (SDP). Culture-based mycological examination was carried out on lesional skin (LS) and non-lesional skin (NLS). A yeasts density was determined by counting the Malassezia colony forming units per tape (CFU/tape). Enzymes production by isolated Malassezia was investigated. Results The most patients with SD were male (76.7%; SDP and 63.3%; SDN) and the intensity of SD was dominantly severe or moderate (76.7%; SDP and 75%; SDN). The presence of Malasseziа was high on LS in both groups (87.3%; SDP and 86.7%; SDN) (p=0.667). The highest yeasts density (mean CFU/tape=67.8) was detected on LS in 53% of SDP group and in 21.7% of SDN group (mean CFU/tape=31.9) (p < 0.01). The presence of negative cultures was lower in SDP group (13.3%) in comparison to HC and SDN groups (37% and 31.7%, respectively). Malassezia density on NLS in SDP group (mean CFU/tape=44.3) was significantly higher in comparison to SDN and HC (p=0.018). M. globosa was the most abundant species identified amongst isolates from the SDP group (42.3%) and exhibited high production of phosphatase and lipase in vitro. Conclusion From this laboratory-based study a positive correlation between SD, PD, M. globosa incidence, high yeast density and high phosphatase and lipase activity was established. Our data

  1. Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts.

    PubMed

    Leite, João Jaime Giffoni; Brito, Erika Helena Salles; Cordeiro, Rossana Aguiar; Brilhante, Raimunda Sâmia Nogueira; Sidrim, José Júlio Costa; Bertini, Luciana Medeiros; Morais, Selene Maia de; Rocha, Marcos Fábio Gadelha

    2009-01-01

    The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13 mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7 mg mL-1 for hexane extract and 8.87 mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-(1), from 0.312 to 0.625 mg mL-1 and from 0.031 to 0.625 mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625 mg mL-1, from 0.08 to 0.156 mg mL-1 and from 0.312 to 0.625 mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.

  2. Skin diseases associated with Malassezia species in humans. Clinical features and diagnostic criteria.

    PubMed

    Difonzo, E M; Faggi, E

    2008-06-01

    Malassezia yeasts not only cause the well known pityriasis versicolor and folliculitis, but also play an important role in other skin diseases, including seborrheic dermatitis and atopic dermatitis. The presence of Malassezia yeasts may be confirmed by direct microscopic examination and cultures of skin scrapings. In pityriasis versicolor the direct microscopic examination is the rapidest and surest test for confirming the clinical diagnosis. The preparation will show a cluster of globose budding spores with thick or double wall and short hyphae. For detecting Malassezia in the other diseases the cultures is preferable. Culture is useful both for confirming the clinical diagnosis and for epidemiological investigations. The identification of the Malassezia species is not easy. The microscopic observation of the colony direct towards the identification of Malassezia species, but it is not enough to identify the colonies definitely. Several biochemical tests are necessary for a precise identification, such as catalase reaction, growth on media without lipid sources, ability to utilize hydrophilic emulsifiers as sole lipid source, esculin test, tryptophan test.

  3. Malassezia furfur in infantile seborrheic dermatitis.

    PubMed

    Wananukul, Siriwan; Chindamporn, Ariya; Yumyourn, Poomjit; Payungporn, Sunchai; Samathi, Chanchuree; Poovorawan, Yong

    2005-01-01

    Our objective was to study both incidence and various strains of Malassezia in infantile seborrheic dermatitis (ISD). Sixty infants between 2 weeks and 2 years old with clinical diagnosis of ISD at the Department of Pediatrics, King Chulalongkorn Memorial Hospital from May 2002 to April 2003 were recruited. Malassezia spp. were isolated from cultured skin samples of the patients, genomic DNA was extracted and the ITS1 rDNA region was amplified. The PCR product was examined by agarose gel electrophoresis and DNA sequences were determined. The ITS1 sequences were also subjected to phylogenetic analysis and species identification. ISD is most commonly found in infants below the age of 2 months (64%), followed by those between 2 and 4 months (28%) old. Cultures yielded yeast-like colonies in 15 specimens. PCR yielded 200-bp products (Candida) in 3 patients and 300-bp products (Malassezia furfur) in 12 patients (18%). Sugar fermentation using API 20C aux performed on the three 200-bp PCR products yielded Candida species. M. furfur was the only Malassezia recovered from skin scrapings of children with ISD.

  4. Crystallization and preliminary crystallographic study of the yeast Malassezia sympodialis allergen Mala s 1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vilhelmsson, Monica, E-mail: monica.vilhelmsson@medks.ki.se; Center for Infectious Medicine, Department of Medicine, Karolinska University Hospital, Huddinge, Stockholm; Hallberg, B. Martin

    2006-02-01

    Crystals of the M. sympodialis allergen Mala s 1 have been obtained using the hanging-drop vapour-diffusion method. A diffraction data set has been collected from native crystals to 1.35 Å resolution. The opportunistic yeast Malassezia sympodialis can act as an allergen and elicit specific IgE- and T-cell reactivity in patients with atopic eczema. The first identified major allergen from M. sympodialis, Mala s 1, is present on the cell surface of the yeast. Recombinant Mala s 1 was expressed in Escherichia coli, purified and refolded in a soluble form. Crystals of Mala s 1 were obtained in 25% PEG 8K,more » 0.2 M (NH{sub 4}){sub 2}SO{sub 4}. Crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 44.4, b = 163.7, c = 50.6 Å, and diffract to 1.35 Å resolution.« less

  5. 75 FR 4692 - Ophthalmic and Topical Dosage Form New Animal Drugs; Miconazole, Polymixin B, and Prednisolone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ... pachydermatis) and bacteria (Staphylococcus pseudintermedius). The NADA is approved as of November 23, 2009, and... (Malassezia pachydermatis) and bacteria (Staphylococcus pseudintermedius). (3) Limitations. Federal law...

  6. In vitro activity of an ear rinse containing tromethamine, EDTA, benzyl alcohol and 0.1% ketoconazole on Malassezia organisms from dogs with otitis externa.

    PubMed

    Cole, Lynette K; Luu, Dao H; Rajala-Schultz, Paivi J; Meadows, Cheyney; Torres, Audrey H

    2007-04-01

    The purpose of this study was to evaluate the in vitro activity of an ear rinse containing tromethamine, EDTA, benzyl alcohol and 0.1% ketoconazole in purified water on Malassezia organisms from dogs with otitis externa. Malassezia organisms were collected from ear swab samples from the external ear canal of 19 dogs with otitis externa plus one control strain of Malassezia pachydermatis. Three test solutions were evaluated: ER (EDTA, tromethamine, benzyl alcohol), ER + keto (EDTA, tromethamine, benzyl alcohol, ketoconazole), and H2O (purified water). Ten-millilitre aliquots of each test solution was transferred into 20 tubes and inoculated with one of the isolates (1 tube per isolate: 19 clinical and 1 control strain). Samples were retrieved from each tube at five time points (0, 15, 30, 45 and 60 min), transferred to Petri dishes, mixed with Sabouraud dextrose agar supplemented with 0.5% Tween 80 and incubated. Following incubation, the plates were examined for growth and colonies counted as colony-forming units per millilitre. The data were analysed using a repeated measures analysis, with pair-wise comparisons of solution-time combinations. There was a significant reduction in Malassezia growth in ER + keto at all time points (P < 0.0001) compared to time zero. Neither ER nor H2O had any effect on the growth of Malassezia. ER + keto was significantly more effective in reducing Malassezia growth (P < 0.0001) at all time points compared to both ER and H2O. ER + keto may be useful in the treatment of Malassezia otitis externa. Future studies should be performed to evaluate the in vivo efficacy of ER + keto as treatment for otic infections caused by Malassezia.

  7. A new procedure for the cloning, expression and purification of the β-carbonic anhydrase from the pathogenic yeast Malassezia globosa, an anti-dandruff drug target.

    PubMed

    Del Prete, Sonia; De Luca, Viviana; Vullo, Daniela; Osman, Sameh M; AlOthman, Zeid; Carginale, Vincenzo; Supuran, Claudiu T; Capasso, Clemente

    2016-12-01

    Malassezia yeasts are almost exclusively the single eukaryotic members of the fungal flora of the skin. Malassezia globosa and Malassezia restricta are found on the skin of practically all humans. Malassezia globosa is highly implicated in the pathogenesis of dandruff and its genome encodes for only one carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the β-class (MgCA). It has been indeed demonstrated that in many pathogenic microorganisms, CAs are essential for their life cycle and their inhibition can lead to growth impairment and defects. In the previous work, the recombinant MgCA was investigated for its inhibition profile with sulfonamides, which in models of dandruff infection were able to protect animals from the fungal infection, allowing us to propose this enzyme as a new antidandruff target. MgCA was cloned as GST-fusion protein, but the yield was rather low and the protein was often found in inclusion bodies. Here, we propose an alternative procedure consisting in cloning the recombinant MgCA as His-Tag fusion protein. This procedure resulted in a good method to express and purify the active recombinant MgCA, and the protein recovery was better with respect to that used for preparing MG-CA (β-CA cloned as GST-fusion protein).

  8. Host Responses to Malassezia spp. in the Mammalian Skin

    PubMed Central

    Sparber, Florian; LeibundGut-Landmann, Salomé

    2017-01-01

    The skin of mammalian organisms is home for a myriad of microbes. Many of these commensals are thought to have beneficial effects on the host by critically contributing to immune homeostasis. Consequently, dysbiosis can have detrimental effects for the host that may manifest with inflammatory diseases at the barrier tissue. Besides bacteria, fungi make an important contribution to the microbiota and among these, the yeast Malassezia widely dominates in most areas of the skin in healthy individuals. There is accumulating evidence that Malassezia spp. are involved in a variety of skin disorders in humans ranging from non- or mildly inflammatory conditions such as dandruff and pityriasis versicolor to more severe inflammatory skin diseases like seborrheic eczema and atopic dermatitis. In addition, Malassezia is strongly linked to the development of dermatitis and otitis externa in dogs. However, the association of Malassezia spp. with such diseases remains poorly characterized. Until now, studies on the fungus–host interaction remain sparse and they are mostly limited to experiments with isolated host cells in vitro. They suggest a multifaceted crosstalk of Malassezia spp. with the skin by direct activation of the host via conserved pattern recognition receptors and indirectly via the release of fungus-derived metabolites that can modulate the function of hematopoietic and/or non-hematopoietic cells in the barrier tissue. In this review, we discuss our current understanding of the host response to Malassezia spp. in the mammalian skin. PMID:29213272

  9. Host Responses to Malassezia spp. in the Mammalian Skin.

    PubMed

    Sparber, Florian; LeibundGut-Landmann, Salomé

    2017-01-01

    The skin of mammalian organisms is home for a myriad of microbes. Many of these commensals are thought to have beneficial effects on the host by critically contributing to immune homeostasis. Consequently, dysbiosis can have detrimental effects for the host that may manifest with inflammatory diseases at the barrier tissue. Besides bacteria, fungi make an important contribution to the microbiota and among these, the yeast Malassezia widely dominates in most areas of the skin in healthy individuals. There is accumulating evidence that Malassezia spp. are involved in a variety of skin disorders in humans ranging from non- or mildly inflammatory conditions such as dandruff and pityriasis versicolor to more severe inflammatory skin diseases like seborrheic eczema and atopic dermatitis. In addition, Malassezia is strongly linked to the development of dermatitis and otitis externa in dogs. However, the association of Malassezia spp. with such diseases remains poorly characterized. Until now, studies on the fungus-host interaction remain sparse and they are mostly limited to experiments with isolated host cells in vitro . They suggest a multifaceted crosstalk of Malassezia spp. with the skin by direct activation of the host via conserved pattern recognition receptors and indirectly via the release of fungus-derived metabolites that can modulate the function of hematopoietic and/or non-hematopoietic cells in the barrier tissue. In this review, we discuss our current understanding of the host response to Malassezia spp. in the mammalian skin.

  10. Analysis of the response of human keratinocytes to Malassezia globosa and restricta strains.

    PubMed

    Donnarumma, Giovanna; Perfetto, Brunella; Paoletti, Iole; Oliviero, Giovanni; Clavaud, Cécile; Del Bufalo, Aurelia; Guéniche, Audrey; Jourdain, Roland; Tufano, Maria Antonietta; Breton, Lionel

    2014-10-01

    Malassezia spp. are saprophyte yeasts involved in skin diseases with different degrees of severity. The aim of our study was to analyze the response of human epidermal keratinocytes to Malassezia globosa and restricta strains evaluating the host defence mechanisms induced by Malassezia spp. colonization. Our results showed a different modulation of the inflammatory and immunomodulatory cytokine pathways obtained with the different strains of Malassezia tested. In addition, this expression is altered by blocking the TLR2 receptor. In comparison with M. furfur, M. globosa and restricta displayed an unexpected and striking cytotoxicity on keratinocytes. The differences observed could be related to the different modalities of interaction between keratinocytes and Malassezia strains, but also to their growth condition. Taken together, these results indicate that M. globosa or M. restricta colonization exert a different control on the cytokine inflammatory response activated in the human keratinocyte in which TLR2 might be involved. M. globosa and M. restricta may play a synergistic role in the exacerbation of skin diseases in which both are found.

  11. Antifungal susceptibility of Malassezia furfur, Malassezia sympodialis, and Malassezia globosa to azole drugs and amphotericin B evaluated using a broth microdilution method.

    PubMed

    Rojas, Florencia D; Sosa, María de los A; Fernández, Mariana S; Cattana, María E; Córdoba, Susana B; Giusiano, Gustavo E

    2014-08-01

    We studied the in vitro activity of fluconazole (FCZ), ketoconazole (KTZ), miconazole (MCZ), voriconazole (VCZ), itraconazole (ITZ) and amphotericin B (AMB) against the three major pathogenic Malassezia species, M. globosa, M. sympodialis, and M. furfur. Antifungal susceptibilities were determined using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute reference document M27-A3. To support lipid-dependent yeast development, glucose, peptone, ox bile, malt extract, glycerol, and Tween supplements were added to Roswell Park Memorial Institute RPMI 1640 medium. The supplemented medium allowed good growth of all three species studied. The minimal inhibitory concentrations (MICs) were recorded after 72 h of incubation at 32ºC. The three species showed different susceptibility profiles for the drugs tested. Malassezia sympodialis was the most susceptible and M. furfur the least susceptible species. KTZ, ITZ, and VCZ were the most active drugs, showing low variability among isolates of the same species. FCZ, MCZ, and AMB showed high MICs and wide MIC ranges. Differences observed emphasize the need to accurately identify and evaluate antifungal susceptibility of Malassezia species. Further investigations and collaborative studies are essential for correlating in vitro results with clinical outcomes since the existing limited data do not allow definitive conclusions. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Pityriasis Versicolor on Penile Shaft in a Renal Transplant Recipient

    PubMed Central

    Ryu, Han-Won; Cho, Jae-We

    2012-01-01

    Pityriasis versicolor is a superficial infection of the stratum corneum, which is caused by the Malassezia species. Tge Malassezia species consist of 12 subspecies, including M. furfur, M. pachydermatis, M. symphodialis and M. globasa. The Malassezia species are classified as a normal flora, particularly in the sebum rich areas of the skin, and they convert from saprophytic yeast to parasitic mycelial morpholgic form to cause clinical disease. But majorities of their distributions are in the upper back, the neck, the thighs, and the forearm, and not in the penis. It is well known that the renal transplant patients, who take immunosuppressive agents, have impairment in the protective cell mediated immunity. Thus, they are more susceptible to infectious diseases, such as a fungal infection. Therefore, clinical manifestations show higher incidence of disease, but they mostly occur in an expected distribution. We here report a case of pityriasis versicolor in a renal transplant recipient on penile shaft, which is an unusual area. PMID:22879720

  13. Identification of Malassezia species from pityriasis versicolor lesions with a new multiplex PCR method.

    PubMed

    Vuran, Emre; Karaarslan, Aydın; Karasartova, Djursun; Turegun, Buse; Sahin, Fikret

    2014-02-01

    Despite the fact that a range of molecular methods have been developed as tools for the diagnosis of Malassezia species, there are several drawbacks associated with them, such as inefficiency of differentiating all the species, high cost, and questionable reproducibility. In addition, most of the molecular methods require cultivation to enhance sensitivity. Therefore, alternative methods eliminating cultivation and capable of identifying species with high accuracy and reliability are needed. Herein, a multiplex polymerase chain reaction (PCR)-based method was especially developed for the detection of eleven Malassezia species. The multiplex PCR was standardized by incorporating a consensus forward primer, along with Malassezia species-specific reverse primers considering the sizes of the PCR products. In the method, the multiplex-PCR primer content is divided into three parts to circumvent the problem of increased nonspecific background resulting from the use of a large number of primers. DNA extraction protocol described by Harju and colleagues was modified using liquid nitrogen instead of -80 °C to break down the yeast membrane. By a modified extraction procedure followed by multiplex PCR and electrophoresis, the method enables identification and differentiation of Malassezia species from both of the samples obtained directly from skin and yeast colonies grown in culture. Fifty-five patients who were confirmed with pityriasis versicolor were enrolled in the study. Multiplex PCR detected and differentiated all 55 samples obtained directly from the patients' skin. However, 50 out of 55 samples yielded Malassezia colony in the culture. In addition, eight of 50 colonies were misdiagnosed or not completely differentiated by conventional methods based on the sequence analysis of eight colonies. The method is capable of identifying species with high accuracy and reliability. In addition, it is simple, quick, and cost-effective. More importantly, the method works

  14. Phylogenetic relationships of Malassezia species based on multilocus sequence analysis.

    PubMed

    Castellá, Gemma; Coutinho, Selene Dall' Acqua; Cabañes, F Javier

    2014-01-01

    Members of the genus Malassezia are lipophilic basidiomycetous yeasts, which are part of the normal cutaneous microbiota of humans and other warm-blooded animals. Currently, this genus consists of 14 species that have been characterized by phenetic and molecular methods. Although several molecular methods have been used to identify and/or differentiate Malassezia species, the sequencing of the rRNA genes and the chitin synthase-2 gene (CHS2) are the most widely employed. There is little information about the β-tubulin gene in the genus Malassezia, a gene has been used for the analysis of complex species groups. The aim of the present study was to sequence a fragment of the β-tubulin gene of Malassezia species and analyze their phylogenetic relationship using a multilocus sequence approach based on two rRNA genes (ITS including 5.8S rRNA and D1/D2 region of 26S rRNA) together with two protein encoding genes (CHS2 and β-tubulin). The phylogenetic study of the partial β-tubulin gene sequences indicated that this molecular marker can be used to assess diversity and identify new species. The multilocus sequence analysis of the four loci provides robust support to delineate species at the terminal nodes and could help to estimate divergence times for the origin and diversification of Malassezia species.

  15. Glutathione as a promising anti-hydrophobicity agent against Malassezia spp.

    PubMed

    Sivasankar, Chandran; Ponmalar, Ayyappan; Bhaskar, James P; Pandian, Shunmugiah K

    2015-10-01

    The genus Malassezia has recently attracted wide attention in medical microbiology and dermatology as a pathogen. They are lipophilic yeasts possessing high level of cell surface hydrophobicity (CSH). L-glutathione (GSH) is a ubiquitous antioxidant which offers protection against microbial infections. This study is intended to investigate the role of GSH as a potential anti-hydrophobicity agent against Malazessia spp. Microbial adherence to hydrocarbon assay was performed to assess the anti-hydrophobicity activity (AHA) of GSH against four Malassezia spp. The assay revealed that GSH at 400 μg ml(-1) concentration inhibited CSH, ranging from 84% to 95% in M. furfur, M. globosa, M. restricta and M. sympodialis without killing the cells. The AHA of GSH was corroborated by auto-aggregation assay and zeta-potential measurement, through which delayed cell aggregation was observed due to reduction in CSH level and not by modification in cell surface charge. In addition, colony-forming unit assay was performed in which 62-93% of CSH reduction was observed in Malassezia spp. tested. Furthermore, GSH treatment enhanced the sensitivity of Malassezia spp. towards human blood at the rate of 64-72%. The AHA was further confirmed through Fourier transform infrared analysis. Thus, this study portrays GSH as a prospective therapeutic alternative for Malassezia-mediated infections. © 2015 Blackwell Verlag GmbH.

  16. Quantitative analysis of the cutaneous Malassezia microbiota in 770 healthy Japanese by age and gender using a real-time PCR assay.

    PubMed

    Sugita, Takashi; Suzuki, Miho; Goto, Seiko; Nishikawa, Akemi; Hiruma, Masataro; Yamazaki, Takashi; Makimura, Koichi

    2010-03-01

    Although the lipophilic yeasts of the genus Malassezia are part of the cutaneous microbiota in healthy individuals, they are also associated with several skin diseases, such as seborrheic dermatitis. However, the effects of age and gender on the Malassezia microbiota have not been completely elucidated. We analyzed the cutaneous Malassezia microbiota of 770 healthy Japanese using the highly accurate real-time PCR with a TaqMan probe to investigate the effects of age and gender on the Malassezia population. The numbers of Malassezia cells increased in males up to 16-18 years of age and in females to 10-12 years old, and subsequently decreased gradually in both genders until senescence. Malassezia restricta overwhelmingly predominated at ages over 16-18 years in males and 23-29 years in females. M. globosa and M. restricta together accounted for more than 70% of Malassezia spp. recovered regardless of gender. The total colonization of Malassezia and the ratio of the two major species change with age and gender in humans.

  17. Molecular Identification and Prevalence of Malassezia Species in Pityriasis Versicolor Patients From Kashan, Iran

    PubMed Central

    Talaee, Rezvan; Katiraee, Farzad; Ghaderi, Maryam; Erami, Mahzad; Kazemi Alavi, Azam; Nazeri, Mehdi

    2014-01-01

    Background: Malassezia species are lipophilic yeasts found on the skin surface of humans and other warm-blooded vertebrates. It is associated with various human diseases, especially pityriasis versicolor, which is a chronic superficial skin disorder. Objectives: The aim of the present study was to identify Malassezia species isolated from patients’ samples affected by pityriasis versicolor, using molecular methods in Kashan, Iran. Patients and Methods: A total of 140 subjects, suspected of having pityriasis versicolor from Kashan, were clinically diagnosed and then confirmed by direct microscopic examination. The scraped skin specimens were inoculated in modified Dixon’s medium. DNA was extracted from the colonies and PCR amplification was carried out for the 26s rDNA region. PCR products were used to further restriction fragment length polymorphism by CfoI enzyme. Results: Direct examination was positive in 93.3% of suspected pityriasis versicolor lesions. No statistically significant difference was observed in the frequency of Malassezia species between women and men. The highest prevalence of tinea versicolor was seen in patients 21–30 years-of-age. No difference could be seen in the frequency of Malassezia species depending on the age of the patients. In total, 65% of patients with pityriasis versicolor had hyperhidrosis. The most commonly isolated Malassezia species in the pityriasis versicolor lesions were; Malassezia globosa (66%), M. furfur (26%), M. restricta (3%), M. sympodialis (3%), and M. slooffiae (2%). Malassezia species were mainly isolated from the neck and chest. Conclusions: This study showed M. globosa to be the most common Malassezia species isolated from Malassezia skin disorders in Kashan, Iran. The PCR-RFLP method was useful in the rapid identification of the Malassezia species. By using these methods, the detection and identification of individual Malassezia species from clinical samples was substantially easier. PMID:25485051

  18. Comparison between Malassezia Folliculitis and Non-Malassezia Folliculitis

    PubMed Central

    Song, Hyo Sang; Kim, Sue Kyung

    2014-01-01

    Background Among the various types of folliculitis, differentiation of Malassezia folliculitis (MF) from other forms of folliculitis is important because it is usually treated with antifungal agents. Objective We attempted to find a method to enhance the detection rate of MF, and examined the differences in the clinical manifestation between MF and non-MF (NMF). Methods We performed a retrospective study involving patients with folliculitis who were previously diagnosed with MF or NMF on the basis of serial tissue sectioning and diastase-Periodic acid-Schiff (d-PAS) staining findings. The clinical features of MF and NMF were compared. Results Among a total of 100 folliculitis patients, 20 were diagnosed with MF and 80 with NMF. Tissues from the 80 patients with NMF were sectioned serially into 10 slices and stained with hematoxylin and eosin stain; among these, 10 had many round-to-oval yeast organisms in the hair follicles that confirmed MF. Finally, d-PAS staining was used to detect the presence of yeast in the NMF slides. Notably, among the 70 d-PAS-stained samples, yeast organisms were found in 6 samples, confirming MF. As a result, the diagnosis of 16 patients changed from NMF to MF. Compared with NMF, MF showed major involvement of the trunk and low involvement of the face and legs as well as male predilection. Conclusion Physicians should consider serial sectioning and/or d-PAS staining of folliculitis lesions, particularly of those on the trunk of male patients, even if no yeast organisms are detected initially. PMID:25324652

  19. In vitro antifungal efficacy of ciclopirox olamine alone and associated with zinc pyrithione compared to ketoconazole against Malassezia globosa and Malassezia restricta reference strains.

    PubMed

    Roques, Christine; Brousse, Sabine; Panizzutti, Cédric

    2006-12-01

    The aim of this study was to determine the in vitro fungicidal and growth inhibitory activity of ciclopirox olamine alone (1% and 1.5%) or in association with 1% zinc pyrithione compared to 2% ketoconazole, against Malassezia species particularly involved in the pathogenesis of seborrheic dermatitis. Experiments were performed on Malassezia globosa IP 2387.96 and M. restricta IP 2392.96 strains. Growth inhibitory activity of the active compounds in solution was evaluated by measuring minimal inhibitory concentrations using a broth micro-method and their fungicidal activity by a filtration method after contact times between solutions and yeasts ranging from 3-5 to 30 min. Concerning the determination of minimal inhibitory concentration of ciclopirox olamine/zinc pyrithione, it revealed the marked synergistic inhibitory effect of the association, leading to a higher efficacy compared to ketoconazole. As to the fungicidal activity of ciclopirox olamine, it significantly increased with the contact time. After 15-30 min of contact between 1.5% ciclopirox olamine and Malassezia strains, a 2-log reduction of Malassezia counts was observed. The 1.5% ciclopirox olamine/1% zinc pyrithione association was characterized by a steady fungicidal efficacy whereas the 2% ketoconazole solution did not express any fungicidal effect. In conclusion, this study demonstrates the in vitro inhibitory and fungicidal efficacy of the ciclopirox olamine/zinc pyrithione association against Malassezia species and underscores its potential interest in the treatment of seborrheic dermatitis.

  20. Distribution of Malassezia species in patients with pityriasis versicolor in Turkey.

    PubMed

    Rodoplu, G; Saracli, M A; Gümral, R; Taner Yildiran, S

    2014-06-01

    Pityriasis versicolor is a common superficial mycotic disease of the skin which is caused by different species of Malassezia genus. The aim of this study was to contribute to the knowledge of the aetiology of pityriasis versicolor (PV) with a mycological study made according to the new species and additionally, the success of the different sampling techniques, duration and recurrence history of the disease, distribution of infecting strains according to the affected body sites were also investigated. In total, 146 patients with pityriasis versicolor were included in this study. Fungal elements could only be visualized by potassium hydroxide examination in 36.4% of the samples. Specimens obtained by scraping skin surface by a sterile scalpel and/or sterile sticky plaster (OpSite) were inoculated in plates containing modified Dixon's medium. Out of 146 samples, 109 (74.7%) yielded a growth which was considered to be Malassezia spp. in culture. Species level identification of suspicious Malassezia yeasts was made according to their macroscopic and microscopic features, and their physiological characteristics. Among the identified species, Malassezia globosa (65.1%) was the most commonly isolated species, followed by Malassezia obtusa (17.4%). However, four Malassezia isolates could not be identified at species level with conventional methods. While most of the patients suffered their first episode of pityriasis versicolor (76%), back of the trunk was the mostly affected body site (39%). In conclusion, Malassezia globosa was found to be the predominant species in pityriasis versicolor patients in our region, and culture of the specimen is necessary for the epidemiologic purposes. Copyright © 2014. Published by Elsevier Masson SAS.

  1. Identification of Malassezia species from immunocompetent and immunocompromised patients with seborrheic dermatitis.

    PubMed

    Prohic, A; Kasumagic-Halilovic, E

    2010-12-01

    Differences in prevalence, clinical and histological manifestations between seborrheic dermatitis (SD) in immunocompetent and immunocompromised patients suggest that these two populations might also differ in a spectrum of isolated Malassezia species. The purpose of our study was to analyse the prevalence of Malassezia species in immunocompromised and non-immunocompromised patients with SD and to examine if the range of isolated yeasts varies between these two study groups. Specimens were taken from 50 patients with SD: 30 without any underlying disease and 20 with confirmed immunosuppression. The samples were obtained by scraping the skin surface of the scalp and trunk lesions of all subjects and then incubated on modified Dixon agar. The yeasts isolated were identified by their morphological and physiological properties according to Guillot et al method. In both groups, the most commonly isolated species from the scalp lesions were Malassenzia restricta and Malassenzia globosa, the later being the most common species isolated from lesional trunk skin. No significant differences were found between immunocompromised and immunocompetent patients from both sampled sites. There is no difference in the distribution of Malassezia species isolated from SD lesions between immunocompetent and immunocompromised patients. However, the much higher percentage of positive cultures in immunocompromised patients confirms that impaired cellular immunity may facilitate fungal survival on the skin.

  2. A noninferiority clinical trial comparing fluconazole and ketoconazole in combination with cephalexin for the treatment of dogs with Malassezia dermatitis.

    PubMed

    Sickafoose, L; Hosgood, G; Snook, T; Westermeyer, R; Merchant, S

    2010-01-01

    This double-blinded noninferiority clinical trial evaluated the use of oral fluconazole for the treatment of Malassezia dermatitis in dogs by comparing it with use of an accepted therapeutic agent, ketoconazole. Dogs presenting with Malassezia dermatitis were treated with either fluconazole or ketoconazole in addition to cephalexin for concurrent bacterial dermatitis. Statistically significant improvements in cytologic yeast count, clinical signs associated with Malassezia dermatitis, and pruritus were seen with both antifungal treatments. There was no statistical difference between the treatments with regard to the magnitude of reduction in these parameters. These results suggest that fluconazole is at least as effective as ketoconazole for the treatment of dogs with Malassezia dermatitis.

  3. Seborrheic dermatitis: predisposing factors and ITS2 secondary structure for Malassezia phylogenic analysis.

    PubMed

    Amado, Yulien; Patiño-Uzcátegui, Anelvi; Cepero de García, Maria C; Tabima, Javier; Motta, Adriana; Cárdenas, Martha; Bernal, Adriana; Restrepo, Silvia; Celis, Adriana

    2013-11-01

    Seborrheic dermatitis (SD) is a chronic, widespread skin condition, which is considered a multifactorial disease influenced, in part, by Malassezia spp. opportunistic activities, as well as various endogenous and exogenous factors. Malassezia species are lipophilic, lipid-dependent yeasts that are members of the normal mycobiota of the human skin. Their isolation from SD lesions varies around the world and the study of the relationship among factors such as gender, age, immunosuppressive condition of the patient and SD development, can lead to a better understanding of this disease. To elucidate the association of age and gender with the development of SD and to precisely determine the Malassezia species involved in the disease, samples were obtained from 134 individuals, including individuals without lesions, human immunodeficiency virus positive patients, individuals with seborrheic dermatitis, and HIV patients with seborrheic dermatitis. Malassezia spp. were identified by phenotypic and genotypic methods and a phylogenetic analysis was performed using Bayesian inference. This study revealed that age and gender are not predisposing factors for SD development, and that the most frequent species of Malassezia related to SD development among the Colombian population is M. restricta. We also report the isolation of M. yamatoensis for the first time in Colombia, and propose an ITS2 secondary structure from Malassezia taxa that can be used for precise identification and to establish more robust phylogenetic relationships.

  4. Distribution of Malassezia species in seborrhoeic dermatitis: correlation with patients' cellular immune status.

    PubMed

    Prohic, Asja

    2010-07-01

    Malassezia species are implicated in the pathogenesis of seborrhoeic dermatitis (SD), but the relationship between each species and the disorder remains unclear. It is hypothesised that the pathogenesis of SD has an immune component, which is supported by the increased incidence in patients with immunosuppressive disorders. The purpose of our study was to analyse the prevalence of Malassezia species in lesional skin of SD, and to assess the distribution of the species according to severity of the disease and cellular immune status of the patients. Forty SD patients with scalp involvement were included in the study. The samples were obtained by scraping the skin surface of the scalp and then incubated on Sabouraud dextrose agar and modified Dixon agar. The yeasts isolated were identified by their morphological and physiological properties according to the method of Guillot et al. In addition, we performed two-colour flow cytometry analysis to investigate the lymphocyte subpopulations in the peripheral blood. The most commonly isolated species was Malassezia restricta (27.5%), followed by Malassezia globosa (17.5%) and Malassezia slooffiae (15%). We demonstrated low helper/suppressor ratios in 70% patients, because of an increase in the suppressor T-cell population, suggesting an impaired cellular immunity. However, we found no significant difference in the distribution of isolated Malassezia species according to the severity of the scalp involvement and changes in the peripheral blood lymphocyte subpopulations.

  5. Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran

    PubMed Central

    Tarazooie, Bita; Kordbacheh, Parivash; Zaini, Farideh; Zomorodian, Kamiar; Saadat, Farshid; Zeraati, Hojjat; Hallaji, Zahra; Rezaie, Sassan

    2004-01-01

    Background Pityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins. Methods Differentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin. Results In pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%), followed by M. furfur (25.3%), M. sympodialis(9.3%), M. obtusa (8.1%) and M. slooffiae (4.0%). The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species. Conclusions According to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered. PMID:15119958

  6. Management of cosmetic embarrassment caused by Malassezia spp. with fruticose lichen Cladia using phylogenetic approach.

    PubMed

    Pandey, Anand; Mishra, Rohit K; Tiwari, Amit K; Kumar, Awadhesh; Bajaj, A K; Dikshit, Anupam

    2013-01-01

    During anti-Malassezia screening of plants by CLSI broth microdilution method, Cladia aggregata (Swartz) Nyl. (family Cladoniaceae), a fruticose lichen from Sikkim (northeast Himalayan region), has been found effective at minimum inhibitory concentrations (mg/mL) of 2.72, 0.63, and 1.28 against yeast-like fungi namely, M. furfur, M. globosa and M. sympodialis, respectively. These test pathogens are responsible for pityriasis versicolor (PV) and seborrheic dermatitis (SD) in humans. We tried to establish the reason for variable MICs against various Malassezia spp. using bioinformatical tools, thereby reducing the cost of the experimentation. This is the first report on anti-Malassezia activity of C. aggregata and thus can serve as a potential source for the development of cosmaceuticals.

  7. Management of Cosmetic Embarrassment Caused by Malassezia spp. with Fruticose Lichen Cladia Using Phylogenetic Approach

    PubMed Central

    Pandey, Anand; Mishra, Rohit K.; Tiwari, Amit K.; Kumar, Awadhesh; Bajaj, A. K.; Dikshit, Anupam

    2013-01-01

    During anti-Malassezia screening of plants by CLSI broth microdilution method, Cladia aggregata (Swartz) Nyl. (family Cladoniaceae), a fruticose lichen from Sikkim (northeast Himalayan region), has been found effective at minimum inhibitory concentrations (mg/mL) of 2.72, 0.63, and 1.28 against yeast-like fungi namely, M. furfur, M. globosa and M. sympodialis, respectively. These test pathogens are responsible for pityriasis versicolor (PV) and seborrheic dermatitis (SD) in humans. We tried to establish the reason for variable MICs against various Malassezia spp. using bioinformatical tools, thereby reducing the cost of the experimentation. This is the first report on anti-Malassezia activity of C. aggregata and thus can serve as a potential source for the development of cosmaceuticals. PMID:24069589

  8. Inhibitory effect of formulated lemongrass shampoo on Malassezia furfur: a yeast associated with dandruff.

    PubMed

    Wuthi-Udomlert, Mansuang; Chotipatoomwan, Ployphand; Panyadee, Sasikan; Gritsanapan, Wandee

    2011-03-01

    Lemongrass (Cymbopogon citratus Stapf) has been used in cooking and in many traditional medicines; the essential oil contains citral as a major constituent. This study evaluated the antifungal activity of lemongrass oil against Malassezia furfur, an opportunistic yeast associated with dandruff, by using a broth dilution assay. From the minimum fungicidal concentration (MFC) obtained, the oil was then incorporated at different percentages into shampoo formulations. The formulated shampoos were kept at room temperature (28 degrees-30 degrees C) and under accelerated condition (45 degrees C). At the end of the first and sixth weeks, after preparation, all formulations were tested again and the appearance was recorded. Selection of an appropriate formula was based on antifungal activity against M. furfur, the physical appearance, the chemical properties and stability of the formula. Two percent lemongrass oil shampoo provided the required qualities necessary for commercial use. After being kept for 6 weeks at 28 degrees-30 degrees C and 45 degrees C, this formulated shampoo gave MFCs against M. furfur of 75 microl/ml and 18.75 microl/ml, respectively.

  9. Chemical Organization of the Cell Wall Polysaccharide Core of Malassezia restricta

    PubMed Central

    Stalhberger, Thomas; Simenel, Catherine; Clavaud, Cécile; Eijsink, Vincent G. H.; Jourdain, Roland; Delepierre, Muriel; Latgé, Jean-Paul; Breton, Lionel; Fontaine, Thierry

    2014-01-01

    Malassezia species are ubiquitous residents of human skin and are associated with several diseases such as seborrheic dermatitis, tinea versicolor, folliculitis, atopic dermatitis, and scalp conditions such as dandruff. Host-Malassezia interactions and mechanisms to evade local immune responses remain largely unknown. Malassezia restricta is one of the most predominant yeasts of the healthy human skin, its cell wall has been investigated in this paper. Polysaccharides in the M. restricta cell wall are almost exclusively alkali-insoluble, showing that they play an essential role in the organization and rigidity of the M. restricta cell wall. Fractionation of cell wall polymers and carbohydrate analyses showed that the polysaccharide core of the cell wall of M. restricta contained an average of 5% chitin, 20% chitosan, 5% β-(1,3)-glucan, and 70% β-(1,6)-glucan. In contrast to other yeasts, chitin and chitosan are relatively abundant, and β-(1,3)-glucans constitute a minor cell wall component. The most abundant polymer is β-(1,6)-glucans, which are large molecules composed of a linear β-(1,6)-glucan chains with β-(1,3)-glucosyl side chain with an average of 1 branch point every 3.8 glucose unit. Both β-glucans are cross-linked, forming a huge alkali-insoluble complex with chitin and chitosan polymers. Data presented here show that M. restricta has a polysaccharide organization very different of all fungal species analyzed to date. PMID:24627479

  10. Chemical organization of the cell wall polysaccharide core of Malassezia restricta.

    PubMed

    Stalhberger, Thomas; Simenel, Catherine; Clavaud, Cécile; Eijsink, Vincent G H; Jourdain, Roland; Delepierre, Muriel; Latgé, Jean-Paul; Breton, Lionel; Fontaine, Thierry

    2014-05-02

    Malassezia species are ubiquitous residents of human skin and are associated with several diseases such as seborrheic dermatitis, tinea versicolor, folliculitis, atopic dermatitis, and scalp conditions such as dandruff. Host-Malassezia interactions and mechanisms to evade local immune responses remain largely unknown. Malassezia restricta is one of the most predominant yeasts of the healthy human skin, its cell wall has been investigated in this paper. Polysaccharides in the M. restricta cell wall are almost exclusively alkali-insoluble, showing that they play an essential role in the organization and rigidity of the M. restricta cell wall. Fractionation of cell wall polymers and carbohydrate analyses showed that the polysaccharide core of the cell wall of M. restricta contained an average of 5% chitin, 20% chitosan, 5% β-(1,3)-glucan, and 70% β-(1,6)-glucan. In contrast to other yeasts, chitin and chitosan are relatively abundant, and β-(1,3)-glucans constitute a minor cell wall component. The most abundant polymer is β-(1,6)-glucans, which are large molecules composed of a linear β-(1,6)-glucan chains with β-(1,3)-glucosyl side chain with an average of 1 branch point every 3.8 glucose unit. Both β-glucans are cross-linked, forming a huge alkali-insoluble complex with chitin and chitosan polymers. Data presented here show that M. restricta has a polysaccharide organization very different of all fungal species analyzed to date.

  11. Sensitization to Malassezia in children with atopic dermatitis combined with food allergy.

    PubMed

    Kekki, O-M; Scheynius, A; Poikonen, S; Koskinen, A; Kautiainen, H; Turjanmaa, K

    2013-05-01

    The yeast Malassezia belongs to our normal cutaneous flora, but is capable of sensitizing individuals with atopic dermatitis (AD). Our objective was to investigate the prevalence of sensitization to Malassezia with a 10-yr follow-up among children suffering from AD combined with food allergy (FA) in relation to the extent of AD in infancy. One hundred and eighty seven infants diagnosed with AD and milk/wheat allergy before 1 yr of age were included in the study. The area of AD was estimated from patient records of the first visit and measured with SCORAD at the 10-yr follow-up. Specific IgE against Malassezia was determined with ImmunoCAP™ at 11 yr of age. In infancy, 24 children (13%) were allergic to milk, 71 (38%) to wheat, and 92 (49%) to both milk and wheat, and 94 (50%) children had mild, 57 (30%) moderate and 36 (19%) severe AD. At the 10-yr follow-up visit, 19 (10%) of the children had ongoing milk and/or wheat allergy; 147 children (79%) had mild AD and 30 (16%) had SCORAD index of 0. Specific IgE against Malassezia mix was positive (≥0.35 kU/l) in 27% and specific IgE against M. sympodialis in 20% of the 187 children. The area of AD in infancy was associated with a greater risk of having allergen-specific IgE to Malassezia at the 10-yr follow-up. The risk ratio for FA was 3.11 (95% CI: 2.05-4.72; p < 0.001) if specific IgE to Malassezia was positive. Infants with severe AD and FA seem to have a greater risk of becoming sensitized to Malassezia during a 10-yr follow-up. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  12. Identification and characterization of lipases from Malassezia restricta, a causative agent of dandruff.

    PubMed

    Sommer, Bettina; Overy, David P; Kerr, Russell G

    2015-11-01

    Dandruff, a skin disorder affecting 50% of the world population, is linked with proliferation of lipophilic yeasts of the genus Malassezia (particularly Malassezia globosa and M. restricta). Most Malassezia species show a unique lipid dependency and require external lipids for growth. Genome mining of the incomplete M. restricta genome led to the identification of eight lipase sequences. Sequences representing the class 3 and LIP lipase families were used to clone the lipases MrLip1, MrLip2 and MrLip3, recombinantly expressed in Pichia pastoris, and tested for their activity using mono-, di- and triacylglycerol substrates. Hydrolysis by the M. restricta lipase MrLip1 and MrLip2 (family class 3) was limited to the mono- and diacylglycerol, while MrLip3 (family LIP) hydrolyzed all three substrates. This result confirms that Malassezia family LIP lipases are responsible for the hydrolysis of triacylglycerols, the main component of human sebum. Furthermore, the information regarding lipases from M. restricta presented here might aid in the search for anti-dandruff agents. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Comparative efficacies of oral ketoconazole and terbinafine for reducing Malassezia population sizes on the skin of Basset Hounds.

    PubMed

    Guillot, Jacques; Bensignor, Emmanuel; Jankowski, François; Seewald, Wolfgang; Chermette, René; Steffan, Jean

    2003-06-01

    The objective of this study was to compare the efficacy of oral ketoconazole and terbinafine for reducing population sizes of Malassezia yeasts on canine skin. Twenty-one Basset Hounds were randomised in three groups of seven according to Malassezia populations. Dogs in the first group were treated by oral administration of ketoconazole (Ketofungol) 200 mg, Janssen-Cilag) at 10 mg x kg-1, every 24 h with food, for 3 weeks. Dogs in the second group were treated by oral administration of terbinafine (Lamisil) 250 mg, Novartis) at 30 mg x kg-1, every 24 h with food, for 3 weeks. The seven remaining dogs were used as controls. Malassezia population sizes were assessed by use of contact plates on four cutaneous sites at days 7, 14 and 21. Both ketoconazole and terbinafine were effective in reducing the baseline levels of Malassezia organisms with no significant difference between the two drugs. In further studies, oral terbinafine should be evaluated for the management of canine cases of Malassezia dermatitis.

  14. Cutaneous fungal microbiome: Malassezia yeasts in seborrheic dermatitis scalp in a randomized, comparative and therapeutic trial.

    PubMed

    Kamamoto, C S L; Nishikaku, A S; Gompertz, O F; Melo, A S; Hassun, K M; Bagatin, E

    2017-01-01

    Malassezia spp in skin microbiome scalp has been implicated in seborrheic dermatitis pathogenesis. Thus, treatment based in antifungal combined to topical keratolitic agents have been indicated as well as oral isotretinoin as it reduces the sebum production, glandular's size and possesses anti-inflammatory properties. This randomized, comparative and therapeutic trial aimed toper form the genotypic identification of Malassezia species before and after low-dose oral isotretinoin or topical antifungal treatments for moderate to severe seborrhea and/or seborrheic dermatitis on scalp. Scales and sebum of the scalp were seeded in the middle of modified Dixon and incubated at 32°C. For genotypic identification polymerase chain reaction primers for the ITS and D1/D2 ribossomal DNA were used and followed by samples sequencing. The procedure was conducted before and after therapeutic and randomized intervention for moderate to severe seborrhea/seborrheic dermatitis on the scalp, including oral isotretinoin, 10 mg, every other day and anti-seborrheic shampoo (piroctone olamine), over six months. The M. globosa and M. restricta were the most frequent species isolated on the scalp before and after both treatments. Other non- Malassezia species were also identified. The Malassezia spp. were maintained in the scalp after both treatments that were equally effective for the control of seborrhea/seborrheic dermatitis clinical signs.

  15. Molecular Analysis of Malassezia Microflora on the Skin of Atopic Dermatitis Patients and Healthy Subjects

    PubMed Central

    Sugita, Takashi; Suto, Hajime; Unno, Tetsushi; Tsuboi, Ryoji; Ogawa, Hideoki; Shinoda, Takako; Nishikawa, Akemi

    2001-01-01

    Members of the genus Malassezia, lipophilic yeasts, are considered to be one of the exacerbating factors in atopic dermatitis (AD). We examined variation in cutaneous colonization by Malassezia species in AD patients and compared it with variation in healthy subjects. Samples were collected by applying transparent dressings to the skin lesions of AD patients. DNA was extracted directly from the dressings and amplified in a specific nested PCR assay. Malassezia-specific DNA was detected in all samples obtained from 32 AD patients. In particular, Malassezia globosa and M. restricta were detected in approximately 90% of the AD patients and M. furfur and M. sympodialis were detected in approximately 40% of the cases. The detection rate was not dependent on the type of skin lesion. In healthy subjects, Malassezia DNA was detected in 78% of the samples, among which M. globosa, M. restricta, and M. sympodialis were detected at frequencies ranging from 44 to 61%, with M. furfur at 11%. The diversity of Malassezia species found in AD patients was greater (2.7 species detected in each individual) than that found in healthy subjects (1.8 species per individual). Our results suggest that M. furfur, M. globosa, M. restricta, and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of AD patients shows more diversity than that of healthy subjects. To our knowledge, this is the first report of the use of a nested PCR as an alternative to fungal culture for analysis of the distribution of cutaneous Malassezia spp. PMID:11574560

  16. The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur

    PubMed Central

    Kim, Su-Han; Ko, Hyun-Chang; Kwon, Kyung-Sool; Oh, Chang-Keun

    2009-01-01

    Background Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-α, IL-6 and IL-1β in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. Objective We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Methods Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. Results The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-α were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). Conclusion According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done. PMID:20523770

  17. The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur.

    PubMed

    Kim, Su-Han; Ko, Hyun-Chang; Kim, Moon-Bum; Kwon, Kyung-Sool; Oh, Chang-Keun

    2009-05-01

    Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-alpha, IL-6 and IL-1beta in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-alpha were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done.

  18. Do Malassezia species play a role in exacerbation of scalp psoriasis?

    PubMed

    Gomez-Moyano, E; Crespo-Erchiga, V; Martínez-Pilar, L; Godoy Diaz, D; Martínez-García, S; Lova Navarro, M; Vera Casaño, A

    2014-06-01

    Clinical expression of psoriasis is in part dependent on external factors, such as drugs, microorganisms or stress. However convincing evidence of the role of Malassezia species in the pathogenesis of the psoriasis is still lacking. Samples taken from scalp skin of 40 psoriatic patients and the same number of healthy individuals were observed under direct microsocopic examination and cultured on modified Dixon agar. Direct microscopy examination of psoriatic scalp scales was positive in 30 (75%) patients; while it was positive in only 12 (30%) healthy subjects (P=0.003). Half of the cultures from healthy subjects showed no growth of colonies, but only 8 (15%) of psoriatic patients were negative. When an exacerbation has occurred in the previous weeks, pseudohyphaes were observed in 12 (40%) patients, Malassezia globosa was isolated in 18 (45%) patients and Malassezia restricta was isolated in 12 (30%) patients. In the group of patients having stable lesion, without any exacerbation in the previous weeks, no pseudohypahes were observed, M. globosa was not isolated, M. restricta was isolated in 4 (10%), and cultures were negative in 6 of them (15%). Malassezia species form an integral part of normal cutaneous microflora in humans, however we found that during the episodes of exacerbation of the disease the presence of these yeasts, and particularly M. globosa, was increased. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  19. A pilot study on seborrheic dermatitis using pramiconazole as a potent oral anti-Malassezia agent.

    PubMed

    Piérard, Gérald E; Ausma, Jannie; Henry, Frédérique; Vroome, Valérie; Wouters, Luc; Borgers, Marcel; Cauwenbergh, Geert; Piérard-Franchimont, Claudine

    2007-01-01

    Seborrheic dermatitis is considered to be a Malassezia-driven disease. Little objective information is available so far from biometrological quantitative assessments of this skin condition. Pramiconazole is a novel triazole with potent in vitro antifungal activity, especially against Malassezia spp. To study the sequential effects of pramiconazole on Malassezia, inflammation and epidermal changes. This study was performed in 2 groups of subjects suffering from seborrheic dermatitis. The first group (n = 17) remained untreated and was used as control. Clinical, mycological and biometrological assessments were performed at inclusion and during the following 2 weeks. The second group of subjects (n = 10) received a single 200-mg oral dose of pramiconazole at inclusion. Clinical, mycological and biometrological evaluations were performed before and during 1 month following the single antifungal intake. For both parts of the study, several parameters were assessed including yeast density, desquamation, erythema, itching and sebum excretion. In the control group, no significant changes were observed in any of the parameters during the observation period. The findings were markedly different in the pramiconazole-treated subjects. The yeast density was significantly improved on days 3, 7 and 28. Desquamation, erythema, itching, and the global clinical evaluation as assessed by the patients and investigators became significantly improved on days 7 and 28. A trend in decrease of scaliness was noted. No effect on sebum excretion was evidenced. In conclusion, a single 200-mg dose of pramiconazole exhibitsin vivo efficacy in controlling some important clinical aspects of seborrheic dermatitis. Following a reduction in the number of yeasts on day 3, a decrease in the severity of clinical signs and symptoms occurred from day 7 onwards. Sebum excretion appeared uninvolved in the clearing process of seborrheic dermatitis. A single 200-mg dose of pramiconazole appears to abate

  20. Cutaneous fungal microbiome: Malassezia yeasts in seborrheic dermatitis scalp in a randomized, comparative and therapeutic trial

    PubMed Central

    Kamamoto, C. S. L.; Nishikaku, A. S.; Gompertz, O. F.; Melo, A. S.; Hassun, K. M.; Bagatin, E.

    2017-01-01

    ABSTRACT Malassezia spp in skin microbiome scalp has been implicated in seborrheic dermatitis pathogenesis. Thus, treatment based in antifungal combined to topical keratolitic agents have been indicated as well as oral isotretinoin as it reduces the sebum production, glandular's size and possesses anti-inflammatory properties. This randomized, comparative and therapeutic trial aimed toper form the genotypic identification of Malassezia species before and after low-dose oral isotretinoin or topical antifungal treatments for moderate to severe seborrhea and/or seborrheic dermatitis on scalp. Scales and sebum of the scalp were seeded in the middle of modified Dixon and incubated at 32°C. For genotypic identification polymerase chain reaction primers for the ITS and D1/D2 ribossomal DNA were used and followed by samples sequencing. The procedure was conducted before and after therapeutic and randomized intervention for moderate to severe seborrhea/seborrheic dermatitis on the scalp, including oral isotretinoin, 10 mg, every other day and anti-seborrheic shampoo (piroctone olamine), over six months. The M. globosa and M. restricta were the most frequent species isolated on the scalp before and after both treatments. Other non-Malassezia species were also identified. The Malassezia spp. were maintained in the scalp after both treatments that were equally effective for the control of seborrhea/seborrheic dermatitis clinical signs. PMID:29484095

  1. Identification and Speciation of Malassezia in Patients Clinically Suspected of Having Pityriasis Versicolor

    PubMed Central

    Shah, Avani; Koticha, Avani; Ubale, Milind; Wanjare, Shashir; Mehta, Preeti; Khopkar, Uday

    2013-01-01

    Background: Malassezia is a lipid-dependent yeast known to cause Pityriasis versicolor, a chronic, recurrent superficial infection of skin and present as hypopigmented or hyperpigmented lesions on areas of skin. If not diagnosed and treated, it may lead to disfigurement of the areas involved and also result in deep invasive infections. Aim: The aim of the present study was to identify and speciate Malassezia in patients clinically suspected of having Pityriasis versicolor. Materials and Methods: Total 139 patients suspected of having Pityriasis versicolor were evaluated clinically and diagnosis was done by Wood's lamp examination, confirmed mycologically by using KOH, cultivation on Sabouraud's dextrose agar and modified Dixon agar at a tertiary care hospital in Mumbai. The total duration of study was 12 months. Results: Majority of the patients were males (59.71%) in the age group of 21-30 years (33.81%) who were students (30.21%) by profession. The incidence of Malassezia in Pityriasis versicolor was 50.35%. The most common isolate was M. globosa (48.57%), followed by M. furfur (34.28%). Majority of the patients had hypopigmented lesions, with M. globosa as the predominant isolate. Neck was the most common site affected; 88.48% were Wood's lamp positive of which 56.91% of Malassezia isolates grew on culture. KOH mount was positive in 82.01% of which 61.40% Malassezia isolates grew on culture. Conclusions: The procedure of culture and antifungal testing is required to be performed as different species of Malassezia are involved in Pityriasis versicolor and susceptibility is different among different species. Thus, it would help to prevent recurrences and any systemic complications. PMID:23723483

  2. Living and Thriving on the Skin: Malassezia Genomes Tell the Story

    PubMed Central

    Coelho, Marco A.; Sampaio, José Paulo; Gonçalves, Paula

    2013-01-01

    ABSTRACT Our understanding of the interactions between normal skin microbiota and the human host has been greatly extended by recent investigations. In their recent study in mBio, A. Gioti et al. (mBio 4[1]:e00572-12, 2013) sequenced the genome of the atopic eczema-associated yeast, Malassezia sympodialis, and compared its gene content and organization with that of Malassezia globosa, a species implicated in dandruff. Their findings were also contrasted with those previously obtained for Ustilago maydis, which is a close relative but ecologically distinct plant parasite. Besides gaining additional insight into key host-specific adaptations and the particular function and molecular evolution of allergens related to atopic eczema, Gioti et al. also uncovered several lines of evidence that elegantly suggest the presence of an extant sexual cycle, with important implications in disease. PMID:23512963

  3. Malassezia Intra-Specific Diversity and Potentially New Species in the Skin Microbiota from Brazilian Healthy Subjects and Seborrheic Dermatitis Patients

    PubMed Central

    Soares, Renan Cardoso; Zani, Marcelo Bergamin; Arruda, Ana Carolina Belini Bazán; de Arruda, Lucia Helena Fávaro; Paulino, Luciana Campos

    2015-01-01

    Malassezia yeasts are part of the resident cutaneous microbiota, and are also associated with skin diseases such as seborrheic dermatitis (SD). The role these fungi play in skin diseases and why they are pathogenic for only some individuals remain unclear. This study aimed to characterize Malassezia microbiota from different body sites in healthy and SD subjects from Brazil. Scalp and forehead samples from healthy, mild SD and severe SD subjects were collected. Non-scalp lesions from severe SD patients were also sampled. 5.8S rDNA/ITS2 amplicons from Malassezia sp. were analyzed by RFLP and sequencing. Results indicate that Malassezia microbiota did not group according to health condition or body area. Phylogenetic analysis revealed that three groups of sequences did not cluster together with any formally described species, suggesting that they might belong to potential new species. One of them was found in high proportions in scalp samples. A large variety of Malassezia subtypes were detected, indicating intra-specific diversity. Higher M. globosa proportions were found in non-scalp lesions from severe SD subjects compared with other areas, suggesting closer association of this species with SD lesions from areas other than scalp. Our results show the first panorama of Malassezia microbiota in Brazilian subjects using molecular techniques and provide new perspectives for further studies to elucidate the association between Malassezia microbiota and skin diseases. PMID:25695430

  4. Malassezia intra-specific diversity and potentially new species in the skin microbiota from Brazilian healthy subjects and seborrheic dermatitis patients.

    PubMed

    Soares, Renan Cardoso; Zani, Marcelo Bergamin; Arruda, Ana Carolina Belini Bazán; Arruda, Lucia Helena Fávaro de; Paulino, Luciana Campos

    2015-01-01

    Malassezia yeasts are part of the resident cutaneous microbiota, and are also associated with skin diseases such as seborrheic dermatitis (SD). The role these fungi play in skin diseases and why they are pathogenic for only some individuals remain unclear. This study aimed to characterize Malassezia microbiota from different body sites in healthy and SD subjects from Brazil. Scalp and forehead samples from healthy, mild SD and severe SD subjects were collected. Non-scalp lesions from severe SD patients were also sampled. 5.8S rDNA/ITS2 amplicons from Malassezia sp. were analyzed by RFLP and sequencing. Results indicate that Malassezia microbiota did not group according to health condition or body area. Phylogenetic analysis revealed that three groups of sequences did not cluster together with any formally described species, suggesting that they might belong to potential new species. One of them was found in high proportions in scalp samples. A large variety of Malassezia subtypes were detected, indicating intra-specific diversity. Higher M. globosa proportions were found in non-scalp lesions from severe SD subjects compared with other areas, suggesting closer association of this species with SD lesions from areas other than scalp. Our results show the first panorama of Malassezia microbiota in Brazilian subjects using molecular techniques and provide new perspectives for further studies to elucidate the association between Malassezia microbiota and skin diseases.

  5. Clinical and mycological evaluation of an herbal antifungal formulation in canine Malassezia dermatitis.

    PubMed

    Nardoni, S; Mugnaini, L; Pistelli, L; Leonardi, M; Sanna, V; Perrucci, S; Pisseri, F; Mancianti, F

    2014-09-01

    Malassezia pachydermatis is a common cause of more widespread dermatitis in dogs (CMD). Recurrences are common, and this disorder can be very troubling for both dogs and for the pet owner. The treatment of 20 dogs affected by dermatitis due to M. pachydermatis, with Malacalm(®), a commercially available mixture consisting of essential oils (Citrus aurantium 1%, Lavandula officinalis 1%, Origanum vulgare 0.5%, Origanum majorana 0.5%, Mentha piperita 0.5% and Helichrysum italicum var. italicum 0.5%, in sweet almond oil and coconut oil) is reported. The effectiveness of the whole mixture, of component essential oils and of their more represented compounds against clinical isolates was evaluated by a microdilution test. Twenty animals were topically administered the mixture twice daily for 1 month. Ten animals were treated with a conventional therapy based on ketoconazole 10mg/kg/day and chlorhexidine 2% twice a week for 3 weeks. At the end of both treatments animals significantly improved their clinical status. Adverse effects were never noticed. Follow-up visit performed on day 180th allowed to observe a recurrence of clinical signs in all the subjects treated conventionally, while not significant clinical changes were referred in dogs treated with Malacalm(®). The overall MIC value of Malacalm(®) was 0.3%. O. vulgare showed the lowest minimum inhibitory concentrations (MIC), being active at 0.8%, followed by M. piperita (1%), O. majorana (1.3%), C. aurantium (2%) and L. officinalis (4%) while H. italicum did not yield any antimycotic effect up to 10%. Active major compounds were thymol, carvacrol, p-cymene, 1,8-cineol, limonene and menthol. The phytotherapic treatment achieved a good clinical outcome, and no recurrence of skin disorders on day 180th was recorded. This herbal remedium appeared to be a safe tool for limiting recurrences of CMD. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. Malassezia globosa and restricta: breakthrough understanding of the etiology and treatment of dandruff and seborrheic dermatitis through whole-genome analysis.

    PubMed

    Dawson, Thomas L

    2007-12-01

    Dandruff and seborrheic dermatitis (D/SD) share an etiology dependent upon three factors: sebum, microbial metabolism (specifically, Malassezia yeasts), and individual susceptibility. Advances in microbiological and analytical techniques permit a more detailed understanding of these etiologic factors, especially the role of Malassezia. Malassezia are lipid-dependent and demonstrate adaptation allowing them to exploit a narrow niche on sebum-rich skin. Work in our and our collaborators' laboratories has focused on understanding these adaptations by detailed analysis of biochemistry and gene expression. We have shown that Malassezia globosa and M. restricta predominate on dandruff scalp, that oleic acid alone can initiate dandruff-like desquamation, that M. globosa is the most likely initiating organism by virtue of its high lipase activity, and that an M. globosa lipase is expressed on human scalp. Considering the importance of M. globosa in D/SD (and the overall importance of commensal fungi), we have sequenced the M. globosa and M. restricta genomes. Genomic analysis indicates key adaptations to the skin environment, several of which yield important clues to the role Malassezia play in human disease. This work offers the promise of defining new treatments to D/SD that are targeted at changing the level or activities of Malassezia genes.

  7. Ketoconazole inhibits Malassezia furfur morphogenesis in vitro under filamentation optimized conditions.

    PubMed

    Youngchim, Sirida; Nosanchuk, Joshua D; Chongkae, Siriporn; Vanittanokom, Nongnuch

    2017-01-01

    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.

  8. Targeting Malassezia species for Novel Synthetic and Natural Antidandruff Agents.

    PubMed

    Angiolella, Letizia; Carradori, Simone; Maccallini, Cristina; Giusiano, Gustavo; Supuran, Claudiu T

    2017-01-01

    Malassezia spp. are lipophilic yeasts not only present in the normal skin microflora, but also responsible of skin-related diseases (pityriasis versicolor, seborrheic/atopic dermatitis and dandruff) as well as systemic fungal infections in humans and animals. Their treatment and eradication are mainly based on old azole drugs, which are characterized by poor compliance, unpredictable clinical efficacy, emerging resistance and several side effects. These drawbacks have prompted the research toward novel synthetic and natural derivatives/ nanomaterials targeting other pivotal enzymes/pathways such as carbonic anhydrase (MgCA) and lipases, alone or in combination, in order to improve the eradication rate of this fungus. This review accomplished an update on this important topic dealing with the latest discoveries of synthetic scaffolds and natural products for the treatment of Malassezia spp.-related diseases, thus suggesting new opportunities to design innovative and alternative anti-dandruff drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Superficial veterinary mycoses.

    PubMed

    Bond, Ross

    2010-03-04

    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. Copyright 2010 Elsevier Inc. All rights reserved.

  10. Comparison of the clinical efficacy of oral terbinafine and ketoconazole combined with cephalexin in the treatment of Malassezia dermatitis in dogs--a pilot study.

    PubMed

    Rosales, Millie S; Marsella, Rosanna; Kunkle, Gail; Harris, Bradley L; Nicklin, Constance F; Lopez, Jennifer

    2005-06-01

    The purpose of this randomized, single blinded clinical trial was to evaluate cytologically and clinically the efficacy of oral cephalexin alone and its combination with terbinafine or ketoconazole for the treatment of Malassezia dermatitis in dogs. Twenty-two client-owned dogs with Malassezia dermatitis completed the 3-week study. All received cephalexin (generic, 250 mg or 500 mg) at 22-30 mg kg(-1) twice daily. Eight dogs received terbinafine at 30 mg kg(-1) once daily and seven dogs received ketoconazole (generic, 200 mg) at 5-10 mg kg(-1) twice daily. The remaining seven dogs received cephalexin alone. At week 0 (visit 1) and week 3 (visit 2), mean yeast counts were determined from three affected areas using tape-strip cytology, a clinical index score (CIS) was assigned to the affected areas, and owners evaluated pruritus using a visual analogue scale. All groups showed reduction in mean yeast counts, CIS and pruritus. There was an 86.8%, 80.2% and 28.8% reduction in mean yeast counts from visit 1 to visit 2 for the terbinafine, ketoconazole and cephalexin-only groups, respectively. However, within treatment group comparisons a significant reduction in mean yeast count was only evident for the terbinafine (P < 0.002) and ketoconazole (P < 0.01) groups. Pruritus reduction was only significant for the terbinafine group. These preliminary results suggest that terbinafine should be further assessed for the treatment of canine Malassezia dermatitis.

  11. In Vitro Anti-Malassezia Activity of Castanea crenata Shell and Oil-Soluble Glycyrrhiza Extracts.

    PubMed

    Han, Song Hee; Hur, Min Seok; Kim, Min Jung; Jung, Won Hee; Park, Minji; Kim, Jeong Hwan; Shin, Hong Ju; Choe, Yong Beom; Ahn, Kyu Joong; Lee, Yang Won

    2017-06-01

    A new shampoo with anti- Malassezia properties obtained from various plants is required to provide seborrheic dermatitis patients with a wider range of treatment options. The aim of this study was to obtain in vitro susceptibility profiles of Malassezia restricta and M. globosa , the most important pathogenic organisms in the development of seborrheic dermatitis, to the plant extracts used in commercial anti-dandruff shampoos. Minimal inhibitory concentrations (MICs) were determined for eight candidate plant extracts and two plant-derived natural products diluted with Leeming and Notman medium to final concentrations of 0.016 to 1 mg/ml. Castanea crenata shell, Camellia sinensis leaf, and oil-soluble Glycyrrhiza extracts presented relatively low MIC values (≤0.5 mg/ml) against both strains. The C. crenata shell and oil-soluble Glycyrrhiza extracts demonstrated especially high anti-Malassezia activity, suggesting their potential use in the treatment of seborrheic dermatitis. The extracts also showed fungistatic activity against other common facultative pathogenic yeasts, Cryptococcus and Candida . C. crenata shell and oil-soluble Glycyrrhiza extracts could potentially be used as active ingredients in anti-seborrheic and anti-dandruff shampoo formulations. They could be helpful for repeated treatments and regular prophylaxis of scalp seborrheic dermatitis.

  12. Extracellular nanovesicles released from the commensal yeast Malassezia sympodialis are enriched in allergens and interact with cells in human skin.

    PubMed

    Johansson, Henrik J; Vallhov, Helen; Holm, Tina; Gehrmann, Ulf; Andersson, Anna; Johansson, Catharina; Blom, Hans; Carroni, Marta; Lehtiö, Janne; Scheynius, Annika

    2018-06-15

    Malassezia sympodialis is a dominant commensal fungi in the human skin mycobiome but is also associated with common skin disorders including atopic eczema (AE). M. sympodialis releases extracellular vesicles, designated MalaEx, which are carriers of small RNAs and allergens, and they can induce inflammatory cytokine responses. Here we explored how MalaEx are involved in host-microbe interactions by comparing protein content of MalaEx with that of the parental yeast cells, and by investigating interactions of MalaEx with cells in the skin. Cryo-electron tomography revealed a heterogeneous population of MalaEx. iTRAQ based quantitative proteomics identified in total 2439 proteins in all replicates of which 110 were enriched in MalaEx compared to the yeast cells. Among the MalaEx enriched proteins were two of the M. sympodialis allergens, Mala s 1 and s 7. Functional experiments indicated an active binding and internalization of MalaEx into human keratinocytes and monocytes, and MalaEx were found in close proximity of the nuclei using super-resolution fluorescence 3D-SIM imaging. Our results provides new insights into host-microbe interactions, supporting that MalaEx may have a role in the sensitization and maintenance of inflammation in AE by containing enriched amounts of allergens and with their ability to interact with skin cells.

  13. Chemical characterization and antifungal activity of Origanum vulgare, Thymus vulgaris essential oils and carvacrol against Malassezia furfur.

    PubMed

    Vinciguerra, Vittorio; Rojas, Florencia; Tedesco, Viviana; Giusiano, Gustavo; Angiolella, Letizia

    2018-05-04

    The composition of the essential oils (EOs) of O. vulgare L. EO and T. vulgaris EO, were analyzed by GC and GC-MS. Antifungal activities of the EOs and its main component, carvacrol, were evaluated against 27 clinical isolates of Malassezia furfur. Minimum inhibitory concentrations (MICs) were measured according to the broth microdilution protocols by Clinical and Laboratory Standards Institute (CLSI) modified for Malassezia spp. EOs and carvacrol showed low MIC values ranged 450-900 μg/ml against M. furfur. No differences in EOs antifungal activity were observed in sensitive to resistant fluconazole isolates. The antifungal activity obtained showed O. vulgare EO, T. vulgaris EO and carvacrol, their compound, as potential antimicrobial agents against M. furfur, yeast associated with human mycoses.

  14. [Malassezia folliculitis in an immunocompromised patient].

    PubMed

    Mota, R; Reifenberger, J; Homey, B; Bruch-Gerharz, D

    2011-10-01

    Malassezia folliculitis (synonym: Pityrosporum folliculitis) is a polymorphic dermatomycosis characterized by the development of small papules and pustules. In severe cases, molluscoid comedonal papules are typical. The disease occurs mainly in sebum-rich areas of the face, back and chest, frequently affecting patients under immunosuppressive therapy. We report a case of Malassezia folliculitis observed in a heart transplant recipient who was successfully treated with itraconazole. Moreover, we summarize the taxonomy of the genus Malassezia as well as diagnostic and therapeutic measures of the related folliculitis.

  15. Identification of small RNAs in extracellular vesicles from the commensal yeast Malassezia sympodialis.

    PubMed

    Rayner, Simon; Bruhn, Sören; Vallhov, Helen; Andersson, Anna; Billmyre, R Blake; Scheynius, Annika

    2017-01-04

    Malassezia is the dominant fungus in the human skin mycobiome and is associated with common skin disorders including atopic eczema (AE)/dermatitis. Recently, it was found that Malassezia sympodialis secretes nanosized exosome-like vesicles, designated MalaEx, that carry allergens and can induce inflammatory cytokine responses. Extracellular vesicles from different cell-types including fungi have been found to deliver functional RNAs to recipient cells. In this study we assessed the presence of small RNAs in MalaEx and addressed if the levels of these RNAs differ when M. sympodialis is cultured at normal human skin pH versus the elevated pH present on the skin of patients with AE. The total number and the protein concentration of the released MalaEx harvested after 48 h culture did not differ significantly between the two pH conditions nor did the size of the vesicles. From small RNA sequence data, we identified a set of reads with well-defined start and stop positions, in a length range of 16 to 22 nucleotides consistently present in the MalaEx. The levels of small RNAs were not significantly differentially expressed between the two different pH conditions indicating that they are not influenced by the elevated pH level observed on the AE skin.

  16. Identification of Malassezia species isolated from patients with extensive forms of pityriasis versicolor in Siena, Italy.

    PubMed

    Romano, Clara; Mancianti, Francesca; Nardoni, Simona; Ariti, Gaetano; Caposciutti, Paola; Fimiani, Michele

    2013-01-01

    Pityriasis versicolor (PV) is an infection caused by various species of Malassezia yeast. There is no agreement in the literature concerning the species of Malassezia and the demographic, clinical, and mycological data. To prospectively identify Malassezia species isolated from lesions of patients with extensive, long standing and recurrent forms of PV and to estimate the relationship between Malassezia species and the demographic and clinical data of the patients. All patients with PV were enrolled over a four-year period. Malassezia species were isolated in cultures and identified by morphological features and physiological tests. In the last 2 years a PCR-based technique was used to confirm the species' identification. A total of 74 patients (43 males and 31 females, mean age 39.5 years) were enrolled. Only one species was isolated in 45 patients, and more than one species were identified in the remaining 28 patients (38%). M. globosa was the most frequently isolated (60.3%) species. There was a significant association between the isolation of 2 or more species and the presence of at least one predisposing factor. In the last 29 cases, which were subjected to PCR, there were no differences in the identification of isolated species as compared to traditional methods. The isolation of more than one species in a single lesion is not infrequent in PV and is related to the presence of one predisposing factor. The isolated species isolated were not influenced by demographic and clinical features. The traditional and more recent (PCR) procedures gave the same results in the isolated species. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  17. In Vitro Anti-Malassezia Activity of Castanea crenata Shell and Oil-Soluble Glycyrrhiza Extracts

    PubMed Central

    Han, Song Hee; Hur, Min Seok; Kim, Min Jung; Jung, Won Hee; Park, Minji; Kim, Jeong Hwan; Shin, Hong Ju; Choe, Yong Beom; Ahn, Kyu Joong

    2017-01-01

    Background A new shampoo with anti-Malassezia properties obtained from various plants is required to provide seborrheic dermatitis patients with a wider range of treatment options. Objective The aim of this study was to obtain in vitro susceptibility profiles of Malassezia restricta and M. globosa, the most important pathogenic organisms in the development of seborrheic dermatitis, to the plant extracts used in commercial anti-dandruff shampoos. Methods Minimal inhibitory concentrations (MICs) were determined for eight candidate plant extracts and two plant-derived natural products diluted with Leeming and Notman medium to final concentrations of 0.016 to 1 mg/ml. Results Castanea crenata shell, Camellia sinensis leaf, and oil-soluble Glycyrrhiza extracts presented relatively low MIC values (≤0.5 mg/ml) against both strains. The C. crenata shell and oil-soluble Glycyrrhiza extracts demonstrated especially high anti-Malassezia activity, suggesting their potential use in the treatment of seborrheic dermatitis. The extracts also showed fungistatic activity against other common facultative pathogenic yeasts, Cryptococcus and Candida. Conclusion C. crenata shell and oil-soluble Glycyrrhiza extracts could potentially be used as active ingredients in anti-seborrheic and anti-dandruff shampoo formulations. They could be helpful for repeated treatments and regular prophylaxis of scalp seborrheic dermatitis. PMID:28566909

  18. Antimycotics suppress the Malassezia extract-induced production of CXC chemokine ligand 10 in human keratinocytes.

    PubMed

    Hau, Carren S; Kanda, Naoko; Makimura, Koichi; Watanabe, Shinichi

    2014-02-01

    Malassezia, a lipophilic yeast, exacerbates atopic dermatitis. Malassezia products can penetrate the disintegrated stratum corneum and encounter subcorneal keratinocytes in the skin of atopic dermatitis patients. Type 1 helper T (Th1) cells infiltrate chronic lesions with atopic dermatitis, and antimycotic agents improve its symptoms. We aimed to identify Malassezia-induced chemokines in keratinocytes and examine whether antimycotics suppressed this induction. Normal human keratinocytes were incubated with a Malassezia restricta extract and antimycotics. Chemokine expression was analyzed by enzyme-linked immunosorbent assays and real-time polymerase chain reaction. Signal transducer and activator of transcription (STAT)1 activity was examined by luciferase assays. The tyrosine-phosphorylation of STAT1 was analyzed by western blotting. The M. restricta extract increased the mRNA and protein expression of Th1-attracting CXC chemokine ligand (CXCL)10 and STAT1 activity and phosphorylation in keratinocytes, which was suppressed by a Janus kinase inhibitor. The antimycotics itraconazole, ketoconazole, luliconazole, terbinafine, butenafine and amorolfine suppressed M. restricta extract-induced CXCL10 mRNA and protein expression and STAT1 activity and phosphorylation. These effects were similarly induced by 15-deoxy-Δ-(12,14) -prostaglandin J2 (15d-PGJ2 ), a prostaglandin D2 metabolite. Antimycotics increased the release of 15d-PGJ2 from keratinocytes. The antimycotic-induced suppression of CXCL10 production and STAT1 activity was counteracted by a lipocalin-type prostaglandin D synthase inhibitor. The antimycotics itraconazole, ketoconazole, luliconazole, terbinafine, butenafine and amorolfine may suppress the M. restricta-induced production of CXCL10 by inhibiting STAT1 through an increase in 15d-PGJ2 production in keratinocytes. These antimycotics may block the Th1-mediated inflammation triggered by Malassezia in the chronic phase of atopic dermatitis. © 2014

  19. Distribution of Malassezia species on the skin of patients with atopic dermatitis, psoriasis, and healthy volunteers assessed by conventional and molecular identification methods.

    PubMed

    Jagielski, Tomasz; Rup, Elżbieta; Ziółkowska, Aleksandra; Roeske, Katarzyna; Macura, Anna B; Bielecki, Jacek

    2014-03-07

    The Malassezia yeasts which belong to the physiological microflora of human skin have also been implicated in several dermatological disorders, including pityriasis versicolor (PV), atopic dermatitis (AD), and psoriasis (PS). The Malassezia genus has repeatedly been revised and it now accommodates 14 species, all but one being lipid-dependent species. The traditional, phenotype-based identification schemes of Malassezia species are fraught with interpretative ambiguities and inconsistencies, and are thus increasingly being supplemented or replaced by DNA typing methods. The aim of this study was to explore the species composition of Malassezia microflora on the skin of healthy volunteers and patients with AD and PS. Species characterization was performed by conventional, culture-based methods and subsequently molecular techniques: PCR-RFLP and sequencing of the internal transcribed spacer (ITS) 1/2 regions and the D1/D2 domains of the 26S rRNA gene. The Chi-square test and Fisher's exact test were used for statistical analysis. Malassezia sympodialis was the predominant species, having been cultured from 29 (82.9%) skin samples collected from 17 out of 18 subjects under the study. Whereas AD patients yielded exclusively M. sympodialis isolates, M. furfur isolates were observed only in PS patients. The isolation of M. sympodialis was statistically more frequent among AD patients and healthy volunteers than among PS patients (P < 0.03). Whether this mirrors any predilection of particular Malassezia species for certain clinical conditions needs to be further evaluated. The overall concordance between phenotypic and molecular methods was quite high (65%), with the discordant results being rather due to the presence of multiple species in a single culture (co-colonization) than true misidentification. All Malassezia isolates were susceptible to cyclopiroxolamine and azole drugs, with M. furfur isolates being somewhat more drug tolerant than other Malassezia species

  20. Isolation and identification of Malassezia species from Chinese and Korean patients with seborrheic dermatitis and in vitro studies on their bioactivity on sebaceous lipids and IL-8 production.

    PubMed

    Kim, Soo Young; Kim, Se Hyun; Kim, Su Na; Kim, Ah-Reum; Kim, Yu Ri; Kim, Min Jung; Park, Won-Seok; Lee, John Hwan; Jung, Won Hee; Lee, Yang Won; Choe, Yong Beom; Ahn, Kyu Joong

    2016-05-01

    We investigated the distribution of Malassezia yeast in 120 Chinese (20 patients from each of six cities) and 20 Korean patients with scalp seborrheic dermatitis (SD) and dandruff (SD/D) using ITS1 and ITS2 polymerase chain reaction-restriction fragment length polymorphism. Bioactivity was studied by quantifying sebum lipid production by human primary sebocytes and inflammatory cytokine, interleukin-8 (IL-8) production was studied by exposing HaCaT keratinocytes with extracts of five standard Malassezia strains; M. globosa, M. restricta, M. sympodialis, M. dermatis and M. slooffiae. M. restricta and M. globosa were the most frequently encountered species from both Chinese and Korean patients. These two Malassezia species also promoted neutral lipid synthesis although the result was not statistically significant and induced significant increase in IL-8 production among the five Malassezia species studied. The study suggests a possible role of these organisms in the pathogenesis of SD/D. © 2016 Blackwell Verlag GmbH.

  1. Clinical and mycological analysis of dog’s oral cavity

    PubMed Central

    Santin, Rosema; Mattei, Antonella Souza; Waller, Stefanie Bressan; Madrid, Isabel Martins; Cleff, Marlete Brum; Xavier, Melissa Orzechowski; de Oliveira Nobre, Márcia; Nascente, Patrícia da Silva; de Mello, João Roberto Braga; Meireles, Mário Carlos Araújo

    2013-01-01

    The oral microbiota of humans and animals is made up of a wide variety of yeasts and bacteria, but microbiota of dogs is not totally described. Although such identification is an important step to establish the etiopathogenesis and adequate therapy for the periodontal disease The aim of this study was to evaluate and correlate oral alterations with the presence of yeasts in oral cavity of female dogs. After clinical evaluation samples from healthy and from dogs with oral diseases were obtained from three different oral sites by swabs, curettes, millimeter periodontal probes and HA membrane tip in cellulose ester. Yeast identification was performed through macroscopic and microscopic colony features and biochemical tests. Dental calculus was the most prevalent occurrence in the oral cavity of 59 females. However, the isolation of yeasts was significantly higher (p < 0.05) in animals suffering from halitosis. Eleven yeast species were identified, namely: Malassezia pachydermatis, Rhodotorula spp., Candida albicans, C. catenulata, C. famata, C. guilliermondii, C. parapsilosis, C. intermedia, Trichosporon asahii, T. mucoides and Cryptococcus albidus. It could be concluded that the yeasts are part of the microbiota from the different sites of the oral cavity of the female canines studied without causing any significant alterations except halitosis. PMID:24159296

  2. Distribution of Malassezia species on the skin of patients with atopic dermatitis, psoriasis, and healthy volunteers assessed by conventional and molecular identification methods

    PubMed Central

    2014-01-01

    Background The Malassezia yeasts which belong to the physiological microflora of human skin have also been implicated in several dermatological disorders, including pityriasis versicolor (PV), atopic dermatitis (AD), and psoriasis (PS). The Malassezia genus has repeatedly been revised and it now accommodates 14 species, all but one being lipid-dependent species. The traditional, phenotype-based identification schemes of Malassezia species are fraught with interpretative ambiguities and inconsistencies, and are thus increasingly being supplemented or replaced by DNA typing methods. The aim of this study was to explore the species composition of Malassezia microflora on the skin of healthy volunteers and patients with AD and PS. Methods Species characterization was performed by conventional, culture-based methods and subsequently molecular techniques: PCR-RFLP and sequencing of the internal transcribed spacer (ITS) 1/2 regions and the D1/D2 domains of the 26S rRNA gene. The Chi-square test and Fisher’s exact test were used for statistical analysis. Results Malassezia sympodialis was the predominant species, having been cultured from 29 (82.9%) skin samples collected from 17 out of 18 subjects under the study. Whereas AD patients yielded exclusively M. sympodialis isolates, M. furfur isolates were observed only in PS patients. The isolation of M. sympodialis was statistically more frequent among AD patients and healthy volunteers than among PS patients (P < 0.03). Whether this mirrors any predilection of particular Malassezia species for certain clinical conditions needs to be further evaluated. The overall concordance between phenotypic and molecular methods was quite high (65%), with the discordant results being rather due to the presence of multiple species in a single culture (co-colonization) than true misidentification. All Malassezia isolates were susceptible to cyclopiroxolamine and azole drugs, with M. furfur isolates being somewhat more drug tolerant

  3. Whole genome sequencing analysis of the cutaneous pathogenic yeast Malassezia restricta and identification of the major lipase expressed on the scalp of patients with dandruff.

    PubMed

    Park, Minji; Cho, Yong-Joon; Lee, Yang Won; Jung, Won Hee

    2017-03-01

    Malassezia species are opportunistic pathogenic fungi that are frequently associated with seborrhoeic dermatitis, including dandruff. Most Malassezia species are lipid dependent, a property that is compensated by breaking down host sebum into fatty acids by lipases. In this study, we aimed to sequence and analyse the whole genome of Malassezia restricta KCTC 27527, a clinical isolate from a Korean patient with severe dandruff, to search for lipase orthologues and identify the lipase that is the most frequently expressed on the scalp of patients with dandruff. The genome of M. restricta KCTC 27527 was sequenced using the Illumina MiSeq and PacBio platforms. Lipase orthologues were identified by comparison with known lipase genes in the genomes of Malassezia globosa and Malassezia sympodialis. The expression of the identified lipase genes was directly evaluated in swab samples from the scalps of 56 patients with dandruff. We found that, among the identified lipase-encoding genes, the gene encoding lipase homolog MRES_03670, named LIP5 in this study, was the most frequently expressed lipase in the swab samples. Our study provides an overview of the genome of a clinical isolate of M. restricta and fundamental information for elucidating the role of lipases during fungus-host interaction. © 2016 Blackwell Verlag GmbH.

  4. Comparison of two shampoos for the treatment of canine Malassezia dermatitis: a randomised controlled trial.

    PubMed

    Maynard, L; Rème, C A; Viaud, S

    2011-11-01

    Two antimicrobial shampoos for treatment of canine Malassezia dermatitis (CMD) were compared in a prospective, randomised, single-blinded, field clinical trial. Sixty-seven dogs with pedal or generalised dermatitis associated with Malassezia overgrowth (MO) were treated with 3% chlorhexidine shampoo (3%CHX) or 2% miconazole-2% chlorhexidine shampoo (2%MIC/CHX) and evaluated for up to 6 weeks until cytological recovery. Pruritus, erythema, papules, greasy seborrhoea, scaling, malodour, excoriations, secondary hairloss, lichenification, hyperpigmentation and lesion extent were each scored on a 0-3 severity scale and combined making an aggregate score. Among 54 dogs with good treatment compliance, reduction of yeast counts by at least 88% was recorded in 21 of 22 dogs with 3%CHX and 30 of 32 dogs with 2%MIC/CHX. No significant difference was detected between products for yeast count reduction (P=0·592). Time to cytological recovery was not significantly different between groups (P=0·960). Lesion score was significantly reduced in both groups after treatment (72·5 ±25·7% with 3%CHX versus 78·7 ±22·3% with 2%MIC/CHX, P=0·309). Four dogs treated with chlorhexidine shampoo showed minor adverse effects. In this study, 3%CHX was clinically as effective as 2%MIC/CHX for treatment of CMD. © 2011 British Small Animal Veterinary Association.

  5. [Malassezia species in patients with seborrheic dermatitis and atopic dermatitis].

    PubMed

    Tajima, Mami

    2005-01-01

    Malassezia species, organisms normally colonizing the skin surface, are thought to play a role as either the cause or an exacerbating factor in a number of skin conditions, including pityriasis versicolor, Malassezia folliculitis, seborrheic dermatitis (SD) and atopic dermatitis (AD). Using a non-cultural PCR method, we analyzed Malassezia spp. extracted from the skin surface of SD and AD patients. The species most commonly detected in both patient groups were M. globosa and M. restricta, and the number of Malassezia spp. In these patients was higher than in healthy subjects. After a topical application of 2% ketoconazole cream, changes in the population of Malassezia spp. in 20 intractable cases of AD were recorded. The addition of the 2% ketoconazole cream to the standard topical treatments was found to have reduced the Malassezia spp. population by 90%, and showed a clinical efficacy rate of 70%. Furthermore, a combination of azole agents and tacrolimus produced a synergistic anti-fungal effect against Malassezia spp. in vitro. A clinical trial using this drug combination conducted on the face and neck of patients with intractable AD showed a 66.6% efficacy rate in both the reduction of the flora and in clinical improvement. From these results it was evident that Malassezia is one of the factors exacerbating AD, and that removal of the organism results in an improvement in the clinical condition of the patient.

  6. [A study of otitis externa associated with Malassezia].

    PubMed

    Shiota, Ryoko; Kaneko, Takamasa; Yano, Hiroaki; Takeshita, Kimiko; Nishioka, Keiko; Makimura, Koichi

    2009-01-01

    Malassezia-positive smears can be recognized from otitis externa, however, there are few references in the literature to the relation between Malassezia and otitis externa. Therefore, the bacterial and clinical characteristics of 72 cases (63 patients) with otitis externa were investigated at the Department of Otorhinolaryngology, Takinomiya General Hospital to analyze this. Thirty-seven cases were bacterial otitis externa, 20 cases were fungal otitis externa, and 15 cases were etiological agents unknown in this study. The causative organisms in fungal otitis externa were the genera Aspergillus (10 cases), Malassezia (5) and Candida (5), respectively. We suspected that 5 cases were caused by Malassezia because Malassezia cell counts were greater than 10 per field (x 400), and a large number of Malassezia were isolated from all cases. In these cases, many squamous epithelial cells were observed by direct examination, and cells from the middle or basal layer of the ear canal were also recognized in three cases. Therefore, accelerated turnover of epidermal cells of the ear canal was suggested. The main symptoms were itching and fullness in the ear, with observations of redness and erosion in objective deterioration, and we felt that these conditions were similar to seborrheic dermatitis (SD). In addition, these five cases were confirmed as fungus-related otitis externa by their improvement with antifungal agents.

  7. Evaluation of selected Indian medicinal plants for antagonistic potential against Malassezia spp. and the synergistic effect of embelin in combination with ketoconazole.

    PubMed

    Sivasankar, Chandran; Gayathri, Subramanian; Bhaskar, James Prabhanand; Krishnan, Venkat; Pandian, Shunmugiah Karutha

    2017-09-01

    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Transmission of the major skin microbiota, Malassezia, from mother to neonate.

    PubMed

    Nagata, Rie; Nagano, Hiroshi; Ogishima, Daiki; Nakamura, Yasushi; Hiruma, Masataro; Sugita, Takashi

    2012-06-01

    Skin surface colonization starts after birth. It is thought that early microbial colonization affects the development of skin immune functions. Although Malassezia is the predominant fungus in the skin microbiota in healthy individuals, the microorganism is associated with atopic dermatitis and seborrheic dermatitis. In the present study, transmission of skin microbiota from mothers to their neonates was elucidated using the Malassezia microbiota as an indicator. Temporal changes in the level of Malassezia colonization of the skin from 27 neonates and mothers were investigated by real-time polymerase chain reaction assay. The genotypes of Malassezia colonizing the neonate and mother were also determined. Malassezia was detected from 89% and 100% of neonate samples on days 0 and 1 after birth, respectively. Subsequently, the level of Malassezia colonization of the neonates increased with time, whereas that of the mothers did not change. The Malassezia diversity of neonates shifted to the adult type by day 30. The genotype of Malassezia colonizing the skin of neonates agreed well with that of Malassezia colonizing the skin of the mothers. Fungal microbiota colonization of neonates began on day 0, and the fungal microbiota of neonates had changed to the adult type by day 30. To our knowledge, this is the first report of a molecular analysis of the fungal microbiota of neonates. © 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.

  9. Treatment Outcomes for Malassezia Folliculitis in theDermatology Department of a University Hospital in Japan.

    PubMed

    Suzuki, Chikako; Hase, Midori; Shimoyama, Harunari; Sei, Yoshihiro

    2016-01-01

    Topical or systemic antifungal therapy was administered to patients diagnosed with Malassezia folliculitis during the 5-year period between March 2007 and October 2013. The diagnosis of Malassezia folliculitis was established on the basis of characteristic clinical features and direct microscopic findings (10 or more yeast-like fungi per follicle). Treatment consisted of topical application of 2% ketoconazole cream or 100 mg oral itraconazole based on symptom severity and patients' preferences. Treatment was given until papules flattened, and flat papules were examined to determine whether the patient's clinical condition had "improved" and the treatment had been "effective". The subjects were 44 patients (35 men, 9 women), with a mean disease period of 25±15 days. In regard to the lesion site, the frontal portion of the chest was the most common, accounting for 60% of all patients. The mean period required for improvement was 27±16 days in 37 patients receiving the topical antifungal agent and 14±4 days in the 7 patients receiving the systemic antifungal agent. The results were "improved" and the treatment was "effective" in all patients. Neither treatment resulted in any adverse reactions. Although administration of oral agents has been recommended for the treatment of Malassezia folliculitis, this study revealed that beneficial results are safely obtained with topical antifungal therapy alone, similar to those of systemic antifungal agents.

  10. Comparison of once-daily versus twice-weekly terbinafine administration for the treatment of canine Malassezia dermatitis - a pilot study.

    PubMed

    Berger, Darren J; Lewis, Thomas P; Schick, Anthea E; Stone, Richard T

    2012-10-01

    Terbinafine, an allylamine antifungal, is used in pulsatile dose regimens for superficial mycoses in human medicine. To compare the clinical efficacy of twice-weekly versus once-daily terbinafine administration to determine whether preliminary proof-of-concept evidence exists for pulsatile administration of terbinafine in the treatment of canine Malassezia dermatitis and to determine whether twice-weekly treatment results in fewer clinical and owner-perceived adverse events. Twenty client-owned dogs with Malassezia dermatitis. In this randomized, single-blinded clinical trial, dogs were randomly assigned to receive terbinafine (30 mg/kg) either once daily for 21 days (n = 10) or once daily on two consecutive days per week for six doses (n = 10). On day 0 and day 21, a mean yeast count was calculated from eight anatomical locations via adhesive tape-strip cytology, clinical lesion scores were assigned to the same locations, and owners assessed pruritus using a visual analog scale. There was no significant difference between treatment groups with respect to the reduction in mean yeast count (P = 0.343) and clinical lesion scores (P = 0.887). Pruritus measured by visual analog scale was significantly decreased in the twice-weekly treatment group compared with the daily treatment group (P = 0.047). Seven of 20 dogs had a clinically measurable or owner-reported adverse event during treatment that included gastrointestinal disturbances, excessive panting and elevated hepatic enzymes, with no significant difference noted between treatment groups. This pilot study indicates that twice-weekly terbinafine administration may be an effective alternative treatment for canine Malassezia dermatitis and merits further investigation. © 2012 The Authors. Veterinary Dermatology © 2012 ESVD and ACVD.

  11. FKBP12-Dependent Inhibition of Calcineurin Mediates Immunosuppressive Antifungal Drug Action in Malassezia

    PubMed Central

    Ianiri, Giuseppe; Applen Clancey, Shelly; Lee, Soo Chan

    2017-01-01

    ABSTRACT The genus Malassezia includes yeasts that are commonly found on the skin or hair of animals and humans as commensals and are associated with a number of skin disorders. We have previously developed an Agrobacterium tumefaciens transformation system effective for both targeted gene deletion and insertional mutagenesis in Malassezia furfur and M. sympodialis. In the present study, these molecular resources were applied to characterize the immunophilin FKBP12 as the target of tacrolimus (FK506), ascomycin, and pimecrolimus, which are calcineurin inhibitors that are used as alternatives to corticosteroids in the treatment of inflammatory skin disorders such as those associated with Malassezia species. While M. furfur and M. sympodialis showed in vitro sensitivity to these agents, fkb1Δ mutants displayed full resistance to all three of them, confirming that FKBP12 is the target of these calcineurin inhibitors and is essential for their activity. We found that calcineurin inhibitors act additively with fluconazole through an FKBP12-dependent mechanism. Spontaneous M. sympodialis isolates resistant to calcineurin inhibitors had mutations in the gene encoding FKBP12 in regions predicted to affect the interactions between FKBP12 and FK506 based on structural modeling. Due to the presence of homopolymer nucleotide repeats in the gene encoding FKBP12, an msh2Δ hypermutator of M. sympodialis was engineered and exhibited an increase of more than 20-fold in the rate of emergence of resistance to FK506 compared to that of the wild-type strain, with the majority of the mutations found in these repeats. PMID:29066552

  12. Malassezia Pneumonia: A Rare Complication of Parenteral Nutrition Therapy.

    PubMed

    Baker, Richelle M; Stegink, Ryan J; Manaloor, John J; Schmitt, Bryan H; Stevens, John C; Christenson, John C

    2016-11-01

    Malassezia species (formerly known as Pityrosporum) are part of normal human skin flora and have been associated with benign dermatologic conditions, such as seborrheic dermatitis and tinea versicolor. In rare cases, however, Malassezia has been associated with systemic disease in immunocompromised patients and infants in the neonatal intensive care unit. Malassezia species require long-chain fatty acids for growth and therefore have a known predilection for individuals receiving lipid containing intravenous parenteral nutrition (PN). Systemic infections are characterized by prolonged fevers and illness but can include nonspecific signs and symptoms. We present the diagnosis and management of a rare case of an immunocompetent, nonneonatal, PN-dependent child with Malassezia furfur pneumonia. © 2015 American Society for Parenteral and Enteral Nutrition.

  13. Association of Malassezia species with psoriatic lesions.

    PubMed

    Rudramurthy, Shivaprakash M; Honnavar, Prasanna; Chakrabarti, Arunaloke; Dogra, Sunil; Singh, Pankaj; Handa, Sanjeev

    2014-08-01

    The aetiology of psoriasis remains elusive. Among multiple factors hypothesised, association of Malassezia spp. is supported by response to topical antifungals. The objective of this study was to evaluate the association of Malassezia spp. with psoriatic lesion. The subjects included 50 consecutive patients with psoriasis, and 50 age- and sex-matched healthy controls. Samples were collected using scotch tape over one square inch area from the lesional and non-lesional sites. The isolated Malassezia spp. were identified by phenotypic methods and confirmed by ITS2 PCR-RFLP and sequencing of D1/D2 region of 26S rDNA. Psoriatic lesions were seen commonly on scalp (28%, 14), chest (22%, 11) and arms (16%, 8). Majority of cases presented with chronic plaque form (76%, 38; P < 0.05). From psoriatic lesions, most frequently isolated Malassezia species was M. furfur (70.6%, 24), followed by M. japonica (11.8%, 4) and M. globosa (8.8%, 3). From healthy individuals M. furfur, M. sympodialis, mixture of M. furfur and M. globosa was isolated in 73.3%, 10% and 16.7% (22, 3 and 5) of cases respectively. The average number of colonies isolated from scalp lesions of the patients was significantly higher (P = 0.03) than healthy areas. Although no strong association of Malassezia species was formed with psoriatic lesion in general, the fungi may play a role in exacerbation of scalp psoriasis. © 2014 Blackwell Verlag GmbH.

  14. Genetic polymorphism of Malassezia furfur isolates from Han and Tibetan ethnic groups in China using DNA fingerprinting.

    PubMed

    Zhang, Hao; Zhang, Ruifeng; Ran, Yuping; Dai, Yaling; Lu, Yao; Wang, Peng

    2010-12-01

    Reported isolation rates of Malassezia yeast from human skin show geographic variations. In China, the populations of the Han (1,182.95 million) and Tibetan (5.41 million) ethnic groups are distributed over 9.6 and 3.27 million square kilometers respectively, making biodiversity research feasible and convenient. Malassezia furfur clinical strains (n = 29) isolated from different individuals, with or without associated dermatoses, of these two ethnic groups (15 Han and 12 Tibetan) were identified and analyzed with DNA fingerprinting using single primers specific to minisatellites. Using the Bionumerics software, we found that almost all M. furfur clinical isolates and type strains formed five distinct group clusters according to their associated skin diseases and the ethnic groups of the patients. These findings are the first to focus on the genetic diversity and relatedness of M. furfur in the Tibetan and Han ethnic groups in China and reveal genetic variation associated with related diseases, host ethnicity and geographic origin.

  15. Three etiologic facets of dandruff and seborrheic dermatitis: Malassezia fungi, sebaceous lipids, and individual sensitivity.

    PubMed

    DeAngelis, Yvonne M; Gemmer, Christina M; Kaczvinsky, Joseph R; Kenneally, Dianna C; Schwartz, James R; Dawson, Thomas L

    2005-12-01

    Application of new molecular and biochemical tools has greatly increased our understanding of the organisms, mechanisms, and treatments of dandruff and seborrheic dermatitis. Dandruff results from at least three etiologic factors: Malassezia fungi, sebaceous secretions, and individual sensitivity. While Malassezia (formerly P. ovale) has long been a suspected cause, implicated by its presence on skin and lipophylic nature, lack of correlation between Malassezia number and the presence and severity of dandruff has remained perplexing. We have previously identified the Malassezia species correlating to dandruff and seborrheic dermatitis. In this report, we show that dandruff is mediated by Malassezia metabolites, specifically irritating free fatty acids released from sebaceous triglycerides. Investigation of the toxic Malassezia free fatty acid metabolites (represented by oleic acid) reveals the component of individual susceptibility. Malassezia metabolism results in increased levels of scalp free fatty acids. Of the three etiologic factors implicated in dandruff, Malassezia, sebaceous triglycerides, and individual susceptibility, Malassezia are the easiest to control. Pyrithione zinc kills Malassezia and all other fungi, and is highly effective against the Malassezia species actually found on scalp. Reduction in fungi reduces free fatty acids, thereby reducing scalp flaking and itch.

  16. Evaluation of Malassezia and Common Fungal Pathogens in Subtypes of Chronic Rhinosinusitis.

    PubMed

    Gelber, Jonathan T; Cope, Emily K; Goldberg, Andrew N; Pletcher, Steven D

    2016-09-01

    Fungal hypersensitivity and fungal microbiome dysbiosis are possible etiologies of chronic rhinosinusitis. The sinus fungal microbiome is not well characterized; novel sinus-associated fungi, including Malassezia, have only recently been described. The goals for this study were to verify Malassezia as a dominant component of the sinus microbiome, to speciate sinus Malassezia, and to compare select fungal species in chronic rhinosinusitis (CRS) subtypes with known fungal association to chronic rhinosinusitis with polyps (CRSwNP) and healthy controls. Twenty-eight patients were enrolled and categorized as CRSwNP (n = 15), fungus ball (n = 3), allergic fungal rhinosinusitis (AFRS, n = 3), or healthy control (n = 7). Brush samples were taken from ethmoid or maxillary sinus mucosa and tested for DNA from 7 index fungi using quantitative polymerase chain reaction. Index fungal species were chosen based on existing data of the sinus fungal microbiome. Malassezia species were detected in 68% of patients, without variation among clinical phenotypes (p > 0.99). Malassezia restricta was more commonly detected than Malassezia globosa (p = 0.029). Presence of one Malassezia species predicted the presence of the other (p = 0.035). Aspergillus was identified in 2 of 3 of fungus ball patients (both A. fumigatus) and 2 of 3 AFRS patients (1 A. fumigatus and 1 A. flavus). Aspergillus was absent in control and CRSwNP patients (p < 0.001). This study confirmed and speciated Malassezia in healthy and diseased sinuses. Presence of Malassezia species in all groups suggests a commensal role for the fungus. Future work will determine whether Malassezia influences CRS pathogenesis. Aspergillus species were identified in fungal CRS subtypes despite negative surgical cultures, highlighting the importance of culture-independent technology. © 2016 ARS-AAOA, LLC.

  17. Fungi on the Skin: Dermatophytes and Malassezia

    PubMed Central

    White, Theodore C.; Findley, Keisha; Dawson, Thomas L.; Scheynius, Annika; Boekhout, Teun; Cuomo, Christina A.; Xu, Jun; Saunders, Charles W.

    2014-01-01

    Several human skin diseases and disorders are associated with two groups of fungi, the dermatophytes and Malassezia. Although these skin-related problems are not generally life threatening, they are among the most common diseases and disorders of mankind. These fungi are phylogenetically divergent, with the dermatophytes within the Ascomycota and Malassezia within Basidiomycota. Genome analysis indicates that the adaptations to the skin environment are different in these two groups of fungi. Malassezia are dependent on host lipids and secrete lipases and phospholipases that likely release host fatty acids. The dermatophytes encode multiple enzymes with potential roles in modulating host interactions: polyketide synthases, nonribosomal peptide synthetases, LysM, proteases, kinases, and pseudokinases. These two fungal groups have maximized their interactions with the host using two very different mechanisms. PMID:25085959

  18. Otitis Externa Associated with Malassezia sympodialis in Two Cats

    PubMed Central

    Crespo, M. J.; Abarca, M. L.; Cabañes, F. J.

    2000-01-01

    The lipid-dependent species Malassezia sympodialis was isolated from two cats with otitis externa. To our knowledge, this is the first report of the isolation of lipid-dependent species of the genus Malassezia associated with skin disease in domestic animals. PMID:10699037

  19. Fungi on the skin: dermatophytes and Malassezia.

    PubMed

    White, Theodore C; Findley, Keisha; Dawson, Thomas L; Scheynius, Annika; Boekhout, Teun; Cuomo, Christina A; Xu, Jun; Saunders, Charles W

    2014-08-01

    Several human skin diseases and disorders are associated with two groups of fungi, the dermatophytes and Malassezia. Although these skin-related problems are not generally life threatening, they are among the most common diseases and disorders of mankind. These fungi are phylogenetically divergent, with the dermatophytes within the Ascomycota and Malassezia within Basidiomycota. Genome analysis indicates that the adaptations to the skin environment are different in these two groups of fungi. Malassezia are dependent on host lipids and secrete lipases and phospholipases that likely release host fatty acids. The dermatophytes encode multiple enzymes with potential roles in modulating host interactions: polyketide synthases, nonribosomal peptide synthetases, LysM, proteases, kinases, and pseudokinases. These two fungal groups have maximized their interactions with the host using two very different mechanisms. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  20. C-type lectin Mincle is an activating receptor for pathogenic fungus, Malassezia

    PubMed Central

    Yamasaki, Sho; Matsumoto, Makoto; Takeuchi, Osamu; Matsuzawa, Tetsuhiro; Ishikawa, Eri; Sakuma, Machie; Tateno, Hiroaki; Uno, Jun; Hirabayashi, Jun; Mikami, Yuzuru; Takeda, Kiyoshi; Akira, Shizuo; Saito, Takashi

    2009-01-01

    Mincle (also called as Clec4e and Clecsf9) is a C-type lectin receptor expressed in activated phagocytes. Recently, we have demonstrated that Mincle is an FcRγ-associated activating receptor that senses damaged cells. To search an exogenous ligand(s), we screened pathogenic fungi using cell line expressing Mincle, FcRγ, and NFAT-GFP reporter. We found that Mincle specifically recognizes the Malassezia species among 50 different fungal species tested. Malassezia is a pathogenic fungus that causes skin diseases, such as tinea versicolor and atopic dermatitis, and fatal sepsis. However, the specific receptor on host cells has not been identified. Mutation of the putative mannose-binding motif within C-type lectin domain of Mincle abrogated Malassezia recognition. Analyses of glycoconjugate microarray revealed that Mincle selectively binds to α-mannose but not mannan. Thus, Mincle may recognize specific geometry of α-mannosyl residues on Malassezia species and use this to distinguish them from other fungi. Malassezia activated macrophages to produce inflammatory cytokines/chemokines. To elucidate the physiological function of Mincle, Mincle-deficient mice were established. Malassezia-induced cytokine/chemokine production by macrophages from Mincle−/− mice was significantly impaired. In vivo inflammatory responses against Malassezia was also impaired in Mincle−/− mice. These results indicate that Mincle is the first specific receptor for Malassezia species to be reported and plays a crucial role in immune responses to this fungus. PMID:19171887

  1. A new yeast, Malassezia yamatoensis, isolated from a patient with seborrheic dermatitis, and its distribution in patients and healthy subjects.

    PubMed

    Sugita, Takashi; Tajima, Mami; Takashima, Masako; Amaya, Misato; Saito, Masuyoshi; Tsuboi, Ryoji; Nishikawa, Akemi

    2004-01-01

    Over the last few years, new Malassezia species have been found regularly in Japanese subjects. We isolated another new Malassezia species from a Japanese patient with seborrheic dermatitis (SD), and named it M. yamatoensis. In its physiological characteristics and the utilization of Tween by M. yamatoensis is similar to that of M. furfur and M. dermatis. It is distinguished by its growth temperature. To examine the distribution of the microorganism in the skin of patients with SD and atopic dermatitis (AD), and healthy subjects, we applied transparent dressings to the skin, and detected M. yamatoensis DNA using a non-culture-based method that consisted of nested PCR with specific primers. M. yamatoensis DNA was detected from 3 of 31 SD patients (9.7%), 5 of 36 AD patients (13.9%), and 1 of 22 healthy subjects (4.6%). Therefore, M. yamatoensis is a rare member of the cutaneous microflora.

  2. [Invasive yeast infections in neutropenic patients].

    PubMed

    Ruiz Camps, Isabel; Jarque, Isidro

    2016-01-01

    Invasive fungal diseases caused by yeasts still play an important role in the morbidity and mortality in neutropenic patients with haematological malignancies. Although the overall incidence of invasive candidiasis has decreased due to widespread use of antifungal prophylaxis, the incidence of non-Candida albicans Candida species is increasing compared with that of C.albicans, and mortality of invasive candidiasis continues to be high. In addition, there has been an increase in invasive infections caused by an array of uncommon yeasts, including species of the genus Malassezia, Rhodotorula, Trichosporon and Saprochaete, characterised by their resistance to echinocandins and poor prognosis. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Increased hydrophobicity in Malassezia species correlates with increased proinflammatory cytokine expression in human keratinocytes.

    PubMed

    Akaza, Narifumi; Akamatsu, Hirohiko; Takeoka, Shiori; Mizutani, Hiroshi; Nakata, Satoru; Matsunaga, Kayoko

    2012-11-01

    Malassezia cells stimulate cytokine production by keratinocytes, although this ability differs among Malassezia species for unknown reasons. The aim of this study was to clarify the factors determining the ability to induce cytokine production by human keratinocytes in response to Malassezia species. M. furfur NBRC 0656, M. sympodialis CBS 7222, M. dermatis JCM 11348, M. globosa CBS 7966, M. restricta CBS 7877, and three strains each of M. globosa, M. restricta, M. dermatis, M. sympodialis, and M. furfur maintained under various culture conditions were used. Normal human epidermal keratinocytes (NHEKs) (1 × 10(5) cells) and the Malassezia species (1 × 10(6) cells) were co-cultured, and IL-1α, IL-6, and IL-8 mRNA levels were determined. Moreover, the hydrophobicity and β-1,3-glucan expression at the surface of Malassezia cells were analyzed. The ability of Malassezia cells to trigger the mRNA expression of proinflammatory cytokines in NHEKs differed with the species and conditions and was dependent upon the hydrophobicity of Malassezia cells not β-1,3-glucan expression.

  4. FKBP12-Dependent Inhibition of Calcineurin Mediates Immunosuppressive Antifungal Drug Action in Malassezia.

    PubMed

    Ianiri, Giuseppe; Applen Clancey, Shelly; Lee, Soo Chan; Heitman, Joseph

    2017-10-24

    The genus Malassezia includes yeasts that are commonly found on the skin or hair of animals and humans as commensals and are associated with a number of skin disorders. We have previously developed an Agrobacterium tumefaciens transformation system effective for both targeted gene deletion and insertional mutagenesis in Malassezia furfur and M. sympodialis In the present study, these molecular resources were applied to characterize the immunophilin FKBP12 as the target of tacrolimus (FK506), ascomycin, and pimecrolimus, which are calcineurin inhibitors that are used as alternatives to corticosteroids in the treatment of inflammatory skin disorders such as those associated with Malassezia species. While M. furfur and M. sympodialis showed in vitro sensitivity to these agents, fkb1 Δ mutants displayed full resistance to all three of them, confirming that FKBP12 is the target of these calcineurin inhibitors and is essential for their activity. We found that calcineurin inhibitors act additively with fluconazole through an FKBP12-dependent mechanism. Spontaneous M. sympodialis isolates resistant to calcineurin inhibitors had mutations in the gene encoding FKBP12 in regions predicted to affect the interactions between FKBP12 and FK506 based on structural modeling. Due to the presence of homopolymer nucleotide repeats in the gene encoding FKBP12, an msh2 Δ hypermutator of M. sympodialis was engineered and exhibited an increase of more than 20-fold in the rate of emergence of resistance to FK506 compared to that of the wild-type strain, with the majority of the mutations found in these repeats. IMPORTANCE Malassezia species are the most abundant fungal components of the mammalian and human skin microbiome. Although they belong to the natural skin commensal flora of humans, they are also associated with a variety of clinical skin disorders. The standard treatment for Malassezia -associated inflammatory skin infections is topical corticosteroids, although their use

  5. Utilization of matrix-assisted laser desorption and ionization time-of-flight mass spectrometry for identification of infantile seborrheic dermatitis-causing Malassezia and incidence of culture-based cutaneous Malassezia microbiota of 1-month-old infants.

    PubMed

    Yamamoto, Mikachi; Umeda, Yoshiko; Yo, Ayaka; Yamaura, Mariko; Makimura, Koichi

    2014-02-01

    Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been utilized for identification of various microorganisms. Malassezia species, including Malassezia restricta, which is associated with seborrheic dermatitis, has been difficult to identify by traditional means. This study was performed to develop a system for identification of Malassezia species with MALDI-TOF-MS and to investigate the incidence and variety of cutaneous Malassezia microbiota of 1-month-old infants using this technique. A Malassezia species-specific MALDI-TOF-MS database was developed from eight standard strains, and the availability of this system was assessed using 54 clinical strains isolated from the skin of 1-month-old infants. Clinical isolates were cultured initially on CHROMagar Malassezia growth medium, and the 28S ribosomal DNA (D1/D2) sequence was analyzed for confirmatory identification. Using this database, we detected and analyzed Malassezia species in 68% and 44% of infants with and without infantile seborrheic dermatitis, respectively. The results of MALDI-TOF-MS analysis were consistent with those of rDNA sequencing identification (100% accuracy rate). To our knowledge, this is the first report of a MALDI-TOF-MS database for major skin pathogenic Malassezia species. This system is an easy, rapid and reliable method for identification of Malassezia. © 2014 Japanese Dermatological Association.

  6. Use of a modified hair strand test to assess the antifungal activity kinetics of dog hair after a 2% climbazole shampoo application.

    PubMed

    Petit, Jean Yanique; Cavana, Paola; Thoumire, Sandra; Guillot, Jacques; Perrot, Sébastien

    2016-06-01

    The "hair strand test" was first developed as a model to evaluate the antifungal activity of antidandruff shampoos. To assess the residual activity of an antifungal shampoo on the hair shafts of dogs after a single application, followed by bathing with a physiological shampoo one month later. Six beagles (two males and four females) from a research colony. Dogs were bathed with a 2% climbazole shampoo. Hairs were collected before application of the shampoo and at scheduled intervals for 30 days after treatment. A physiological shampoo was then applied to all dogs and hairs were collected following the same schedule. The inhibition zone around the hair shafts was measured after incubation on Sabouraud's dextrose agar plates streaked with three Malassezia pachydermatis strains. Inhibition zones around hairs collected from dogs bathed with 2% climbazole shampoo were significantly larger than those around hairs collected before shampooing at all time points (P = 0.003). An increase in the width of the inhibition zones around climbazole treated hairs was observed following physiological shampoo on Day 30 (P = 0.005). No significant differences were observed between Malassezia pachydermatis isolates (P = 0.571). No inhibition zones were seen around the hairs of dogs bathed with physiological shampoo only. The modified hair strand test is useful for the assessment of residual antifungal activity on animal hairs. Use of a physiological shampoo following antifungal shampoo therapy may increase the efficacy of the antifungal product for the control of Malassezia overgrowth. © 2016 ESVD and ACVD.

  7. Diagnostic value of nested-PCR for identification of Malassezia species in dandruff

    NASA Astrophysics Data System (ADS)

    Jusuf, N. K.; Nasution, T. A.; Ullyana, S.

    2018-03-01

    Dandruff or pityriasis simplex is a condition of abnormal occurrence of formation of yellowish white scales from the scalp. Many factors play a role in the pathogenesis of dandruff, i.e.colonization of Malassezia species. Examination of Malassezia species previously done by culture as the gold standard. However, there are various difficulties in doing the culture. Identification method with anested-polymerase chain reaction (nested-PCR) is expected to provide quickly and easily detected. This study aimedto determine the diagnostic value of nested-PCR in the identification of Malassezia species in dandruff. From 21 subjects, scales from the scalp were taken and sent to the laboratory for nested-PCR identification. Statistical analysis of diagnostic test carried out to determine sensitivity, specificity, positive predictive value, and negative predictive value. The results showed nested-PCR detected 10 sample (47.6%) positive for Malassezia species consist of M. sympodialis (23.8%); M. slooffiae (9.5%); M. furfur (4.8%); M. globosa and M. furfur (4.8%); and M. restricta and M. sympodialis (4.8%). Detection of Malassezia species by nested-PCR has 100% in sensitivity whereas the specificity was 55%. Nested-PCR test has high sensitivity. Therefore nested-PCR may be considered for a faster and simpler alternative examination in identification for Malassezia species in dandruff.

  8. Distribution of malassezia species on the scalp in korean seborrheic dermatitis patients.

    PubMed

    Lee, Yang Won; Byun, Hee Jin; Kim, Beom Joon; Kim, Dong Ha; Lim, Yun Young; Lee, Jin Woong; Kim, Myeung Nam; Kim, Donghak; Chun, Young-Jin; Mun, Seog Kyun; Kim, Chan Woong; Kim, Sung Eun; Hwang, Jae Sung

    2011-05-01

    Malassezia species play an important role in the pathogenesis of seborrheic dermatitis. In particular, M. restricta and M. globosa are considered to be the predominant organisms in seborrheic dermatitis of Western countries. However, species distribution of Malassezia in seborrheic dermatitis has not been clearly determined yet in Asia. To identify the distribution of Malassezia species on the scalp of seborrheic dermatitis patients in Korea using 26S rDNA PCR-RFLP analysis. A total of 40 seborrheic dermatitis patients and 100 normal healthy volunteers were included in this study. For the identification of Malassezia species, the scalp scales of the subjects were analyzed by 26S rDNA PCR-RFLP analysis. The most commonly identified Malassezia species were M. restricta in the seborrheic dermatitis patients, and M. globosa in the normal controls. In the seborrheic dermatitis group, M. restricta was identified in 47.5%, M. globosa in 27.5%, M. furfur in 7.5%, and M. sympodialis in 2.5% of patients. In the healthy control group, M. globosa was identified in 32.0%, M. restricta in 25.0%, M. furfur in 8.0%, M. obtusa in 6.0%, M. slooffiae in 6.0%, and M. sympodialis in 4.0% of subjects. M. restricta is considered to be the most important Malassezia species in Korean seborrheic dermatitis patients.

  9. Distribution of Malassezia Species on the Scalp in Korean Seborrheic Dermatitis Patients

    PubMed Central

    Lee, Yang Won; Byun, Hee Jin; Kim, Dong Ha; Lim, Yun Young; Lee, Jin Woong; Kim, Myeung Nam; Kim, Donghak; Chun, Young-Jin; Mun, Seog Kyun; Kim, Chan Woong; Kim, Sung Eun; Hwang, Jae Sung

    2011-01-01

    Background Malassezia species play an important role in the pathogenesis of seborrheic dermatitis. In particular, M. restricta and M. globosa are considered to be the predominant organisms in seborrheic dermatitis of Western countries. However, species distribution of Malassezia in seborrheic dermatitis has not been clearly determined yet in Asia. Objective To identify the distribution of Malassezia species on the scalp of seborrheic dermatitis patients in Korea using 26S rDNA PCR-RFLP analysis. Methods A total of 40 seborrheic dermatitis patients and 100 normal healthy volunteers were included in this study. For the identification of Malassezia species, the scalp scales of the subjects were analyzed by 26S rDNA PCR-RFLP analysis. Results The most commonly identified Malassezia species were M. restricta in the seborrheic dermatitis patients, and M. globosa in the normal controls. In the seborrheic dermatitis group, M. restricta was identified in 47.5%, M. globosa in 27.5%, M. furfur in 7.5%, and M. sympodialis in 2.5% of patients. In the healthy control group, M. globosa was identified in 32.0%, M. restricta in 25.0%, M. furfur in 8.0%, M. obtusa in 6.0%, M. slooffiae in 6.0%, and M. sympodialis in 4.0% of subjects. Conclusion M. restricta is considered to be the most important Malassezia species in Korean seborrheic dermatitis patients. PMID:21747613

  10. Prolonged fever and splenic lesions caused by Malassezia restricta in an immunocompromised patient.

    PubMed

    de St Maurice, Annabelle; Frangoul, Haydar; Coogan, Alice; Williams, John V

    2014-12-01

    Malassezia species are commonly found on human skin as commensals but can cause invasive infections in premature infants and immunocompromised hosts. Due to their fastidious growth, diagnosis of Malassezia infections can prove challenging. Molecular techniques can aid in diagnosis and treatment of invasive infections. We describe the case of a pediatric oncology patient with splenic lesions secondary to Malassezia restricta. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Photodynamic therapy: new treatment for recalcitrant Malassezia folliculitis.

    PubMed

    Lee, Jin Woong; Kim, Beom Joon; Kim, Myeung Nam

    2010-02-01

    Malassezia folliculitis commonly has been treated with oral antifungal medications. However, it has many therapeutic weaknesses such as infection relapse, drug resistance, or adverse effects like hepatotoxicity and gastrointestinal discomfort. Hence, there remains an ongoing need for alternative treatments for recalcitrant Malassezia folliculitis. Recently, many dermatologists suggest photodynamic therapy (PDT) as an alternative therapeutic option for its antimicrobial effect. To investigate the efficacy of methyl 5-aminolevulinic acid (MAL)-PDT for the treatment of recalcitrant Malassezia folliculitis. Six Korean patients aged 23-47 years with recalcitrant Malassezia folliculitis were enrolled in this study. The patients enrolled in this study either refused oral medication or were unable to take oral antifungal agents due to hepatotoxicity concerns. Thus, we offered these patients MAL-PDT as an alternative treatment option. For all patients, photographs of the lesion(s) were taken prior to initiating treatment. MAL cream (Metvix, Galderma, France) was applied to each lesion (located on the patients' trunks) and covered with an adhesive occlusive dressing polyurethane film (Tegaderm, 3M Healthcare, St. Paul, MN). After 3 hours, the cream was wiped off and illumination was performed immediately thereafter with non-coherent red light using light-emitting diodes (Aktilite lamp, PhotoCure, Oslo, Norway, average wavelength 630 nm, light dose 37 J/cm(2)). Illumination was performed for 7.5 minutes. Patients underwent totally three sessions of MAL-PDT at 2-week intervals. One month after the last PDT treatment, patients returned to the hospital and lesions were photographed. After three sessions of MAL-PDT, inflammatory lesions had decreased and improved obviously in four patients, had improved slightly in one patient, and had not improved in one patient. MAL-PDT may be an effective treatment option for patients with recalcitrant Malassezia folliculitis. However, the

  12. Genus-Wide Comparative Genomics of Malassezia Delineates Its Phylogeny, Physiology, and Niche Adaptation on Human Skin

    PubMed Central

    Wu, Guangxi; Zhao, He; Li, Chenhao; Rajapakse, Menaka Priyadarsani; Wong, Wing Cheong; Xu, Jun; Saunders, Charles W.; Reeder, Nancy L.; Reilman, Raymond A.; Scheynius, Annika; Sun, Sheng; Billmyre, Blake Robert; Li, Wenjun; Averette, Anna Floyd; Mieczkowski, Piotr; Heitman, Joseph; Theelen, Bart; Schröder, Markus S.; De Sessions, Paola Florez; Butler, Geraldine; Maurer-Stroh, Sebastian; Boekhout, Teun; Nagarajan, Niranjan; Dawson, Thomas L.

    2015-01-01

    Malassezia is a unique lipophilic genus in class Malasseziomycetes in Ustilaginomycotina, (Basidiomycota, fungi) that otherwise consists almost exclusively of plant pathogens. Malassezia are typically isolated from warm-blooded animals, are dominant members of the human skin mycobiome and are associated with common skin disorders. To characterize the genetic basis of the unique phenotypes of Malassezia spp., we sequenced the genomes of all 14 accepted species and used comparative genomics against a broad panel of fungal genomes to comprehensively identify distinct features that define the Malassezia gene repertoire: gene gain and loss; selection signatures; and lineage-specific gene family expansions. Our analysis revealed key gene gain events (64) with a single gene conserved across all Malassezia but absent in all other sequenced Basidiomycota. These likely horizontally transferred genes provide intriguing gain-of-function events and prime candidates to explain the emergence of Malassezia. A larger set of genes (741) were lost, with enrichment for glycosyl hydrolases and carbohydrate metabolism, concordant with adaptation to skin’s carbohydrate-deficient environment. Gene family analysis revealed extensive turnover and underlined the importance of secretory lipases, phospholipases, aspartyl proteases, and other peptidases. Combining genomic analysis with a re-evaluation of culture characteristics, we establish the likely lipid-dependence of all Malassezia. Our phylogenetic analysis sheds new light on the relationship between Malassezia and other members of Ustilaginomycotina, as well as phylogenetic lineages within the genus. Overall, our study provides a unique genomic resource for understanding Malassezia niche-specificity and potential virulence, as well as their abundance and distribution in the environment and on human skin. PMID:26539826

  13. Genus-Wide Comparative Genomics of Malassezia Delineates Its Phylogeny, Physiology, and Niche Adaptation on Human Skin.

    PubMed

    Wu, Guangxi; Zhao, He; Li, Chenhao; Rajapakse, Menaka Priyadarsani; Wong, Wing Cheong; Xu, Jun; Saunders, Charles W; Reeder, Nancy L; Reilman, Raymond A; Scheynius, Annika; Sun, Sheng; Billmyre, Blake Robert; Li, Wenjun; Averette, Anna Floyd; Mieczkowski, Piotr; Heitman, Joseph; Theelen, Bart; Schröder, Markus S; De Sessions, Paola Florez; Butler, Geraldine; Maurer-Stroh, Sebastian; Boekhout, Teun; Nagarajan, Niranjan; Dawson, Thomas L

    2015-11-01

    Malassezia is a unique lipophilic genus in class Malasseziomycetes in Ustilaginomycotina, (Basidiomycota, fungi) that otherwise consists almost exclusively of plant pathogens. Malassezia are typically isolated from warm-blooded animals, are dominant members of the human skin mycobiome and are associated with common skin disorders. To characterize the genetic basis of the unique phenotypes of Malassezia spp., we sequenced the genomes of all 14 accepted species and used comparative genomics against a broad panel of fungal genomes to comprehensively identify distinct features that define the Malassezia gene repertoire: gene gain and loss; selection signatures; and lineage-specific gene family expansions. Our analysis revealed key gene gain events (64) with a single gene conserved across all Malassezia but absent in all other sequenced Basidiomycota. These likely horizontally transferred genes provide intriguing gain-of-function events and prime candidates to explain the emergence of Malassezia. A larger set of genes (741) were lost, with enrichment for glycosyl hydrolases and carbohydrate metabolism, concordant with adaptation to skin's carbohydrate-deficient environment. Gene family analysis revealed extensive turnover and underlined the importance of secretory lipases, phospholipases, aspartyl proteases, and other peptidases. Combining genomic analysis with a re-evaluation of culture characteristics, we establish the likely lipid-dependence of all Malassezia. Our phylogenetic analysis sheds new light on the relationship between Malassezia and other members of Ustilaginomycotina, as well as phylogenetic lineages within the genus. Overall, our study provides a unique genomic resource for understanding Malassezia niche-specificity and potential virulence, as well as their abundance and distribution in the environment and on human skin.

  14. Gene Function Analysis in the Ubiquitous Human Commensal and Pathogen Malassezia Genus

    PubMed Central

    Ianiri, Giuseppe; Averette, Anna F.; Kingsbury, Joanne M.; Heitman, Joseph

    2016-01-01

    ABSTRACT The genus Malassezia includes 14 species that are found on the skin of humans and animals and are associated with a number of diseases. Recent genome sequencing projects have defined the gene content of all 14 species; however, to date, genetic manipulation has not been possible for any species within this genus. Here, we develop and then optimize molecular tools for the transformation of Malassezia furfur and Malassezia sympodialis using Agrobacterium tumefaciens delivery of transfer DNA (T-DNA) molecules. These T-DNAs can insert randomly into the genome. In the case of M. furfur, targeted gene replacements were also achieved via homologous recombination, enabling deletion of the ADE2 gene for purine biosynthesis and of the LAC2 gene predicted to be involved in melanin biosynthesis. Hence, the introduction of exogenous DNA and direct gene manipulation are feasible in Malassezia species. PMID:27899504

  15. Is Malassezia nana the main species in horses' ear canal microbiome?

    PubMed

    Aldrovandi, Ana Lúcia; Osugui, Lika; Acqua Coutinho, Selene Dall'

    2016-01-01

    The objective of this study was to characterize genotypically Malassezia spp. isolated from the external ear canal of healthy horses. Fifty-five horses, 39 (70.9%) males and 16 (29.1%) females, from different breeds and adults were studied. External ear canals were cleaned and a sterile cotton swab was introduced to collect cerumen. A total of 110 samples were cultured into Dixon medium and were incubated at 32°C for up to 15 days. Macro- and micromorphology and phenotypic identification were performed. DNA was extracted, strains were submitted to polymerase chain reaction technique, and the products obtained were submitted to Restriction Fragment Length Polymorphism using the restriction enzymes BstCI and HhaI. Strains were sent off to genetic sequencing of the regions 26S rDNA D1/D2 and ITS1-5.8S-ITS2 rDNA. Malassezia spp. were isolated from 33/55 (60%) animals and 52/110 (47%) ear canals. No growth on Sabouraud dextrose agar was observed, confirming the lipid dependence of all strains. Polymerase chain reaction-Restriction fragment length polymorphism permitted the molecular identification of Malassezia nana - 42/52 (81%) and Malassezia slooffiae - 10/52 (19%). Sequencing confirmed RFLP identification. It was surprising that M. nana represented over 80% of the strains and no Malassezia equina was isolated in this study, differing from what was expected. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  16. Malassezia infection associated with chronic spontaneous urticaria without angioedema: a report on five cases.

    PubMed

    Zawar, Vijay; Pawar, Manoj; Kumavat, Shrikant

    2018-06-01

    Chronic spontaneous urticaria (CSU) is a challenging condition to treat and it significantly affects quality of life. Bacterial, viral, parasitic, and fungal infections have been associated with triggering and/or perpetuating urticaria in certain individuals. There is a paucity of literature on CSU associated with Malassezia infection. We present a case series of five patients with CSU without angioedema in whom we observed temporal association of Malassezia infection with CSU. The presence of Malassezia was confirmed by clinical examination, Wood's lamp, and KOH examination. The patients with CSU experienced improvement after specific antifungal therapy. Malassezia infection may be associated with recurrent and chronic urticaria in a certain group of susceptible patients and thus specific targeted therapy against it might result in complete remission of urticaria along with clearing of the infection.

  17. Gene Function Analysis in the Ubiquitous Human Commensal and Pathogen Malassezia Genus.

    PubMed

    Ianiri, Giuseppe; Averette, Anna F; Kingsbury, Joanne M; Heitman, Joseph; Idnurm, Alexander

    2016-11-29

    The genus Malassezia includes 14 species that are found on the skin of humans and animals and are associated with a number of diseases. Recent genome sequencing projects have defined the gene content of all 14 species; however, to date, genetic manipulation has not been possible for any species within this genus. Here, we develop and then optimize molecular tools for the transformation of Malassezia furfur and Malassezia sympodialis using Agrobacterium tumefaciens delivery of transfer DNA (T-DNA) molecules. These T-DNAs can insert randomly into the genome. In the case of M. furfur, targeted gene replacements were also achieved via homologous recombination, enabling deletion of the ADE2 gene for purine biosynthesis and of the LAC2 gene predicted to be involved in melanin biosynthesis. Hence, the introduction of exogenous DNA and direct gene manipulation are feasible in Malassezia species. Species in the genus Malassezia are a defining component of the microbiome of the surface of mammals. They are also associated with a wide range of skin disease symptoms. Many species are difficult to culture in vitro, and although genome sequences are available for the species in this genus, it has not been possible to assess gene function to date. In this study, we pursued a series of possible transformation methods and identified one that allows the introduction of DNA into two species of Malassezia, including the ability to make targeted integrations into the genome such that genes can be deleted. This research opens a new direction in terms of now being able to analyze gene functions in this little understood genus. These tools will contribute to define the mechanisms that lead to the commensalism and pathogenicity in this group of obligate fungi that are predominant on the skin of mammals. Copyright © 2016 Ianiri et al.

  18. The spectrum of Malassezia species isolated from students with pityriasis vesicolor in Nigeria.

    PubMed

    Ibekwe, P U; Ogunbiyi, A O; Besch, R; Ruzicka, T; Sárdy, M

    2015-04-01

    Pityriasis versicolor (PV) is a common superficial fungal infection of the skin caused by Malassezia. Initially M. furfur was suggested as its main aetiological agent; however, more recent studies suggest M. globosa as the dominant species. The possibility of a variance in predominant species based on geographical basis has not been fully evaluated. The objective of this study was to identify the Malassezia species on affected and non-affected skin of students with PV who reside in a tropical environment (Abuja, Nigeria) and correlate them to clinical characteristics. In this study, the literature on prevalence of Malassezia genus in PV was also reviewed. Samples were taken from 304 PV lesions and 110 normal appearing skin. Microscopy, culture and identification of Malassezia species utilising polymerase chain reaction-restriction fragment length polymorphism analysis were performed. Three Malassezia species were detected in PV with the major species being M. furfur. On normal appearing skin, M. furfur (77.6%) and M. restricta (10.4%) were both detected. No case of M. globosa was identified in this study. There was no significant difference between species identified and clinical features of PV. M. furfur is probably still the most predominant species causing PV in the tropical environment. © 2015 Blackwell Verlag GmbH.

  19. Proteogenomics produces comprehensive and highly accurate protein-coding gene annotation in a complete genome assembly of Malassezia sympodialis

    PubMed Central

    Tellgren-Roth, Christian; Baudo, Charles D.; Kennell, John C.; Sun, Sheng; Billmyre, R. Blake; Schröder, Markus S.; Andersson, Anna; Holm, Tina; Sigurgeirsson, Benjamin; Wu, Guangxi; Sankaranarayanan, Sundar Ram; Siddharthan, Rahul; Sanyal, Kaustuv; Lundeberg, Joakim; Nystedt, Björn; Boekhout, Teun; Dawson, Thomas L.; Heitman, Joseph

    2017-01-01

    Abstract Complete and accurate genome assembly and annotation is a crucial foundation for comparative and functional genomics. Despite this, few complete eukaryotic genomes are available, and genome annotation remains a major challenge. Here, we present a complete genome assembly of the skin commensal yeast Malassezia sympodialis and demonstrate how proteogenomics can substantially improve gene annotation. Through long-read DNA sequencing, we obtained a gap-free genome assembly for M. sympodialis (ATCC 42132), comprising eight nuclear and one mitochondrial chromosome. We also sequenced and assembled four M. sympodialis clinical isolates, and showed their value for understanding Malassezia reproduction by confirming four alternative allele combinations at the two mating-type loci. Importantly, we demonstrated how proteomics data could be readily integrated with transcriptomics data in standard annotation tools. This increased the number of annotated protein-coding genes by 14% (from 3612 to 4113), compared to using transcriptomics evidence alone. Manual curation further increased the number of protein-coding genes by 9% (to 4493). All of these genes have RNA-seq evidence and 87% were confirmed by proteomics. The M. sympodialis genome assembly and annotation presented here is at a quality yet achieved only for a few eukaryotic organisms, and constitutes an important reference for future host-microbe interaction studies. PMID:28100699

  20. Identification of Malassezia species in the facial lesions of Chinese seborrhoeic dermatitis patients based on DNA sequencing.

    PubMed

    Lian, C-h; Shen, L-l; Gao, Q-y; Jiang, M; Zhao, Z-j; Zhao, J-j

    2014-12-01

    The genus Malassezia is important in the aetiology of facial seborrhoeic dermatitis (FSD), which is the most common clinical type. The purpose of this study was to analyse the distribution of Malassezia species in the facial lesions of Chinese seborrhoeic dermatitis (SD) patients and healthy individuals. Sixty-four isolates of Malassezia were isolated from FSD patients and 60 isolates from healthy individuals. Sequence analysis of the internal transcribed spacer (ITS) region was used to identify the isolates. The most frequently identified Malassezia species associated with FSD was M. furfur (76.56%), followed by M. sympodialis (12.50%) and M. japonica (9.38%). The most frequently isolated species in healthy individuals were M. furfur (61.67%), followed by M. sympodialis (25.00%), M. japonica (6.67%), M. globosa (3.33%), and M. obtusa (3.33%). Overall, our study revealed that while M. furfur is the predominant Malassezia species in Chinese SD patients, there is no significant difference in the distribution of Malassezia species between Chinese SD patients and healthy individuals. © 2014 Blackwell Verlag GmbH.

  1. Follicular variant of seborrheic dermatitis: is it identical to Malassezia folliculitis?

    PubMed

    Valentine, Mark C

    2011-01-01

    Follicular accentuation in some patients with seborrheic dermatitis of the back and chest has been recognized for more than a century. The recognition of Malassezia folliculitis in recent decades has led to some confusion regarding categorization of these cases. The author proposes that there is sufficient clinical variation between the typical case of Malassezia folliculitis and patients with follicular seborrheic dermatitis to justify continued separation of these entities until further study provides more clarification.

  2. Skin Colonization by Malassezia spp. in hospitalized neonates and infants in a tertiary care centre in North India.

    PubMed

    Gupta, Prerna; Chakrabarti, Arunaloke; Singhi, Sunit; Kumar, Praveen; Honnavar, Prasanna; Rudramurthy, Shivaprakash M

    2014-10-01

    Malassezia, a skin colonizer, is associated with multiple skin disorders in adults, and cephalic pustulosis and folliculitis in children. It can cause fungemia in infants and neonates. The time and pattern of colonization, risk factors associated with colonization and causing fungemia in children, are not well understood. The prospective cohort study was conducted to determine the rate of Malassezia species colonization and associated factors in hospitalized neonates and infants. Consecutive 50 neonates and infants admitted in neonatal and pediatric intensive care units were studied. The skin swabs were collected on the day of admission and every fifth day, thereafter, till the patient was discharged or died. Putative risk factors for the colonization of Malassezia species were recorded. Isolates were identified by phenotypic methods and sequencing of the D1 and D2 region of rDNA. Neonates were not colonized at the time of entry in neonatal ICU or at birth. Nineteen (38 %) neonates were colonized with Malassezia species during their hospital stay. Among the infants, three (6 %) came to ICU with Malassezia colonization and 26 (52 %) acquired Malassezia during ICU stay. Mechanical ventilation, duration of hospital stay, central venous catheterization, and antifungal therapy were the significantly associated factors for colonization. Malassezia furfur was the most common species isolated from the skin of infants and neonates. Colonization by Malassezia species in infants and neonates in a hospital is not uncommon and can be a potential source of nosocomial infection.

  3. [Dermatomycoses due to pets and farm animals : neglected infections?].

    PubMed

    Nenoff, P; Handrick, W; Krüger, C; Vissiennon, T; Wichmann, K; Gräser, Y; Tchernev, G

    2012-11-01

    Dermatomycoses due to contact with pets and livestock frequently affect children and young adults. Zoophilic dermatophytes are the main important causative agents. It has long been known that the often high inflammatory dermatophytoses of the skin and the scalp are caused mostly by Microsporum canis. Due to an absence of an obligation for reporting fungal infections of the skin to the Public Health Office in Germany, an unnoticed but significant change in responsible pathogens has occurred. Today an increasing number of infections due to zoophilic strains of Trichophyton interdigitale (formerly Trichophyton mentagrophytes) and Trichophyton species of Arthroderma benhamiae are found. The latter mentioned dermatophyte is the anamorph species of the teleomorph Arthroderma benhamiae, which originally was isolated in the Far East (Japan). Source of infection of these dermatophytes are small rodents, in particular guinea pigs. These animals are bought in pet shops by the parents of those children who later are affected by the fungal infection. The coincidental purchase of the relevant fungal pathogen is not obvious to the parents. As a consequence, highly contagious dermatophytoses occur, often tinea capitis sometimes with kerion formation. Further dermatophytes should be considered as cause of a zoophilic dermatomycosis. Both Trichophyton verrucosum, the cause of the ringworm in cattle, and Trichophyton erinacei following contact to hedgehogs are worthy of note. Yeasts cannot be ignored as cause of dermatomycosis, especially Malassezia pachydermatis, the only non-lipophilic species within the genus Malassezia, which can be transferred from dog to men. Cryptococcus neoformans also comes from animal sources. The mucous yeast occurs in bird's dropping, and it causes both pulmonary and central nervous system infections, but also primary and secondary cutaneous cryptococcosis in immunocompromised patients (HIV/AIDS) as possible consequence after contact to these animals.

  4. Comparative in vitro antimicrobial efficacy of commercial ear cleaners.

    PubMed

    Swinney, Alison; Fazakerley, Jennifer; McEwan, Neil; Nuttall, Tim

    2008-12-01

    The aim of this study was to compare the antimicrobial efficacy of ear cleaners against Staphylococcus intermedius, Pseudomonas aeruginosa and Malassezia pachydermatis. Single isolates of each organism were incubated in duplicate at 38 degrees C for 30 min with each ear cleaner diluted 1/2 to 1/256 in phosphate-buffered saline. Positive and negative controls were included. Aliquots were then incubated for 16-18 h on sheep blood agar (bacteria) or for 3 days on Sabouraud's dextrose agar (Malassezia) at 38 degrees C. The lowest dilutions exhibiting 100% antimicrobial efficacy for S. intermedius were: Cleanaural Dog 1/32; Sancerum 1/16; Otoclean 1/4; EpiOtic 1/2; MalAcetic 1/2; and Triz Plus 1/2. The results for P. aeruginosa were Sancerum and Triz Plus 1/16; Cleanaural Dog and EpiOtic 1/8; Otoclean 1/4; and MalAcetic 1/2. Results for M. pachydermatis were: Cleanaural Dog 1/32; Sancerum, Otoclean, EpiOtic and Triz Plus 1/8; and MalAcetic 1/4. Cleanaural Cat, MalAcetic HC and Triz EDTA did not display any antimicrobial activity at any dilution. Antimicrobial activity appeared to be associated with the presence of isopropyl alcohol, parachlorometaxylenol and a low pH. The results of this study may help clinicians make evidence-based decisions when selecting ear cleaners for use in individual cases.

  5. Microorganisms inhabiting follicular contents of facial acne are not only Propionibacterium but also Malassezia spp.

    PubMed

    Akaza, Narifumi; Akamatsu, Hirohiko; Numata, Shigeki; Yamada, Shunji; Yagami, Akiko; Nakata, Satoru; Matsunaga, Kayoko

    2016-08-01

    To clarify the relationship between major cutaneous microorganisms (Propionibacterium, Staphylococcus and Malassezia spp.) and acne vulgaris (acne), we examined the microbiota quantitatively in the follicular contents of inflammatory acne and on the facial skin of patients with acne. Fifteen Japanese untreated acne outpatients were studied. The follicular contents from inflammatory acne lesions of the face were collected using a comedo extractor. The skin surface samples were obtained by the swab method from 10 cm(2) of facial skin. The microbiota was analyzed using polymerase chain reaction. The microbiota in follicular contents was similar to that on the skin surface, namely, there were large populations of Propionibacterium spp., Staphylococcus spp. and Malassezia spp. Moreover, the number of Malassezia spp. on the skin surface was correlated with that of inflammatory acne and that in follicular contents. This study clarified that there are large populations of Propionibacterium spp., Staphylococcus spp. and Malassezia spp. in follicular contents. These results suggest the possibility that not only Propionibacterium acnes but also other cutaneous resident microorganisms are related to acne. Particularly, we considered that Malassezia spp. is closely related. © 2015 Japanese Dermatological Association.

  6. Malassezia species retrieved from skin with pityriasis versicolor, seborrheic dermatitis and skin free of lesions: a comparison of two sampling methods.

    PubMed

    Pedrosa, A F; Lisboa, C; Faria-Ramos, I; Silva, R M; Miranda, I M; Rodrigues, A G

    2018-03-05

    Malassezia are involved in the pathogenesis of different skin diseases including pityriasis versicolor (PV) and seborrheic dermatitis (SD), but these yeasts are also important inhabitants of the skin microbiome. Culture is not performed routinely, although it may be of value in doubtful cases to support the diagnosis; culture is crucial for identification tools such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Culture is also critical to assess the number of organisms and viability and, eventually, to perform antifungal susceptibility tests. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Prevalence of different Malassezia species in pityriasis versicolor in central India.

    PubMed

    Chaudhary, Rahul; Singh, Sanjay; Banerjee, Tuhina; Tilak, Ragini

    2010-01-01

    In the last 10 years, different studies have shown interesting geographical variations in the prevalence of different Malassezia species in pityriasis versicolor. Identification of Malassezia species isolated from patients with pityriasis versicolor. In 100 patients with pityriasis versicolor, Malassezia species were identified by culture in Sabouraud's dextrose agar containing cycloheximide with olive oil overlay and modified Dixon agar and by doing biochemical tests (catalase reaction, assimilation of glycine, and Tween utilisation tests). In 10 patients, 10% KOH smear was negative, while in 90 patients the smear showed characteristic "spaghetti and meatball" appearance. Of these 90 cases, growth was obtained on modified Dixon's agar in 87 cases. Fifty of the isolates (57.5%) were M. globosa, 15 (17.2%) were M. sympodialis, seven (8.0%) were suspected M. sympodialis, 6 (6.9%) each of the isolates were M. furfur and M. obtusa, and three (3.4%) isolates were M. restricta. M. globosa was the most common species, followed by M. sympodialis, M. furfur, M. obtusa, and M. restricta.

  8. Proteogenomics produces comprehensive and highly accurate protein-coding gene annotation in a complete genome assembly of Malassezia sympodialis.

    PubMed

    Zhu, Yafeng; Engström, Pär G; Tellgren-Roth, Christian; Baudo, Charles D; Kennell, John C; Sun, Sheng; Billmyre, R Blake; Schröder, Markus S; Andersson, Anna; Holm, Tina; Sigurgeirsson, Benjamin; Wu, Guangxi; Sankaranarayanan, Sundar Ram; Siddharthan, Rahul; Sanyal, Kaustuv; Lundeberg, Joakim; Nystedt, Björn; Boekhout, Teun; Dawson, Thomas L; Heitman, Joseph; Scheynius, Annika; Lehtiö, Janne

    2017-03-17

    Complete and accurate genome assembly and annotation is a crucial foundation for comparative and functional genomics. Despite this, few complete eukaryotic genomes are available, and genome annotation remains a major challenge. Here, we present a complete genome assembly of the skin commensal yeast Malassezia sympodialis and demonstrate how proteogenomics can substantially improve gene annotation. Through long-read DNA sequencing, we obtained a gap-free genome assembly for M. sympodialis (ATCC 42132), comprising eight nuclear and one mitochondrial chromosome. We also sequenced and assembled four M. sympodialis clinical isolates, and showed their value for understanding Malassezia reproduction by confirming four alternative allele combinations at the two mating-type loci. Importantly, we demonstrated how proteomics data could be readily integrated with transcriptomics data in standard annotation tools. This increased the number of annotated protein-coding genes by 14% (from 3612 to 4113), compared to using transcriptomics evidence alone. Manual curation further increased the number of protein-coding genes by 9% (to 4493). All of these genes have RNA-seq evidence and 87% were confirmed by proteomics. The M. sympodialis genome assembly and annotation presented here is at a quality yet achieved only for a few eukaryotic organisms, and constitutes an important reference for future host-microbe interaction studies. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. Distribution of Malassezia Species in Patients with Different Dermatological Disorders and Healthy Individuals.

    PubMed

    Prohić, Asja; Jovović Sadiković, Tamara; Kuskunović-Vlahovljak, Suada; Baljić, Rusmir

    2016-12-01

    There are differences with respect to the commonly isolated Malassezia species, not only between healthy individuals and the patients with various skin diseases, but also between different countries. We investigated the species composition of Malassezia microflora on the skin of patients with Malassezia-associated diseases and of healthy subjects (HS). Two hundred and fifty skin scrapings from patients with pityriasis versicolor (PV), seborrheic dermatitis (SD), atopic dermatitis (AD), psoriasis (PS), and healthy subjects (HS), fifty each, were inoculated into Sabouraud dextrose agar and into modified Dixon agar and identified using conventional culture-based methods. In PV and PS lesions, the most common species was M. globosa (62% and 52%, respectively), while M. restricta was predominant in SD lesions (28%). M. sympodialis was the most common species recovered from AD (52%) and healthy trunk skin (30%). Fewer cultures were positive for Malassezia growth in patients with AD than in patients with other skin conditions, and even in controls. Our data are in agreement with other studies and suggest that the pathogenic species of PV is M. globosa. The evidence that any given species is clinically important in the pathogenicity of SD, AD and PS is still lacking.

  10. Malassezia spp on the periocular skin of dogs and their association with blepharitis, ocular discharge, and the application of ophthalmic medications.

    PubMed

    Newbold, Georgina M; Outerbridge, Catherine A; Kass, Philip H; Maggs, David J

    2014-06-01

    To determine how frequently Malassezia spp were identified on the periocular skin of dogs and assess the respective associations between the presence of Malassezia spp on the periocular skin and blepharitis, ocular discharge, and the application of ophthalmic medications. Prospective clinical study. 167 eyelids of 84 dogs. Samples obtained from the surface of the eyelid skin by use of adhesive tape were evaluated cytologically for the presence of Malassezia spp. Dogs were grouped on the basis of the presence of blepharitis, nature of ocular discharge, and whether ophthalmic medications were applied, and the proportion of samples with Malassezia spp was compared among the groups. Malassezia spp were detected in 19 samples, of which 15 were obtained from eyes without blepharitis and 14 were obtained from eyes treated with topical ophthalmic medications. The proportion of samples with Malassezia spp was significantly higher for eyes with ocular discharge than for eyes without ocular discharge, especially if that discharge was mucoid or mucopurulent, and for eyes that were treated with aqueous-based medications only or a combination of oil- and aqueous-based medications than for eyes that were not treated. Malassezia organisms were detected on the periocular skin of 3 of 56 (5%) clinically normal dogs. Malassezia organisms were also frequently found on the periocular skin of dogs that had mucoid or mucopurulent ocular discharge or that were administered topical aqueous-based ophthalmic medications, and the periocular skin of these dogs should be cytologically evaluated for Malassezia organisms.

  11. Phenotypic and molecular characterization of Malassezia japonica isolated from psoriasis vulgaris patients.

    PubMed

    Honnavar, Prasanna; Chakrabarti, Arunaloke; Dogra, Sunil; Handa, Sanjeev; Rudramurthy, Shivaprakash M

    2015-03-01

    Malassezia species, which are skin colonizers, are being debated as to their pathogenic role in various cutaneous diseases. Species identification of Malassezia is important as particular species have been implicated in or associated with specific diseases. Malassezia japonica, a relatively newly described species, has not been completely characterized owing to the rarity of its isolation. In the present study we describe phenotypic and molecular characterization of six M. japonica strains isolated from patients with psoriasis vulgaris. In contrast to the physiological and biochemical properties of the M. japonica type strain, CBS9348, all our isolates assimilated Tween 20 and showed positive β-glucosidase activity, and the Cremophor EL utilization test was negative. However, the sequences of the D1/D2 region of rDNA, ITS2 and IGS1 regions of all our isolates clustered with the type strain of M. japonica. © 2015 The Authors.

  12. Evidence-based Danish guidelines for the treatment of Malassezia-related skin diseases.

    PubMed

    Hald, Marianne; Arendrup, Maiken C; Svejgaard, Else L; Lindskov, Rune; Foged, Erik K; Saunte, Ditte Marie L

    2015-01-01

    Internationally approved guidelines for the diagnosis and management of Malassezia-related skin diseases are lacking. Therefore, a panel of experts consisting of dermatologists and a microbiologist under the auspices of the Danish Society of Dermatology undertook a data review and compiled guidelines for the diagnostic procedures and management of pityriasis versicolor, seborrhoeic dermatitis and Malassezia folliculitis. Main recommendations in most cases of pityriasis versicolor and seborrhoeic dermatitis include topical treatment which has been shown to be sufficient. As first choice, treatment should be based on topical antifungal medication. A short course of topical corticosteroid or topical calcineurin inhibitors has an anti-inflammatory effect in seborrhoeic dermatitis. Systemic antifungal therapy may be indicated for widespread lesions or lesions refractory to topical treatment. Maintenance therapy is often necessary to prevent relapses. In the treatment of Malassezia folliculitis systemic antifungal treatment is probably more effective than topical treatment but a combination may be favourable.

  13. IgE-mediated sensitization to malassezia in atopic dermatitis: more common in male patients and in head and neck type.

    PubMed

    Brodská, Petra; Panzner, Petr; Pizinger, Karel; Schmid-Grendelmeier, Peter

    2014-01-01

    Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Malassezia, the predominant skin microbiota fungus, is considered to exacerbate AD, especially in a subset of patients with head and neck type AD (HNAD). In the present study, the relationship between AD and sensitization to Malassezia antigens was investigated. We assessed 173 patients with AD. The severity of eczema was determined with Eczema Area and Severity Index (EASI); the type of AD, namely, head and neck type, was reported as well. The total serum IgE and specific IgE to Malassezia were determined and correlated with clinical picture of AD, sex, age, and the EASI. Total IgE was elevated in 77.7% of patients. Specific IgE to Malassezia was positive (≥0.35 kU/L) in 49.1% of patients. Men were significantly more often sensitized to Malassezia antigen (58% of men vs 42% of women; P value, 0.04). Concurrently, 58% of patients with HNAD versus 42% non-HNAD patients had higher levels of specific IgE to Malassezia, this difference being nearly significant (P value, 0.06). Patients with atopy were also more frequently sensitized to Malassezia. No significant relationship between EASI and the level of total IgE or specific IgE to Malassezia was observed. In our population, IgE-mediated sensitization was found in up to 49% of all patients with AD, most common in men and in head and neck type.

  14. Antifungal Activity of Thapsia villosa Essential Oil against Candida, Cryptococcus, Malassezia, Aspergillus and Dermatophyte Species.

    PubMed

    Pinto, Eugénia; Gonçalves, Maria-José; Cavaleiro, Carlos; Salgueiro, Lígia

    2017-09-22

    The composition of the essential oil (EO) of Thapsia villosa (Apiaceae), isolated by hydrodistillation from the plant's aerial parts, was analysed by GC and GC-MS. Antifungal activity of the EO and its main components, limonene (57.5%) and methyleugenol (35.9%), were evaluated against clinically relevant yeasts ( Candida spp., Cryptococcus neoformans and Malassezia furfur ) and moulds ( Aspergillus spp. and dermatophytes). Minimum inhibitory concentrations (MICs) were measured according to the broth macrodilution protocols by Clinical and Laboratory Standards Institute (CLSI). The EO, limonene and methyleugenol displayed low MIC and MFC (minimum fungicidal concentration) values against Candida spp., Cryptococcus neoformans , dermatophytes, and Aspergillus spp. Regarding Candida species, an inhibition of yeast-mycelium transition was demonstrated at sub-inhibitory concentrations of the EO (MIC/128; 0.01 μL/mL) and their major compounds in Candida albicans . Fluconazole does not show this activity, and the combination with low concentrations of EO could associate a supplementary target for the antifungal activity. The association of fluconazole with T. villosa oil does not show antagonism, but the combination limonene/fluconazole displays synergism. The fungistatic and fungicidal activities revealed by T. villosa EO and its main compounds, associated with their low haemolytic activity, confirm their potential antimicrobial interest against fungal species often associated with human mycoses.

  15. In vitro activity of kombucha tea ethyl acetate fraction against Malassezia species isolated from seborrhoeic dermatitis.

    PubMed

    Mahmoudi, E; Saeidi, M; Marashi, M A; Moafi, A; Mahmoodi, V; Zeinolabedini Zamani, M

    2016-12-01

    Seborrheic dermatitis is a chronic and recurrent superficial dermatitis in which Malassezia species play an important role. There are different Malassezia species, which have been recently reported to be resistant to common antifungals. Natural sources can be useful alternatives to reduce the emergence of this resistance. Kombucha tea is believed to have potential antimicrobial properties. Regarding this, the present study aimed to investigate the antifungal activity of Kombucha tea ethyl acetate fraction (KEAF) against Malassezia species obtained from the patients with seborrheic dermatitis. A total of 23 clinical isolates were identified by direct microscopic examination and Tween assimilation, and then confirmed by DNA sequencing of ITS regions for Malassezia species. Kombucha tea was fractionated using ethyl acetate (1:2 v/v). The minimum inhibitory concentration (MIC) microdilution assay was used to evaluate the anti- Malssezia activity of KEAF at three concentrations of 10, 40, and 80 mg/mL. The results of the DNA sequence analysis indicated that M. furfur (39.13%) was the predominant species, followed by M. globosa (30.43%), M. sloofie (13.04%), M. sympodialis (13.04%), and M. restricta (4.34%), respectively. Furthermore, KEAF showed inhibitory activity against Malassezia species. Accordingly, KEAF had the lowest and highest MIC value against M. sloofie and M. restricta , respectively. Moreover, the inhibitory effect of the extract was equivalent to that of ketoconazole at 4.8 µg/mL. The findings of the current study highlighted the antifungal properties of KEAF. Therefore, this extract can be promoted as complementary medicine for the treatment of the infections caused by Malassezia .

  16. Molecular analysis of Malassezia microflora in seborrheic dermatitis patients: comparison with other diseases and healthy subjects.

    PubMed

    Tajima, Mami; Sugita, Takashi; Nishikawa, Akemi; Tsuboi, Ryoji

    2008-02-01

    Malassezia species colonize the skin of normal and various pathological conditions including pityriasis versicolor (PV), seborrhoeic dermatitis (SD) and atopic dermatitis (AD). To elucidate the pathogenic role of Malassezia species in SD, Malassezia microflora of 31 Japanese SD patients was analyzed using a PCR-based, culture-independent method. Nested PCR assay using the primers in the rRNA gene indicated that the major Malassezia species in SD were M. globosa and M. restricta, found in 93 and 74% of the patients, respectively. The detection rate and number of each species varied similarly in SD, PV and healthy subjects (HSs), whereas AD showed higher values. Real-time PCR assay showed that the lesional skin harbored approximately three times the population of genus Malassezia found in nonlesional skin (P<0.05), and that M. restricta is a significantly more common species than M. globosa in SD (P<0.005). Genotypic analysis of the rRNA gene showed that the M. globosa and M. restricta from SD patients fell into specific clusters, and could be distinguished from those collected from HSs, but not from those colleted from AD patients. Our results indicate that certain strains of M. restricta occur in the lesional skin of SD patients.

  17. Dandruff-associated Malassezia genomes reveal convergent and divergent virulence traits shared with plant and human fungal pathogens.

    PubMed

    Xu, Jun; Saunders, Charles W; Hu, Ping; Grant, Raymond A; Boekhout, Teun; Kuramae, Eiko E; Kronstad, James W; Deangelis, Yvonne M; Reeder, Nancy L; Johnstone, Kevin R; Leland, Meredith; Fieno, Angela M; Begley, William M; Sun, Yiping; Lacey, Martin P; Chaudhary, Tanuja; Keough, Thomas; Chu, Lien; Sears, Russell; Yuan, Bo; Dawson, Thomas L

    2007-11-20

    Fungi in the genus Malassezia are ubiquitous skin residents of humans and other warm-blooded animals. Malassezia are involved in disorders including dandruff and seborrheic dermatitis, which together affect >50% of humans. Despite the importance of Malassezia in common skin diseases, remarkably little is known at the molecular level. We describe the genome, secretory proteome, and expression of selected genes of Malassezia globosa. Further, we report a comparative survey of the genome and secretory proteome of Malassezia restricta, a close relative implicated in similar skin disorders. Adaptation to the skin environment and associated pathogenicity may be due to unique metabolic limitations and capabilities. For example, the lipid dependence of M. globosa can be explained by the apparent absence of a fatty acid synthase gene. The inability to synthesize fatty acids may be complemented by the presence of multiple secreted lipases to aid in harvesting host lipids. In addition, an abundance of genes encoding secreted hydrolases (e.g., lipases, phospholipases, aspartyl proteases, and acid sphingomyelinases) was found in the M. globosa genome. In contrast, the phylogenetically closely related plant pathogen Ustilago maydis encodes a different arsenal of extracellular hydrolases with more copies of glycosyl hydrolase genes. M. globosa shares a similar arsenal of extracellular hydrolases with the phylogenetically distant human pathogen, Candida albicans, which occupies a similar niche, indicating the importance of host-specific adaptation. The M. globosa genome sequence also revealed the presence of mating-type genes, providing an indication that Malassezia may be capable of sex.

  18. Differentiation of three biotypes of Malassezia species on human normal skin. correspondence with M. globosa, M. sympodialis and M. restricta.

    PubMed

    Aspiroz, C; Moreno, L A; Rezusta, A; Rubio, C

    1999-01-01

    One hundred and twenty lipid dependent Malassezia spp. isolates were obtained from the clinically normal skin of 38 healthy adult volunteers by swabbing three different body sites (back, chest and scalp). Ninety-six percent of these strains could be grouped into three biotypes on the basis of microscopic, cultural, metabolic and biochemical (catalase, esculin and lipase (C-14)) characteristics. The differential features were simple to determine and easily reproduced. Moreover, the three biotypes were referable to the species M. globosa (biotype 1), M. sympodialis (biotype 2) and M. restricta (biotype 3). Based on their microscopic features, cultural properties and body site locations, we suggest that biotype 1 /M. globosa corresponds to the description of Pityrosporum orbiculare (round yeast cells with a narrow base, very frequently found on the upper trunk), and biotype 3/M. restricta corresponds to the concept of P. ovale (oval yeast cells with a broad budding base, located mainly on the scalp). Pleomorphic biotype 2/M. sympodialis, most frequently found in the back, does not clearly fit into any of the Pityrosporum species.

  19. In vitro activity of kombucha tea ethyl acetate fraction against Malassezia species isolated from seborrhoeic dermatitis

    PubMed Central

    Mahmoudi, E; Saeidi, M; Marashi, MA; Moafi, A; Mahmoodi, V; Zeinolabedini Zamani, M

    2016-01-01

    Background and Purpose: Seborrheic dermatitis is a chronic and recurrent superficial dermatitis in which Malassezia species play an important role. There are different Malassezia species, which have been recently reported to be resistant to common antifungals. Natural sources can be useful alternatives to reduce the emergence of this resistance. Kombucha tea is believed to have potential antimicrobial properties. Regarding this, the present study aimed to investigate the antifungal activity of Kombucha tea ethyl acetate fraction (KEAF) against Malassezia species obtained from the patients with seborrheic dermatitis. Materials and Methods: A total of 23 clinical isolates were identified by direct microscopic examination and Tween assimilation, and then confirmed by DNA sequencing of ITS regions for Malassezia species. Kombucha tea was fractionated using ethyl acetate (1:2 v/v). The minimum inhibitory concentration (MIC) microdilution assay was used to evaluate the anti-Malssezia activity of KEAF at three concentrations of 10, 40, and 80 mg/mL. Results: The results of the DNA sequence analysis indicated that M. furfur (39.13%) was the predominant species, followed by M. globosa (30.43%), M. sloofie (13.04%), M. sympodialis (13.04%), and M. restricta (4.34%), respectively. Furthermore, KEAF showed inhibitory activity against Malassezia species. Accordingly, KEAF had the lowest and highest MIC value against M. sloofie and M. restricta, respectively. Moreover, the inhibitory effect of the extract was equivalent to that of ketoconazole at 4.8 µg/mL. Conclusion: The findings of the current study highlighted the antifungal properties of KEAF. Therefore, this extract can be promoted as complementary medicine for the treatment of the infections caused by Malassezia. PMID:28959793

  20. Dandruff-associated Malassezia genomes reveal convergent and divergent virulence traits shared with plant and human fungal pathogens

    PubMed Central

    Xu, Jun; Saunders, Charles W.; Hu, Ping; Grant, Raymond A.; Boekhout, Teun; Kuramae, Eiko E.; Kronstad, James W.; DeAngelis, Yvonne M.; Reeder, Nancy L.; Johnstone, Kevin R.; Leland, Meredith; Fieno, Angela M.; Begley, William M.; Sun, Yiping; Lacey, Martin P.; Chaudhary, Tanuja; Keough, Thomas; Chu, Lien; Sears, Russell; Yuan, Bo; Dawson, Thomas L.

    2007-01-01

    Fungi in the genus Malassezia are ubiquitous skin residents of humans and other warm-blooded animals. Malassezia are involved in disorders including dandruff and seborrheic dermatitis, which together affect >50% of humans. Despite the importance of Malassezia in common skin diseases, remarkably little is known at the molecular level. We describe the genome, secretory proteome, and expression of selected genes of Malassezia globosa. Further, we report a comparative survey of the genome and secretory proteome of Malassezia restricta, a close relative implicated in similar skin disorders. Adaptation to the skin environment and associated pathogenicity may be due to unique metabolic limitations and capabilities. For example, the lipid dependence of M. globosa can be explained by the apparent absence of a fatty acid synthase gene. The inability to synthesize fatty acids may be complemented by the presence of multiple secreted lipases to aid in harvesting host lipids. In addition, an abundance of genes encoding secreted hydrolases (e.g., lipases, phospholipases, aspartyl proteases, and acid sphingomyelinases) was found in the M. globosa genome. In contrast, the phylogenetically closely related plant pathogen Ustilago maydis encodes a different arsenal of extracellular hydrolases with more copies of glycosyl hydrolase genes. M. globosa shares a similar arsenal of extracellular hydrolases with the phylogenetically distant human pathogen, Candida albicans, which occupies a similar niche, indicating the importance of host-specific adaptation. The M. globosa genome sequence also revealed the presence of mating-type genes, providing an indication that Malassezia may be capable of sex. PMID:18000048

  1. The assessment of epiphytic yeast diversity in sugarcane phyllosphere in Thailand by culture-independent method.

    PubMed

    Nasanit, Rujikan; Tangwong-O-Thai, Apirat; Tantirungkij, Manee; Limtong, Savitree

    2015-12-01

    The diversity of epiphytic yeasts from sugarcane (Saccharum officinarum Linn.) phyllospheres in Thailand was investigated by culture-independent method based on the analysis of the D1/D2 domains of the large subunit rRNA gene sequences. Forty-five samples of sugarcane leaf were collected randomly from ten provinces in Thailand. A total of 1342 clones were obtained from 45 clone libraries. 426 clones (31.7 %) were closely related to yeast strains in the GenBank database, and they were clustered into 31 operational taxonomic units (OTUs) with a similarity threshold of 99 %. All OTU sequences were classified in phylum Basidiomycota which were closely related to 11 yeast species in seven genera including Cryptococcus flavus, Hannaella coprosmaensis, Rhodotorula taiwanensis, Jaminaea angkoreiensis, Malassezia restricta, Pseudozyma antarctica, Pseudozyma aphidis, Pseudozyma hubeiensis, Pseudozyma prolifica, Pseudozyma shanxiensis, and Sporobolomyces vermiculatus. The most predominant yeasts detected belonged to Ustilaginales with 89.4 % relative frequency and the prevalent yeast genus was Pseudozyma. However, the majority were unable to be identified as known yeast species and these sequences may represent the sequences of new yeast taxa. In addition, The OTU that closely related to P. prolifica was commonly detected in sugarcane phyllosphere. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  2. Epidemiological characteristics of Malassezia folliculitis and use of the May-Grünwald-Giemsa stain to diagnose the infection.

    PubMed

    Durdu, Murat; Güran, Mümtaz; Ilkit, Macit

    2013-08-01

    Various bacterial, fungal, parasitic, and viral pathogens can cause folliculitis, which is often mistakenly treated with antibiotics for months or even years. A laboratory diagnosis is required before therapy can be planned. Here, we describe the prevalence and risk factors, as well as the clinical, cytological, and mycological characteristics, of patients with Malassezia folliculitis (MF) in Adana, Turkey. We also report the treatment responses of the MF patients and describe the Malassezia spp. using culture-based molecular methods. Cytological examinations were performed in 264 folliculitis patients, 49 of whom (18.5%) were diagnosed with MF. The positivity of the May-Grünwald-Giemsa (MGG) smear was higher (100%) than that of the potassium hydroxide test (81.6%). Using Wood's light, yellow-green fluorescence was observed in 66.7% of the MF patients. Identification using the rDNA internal transcribed spacer region revealed that Malassezia globosa was the most common species, followed by Malassezia sympodialis, Malassezia restricta, and Malassezia furfur. The MF patients were treated with itraconazole capsules (200 mg/d) for 2 weeks. Complete recovery was observed in 79.6% of the patients. These novel findings help improve our current understanding of the epidemiological characteristics of MF and establish MGG as a practical tool for the diagnosis of MF. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Genotype analyses of human commensal scalp fungi, Malassezia globosa, and Malassezia restricta on the scalps of patients with dandruff and healthy subjects.

    PubMed

    Hiruma, Midori; Cho, Otomi; Hiruma, Masataro; Kurakado, Sanae; Sugita, Takashi; Ikeda, Shigaku

    2014-06-01

    Dandruff and seborrheic dermatitis are common afflictions of the human scalp caused by commensal scalp fungi belonging to the genus Malassezia. Malassezia globosa and Malassezia restricta are the predominant species found on the scalp. The intergenic spacer regions of these species' rRNA genes contain short sequence repeats (SSR): (GT)n and (CT)n in M. globosa and (CT)n and (AT)n in M. restricta. In the present study, we compared the genotypes (SSR) of M. globosa and M. restricta colonizing the scalps of patients with dandruff and healthy individuals. For M. globosa, the genotype (GT)10:(CT)8 (40.3 %, 25/62) was predominant followed by (GT)9:(CT)8 (14.5 %, 9/62) and (GT)11:(CT)8 (14.5 %, 9/62) in patients with dandruff, whereas the genotypes in healthy subjects were diverse. For M. restricta, the genotype (CT)6:(AT)6 (59.7 %, 37/62) was predominant followed by (CT)6:(AT)8 (24.2 %, 15/62) in patients with dandruff, while four genotypes, (CT)6:(AT)6 (10.5 %, 6/57), (CT)6:(AT)7 (22.8 %, 13/57), (CT)6:(AT)8 (17.5 %, 10/57), and (CT)6:(AT)10 (21.1 %, 12/57), accounted for 71.9 % of all combinations in healthy subjects. The results of this study suggest that the M. globosa genotype (GT)10:(CT)8 and the M. restricta genotype (CT)6:(AT)6 may be involved in the development of dandruff.

  4. Polymorphism of Malassezia furfur.

    PubMed

    Salkin, I F; Gordon, M A

    1977-04-01

    Alterations in the morphologic and physiologic characters of 11 isolates of Pityrosporum orbiculare were noted upon prolonged maintenance in pure culture. Successive subculturing of each isolate resulted in its progressive conversion from globose (P. orbiculare) through ovoid to cylindrical (P. ovale) form. Globose forms utilized neither olive oil nor Tween 20 as a sole carbon source, nor KNO3 as a sole source of nitrogen, while ovoid and cylindrical forms utilized both of these carbon sources, and one of four strains of the cylindrical form assimilated KNO3. These results suggest that P. orbiculare and P. ovale are stages in the complex developmental cycle of a single species (Malassezia furfur), but the three names should be preserved until the life cycle is more fully understood.

  5. Amino acid metabolism of Malassezia furfur.

    PubMed

    El-Gothamy, Z

    1981-01-01

    The mechanism responsible for the hypopigmentation which follows pityriasis versicolor (P.V.) infection has not yet been satisfactorily explained. This work was done in order to study the effect of Malassezia furfur on the decomposition or the utilization of the amino acid tyrosine in vitro. No effect could be noted, which points to the assumption that the effect of the causative fungus of P.V. on melanogenesis is most probably due to the blocking of melanine synthesis by one of the product of M. furfur metabolism without using tyrosine.

  6. Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

    NASA Astrophysics Data System (ADS)

    Kyauk, C.; Belisle, M.; Fukami, T.

    2009-12-01

    Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

  7. Evidence-based veterinary dermatology: a systematic review of interventions for Malassezia dermatitis in dogs.

    PubMed

    Negre, Amélie; Bensignor, Emmanuel; Guillot, Jacques

    2009-02-01

    The aim of this systematic review was to evaluate the efficacy of antifungal treatments for Malassezia dermatitis in dogs and, when possible, to propose recommendation for or against their use. Electronic searches were carried out using PubMed MEDLINE(R), CABDirect and CONSULTANT database. The volumes of Advances in Veterinary Dermatology, the proceedings of ESVD/ECVD and AAVD/ACVD congresses were hand-searched for studies relevant to this review. All articles and book chapters discussing treatment of Malassezia dermatitis were scanned for additional citations. Lastly, a request was sent to the Vetderm Listserv to share recent clinical trials. The analysis evaluated study design, methodology quality, subject enrolment quality, type of interventions and outcome measures. The searches identified 35 articles, and 14 trials that fulfilled the following selection criteria: (i) in vivo clinical trials, (ii) dogs showing clinical lesions of Malassezia dermatitis and (iii) enrolment of at least five dogs. Among these, only eight studies fulfilled the following additional criterion: (iv) prospective in vivo clinical trials reporting clinical and mycological outcome measures. A total number of 14 different treatment protocols included four blinded, randomized and controlled trials (quality of evidence grade A), four controlled studies lacking blinding and/or randomization (grade B), five open uncontrolled trials (grade C) and one descriptive study (grade D). This systematic review allowed us to recommend, with good evidence, the use of only one topical treatment of Malassezia dermatitis (2% miconazole nitrate +2% chlorhexidine, twice a week for 3 weeks) and with fair evidence the use of two systemic treatments with azole derivatives (ketoconazole, 10 mg kg(-1) day(-1) and itraconazole, 5 mg kg(-1) day(-1) for 3 weeks).

  8. Survey of Malassezia sp and dermatophytes in the cutaneous microbiome of free-ranging golden-headed lion tamarins (Leontopithecus chrysomelas - Kuhl, 1820).

    PubMed

    Neves, Juan Ja; Francelino, Marcelo; Silva, Flavia Gl; Baptista, Luana Cl; Bueno, Marina G; Catão-Dias, José L; Molina, Camila; Kierulff, Maria Cm; Pissinatti, Alcides; Coutinho, Selene DA

    2017-06-01

    Data about the presence of fungi on the cutaneous surface of wild animals are scarce. The aim of this study was to survey dermatophytes and Malassezia sp in the external ear canal and haircoat of Leontopithecus chrysomelas. A total of 928 clinical samples were collected from 232 animals: For Malassezia screening 696 samples were studied, 464 of cerumen and 232 of haircoat; another 232 haircoat samples were studied for dermatophyte analysis. A geophilic dermatophyte, Microsporum cookie, was isolated from one young female. Lipodependent Malassezia was isolated from 76 animals and 87 clinical samples, 26 from the cerumen and 61 from the haircoat (statistically significant); there were no differences related to gender and age. Results suggested that lipodependent Malassezia is part of the skin microbiome of these animals. The prevalence of dermatophytes was too low and probably not relevant for the health of the studied population. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Zinc Pyrithione Inhibits Yeast Growth through Copper Influx and Inactivation of Iron-Sulfur Proteins▿†

    PubMed Central

    Reeder, Nancy L.; Kaplan, Jerry; Xu, Jun; Youngquist, R. Scott; Wallace, Jared; Hu, Ping; Juhlin, Kenton D.; Schwartz, James R.; Grant, Raymond A.; Fieno, Angela; Nemeth, Suzanne; Reichling, Tim; Tiesman, Jay P.; Mills, Tim; Steinke, Mark; Wang, Shuo L.; Saunders, Charles W.

    2011-01-01

    Zinc pyrithione (ZPT) is an antimicrobial material with widespread use in antidandruff shampoos and antifouling paints. Despite decades of commercial use, there is little understanding of its antimicrobial mechanism of action. We used a combination of genome-wide approaches (yeast deletion mutants and microarrays) and traditional methods (gene constructs and atomic emission) to characterize the activity of ZPT against a model yeast, Saccharomyces cerevisiae. ZPT acts through an increase in cellular copper levels that leads to loss of activity of iron-sulfur cluster-containing proteins. ZPT was also found to mediate growth inhibition through an increase in copper in the scalp fungus Malassezia globosa. A model is presented in which pyrithione acts as a copper ionophore, enabling copper to enter cells and distribute across intracellular membranes. This is the first report of a metal-ligand complex that inhibits fungal growth by increasing the cellular level of a different metal. PMID:21947398

  10. An Analysis of the Malassezia Species Distribution in the Skin of Patients with Pityriasis Versicolor in Chengdu, China

    PubMed Central

    Xie, Zhen; Ran, Yuping; Zhang, Hao; Zhang, Min; Wan, Huiying; Li, Conghui

    2014-01-01

    Pityriasis versicolor (PV) is a common clinical problem associated with Malassezia species (Malassezia spp.). Controversies remain regarding the specific species involved in the development of PV. This study analyzed the difference in Malassezia spp. distribution in lesional and nonlesional skin in Chinese PV patients. A paired design was applied. Lesional and nonlesional scales from 24 cases were collected; real-time fluorescence quantitative PCR was used to detect 10 different Malassezia spp. In lesional skin, the highest detection rates were for M. globosa (95.8%), M. restricta (91.7%), and M. sympodialis (50.0%). In nonlesional skin, the highest detection rates were for M. globosa (87.5%), M. restricta (79.2%), and M. dermatis (33.3%). A significant difference in the detection rate was only found for M. sympodialis (50.8% versus 20.8%, P = 0.04). Compared with nonlesional skin, the amount of M. globosa, M. restricta, and M. sympodialis in lesional skin was significantly higher (3.8 ± 1.3,  2.5 ± 1.1, and 3.2 ± 1.6 times higher, resp.). The results of this study do not indicate that M. globosa and M. restricta are directly correlated with PV development; however, M. sympodialis is more likely related to PV development in Chinese individuals. PMID:25177714

  11. An analysis of the Malassezia species distribution in the skin of patients with pityriasis versicolor in Chengdu, China.

    PubMed

    Xie, Zhen; Ran, Yuping; Zhang, Hao; Zhang, Min; Wan, Huiying; Li, Conghui

    2014-01-01

    Pityriasis versicolor (PV) is a common clinical problem associated with Malassezia species (Malassezia spp.). Controversies remain regarding the specific species involved in the development of PV. This study analyzed the difference in Malassezia spp. distribution in lesional and nonlesional skin in Chinese PV patients. A paired design was applied. Lesional and nonlesional scales from 24 cases were collected; real-time fluorescence quantitative PCR was used to detect 10 different Malassezia spp. In lesional skin, the highest detection rates were for M. globosa (95.8%), M. restricta (91.7%), and M. sympodialis (50.0%). In nonlesional skin, the highest detection rates were for M. globosa (87.5%), M. restricta (79.2%), and M. dermatis (33.3%). A significant difference in the detection rate was only found for M. sympodialis (50.8% versus 20.8%, P = 0.04). Compared with nonlesional skin, the amount of M. globosa, M. restricta, and M. sympodialis in lesional skin was significantly higher (3.8 ± 1.3,  2.5 ± 1.1, and 3.2 ± 1.6 times higher, resp.). The results of this study do not indicate that M. globosa and M. restricta are directly correlated with PV development; however, M. sympodialis is more likely related to PV development in Chinese individuals.

  12. In vitro activity of two amphotericin B formulations against Malassezia furfur strains recovered from patients with bloodstream infections.

    PubMed

    Iatta, Roberta; Immediato, Davide; Montagna, Maria Teresa; Otranto, Domenico; Cafarchia, Claudia

    2015-04-01

    Although guidelines for the treatment of Malassezia furfur fungemia are not yet defined, clinical data suggest that amphotericin B (AmB) is effective for treating systemic infections. In the absence of clinical breakpoints for Malassezia yeasts, epidemiological cut-off values (ECVs) are useful to discriminate between isolates with and without drug resistance. This study aimed to compare the distribution of minimal inhibitory concentration (MIC) and the ECVs for AmB of both deoxycholate (d-AmB) and liposomal (l-AmB) formulations of M. furfur isolates. The 84 M. furfur strains analyzed, which included 56 from blood, sterile sites and catheters, and 28 from skin, were isolated from patients with bloodstream infections. MICs were determined by the modified broth microdilution method of the Clinical and Laboratory Standards Institute (CLSI). The l-AmB MIC and the ECVs were two-fold lower than those of d-AmB and a lower l-AmB mean MIC value was found for blood isolates than from skin. The ECVs for l-AmB and d-AmB were 8 mg/l and 32 mg/l, respectively. Three strains (3.6%) showed l-AmB MIC higher than ECV (MIC > 8 mg/l) of which two were isolated from the catheter tip of patients treated with micafugin, l-Amb and fluconazole, and one from skin. The results showed that the l-AmB might be employed for assessing the in vitro antifungal susceptibility of M. furfur by a modified CLSI protocol and that ECVs might be useful for detecting the emergence of resistance. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Evaluation of Expression of Lipases and Phospholipases of Malassezia restricta in Patients with Seborrheic Dermatitis

    PubMed Central

    Lee, Yang Won; Lee, Shin Yung; Lee, Younghoon

    2013-01-01

    Background Malassezia species (spp.) are cutaneous opportunistic pathogens and associated with various dermatological diseases including seborrheic dermatitis, dandruff and atopic dermatitis. Almost all Malassezia spp. are obligatorily lipid-dependent, which might be caused by lack of the myristic acid synthesis. Recent genome analysis of M. restricta and M. globosa suggested that the absence of a gene encoding fatty acid synthesis might be compensated by abundant genes encoding hydrolases, which produce fatty acids, and that lipases and phospholipases may play a role in virulence of the fungus. Objective The current study aimed to investigate the contribution of lipases and phospholipases in virulence of the M. restricta as being the most frequently isolated Malassezia spp. from the human skin. Methods Swap samples of two different body sites of at least 18 patients with seborrheic dermatitis were obtained and in vivo expression of lipases and phospholipases of M. restricta was analyzed by the gene specific two-step nested RT-PCR. Results The results of the current study suggest that majority of the patients display expression of lipase RES_0242. Conclusion These data imply a possible role of lipase in the host environment to produce free fatty acids for the fungus. PMID:24003273

  14. Evaluation of Expression of Lipases and Phospholipases of Malassezia restricta in Patients with Seborrheic Dermatitis.

    PubMed

    Lee, Yang Won; Lee, Shin Yung; Lee, Younghoon; Jung, Won Hee

    2013-08-01

    Malassezia species (spp.) are cutaneous opportunistic pathogens and associated with various dermatological diseases including seborrheic dermatitis, dandruff and atopic dermatitis. Almost all Malassezia spp. are obligatorily lipid-dependent, which might be caused by lack of the myristic acid synthesis. Recent genome analysis of M. restricta and M. globosa suggested that the absence of a gene encoding fatty acid synthesis might be compensated by abundant genes encoding hydrolases, which produce fatty acids, and that lipases and phospholipases may play a role in virulence of the fungus. The current study aimed to investigate the contribution of lipases and phospholipases in virulence of the M. restricta as being the most frequently isolated Malassezia spp. from the human skin. Swap samples of two different body sites of at least 18 patients with seborrheic dermatitis were obtained and in vivo expression of lipases and phospholipases of M. restricta was analyzed by the gene specific two-step nested RT-PCR. The results of the current study suggest that majority of the patients display expression of lipase RES_0242. These data imply a possible role of lipase in the host environment to produce free fatty acids for the fungus.

  15. Presence and distribution of yeasts in the reproductive tract in healthy female horses.

    PubMed

    Azarvandi, A; Khosravi, A R; Shokri, H; Talebkhan Garoussi, M; Gharahgouzlou, F; Vahedi, G; Sharifzadeh, A

    2017-09-01

    Yeasts are commensal organisms found in the reproductive and gastrointestinal tracts, and on the skin and other mucosa in mammals. The purpose of this study was to isolate and identify yeast flora in the caudal reproductive tract in healthy female horses. Longitudinal study. A total of 453 samples were collected using double-guarded swabs from the vestibule, clitoral fossa and vagina in 151 horses. All samples were cultured on Sabouraud 4% dextrose agar and incubated at 35°C for 7-10 days. Isolates were identified according to their morphological characteristics and biochemical profiles. Yeast colonies were isolated from 60 (39.7%) of the 151 horses. The isolated yeasts belonged to nine genera, and included Candida spp. (53.2%), Cryptococcus spp. (12.2%), Saccharomyces spp. (10.5%), Geotrichum spp. (8.0%), Rhodotorula spp. (7.1%), Malassezia spp. (3.7%), Trichosporon spp. (2.6%), Kluyveromyces spp. (2.6%) and Sporothrix spp. (0.2%). Candida krusei (43.1%) was the most frequent Candida species isolated. There was a significant difference in prevalence between C. krusei and other Candida species (P<0.05). The vestibule contained more yeast isolates (48.0%) than the vagina (18.3%). The isolation of yeast colonies from multiparous females (76.8%) was significantly higher than from maiden mares (P<0.05). The study was limited by the difficulty of distinguishing between normal flora and potential pathogens. Candida spp., in particular C. krusei, represent important flora resident in the caudal reproductive tract in healthy female horses. This is particularly important in contexts that require the initiation of empirical treatment prior to the completion of culture results. © 2016 EVJ Ltd.

  16. Exploration of anti-Malassezia potential of Nyctanthes arbor-tristis L. and their application to combat the infection caused by Mala s1 a novel allergen.

    PubMed

    Mishra, Rohit K; Mishra, Vani; Pandey, Anand; Tiwari, Amit K; Pandey, Himanshu; Sharma, Shivesh; Pandey, Avinash C; Dikshit, Anupam

    2016-03-31

    Malassezia commensal yeasts along with multitude of antigens have been found to be associated with various skin disorders including Pityriasis versicolor (PV). Amongst them Mala s1, a 37 kDa protein has been proved to be a major allergen reacting with a large panel of sera. However, there exists no therapeutic alternative to combat such problems in form of plant based natural compounds. The purpose of this study is in the first place, to determine the anti-Malassezia activity of Nyctanthes arbor-tristis L. (NAT) ethanolic leaf extract through turbidimetric growth curves, disruption of plasma membrane and secondly, it aims to present in silico validation of its active constituents over Mala s1a novel allergen. The antifungal susceptibility 50 % ethanolic extract of NAT was determined by broth microdilution method according to CLSI guidelines. Further MICs and IC50 were determined spectrophotometrically using the software SoftMax® Pro-5 (Molecular Devices, USA). Active constituents mediated disruption of plasma membrane was studied through flowcytometry by permeabilization of fluorescent dye Propidium Iodide (PI). Antioxidant activity of the extract was determined using the DPPH stable radical. Molecular validation of fungal DNA from the extract was observed using PCR amplification. In silico analysis of its active constituents over Mala s1 was performed using HEX software and visualized through Pymol. The anti-Malassezia potential of NAT leaf extracts reflected moderate MIC 1.05 μg/μl against M. globosa, while least effective against M. restricta with MIC 1.47 μg/μl. A linear correlation coefficient R (2) = 0.866 was obtained in case of M. globosa while minimum was observed in M. restricta with R (2) = 0.732. The flow cytometric data reveal ~ 75 % cell death when treated with active constituents β-Sitosterol and Calceolarioside A. The docking confirmations and the interaction energies between Mala s1 and the active constituents (β-Sitosterol and

  17. Comparative in vitro efficacy of antimicrobial shampoos: a pilot study.

    PubMed

    Young, Rebecca; Buckley, Laura; McEwan, Neil; Nuttall, Tim

    2012-02-01

    This study compared the antimicrobial efficacy of shampoos against meticillin-sensitive Staphylococcus pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP), antibiotic-sensitive Pseudomonas aeruginosa (PA), multidrug-resistant P. aeruginosa (MDR-PA) and Malassezia pachydermatis. Three isolates were incubated for 10, 30 and 60 min with each shampoo diluted in phosphate-buffered saline. Aliquots were then incubated for 16-18 h on sheep blood agar (bacteria) or for 3 days on Sabouraud's dextrose agar (Malassezia). The minimal bactericidal concentrations (MBCs) for chlorhexidine products (Malaseb(®), Pyoderm(®)/Microbex(®) and Hibiscrub(®)) were 1:1,024-1:2,048 for MSSP and MRSP, 1:512-1:1,024 for PA and MDR-PA, and 1:2,048-1:5,096 for Malassezia at all time points. The MBCs for benzoyl peroxide (Paxcutol(®)) for MSSP and MRSP were 1:2-1:8 at 10 min, and 1:256 after 30 and 60 min. A 1:2 dilution was effective against Pseudomonas, and 1:512-1:1,024 dilutions were effective against Malassezia at all time points. The MBCs for ethyl lactate (Etiderm(®)) for MSSP and MRSP were 1:2 at 10 min, and 1:2-1:16 after 30 and 60 min. A 1:2 dilution was effective against Pseudomonas, and a 1:512 dilution was effective against Malassezia at all time points. Chloroxylenol (Coatex(®)) and acetic acid-boric acid (Malacetic(®)) were not effective against MSSP, MRSP or Pseudomonas. Both were effective against Malassezia at 1:8-1:16 dilution at 10 min, and at 1:8-1:32 dilution after 30 and 60 min. In conclusion, chlorhexidine appeared to be the most effective topical biocide, and MRSP and MDR-PA were no less susceptible than antibiotic-sensitive organisms. These results should, however, be confirmed with larger numbers of isolates. © 2011 The Authors. Veterinary Dermatology. © 2011 ESVD and ACVD.

  18. Differences in fungi present in induced sputum samples from asthma patients and non-atopic controls: a community based case control study

    PubMed Central

    2013-01-01

    Background There is emerging evidence for the presence of an extensive microbiota in human lungs. It is not known whether variations in the prevalence of species of microbiota in the lungs may have aetiological significance in respiratory conditions such as asthma. The aim of the study was to undertake semi-quantitative analysis of the differences in fungal species in pooled sputum samples from asthma patients and controls. Methods Induced sputum samples were collected in a case control study of asthma patients and control subjects drawn from the community in Wandsworth, London. Samples from both groups were pooled and then tested for eukaryotes. DNA was amplified using standard PCR techniques, followed by pyrosequencing and comparison of reads to databases of known sequences to determine in a semi-quantitative way the percentage of DNA from known species in each of the two pooled samples. Results A total of 136 fungal species were identified in the induced sputum samples, with 90 species more common in asthma patients and 46 species more common in control subjects. Psathyrella candolleana, Malassezia pachydermatis, Termitomyces clypeatus and Grifola sordulenta showed a higher percentage of reads in the sputum of asthma patients and Eremothecium sinecaudum, Systenostrema alba, Cladosporium cladosporioides and Vanderwaltozyma polyspora showed a higher percentage of reads in the sputum of control subjects. A statistically significant difference in the pattern of fungi that were present in the respective samples was demonstrated using the Phylogenetic (P) test (P < 0.0001). Conclusion This study is novel in providing evidence for the widespread nature of fungi in the sputum of healthy and asthmatic individuals. Differences in the pattern of fungi present in asthma patients and controls merit further investigation. Of particular interest was the presence of Malassezia pachydermatis, which is known to be associated with atopic dermatitis. PMID:23384395

  19. Differences in fungi present in induced sputum samples from asthma patients and non-atopic controls: a community based case control study.

    PubMed

    van Woerden, Hugo Cornelis; Gregory, Clive; Brown, Richard; Marchesi, Julian Roberto; Hoogendoorn, Bastiaan; Matthews, Ian Price

    2013-02-05

    There is emerging evidence for the presence of an extensive microbiota in human lungs. It is not known whether variations in the prevalence of species of microbiota in the lungs may have aetiological significance in respiratory conditions such as asthma. The aim of the study was to undertake semi-quantitative analysis of the differences in fungal species in pooled sputum samples from asthma patients and controls. Induced sputum samples were collected in a case control study of asthma patients and control subjects drawn from the community in Wandsworth, London. Samples from both groups were pooled and then tested for eukaryotes. DNA was amplified using standard PCR techniques, followed by pyrosequencing and comparison of reads to databases of known sequences to determine in a semi-quantitative way the percentage of DNA from known species in each of the two pooled samples. A total of 136 fungal species were identified in the induced sputum samples, with 90 species more common in asthma patients and 46 species more common in control subjects. Psathyrella candolleana, Malassezia pachydermatis, Termitomyces clypeatus and Grifola sordulenta showed a higher percentage of reads in the sputum of asthma patients and Eremothecium sinecaudum, Systenostrema alba, Cladosporium cladosporioides and Vanderwaltozyma polyspora showed a higher percentage of reads in the sputum of control subjects. A statistically significant difference in the pattern of fungi that were present in the respective samples was demonstrated using the Phylogenetic (P) test (P < 0.0001). This study is novel in providing evidence for the widespread nature of fungi in the sputum of healthy and asthmatic individuals. Differences in the pattern of fungi present in asthma patients and controls merit further investigation. Of particular interest was the presence of Malassezia pachydermatis, which is known to be associated with atopic dermatitis.

  20. Treatment of Malassezia species associated seborrheic blepharitis with fluconazole.

    PubMed

    Zisova, Lilia G

    2009-01-01

    The AIM of the present study was to evaluate the therapeutic effect of fluconazole (FungoIon) in patients with seborrheic blepharitis. Four seborrheic blepharitis patients with Malassezia spp. positive cultures on Dixon's agar were treated with fluconazole (Fungolon) (0.200) weekly for 4 weeks. The therapeutic effect of the treatment was positive in all patients--the clinical symptoms withdrew and cultures became mycologically negative. The results indicate that antifungal agents are efficient in the treatment of seborrheic dermatitis.

  1. [In vitro antifungal activity of azoles and amphotericin B against Malassezia furfur by the CLSI M27-A3 microdilution and Etest® methods].

    PubMed

    Galvis-Marín, Juan Camilo; Rodríguez-Bocanegra, María Ximena; Pulido-Villamarín, Adriana Del Pilar; Castañeda-Salazar, Rubiela; Celis-Ramírez, Adriana Marcela; Linares-Linares, Melva Yomary

    Malassezia furfur is a human skin commensal yeast that can cause skin and opportunistic systemic infections. Given its lipid dependant status, the reference methods established by the Clinical and Laboratory Standards Institute (CLSI) to evaluate antifungal susceptibility in yeasts are not applicable. To evaluate the in vitro susceptibility of M. furfur isolates from infections in humans to antifungals of clinical use. The susceptibility profile to amphotericin B, itraconazole, ketoconazole and voriconazole of 20 isolates of M. furfur, using the broth microdilution method (CLSI M27-A3) and Etest ® , was evaluated. Itraconazole and voriconazole had the highest antifungal activity against the isolates tested. The essential agreement between the two methods for azoles antifungal activity was in the region of 60-85% and the categorical agreement was around 70-80%, while the essential and categorical agreement for amphotericin B was 10%. The azoles were the compounds that showed the highest antifungal activity against M. furfur, as determined by the two techniques used; however more studies need to be performed to support that Etest ® is a reliable method before its implementation as a routine clinical laboratory test. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Precipitation of free fatty acids generated by Malassezia - a possible explanation for the positive effects of lithium succinate in seborrhoeic dermatitis.

    PubMed

    Mayser, P; Schulz, S

    2016-08-01

    Lithium succinate and gluconate are effective alternative options licensed for the topical treatment of seborrhoeic dermatitis (SD). Their mode of action is not fully elucidated. Minimal inhibitory concentrations against Malassezia (M.) yeasts, which play an important role in SD, are very high. An assay based on the hydrolysis of ethyl octanoate enables us to test the hydrolytic activity of reference strains of the species M. globosa, M. sympodialis and M. furfur solely without interference by fungal growth as the free octanoic acid generated has antifungal activity. In this assay the presence of alkali salts (lithium, sodium and potassium succinate resp.) in concentrations of 2%, 4% and 8% does not influence hydrolytic activity but the availability of the generated free fatty acid in a dose-dependent manner which was analysed by means of high-performance thin layer chromatography and densitometry. This was best effected with the lithium, followed by the sodium and only to a low degree by the potassium salt. As shown by attenuated total reflection Fourier transform infrared spectroscopy the free fatty acid reacted to the respective alkali soap and precipitate from solution. The alkali soaps could not be utilized by the M. spp. as shown in a modified Tween auxanogram and in lack of fungal growth by ethyl oleate in the presence of 8% lithium succinate. The effect of lithium succinate on growth of M. yeasts and presumably in SD can be explained by a precipitation of free fatty acids as alkali soaps limiting their availability for the growth of these lipid-dependent yeasts. © 2016 European Academy of Dermatology and Venereology.

  3. Novel inhibitor against Malassezia globosa LIP1 (SMG1), a potential anti-dandruff target.

    PubMed

    Guo, Shaohua; Huang, Wenkang; Zhang, Jian; Wang, Yonghua

    2015-09-01

    Compelling evidence have demonstrated the role of lipase activity in the pathogenicity of Malassezia globosa toward dandruff and seborrheic dermatitis (D/SD). As a representative secreted lipase from M. globosa CBS 7966, Malassezia globosa LIP1 (SMG1) is considered a potential anti-dandruff target. In this study, homology modeling, docking-based virtual screening and in vitro lipase-based assay were integrated to identify the first hit compound against SMG1, with an IC50 of 20 μM against synthetic lipase substrate, and of 0.19 μM when using natural lipase substrate. Evaluation of similar compounds, along with docking, offered information on the binding patterns of the hit compound. This work is expected to serve as a starting point for the rational design of more potent inhibitors against SMG1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. [Pityriasis versicolor in Santo Domingo, Dominican Republic. In vivo morphological data of Malasezzia spp. in 100 cases].

    PubMed

    Arenas, R; Isa-Isa, R; Cruz, A C

    2001-03-01

    Pityriasis versicolor is caused by Malassezia spp. It is a common world wide mycosis. Seven species are known of the Malassezia genus, and are identified in vitro by their morphological characteristics, biochemical tests and by molecular biology. to determine clinical and epidemiological data of pityriasis versicolor as well as morphological aspects of Malassezia in vivo. we performed a direct examination of the scales and classified the microscopic mycological elements as oval and orbicular spores, short and long hyphae. pityriasis versicolor mainly affected the thorax. Orbiculare yeasts and short hyphae frequently present. We could corroborate the wide morphological range of Malassezia spp. The morphological study of Malassezia spp. in vivo is not sufficient to determine the distribution of the various species.

  5. Functional expression and characterization of CYP51 from dandruff-causing Malassezia globosa.

    PubMed

    Kim, Donghak; Lim, Young-Ran; Ohk, Seul Ong; Kim, Beom Joon; Chun, Young-Jin

    2011-02-01

    Malassezia globosa is one of the most common yeasts to cause various human skin diseases including dandruff and seborrheic dermatitis. Genomic analysis of M. globosa revealed four putative cytochrome P450 (CYP) enzymes. Here, we report the purification and characterization of recombinant CYP51, a putative lanosterol 14α-demethylase, from M. globosa. The M. globosa CYP51 was expressed heterologously in Escherichia coli, followed by purification. Purified CYP51 showed a typical reduced CO-difference spectrum of P450, with a maximum absorption at 447 nm. Purified CYP51 exhibited tight binding to azole antifungal agents such as ketoconazole, econazole, fluconazole, or itraconazole, with K(d) values around 0.26-0.84 μM, which suggests that CYP51 is an orthologous target for antifungal agents in the M. globosa. In addition, three mutations (Y127F, A169S, and K176N) in the amino acid sequence of M. globosa CYP51 were identified in one of the azole-resistant strains. Homology modeling of M. globosa CYP51 suggested that the Y127F mutation may influence the resistance to azoles by blocking substrate access channels. Taken together, functional expression and characterization of the CYP51 enzyme can provide a fundamental basis for a specific antifungal drug design for dandruff caused by M. globosa. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  6. Fungal Skin Infections

    MedlinePlus

    ... Skin Infections Overview of Fungal Skin Infections Candidiasis (Yeast Infection) Dermatophytid Reaction Intertrigo Tinea Versicolor Overview of ... breasts. Common fungal skin infections are caused by yeasts (such as Candida or Malassezia furfur ) or dermatophytes , ...

  7. Characterisation and Expression Analysis of MrLip1, a Class 3 Family Lipase of Malassezia restricta.

    PubMed

    Park, Minji; Jung, Won Hee; Han, Song Hee; Lee, Young Hoon; Lee, Yang Won

    2015-11-01

    The genus Malassezia is associated with a wide range of skin diseases and is the predominant fungal genus isolated from human skin. Of the 14 Malassezia species identified, M. restricta is the most abundant fungal species found from both healthy and diseased skin. Emerging evidences have suggested that extracellular lipases of Malassezia play a critical role in its survival on the host skin surface. This study aimed to characterise the lipase 1 homologue (MrLip1) in M. restricta and to analyse its expression under different environmental conditions. The full sequence of the gene encoding MrLip1 was determined by rapid amplification of cDNA ends, and it was then heterologously expressed in Pichia pastoris. MrLip1 protein was successfully purified and used for lipase assay and specific antibody generation for use in expression analysis. The optimum pH and temperature for the activity of purified MrLip1 were pH 5.0 and 34 °C respectively. Furthermore, the expression of MrLip1 peaked at a similar pH and temperature, suggesting that the optimal conditions for MrLip1 protein activity and expression are similar to that found on the human skin surface. This study provides data to improve our understanding of the role and characteristics of lipase 1 in M. restricta. © 2015 Blackwell Verlag GmbH.

  8. Screening of plant extracts for antimicrobial activity against bacteria and yeasts with dermatological relevance.

    PubMed

    Weckesser, S; Engel, K; Simon-Haarhaus, B; Wittmer, A; Pelz, K; Schempp, C M

    2007-08-01

    There is cumulative resistance against antibiotics of many bacteria. Therefore, the development of new antiseptics and antimicrobial agents for the treatment of skin infections is of increasing interest. We have screened six plant extracts and isolated compounds for antimicrobial effects on bacteria and yeasts with dermatological relevance. The following plant extracts have been tested: Gentiana lutea, Harpagophytum procumbens, Boswellia serrata (dry extracts), Usnea barbata, Rosmarinus officinalis and Salvia officinalis (supercritical carbon dioxide [CO2] extracts). Additionally, the following characteristic plant substances were tested: usnic acid, carnosol, carnosic acid, ursolic acid, oleanolic acid, harpagoside, boswellic acid and gentiopicroside. The extracts and compounds were tested against 29 aerobic and anaerobic bacteria and yeasts in the agar dilution test. U. barbata-extract and usnic acid were the most active compounds, especially in anaerobic bacteria. Usnea CO2-extract effectively inhibited the growth of several Gram-positive bacteria like Staphylococcus aureus (including methicillin-resistant strains - MRSA), Propionibacterium acnes and Corynebacterium species. Growth of the dimorphic yeast Malassezia furfur was also inhibited by Usnea-extract. Besides the Usnea-extract, Rosmarinus-, Salvia-, Boswellia- and Harpagophytum-extracts proved to be effective against a panel of bacteria. It is concluded that due to their antimicrobial effects some of the plant extracts may be used for the topical treatment of skin disorders like acne vulgaris and seborrhoic eczema.

  9. Ciclopirox 1% shampoo for the treatment of seborrheic dermatitis.

    PubMed

    Gupta, Aditya K; Nicol, Karyn A

    2006-01-01

    Seborrheic dermatitis is a chronic superficial fungal infection of the skin, particularly affecting sites rich in sebaceous glands. Although the precise etiology of seborrheic dermatitis is uncertain, yeasts of the genus Malassezia are known to play a causative role. Ciclopirox is a broad-spectrum, hydroxypyridone-derived, synthetic antifungal agent, which also has anti-inflammatory properties. Ciclopirox is effective both in vitro and in vivo against Malassezia yeasts, making it a valuable option for the treatment of seborrheic dermatitis. Varying frequencies and concentrations of ciclopirox shampoo have been shown to be effective and safe in the treatment of seborrheic dermatitis of the scalp.

  10. Efficacy of an ethanol/guar/triclosan/glycerine gel on bacteria and yeast loads in canine pododermatitis: a pilot study.

    PubMed

    Ortalda, C; Noli, C; Cena, T

    2016-04-01

    To assess efficacy of a gel compound containing guar, glycerine, triclosan and ethanol (Pawcare®, JOKER Technologies, Kerzers, Switzerland) in decreasing bacterial and yeast loads on the paws of dogs with erythematous, greasy and/or malodorous pododermatitis. In 20 dogs, each with at least two affected paws, semiquantitative Malassezia species counts were performed on 10 oil-immersion fields (range: 0 to 30) from acetate tapes pressed on the palmar/plantar surface of one paw. Half of the area was sampled before and the other half immediately after the application of Pawcare(®) . With a similar procedure, swab samples were collected from the other paw for bacterial culture, identification and evaluation of colony-forming units before and immediately after treatment. Statistical evaluation of pre- and posttreatment counts was performed with the Wilcoxon signed-rank test. Nine dogs were positive for Malassezia species Mean acetate tape preparation counts decreased significantly from 8·78 (±8·03) to 5·668 (±6·65) (P=0·0039) after treatment. Twenty-five bacterial isolates of 11 different species were cultured in 19 dogs. Posttreatment cultures were sterile in 8 dogs that had an initial zero or low number (1 to 2 log counts) of colony-forming units. In cases with a higher pre-treatment number of colony forming units (2 to 6 log counts), there was a significant decrease - by a mean of 1·16 log counts (pre 3·12 ±1·69, post 1·96 ±1·57) (P=0·0002). The findings of the present study support the use of PawCare® gel to decrease bacterial and yeast loads in dogs affected by chronic diseases involving the inter-digital spaces. © 2016 British Small Animal Veterinary Association.

  11. Rare opportunistic (non-Candida, non-Cryptococcus) Yeast Bloodstream Infections in Patients with Cancer

    PubMed Central

    Chitasombat, Maria N.; Kofteridis, Diamantis P.; Jiang, Ying; Tarrand, Jeffrey; Lewis, Russell E.; Kontoyiannis, Dimitrios P.

    2013-01-01

    Background Rare opportunistic (non-Candida, non-Cryptococcus) yeast bloodstream infections (ROYBSIs) are rare, even in cancer patients. Methods We retrospectively reviewed all episodes of ROYBSIs occurring from 1998 to 2010 in our cancer center. Results Of 2984 blood cultures positive for Candida and non-Candida yeasts, 94 (3.1%) were positive for non-Candida yeasts, representing 41 ROYBSIs (incidence, 2.1 cases/100,000 patient-days). Catheter-associated fungemia occurred in 21 (51%) patients. Breakthrough ROYBSIs occurred in 20 (49%) patients. The yeast species distribution was Rhodotorula in 21 (51%) patients, Trichosporon in 8 (20%) patients, Saccharomyces cerevisiae in 8 (20%) patients, Geotrichum in 2 (5%) patients, Pichia anomala, and Malassezia furfur in 1 patient each. All tested Trichosporon, Geotrichum, and Pichia isolates were azole-susceptible, whereas the Rhodotorula isolates were mostly azole-resistant. We noted echinocandin nonsusceptibility (minimal inhibitory concentration ≥ 2 mg/L) in all but the S. cerevisiae isolates. Most of the isolates (28/33 [85%]) were susceptible to amphotericin B. The mortality rate in all patients at 30 days after ROYBSIs diagnosis was 34%. Multivariate survival analysis revealed increased risk of death in patients with S. cerevisiae infections (hazard ratio, 3.7), Geotrichum infections (hazard ratio, 111.3), or disseminated infections (hazard ratio, 33.4) and reduced risk in patients who had catheter removal (hazard ratio, 0.1). Conclusions ROYBSIs are uncommon in patients with cancer, and catheters are common sources of them. Half of the ROYBSIs occurred as breakthrough infections, and in vitro species-specific resistance to echinocandins and azoles was common. Disseminated infections resulted in the high mortality rate. PMID:22101079

  12. Superficial fungal infections.

    PubMed

    Schwartz, Robert A

    Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of infection will be covered: tinea versicolor, piedra, and tinea nigra. Tinea versicolor is common worldwide and is caused by Malassezia spp, which are human saprophytes that sometimes switch from yeast to pathogenic mycelial form. Malassezia furfur, Malassezia globosa, and Malassezia sympodialis are most closely linked to tinea versicolor. White and black piedra are both common in tropical regions of the world; white piedra is also endemic in temperate climates. Black piedra is caused by Piedraia hortae; white piedra is due to pathogenic species of the Trichosporon genus. Tinea nigra is also common in tropical areas and has been confused with melanoma.

  13. Utility of Gram staining for diagnosis of Malassezia folliculitis.

    PubMed

    Tu, Wei-Ting; Chin, Szu-Ying; Chou, Chia-Lun; Hsu, Che-Yuan; Chen, Yu-Tsung; Liu, Donald; Lee, Woan-Ruoh; Shih, Yi-Hsien

    2018-02-01

    Malassezia folliculitis (MalF) mimics acne vulgaris and bacterial folliculitis in clinical presentations. The role of Gram staining in rapid diagnosis of MalF has not been well studied. In our study, 32 patients were included to investigate the utility of Gram staining for MalF diagnosis. The final diagnoses of MalF were determined according to clinical presentation, pathological result and treatment response to antifungal agents. Our results show that the sensitivity and specificity of Gram staining are 84.6% and 100%, respectively. In conclusion, Gram staining is a rapid, non-invasive, sensitive and specific method for MalF diagnosis. © 2017 Japanese Dermatological Association.

  14. In vitro antifungal activity of extracts obtained from Hypericum perforatum adventitious roots cultured in a mist bioreactor against planktonic cells and biofilm of Malassezia furfur.

    PubMed

    Simonetti, Giovanna; Tocci, Noemi; Valletta, Alessio; Brasili, Elisa; D'Auria, Felicia Diodata; Idoux, Alicia; Pasqua, Gabriella

    2016-01-01

    Xanthone-rich extracts from Hypericum perforatum root cultures grown in a Mist Bioreactor as antifungal agents against Malassezia furfur. Extracts of Hypericum perforatum roots grown in a bioreactor showed activity against planktonic cells and biofilm of Malassezia furfur. Dried biomass, obtained from roots grown under controlled conditions in a ROOTec mist bioreactor, has been extracted with solvents of increasing polarity (i.e. chloroform, ethyl acetate and methanol). The methanolic fraction was the richest in xanthones (2.86 ± 0.43 mg g(-1) DW) as revealed by HPLC. The minimal inhibitory concentration of the methanol extract against M. furfur planktonic cells was 16 μg mL(-1). The inhibition percentage of biofilm formation, at a concentration of 16 μg mL(-1), ranged from 14% to 39%. The results show that H. perforatum root extracts could be used as new antifungal agents in the treatment of Malassezia infections.

  15. Phenotypic and genetic diversity of Malassezia furfur from domestic and zoo animals.

    PubMed

    Puig, Laura; Bragulat, M Rosa; Castellá, Gemma; Cabañes, F Javier

    2017-12-27

    Malassezia furfur is traditionally associated to human skin, although more recent studies have been revealing its presence in a variety of animals. The aim of this study was to analyze phenotypically and genetically the diversity among strains isolated from animals of this species. We have examined 21 strains of M. furfur from domestic and wild animals held in captivity. On the one hand, their phenotypic characteristics were studied, by assessing its growth at different incubation temperatures, their catalase and β-glucosidase activities and the Tween diffusion test on Sabouraud glucose agar (SGA), and on yeast nitrogen base agar (YNBA), a synthetic medium without lipids. On the other hand, the large subunit (LSU) and the internal transcribed spacer (ITS) of ribosomal RNA and the β-tubulin gene were sequenced. Different sequence types were identified for each target gene, and fourteen genotypes were revealed. While several genotypes were obtained from the strains from domestic animals, the strains from zoo animals appeared to be genetically more stable. With ITS and β-tubulin gene, M. furfur strains grouped in two clades. One clade included the strains from domestic animals and the other clade included the strains from zoo animals. The phenotypic tests also revealed a remarkable diversity within this species, which appeared to be more significant among strains from domestic animals. Moreover, the Tween diffusion test using YNBA was more useful to observe differences among strains, which could not be perceived using SGA. © The Author(s) 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. AhR ligands, malassezin, and indolo[3,2-b]carbazole are selectively produced by Malassezia furfur strains isolated from seborrheic dermatitis.

    PubMed

    Gaitanis, George; Magiatis, Prokopios; Stathopoulou, Konstantina; Bassukas, Ioannis D; Alexopoulos, Evangelos C; Velegraki, Aristea; Skaltsounis, Alexios-Leandros

    2008-07-01

    Malassezia yeasts are connected with seborrheic dermatitis (SD) whereas M. furfur pathogenicity is associated with the production of bioactive indoles. In this study, the production of indoles by M. furfur isolates from healthy and diseased skin was compared, the respective HPLC patterns were analyzed, and substances that are preferentially synthesized by strains isolated from SD lesions were isolated and characterized. Malassezin, pityriacitrin, indole-3-carbaldehyde, and indolo[3,2-b]carbazole (ICZ) were isolated by HPLC from extracts of M. furfur grown in L-tryptophan agar, and identified by nuclear magnetic resonance and mass spectroscopy. Of these, ICZ, a potent ligand of the aryl hydrocarbon receptor (AhR), is described for the first time to our knowledge as a M. furfur metabolite. HPLC-photodiode array detection analysis of strain extracts from 7 healthy subjects and 10 SD patients showed that M. furfur isolates from only SD patients consistently produce malassezin and ICZ. This discriminatory production of AhR agonists provides initial evidence for a previously unreported mechanism triggering development of SD and indicates that the variable pathogenicity patterns recorded for M. furfur-associated SD conditions may be attributed to selective production (P<0.001) of measurable bioactive indoles.

  17. Seborrheic dermatitis: etiology, risk factors, and treatments: facts and controversies.

    PubMed

    Dessinioti, Clio; Katsambas, Andreas

    2013-01-01

    Seborrheic dermatitis (SD) is a common skin condition seen frequently in clinical practice. The use of varying terms such as sebopsoriasis, seborrheic dermatitis, seborrheic eczema, dandruff, and pityriasis capitis reflects the complex nature of this condition. Despite its frequency, much controversy remains regarding the pathogenesis of SD. This controversy extends to its classification in the spectrum of cutaneous diseases, having being classified as a form of dermatitis, a fungal disease, or an inflammatory disease, closely related with psoriasis. Some have postulated that SD is caused by Malassezia yeasts, based on the observation of their presence in affected skin and the therapeutic response to antifungal agents. Others have proposed that Malassezia is incidental to a primary inflammatory dermatosis that resulted in increased cell turnover, scaling, and inflammation in the epidermis, similar to psoriasis. The presence of host susceptibility factors, permitting the transition of M furfur to its pathogenic form, may be associated with immune response and inflammation. Metabolites produced by Malassezia species, including oleic acid, malssezin, and indole-3-carbaldehyde, have been implicated. SD also has been traditionally considered to be a form of dermatitis based on the presence of Malassezia in healthy skin, the absence the pathogenic mycelial form of Malassezia yeasts in SD, and its chronic course. As a result, proposed treatments vary, ranging from topical corticosteroids to topical antifungals and antimicrobial peptides. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Anti-Dermatophyte and Anti-Malassezia Activity of Extracts Rich in Polymeric Flavan-3-ols Obtained from Vitis vinifera Seeds.

    PubMed

    Simonetti, Giovanna; D'Auria, Felicia Diodata; Mulinacci, Nadia; Innocenti, Marzia; Antonacci, Donato; Angiolella, Letizia; Santamaria, Anna Rita; Valletta, Alessio; Donati, Livia; Pasqua, Gabriella

    2017-01-01

    Several human skin diseases are associated with fungi as dermatophytes and Malassezia. Skin mycoses are increasing and new alternatives to conventional treatments with improved efficacy and/or safety profiles are desirable. For the first time, the anti-dermatophytes and the anti-Malassezia activities of Vitis vinifera seed extracts obtained from different table and wine cultivars have been evaluated. Geometric minimal inhibitory concentration ranged from 20 to 97 µg/mL for dermatophytes and from 32 to 161 µg/mL for Malassezia furfur. Dried grape seed extracts analyzed by HPLC/DAD/ESI/MS showed different quali-quantitative compositions in terms of monomeric and polymeric flavan-3-ols. The minimal inhibitory concentrations for Trichophyton mentagrophytes and for M. furfur were inversely correlated with the amount of the polymeric fraction (r = -0.7639 and r = -0.7228, respectively). Differently, the antifungal activity against T. mentagrophytes was not correlated to the content of flavan-3-ol monomers (r = 0.2920) and only weakly correlated for M. furfur (r = -0.53604). These results suggest that extracts rich in polymeric flavan-3-ols, recovered from V.  vinifera seeds, could be used for the treatment of skin fungal infections. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Contact allergy to corticosteroids and Malassezia furfur in seborrhoeic dermatitis patients.

    PubMed

    Ljubojevic, S; Lipozencic, J; Basta-Juzbasic, A

    2011-06-01

    Seborrhoeic dermatitis (SD) is a chronic skin disease, requiring long-term treatment, which might promote sensitization. Malassezia furfur (Mf) plays an important role in seborrhoeic dermatitis. Objectives  The aim of this study was to determine the frequency of contact sensitivity in SD patients. A total of 100 patients and 20 healthy controls (HC) were investigated: 50 suffering from SD with no previous local corticosteroid treatment (SDN), 50 SD patients treated with local corticosteroids (SDC). Mycological examination for Mf was performed. All patients were patch tested with the baseline standard, corticosteroid series, with 12 commercial corticosteroid preparations frequently used in Croatia; and also with Mf. Malassezia furfur was found in 44 (88%) SDN, 37 (74%) SDC, and in 4 (20%) HC; patch test reaction to Mf was positive in one SDN and in three SDC. Positive patch tests to standard allergens were observed in 17 (34%) SDN, 33 (66%) SDC and 2 (10%) HC. Patch tests to the corticosteroid series revealed positive reactions in 4 SDC and to commercial corticosteroids in seven patients, i.e. 2 SD and 5 SDC. Patch tests to the baseline series and to both individual corticosteroid and commercial corticosteroid preparations should be performed in SD patients with persistent dermatitis, as contact-allergic reactions may complicate their dermatitis. Sensitization to Mf was found to be infrequent. © 2010 The Authors. Journal of the European Academy of Dermatology and Venereology © 2010 European Academy of Dermatology and Venereology.

  20. Ciclopirox shampoo for treating seborrheic dermatitis.

    PubMed

    Gupta, A K; Bluhm, R

    2004-01-01

    Seborrheic dermatitis is a common inflammatory skin disease, affecting between 1% and 3% of immunocompetent adults. While its cause is unknown, a number of predisposing factors have been reported, including the implications of Malassezia yeasts. Various treatment options are available, such as ciclopirox shampoo, which combines anti-Malassezia activity with an anti-inflammatory action. This agent has been shown to be an effective and safe treatment for seborrheic dermatitis of the scalp.

  1. Fungemia and interstitial lung compromise caused by Malassezia sympodialis in a pediatric patient.

    PubMed

    Aguirre, Clarisa; Euliarte, Cristina; Finquelievich, Jorge; Sosa, María de los Ángeles; Giusiano, Gustavo

    2015-01-01

    A case of fungemia with interstitial lung compromise caused by Malassezia sympodialis is reported in an obese pediatric patient on long-term treatment with inhaled corticosteroids for asthma. The patient was hospitalized due to a post-surgical complication of appendicitis. The patient was treated with amphotericin B for 3 weeks, with good clinical evolution and subsequent negative cultures. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  2. Seborrheic dermatitis

    MedlinePlus

    Dandruff; Seborrheic eczema; Cradle cap ... The exact cause of seborrheic dermatitis is unknown. It may be due to a combination of factors: Oil gland activity Yeasts, called malassezia, which live on the ...

  3. In Vitro Susceptibilities of Malassezia Species to a New Triazole, Albaconazole (UR-9825), and Other Antifungal Compounds

    PubMed Central

    Garau, Margarita; Pereiro, Jr., Manolo; del Palacio, Amalia

    2003-01-01

    The in vitro activity of the new triazole albaconazole (UR-9825) in comparison with those of flucytosine, fluconazole, ketoconazole, itraconazole, and voriconazole against 70 strains of Malassezia spp. was determined by a microdilution method using a colorimetric indicator for metabolic activity. Albaconazole showed an in vitro profile similar to those of the different antifungals tested (MIC ≤ 0.06 μg/ml for all the strains). PMID:12821494

  4. [Tropical and travel-related dermatomycoses : Part 2: cutaneous infections due to yeasts, moulds, and dimorphic fungi].

    PubMed

    Nenoff, P; Reinel, D; Krüger, C; Grob, H; Mugisha, P; Süß, A; Mayser, P

    2015-07-01

    Besides dermatophytoses, a broad range of cutaneous infections due to yeasts and moulds may occur in subtropical and tropical countries where they can affect travellers. Not to be forgotten are endemic occurring dimorphic or biphasic fungi in countries with hot climate, which cause systemic and secondary cutaneous infections in immunosuppressed and immunocompetent people. In the tropics, the prevalence of pityriasis versicolor, caused by the lipophilic yeast Malassezia spp., is about 30-40 %, in distinct areas even 50 %. Increased hyperhidrosis under tropical conditions and simultaneously humidity congestion have to be considered as significant disposing factors for pityriasis versicolor. In tropical countries, therefore, an exacerbation of a preexisting pityriasis versicolor in travellers is not rare. Today, mostly genital yeast infections due to the new species Candida africana can be found worldwide. Due to migration from Africa this yeast pathogen has reached Germany and Europe. Eumycetomas due to mould fungi are rarely diagnosed in Europe. These deep cutaneous mould infections are only found in immigrants from African countries. The therapy of eumycetoma is protracted and often not successful. Cutaneous cryptococcoses due to the yeast species Cryptococcus neoformans and Cryptococcus gattii occur worldwide; however, they are found more frequently in the tropics. Immunosuppressed patients, especially those with HIV/AIDS, are affected by cryptococcoses. Furthermore, Cryptococcus gattii also causes infections in immunocompetent hosts in Central Africa, Australia, California, and Central America.Rarely found are infections due to dimorphic fungi after travel to countries where these fungal pathogens are endemic. In individual cases, cutaneous or lymphogenic transferred sporotrichosis due to Sporothrix schenkii can occur. Furthermore, scarcely known is secondary cutaneous coccidioidomycosis due to Coccidioides immitis after travelling to desert-like endemic

  5. Seborrheic dermatitis: a clinical practice snapshot.

    PubMed

    Schmidt, Jennifer A

    2011-08-01

    Seborrheic dermatitis is a chronic, recurring skin disorder that has no cure.Current clinical research has implicated Malassezia yeast in the etiology. Using a clear, concise clinical picture and a thorough patient history, even the novice NP can formulate an effective treatment plan.

  6. Temporal changes in the skin Malassezia microbiota of members of the Japanese Antarctic Research Expedition (JARE): A case study in Antarctica as a pseudo-space environment.

    PubMed

    Sugita, Takashi; Yamazaki, Takashi; Yamada, Shin; Takeoka, Hajime; Cho, Otomi; Tanaka, Takafumi; Ohno, Giichiro; Watanabe, Kentaro; Makimura, Koichi; Ohshima, Hiroshi; Ishioka, Noriaki; Mukai, Chiaki

    2015-09-01

    The International Space Station (ISS) is located approximately 400 km above the Earth. Astronauts staying at the ISS are under microgravity and are thus unable to bathe or shower; instead, they wash their bodies using wet tissues. For astronauts, skin hygiene management is important to maintain the quality of life during long-term stays on the ISS. In Antarctica, members of a Japanese geological investigation team negotiate their way over land using snowmobiles. During their 3-month stay, they are subject to a "pseudo-space" environment similar to that experienced by ISS astronauts, including the inability to bathe or shower. In this study, temporal changes in the colonization levels of skin lipophilic fungi, Malassezia were investigated in 16 team members. Compared to the levels before their trip to Antarctica, the fold changes in Malassezia colonization levels during the researchers' stay in Antarctica were in the range of 3.0 ± 1.9 to 5.3 ± 7.5 in cheek samples, 8.9 ± 10.6 to 22.2 ± 40.0 in anterior chest samples, 6.2 ± 5.4 to 16.9 ± 25.5 in behind-the-ear samples, and 1.7 ± 0.9 to 17.4 ± 33.4 in sole-of-the-foot samples. On the scalp, the level of Malassezia colonization increased dramatically, by 96.7 ± 113.8 to 916.9 ± 1251.5 fold. During their stay in Antarctica, the team members experienced itchy scalps and produced a large number of scales. The relative proportions of Malassezia globosa and M. restricta shifted to seborrheic dermatitis/dandruff types. These results provide useful information for the development of skin hygiene management plans for astronauts staying at the ISS. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. FUNGI ISOLATED FROM THE EXCRETA OF WILD BIRDS IN SCREENING CENTERS IN PELOTAS, RS, BRAZIL

    PubMed Central

    Mendes, Josiara Furtado; Albano, Ana Paula Neuschrank; Coimbra, Marco Antônio A.; de Ferreira, Gracialda Ferreira; Gonçalves, Carolina Lambrecht; Nascente, Patrícia da Silva; de Mello, João Roberto Braga

    2014-01-01

    The identification of the fungal species belonging to the healthy microflora in animals is a precondition for the recognition of pathological processes causing them. The aim of this study was to investigate the presence of potentially pathogenic fungi in the feces of wild birds collected in Screening Centers. Samples were collected from the feces of 50 cages with different species of birds. The samples were processed according to the modified method STAIB and the plates incubated at 32 °C for up to ten days with daily observation for detection of fungal growth. The isolation of the following species was observed: Malassezia pachydermatis, Candida albicans, C. famata, C. guilliermondii, C. sphaerica, C. globosa, C. catenulata, C. ciferri, C. intermedia, Cryptococcus laurentii, Trichosporon asahii, Geotrichum klebahnii, Aspergillus spp., A. niger and Penicillium spp. Knowing the character of some opportunistic fungi is important in identifying them, facilitating the adoption of preventive measures, such as proper cleaning of cages, since the accumulation of excreta may indicate a risk for both health professionals and centers for screening public health. PMID:25351548

  8. A traditional Chinese remedy points to a natural skin habitat: Indirubin (indigo naturalis) for psoriasis and the Malassezia metabolome.

    PubMed

    Gaitanis, G; Magiatis, P; Velegraki, A; Bassukas, I D

    2018-05-23

    We read with extreme interest the evidence for an impressively high, comparable to current systemic therapies, dose related efficacy of indirubin in plaque psoriasis. 1 Lin and co-authors 1 appropriately discuss their results, yet we would like to draw attention to a noteworthy aspect of the proposed therapeutic modality: The effectiveness of indirubin highlights the significance of the Malassezia metabolome in psoriasis, a long-term disputed issue. 2 This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. Yeast Based Sensors

    NASA Astrophysics Data System (ADS)

    Shimomura-Shimizu, Mifumi; Karube, Isao

    Since the first microbial cell sensor was studied by Karube et al. in 1977, many types of yeast based sensors have been developed as analytical tools. Yeasts are known as facultative anaerobes. Facultative anaerobes can survive in both aerobic and anaerobic conditions. The yeast based sensor consisted of a DO electrode and an immobilized omnivorous yeast. In yeast based sensor development, many kinds of yeast have been employed by applying their characteristics to adapt to the analyte. For example, Trichosporon cutaneum was used to estimate organic pollution in industrial wastewater. Yeast based sensors are suitable for online control of biochemical processes and for environmental monitoring. In this review, principles and applications of yeast based sensors are summarized.

  10. An outbreak of Candida albicans folliculitis masquerading as Malassezia folliculitis in a prison population.

    PubMed

    Jalalat, Sheila; Hunter, Lindsey; Yamazaki, Mika; Head, Elizabeth; Kelly, Brent

    2014-04-01

    Several inmates from a non-air-conditioned prison were sent to the University of Texas Medical Branch dermatology clinic for unexplained eruptions not responding to various treatments. They were initially diagnosed with Malassezia folliculitis based on clinical examination and histological findings. The patients' cultures from skin scrapings, however, revealed Candida albicans confirmed by growth on Mycosel agar and further by the germ tube production method. Five cases were brought to the clinic, but at least 30 other inmates were reported to have similar cutaneous eruptions. Given that these patients were generally immunocompetent, this is a rare finding. Factors favoring pseudohyphal growth for these patients included use of topical steroids and/or systemic antibiotics and hot and humid climate. All patients' folliculitis resolved with fluconazole and/or antifungal cream with no further complications.

  11. Nanovesicles from Malassezia sympodialis and Host Exosomes Induce Cytokine Responses – Novel Mechanisms for Host-Microbe Interactions in Atopic Eczema

    PubMed Central

    Gehrmann, Ulf; Qazi, Khaleda Rahman; Johansson, Catharina; Hultenby, Kjell; Karlsson, Maria; Lundeberg, Lena

    2011-01-01

    Background Intercellular communication can occur via the release of membrane vesicles. Exosomes are nanovesicles released from the endosomal compartment of cells. Depending on their cell of origin and their cargo they can exert different immunoregulatory functions. Recently, fungi were found to produce extracellular vesicles that can influence host-microbe interactions. The yeast Malassezia sympodialis which belongs to our normal cutaneous microbial flora elicits specific IgE- and T-cell reactivity in approximately 50% of adult patients with atopic eczema (AE). Whether exosomes or other vesicles contribute to the inflammation has not yet been investigated. Objective To investigate if M. sympodialis can release nanovesicles and whether they or endogenous exosomes can activate PBMC from AE patients sensitized to M. sympodialis. Methods Extracellular nanovesicles isolated from M. sympodialis, co-cultures of M. sympodialis and dendritic cells, and from plasma of patients with AE and healthy controls (HC) were characterised using flow cytometry, sucrose gradient centrifugation, Western blot and electron microscopy. Their ability to stimulate IL-4 and TNF-alpha responses in autologous CD14, CD34 depleted PBMC was determined using ELISPOT and ELISA, respectively. Results We show for the first time that M. sympodialis releases extracellular vesicles carrying allergen. These vesicles can induce IL-4 and TNF-α responses with a significantly higher IL-4 production in patients compared to HC. Exosomes from dendritic cell and M. sympodialis co-cultures induced IL-4 and TNF-α responses in autologous CD14, CD34 depleted PBMC of AE patients and HC while plasma exosomes induced TNF-α but not IL-4 in undepleted PBMC. Conclusions Extracellular vesicles from M. sympodialis, dendritic cells and plasma can contribute to cytokine responses in CD14, CD34 depleted and undepleted PBMC of AE patients and HC. These novel observations have implications for understanding host

  12. Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

    NASA Astrophysics Data System (ADS)

    van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

    Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

  13. Yeast Infection (Vaginal)

    MedlinePlus

    Yeast infection (vaginal) Overview A vaginal yeast infection is a fungal infection that causes irritation, discharge and intense itchiness ... symptoms Causes The fungus candida causes a vaginal yeast infection. Your vagina naturally contains a balanced mix of yeast, including ...

  14. Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.

    PubMed

    Gonçalves, Margarida; Pontes, Ana; Almeida, Pedro; Barbosa, Raquel; Serra, Marta; Libkind, Diego; Hutzler, Mathias; Gonçalves, Paula; Sampaio, José Paulo

    2016-10-24

    Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Low DNA Sequence Diversity of the Intergenic Spacer 1 Region in the Human Skin Commensal Fungi Malassezia sympodialis and M. dermatis Isolated from Patients with Malassezia-Associated Skin Diseases and Healthy Subjects.

    PubMed

    Cho, Otomi; Sugita, Takashi

    2016-12-01

    As DNA sequences of the intergenic spacer (IGS) region in the rRNA gene show remarkable intraspecies diversity compared with the small subunit, large subunit, and internal transcribed spacer region, the IGS region has been used as an epidemiological tool in studies on Malassezia globosa and M. restricta, which are responsible for the exacerbation of atopic dermatitis (AD) and seborrheic dermatitis (SD). However, the IGS regions of M. sympodialis and M. dermatis obtained from the skin of patients with AD and SD, as well as healthy subjects, lacked sequence diversity. Of the 105 M. sympodialis strains and the 40 M. dermatis strains, the sequences of 103 (98.1 %) and 39 (97.5 %), respectively, were identical. Thus, given the lack of intraspecies diversity in the IGS regions of M. sympodialis and M. dermatis, studies of the diversity of these species should be performed using appropriate genes and not the IGS.

  16. Functional expression and characterization of recombinant NADPH-P450 reductase from Malassezia globosa.

    PubMed

    Lee, Hwayoun; Park, Hyoung-Goo; Lim, Young-Ran; Lee, Im-Soon; Kim, Beom Joon; Seong, Cheul-Hun; Chun, Young-Jin; Kim, Donghak

    2012-01-01

    Malassezia globosa is a common pathogenic fungus that causes skin diseases including dandruff and seborrheic dermatitis in humans. Analysis of its genome identified a gene (MGL_1677) coding for a putative NADPH-P450 reductase (NPR) to support the fungal cytochrome P450 enzymes. The heterologously expressed recombinant M. globosa NPR protein was purified, and its functional features were characterized. The purified protein generated a single band on SDS-PAGE at 80.74 kDa and had an absorption maximum at 452 nm, indicating its possible function as an oxidized flavin cofactor. It evidenced NADPH-dependent reducing activity for cytochrome c or nitroblue tetrazolium. Human P450 1A2 and 2A6 were able to successfully catalyze the O-deethylation of 7- ethoxyresorufin and the 7-hydroxylation of coumarin, respectively, with the support of the purified NPR. These results demonstrate that purified NPR is an orthologous reductase protein that supports cytochrome P450 enzymes in M. globosa.

  17. Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate

    PubMed Central

    Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

    2012-01-01

    Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast density and species composition. When yeast densities were compared in pieces of the same fruits assigned to different treatments, fruits that developed low yeast densities in the absence of flies developed significantly higher yeast densities when exposed to larvae. Across all of the fruits, larvae regulated yeast densities within narrow limits, as compared to a much wider range of yeast densities that developed in pieces of the same fruits not exposed to flies. Larvae also affected yeast species composition, dramatically reducing species diversity across fruits, reducing variation in yeast communities from one fruit to the next (beta diversity), and encouraging the consistent development of a yeast community composed of three species of yeast (Candida californica, C. zemplinina, and Pichia kluvyeri), all of which were palatable to larvae. Larvae excreted viable cells of these three yeast species in their fecal pools, and discouraged the growth of filamentous fungi, processes which may have contributed to their effects on the yeast communities in banana fruits. These and other findings suggest that D. melanogaster adults and their larval offspring together engage in ‘niche construction’, facilitating a predictable microbial environment in the fruit substrates in which the larvae live and develop. PMID:22860093

  18. Prions in Yeast

    PubMed Central

    Liebman, Susan W.; Chernoff, Yury O.

    2012-01-01

    The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the “protein only” model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-β aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions. PMID:22879407

  19. Yeast for virus research

    PubMed Central

    Zhao, Richard Yuqi

    2017-01-01

    Budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are two popular model organisms for virus research. They are natural hosts for viruses as they carry their own indigenous viruses. Both yeasts have been used for studies of plant, animal and human viruses. Many positive sense (+) RNA viruses and some DNA viruses replicate with various levels in yeasts, thus allowing study of those viral activities during viral life cycle. Yeasts are single cell eukaryotic organisms. Hence, many of the fundamental cellular functions such as cell cycle regulation or programed cell death are highly conserved from yeasts to higher eukaryotes. Therefore, they are particularly suited to study the impact of those viral activities on related cellular activities during virus-host interactions. Yeasts present many unique advantages in virus research over high eukaryotes. Yeast cells are easy to maintain in the laboratory with relative short doubling time. They are non-biohazardous, genetically amendable with small genomes that permit genome-wide analysis of virologic and cellular functions. In this review, similarities and differences of these two yeasts are described. Studies of virologic activities such as viral translation, viral replication and genome-wide study of virus-cell interactions in yeasts are highlighted. Impacts of viral proteins on basic cellular functions such as cell cycle regulation and programed cell death are discussed. Potential applications of using yeasts as hosts to carry out functional analysis of small viral genome and to develop high throughput drug screening platform for the discovery of antiviral drugs are presented. PMID:29082230

  20. Seborrheic dermatitis flare in a Dutch male due to commensal Malassezia furfur overgrowth.

    PubMed

    Ran, Yuping; He, Xiaodan; Zhang, Hao; Dai, Yaling; Li, Lina; Bulmer, G S

    2008-09-01

    This is a case of seborrheic dermatitis (SD) barbae from which Malassezia furfur (M. furfur) was isolated. The patient was a 57-year-old Dutch male, who was hospitalized for fever and weakness of extremities. He presented with symmetrical erythema with an abundance of greasy chaffy scales on his beard area. No reasons were detected for his fever following a routine search. M. furfur was identified through mycological examination, including direct microscopic examination, culture, Tween test, esculine splitting test and DNA sequencing, of samples from the skin lesions. The patient was treated with oral itraconazole capsules (200 mg, b.i.d. for 8 days, then 200 mg o.d. for 13 days), washing his scalp and face with 2% ketoconazole shampoo (once a day) and topical application of a cream containing 1% naftifine hydrochloride and 0.25% ketoconazole (b.i.d.). After treatment the fever subsided and the SD lesion gradually healed. M. furfur was not isolated again from skin scrapings and 7 days later therapy was terminated and no recurrence was noted after one week follow-up since the cessation of treatment.

  1. L-arabinose fermenting yeast

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Min; Singh, Arjun; Suominen, Pirkko

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  2. L-arabinose fermenting yeast

    DOEpatents

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2014-09-23

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  3. Prevention of Yeast Spoilage in Feed and Food by the Yeast Mycocin HMK

    PubMed Central

    Lowes, K. F.; Shearman, C. A.; Payne, J.; MacKenzie, D.; Archer, D. B.; Merry, R. J.; Gasson, M. J.

    2000-01-01

    The yeast Williopsis mrakii produces a mycocin or yeast killer toxin designated HMK; this toxin exhibits high thermal stability, high pH stability, and a broad spectrum of activity against other yeasts. We describe construction of a synthetic gene for mycocin HMK and heterologous expression of this toxin in Aspergillus niger. Mycocin HMK was fused to a glucoamylase protein carrier, which resulted in secretion of biologically active mycocin into the culture media. A partial purification protocol was developed, and a comparison with native W. mrakii mycocin showed that the heterologously expressed mycocin had similar physiological properties and an almost identical spectrum of biological activity against a number of yeasts isolated from silage and yoghurt. Two food and feed production systems prone to yeast spoilage were used as models to assess the ability of mycocin HMK to act as a biocontrol agent. The onset of aerobic spoilage in mature maize silage was delayed by application of A. niger mycocin HMK on opening because the toxin inhibited growth of the indigenous spoilage yeasts. This helped maintain both higher lactic acid levels and a lower pH. In yoghurt spiked with dairy spoilage yeasts, A. niger mycocin HMK was active at all of the storage temperatures tested at which yeast growth occurred, and there was no resurgence of resistant yeasts. The higher the yeast growth rate, the more effective the killing action of the mycocin. Thus, mycocin HMK has potential applications in controlling both silage spoilage and yoghurt spoilage caused by yeasts. PMID:10698773

  4. Effect of wine yeast monoculture practice on the biodiversity of non-Saccharomyces yeasts.

    PubMed

    Ganga, M A; Martínez, C

    2004-01-01

    The objective of this work was to study the effect of the use of Saccharomyces cerevisiae monocultures over the biodiversity of non-Saccharomyces yeasts in wine-producing areas in Chile. Microvinifications were carried out with grape musts of two areas. In one of them, the fermentation is carried out mainly in a spontaneous manner, whereas in the other the musts are inoculated with commercial yeasts. The isolated yeasts were identified by the internal transcribed (ITS)/restriction fragment length polymorphism technique. In the industrial production area less variability of yeast genera was observed as compared with the traditional area, an observation that is greatest at the end of the fermentation. Furthermore, a study of the production of extracellular enzymes was done. The majority of the yeasts showed at least one of the activities assayed with the exception of beta-glycosidase. The results suggest that in the industrialized area the diversity of yeasts is less in the traditional area. Likewise, the potentiality of the non-Saccharomyces yeasts as enzyme producers with industrial interest has been confirmed. This study shows the negative effect of the use of monocultures over the biodiversity of yeasts in wine-producing regions.

  5. Inhibition of the β-carbonic anhydrase from the dandruff-producing fungus Malassezia globosa with monothiocarbamates.

    PubMed

    Nocentini, Alessio; Vullo, Daniela; Del Prete, Sonia; Osman, Sameh M; Alasmary, Fatmah A S; AlOthman, Zeid; Capasso, Clemente; Carta, Fabrizio; Gratteri, Paola; Supuran, Claudiu T

    2017-12-01

    A series of monothiocarbamates (MTCs) was investigated for the inhibition of the β-class carbonic anhydrase (CAs, EC 4.2.1.1) from the fungal parasite Malassezia globosa, MgCA. These MTCs incorporate various scaffolds, among which aliphatic amine with 1-4 carbons atom in their molecule, morpholine, piperazine, as well as phenethylamine and benzylamine derivatives. All the reported MTCs displayed a better efficacy in inhibiting MgCA compared to the clinically used sulphonamide drug acetazolamide (K I of 74 μM), with K I s spanning between 1.85 and 18.9 μM. The homology model of the enzyme previously reported by us was used to rationalize the results by docking some of these MTCs within the fungal CA active site. This study might be useful to enrich the knowledge of the MgCA inhibition profile, eliciting novel ideas pertaining the design of modulators with potential efficacy in combatting dandruff or other fungal infections.

  6. Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

    PubMed

    Palková, Zdena; Váchová, Libuše

    2016-09-01

    Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. L-arabinose fermenting yeast

    DOEpatents

    Zhang, Min; Singh, Arjun; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric; Suominen, Pirkko

    2010-12-07

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

  8. Nitrile Metabolizing Yeasts

    NASA Astrophysics Data System (ADS)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

  9. Genome dynamics and evolution in yeasts: A long-term yeast-bacteria competition experiment

    PubMed Central

    Katz, Michael; Knecht, Wolfgang; Compagno, Concetta; Piškur, Jure

    2018-01-01

    There is an enormous genetic diversity evident in modern yeasts, but our understanding of the ecological basis of such diversifications in nature remains at best fragmented so far. Here we report a long-term experiment mimicking a primordial competitive environment, in which yeast and bacteria co-exist and compete against each other. Eighteen yeasts covering a wide phylogenetic background spanning approximately 250 million years of evolutionary history were used to establish independent evolution lines for at most 130 passages. Our collection of hundreds of modified strains generated through such a rare two-species cross-kingdom competition experiment re-created the appearance of large-scale genomic rearrangements and altered phenotypes important in the diversification history of yeasts. At the same time, the methodology employed in this evolutionary study would also be a non-gene-technological method of reprogramming yeast genomes and then selecting yeast strains with desired traits. Cross-kingdom competition may therefore be a method of significant value to generate industrially useful yeast strains with new metabolic traits. PMID:29624585

  10. New yeasts-new brews: modern approaches to brewing yeast design and development.

    PubMed

    Gibson, B; Geertman, J-M A; Hittinger, C T; Krogerus, K; Libkind, D; Louis, E J; Magalhães, F; Sampaio, J P

    2017-06-01

    The brewing industry is experiencing a period of change and experimentation largely driven by customer demand for product diversity. This has coincided with a greater appreciation of the role of yeast in determining the character of beer and the widespread availability of powerful tools for yeast research. Genome analysis in particular has helped clarify the processes leading to domestication of brewing yeast and has identified domestication signatures that may be exploited for further yeast development. The functional properties of non-conventional yeast (both Saccharomyces and non-Saccharomyces) are being assessed with a view to creating beers with new flavours as well as producing flavoursome non-alcoholic beers. The discovery of the psychrotolerant S. eubayanus has stimulated research on de novo S. cerevisiae × S. eubayanus hybrids for low-temperature lager brewing and has led to renewed interest in the functional importance of hybrid organisms and the mechanisms that determine hybrid genome function and stability. The greater diversity of yeast that can be applied in brewing, along with an improved understanding of yeasts' evolutionary history and biology, is expected to have a significant and direct impact on the brewing industry, with potential for improved brewing efficiency, product diversity and, above all, customer satisfaction. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Stratum corneum dysfunction in dandruff

    PubMed Central

    Turner, G A; Hoptroff, M; Harding, C R

    2012-01-01

    Summary Synopsis Dandruff is characterized by a flaky, pruritic scalp and affects up to half the world’s population post-puberty. The aetiology of dandruff is multifactorial, influenced by Malassezia, sebum production and individual susceptibility. The commensal yeast Malassezia is a strong contributory factor to dandruff formation, but the presence of Malassezia on healthy scalps indicates that Malassezia alone is not a sufficient cause. A healthy stratum corneum (SC) forms a protective barrier to prevent water loss and maintain hydration of the scalp. It also protects against external insults such as microorganisms, including Malassezia, and toxic materials. Severe or chronic barrier damage can impair proper hydration, leading to atypical epidermal proliferation, keratinocyte differentiation and SC maturation, which may underlie some dandruff symptoms. The depleted and disorganized structural lipids of the dandruff SC are consistent with the weakened barrier indicated by elevated transepidermal water loss. Further evidence of a weakened barrier in dandruff includes subclinical inflammation and higher susceptibility to topical irritants. We are proposing that disruption of the SC of the scalp may facilitate dandruff generation, in part by affecting susceptibility to metabolites from Malassezia. Treatment of dandruff with cosmetic products to directly improve SC integrity while providing effective antifungal activity may thus be beneficial. Résumé Les pellicules se caractérisent par un cuir chevelu prurigineux, squameux, et affectent jusqu’à la moitié de la population post-pubertaire du monde. L’étiologie des pellicules est multifactorielle, influencée par Malassezia, par la production de sébum, et par la susceptibilité individuelle. La levure commensale Malassezia est un facteur fortement contributif à la formation de pellicules, mais la présence de Malassezia aussi sur les cuirs chevelus sains indique que Malassezia seule n’est pas une cause

  12. Vaginal yeast infection

    MedlinePlus

    Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts in the ...

  13. Schizosaccharomyces japonicus: the fission yeast is a fusion of yeast and hyphae.

    PubMed

    Niki, Hironori

    2014-03-01

    The clade of Schizosaccharomyces includes 4 species: S. pombe, S. octosporus, S. cryophilus, and S. japonicus. Although all 4 species exhibit unicellular growth with a binary fission mode of cell division, S. japonicus alone is dimorphic yeast, which can transit from unicellular yeast to long filamentous hyphae. Recently it was found that the hyphal cells response to light and then synchronously activate cytokinesis of hyphae. In addition to hyphal growth, S. japonicas has many properties that aren't shared with other fission yeast. Mitosis of S. japonicas is referred to as semi-open mitosis because dynamics of nuclear membrane is an intermediate mode between open mitosis and closed mitosis. Novel genetic tools and the whole genomic sequencing of S. japonicas now provide us with an opportunity for revealing unique characters of the dimorphic yeast. © 2013 The Author. Yeast Published by John Wiley & Sons Ltd.

  14. Marine yeast isolation and industrial application.

    PubMed

    Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

    2014-09-01

    Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. © 2014 The Authors FEMS Yeast Research published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

  15. Yeast ecology of Kombucha fermentation.

    PubMed

    Teoh, Ai Leng; Heard, Gillian; Cox, Julian

    2004-09-01

    Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species.

  16. Marine yeast isolation and industrial application

    PubMed Central

    Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

    2014-01-01

    Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. PMID:24738708

  17. Wine yeasts for the future.

    PubMed

    Fleet, Graham H

    2008-11-01

    International competition within the wine market, consumer demands for newer styles of wines and increasing concerns about the environmental sustainability of wine production are providing new challenges for innovation in wine fermentation. Within the total production chain, the alcoholic fermentation of grape juice by yeasts is a key process where winemakers can creatively engineer wine character and value through better yeast management and, thereby, strategically tailor wines to a changing market. This review considers the importance of yeast ecology and yeast metabolic reactions in determining wine quality, and then discusses new directions for exploiting yeasts in wine fermentation. It covers criteria for selecting and developing new commercial strains, the possibilities of using yeasts other than those in the genus of Saccharomyces, the prospects for mixed culture fermentations and explores the possibilities for high cell density, continuous fermentations.

  18. An unresponsive progressive pustular and crusting dermatitis with acantholysis in nine cats.

    PubMed

    Outerbridge, Catherine A; Affolter, Verena K; Lyons, Leslie A; Crothers, Samantha L; Lam, Andrea T H; Bonenberger, Terri E; Ihrke, Peter J; White, Stephen D

    2018-02-01

    Between 2000 and 2012, nine cats were examined with a visually distinctive, progressive crusting dermatitis that was poorly responsive to all attempted therapies. Documentation of clinical and histopathological findings of this disease. Nine privately owned cats. Retrospective study. Eight neutered males and one (presumably spayed) female ranging in age from two to eight years, presented for a progressive, well-demarcated, crusting dermatitis with variable pruritus of 1.5 months to five years duration. All cats lived in northern California, USA; seven lived within a 30 mile radius. Two males were littermates. Histopathological investigation showed both parakeratotic and orthokeratotic crusts, intraepidermal pustules and superficial folliculitis with rare to frequent acantholytic cells. Bacterial and fungal cultures were performed in six cats: meticillin-susceptible Staphylococcus pseudintermedius was isolated in three cats, two colonies of Trichophyton terrestre and three of Malassezia pachydermatis were isolated from one cat each. Treatment with various antibiotics, antifungal and a variety of immunosuppressive medications did not alter the progressive nature of the skin disease. The described disease shares some clinical and histopathological features with pemphigus foliaceus, but the lack of response to treatment, its progressive nature and the possible relatedness of some of the cats set it apart. The aetiology of this acantholytic dermatitis remains unknown. © 2017 ESVD and ACVD.

  19. Discussion of teleomorphic and anamorphic Ascomycetous yeasts and yeast-like taxa

    USDA-ARS?s Scientific Manuscript database

    The relationship of ascomycetous yeasts with other members of the ascomycete fungi (Ascomycota) has been controversial for over 100 years. Because yeasts are morphologically simple, it was proposed that they represent primitive forms of ascomycetes (e.g., Guilliermond 1912). Alternatively, the ide...

  20. Yeasts and yeast-like organisms associated with fruits and blossoms of different fruit trees.

    PubMed

    Vadkertiová, Renáta; Molnárová, Jana; Vránová, Dana; Sláviková, Elena

    2012-12-01

    Yeasts are common inhabitants of the phyllosphere, but our knowledge of their diversity in various plant organs is still limited. This study focused on the diversity of yeasts and yeast-like organisms associated with matured fruits and fully open blossoms of apple, plum, and pear trees, during 2 consecutive years at 3 localities in southwest Slovakia. The occurrence of yeasts and yeast-like organisms in fruit samples was 2½ times higher and the yeast community more diverse than that in blossom samples. Only 2 species (Aureobasidium pullulans and Metschnikowia pulcherrima) occurred regularly in the blossom samples, whereas Galactomyces candidus, Hanseniaspora guilliermondii, Hanseniaspora uvarum, M. pulcherrima, Pichia kluyveri, Pichia kudriavzevii, and Saccharomyces cerevisiae were the most frequently isolated species from the fruit samples. The ratio of the number of samples where only individual species were present to the number of samples where 2 or more species were found (consortium) was counted. The occurrence of individual species in comparison with consortia was much higher in blossom samples than in fruit samples. In the latter, consortia predominated. Aureobasidium pullulans, M. pulcherrima, and S. cerevisiae, isolated from both the fruits and blossoms, can be considered as resident yeast species of various fruit tree species cultivated in southwest Slovakia localities.

  1. Forces in yeast flocculation

    NASA Astrophysics Data System (ADS)

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Abellán Flos, Marta; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2015-01-01

    In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (``flocculation'') is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding.

  2. The yeast actin cytoskeleton.

    PubMed

    Mishra, Mithilesh; Huang, Junqi; Balasubramanian, Mohan K

    2014-03-01

    The actin cytoskeleton is a complex network of dynamic polymers, which plays an important role in various fundamental cellular processes, including maintenance of cell shape, polarity, cell division, cell migration, endocytosis, vesicular trafficking, and mechanosensation. Precise spatiotemporal assembly and disassembly of actin structures is regulated by the coordinated activity of about 100 highly conserved accessory proteins, which nucleate, elongate, cross-link, and sever actin filaments. Both in vivo studies in a wide range of organisms from yeast to metazoans and in vitro studies of purified proteins have helped shape the current understanding of actin dynamics and function. Molecular genetics, genome-wide functional analysis, sophisticated real-time imaging, and ultrastructural studies in concert with biochemical analysis have made yeast an attractive model to understand the actin cytoskeleton, its molecular dynamics, and physiological function. Studies of the yeast actin cytoskeleton have contributed substantially in defining the universal mechanism regulating actin assembly and disassembly in eukaryotes. Here, we review some of the important insights generated by the study of actin cytoskeleton in two important yeast models the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  3. [Thermoresistance in Saccharomyces cerevisiae yeasts].

    PubMed

    Kaliuzhin, V A

    2011-01-01

    Under natural conditions, yeast Saccharomyces cerevisiae reproduce, as a rule, on the surface of solid or liquid medium. Thus, life cycle of yeast populations is substantially influenced by diurnal changes in ambient temperature. The pattern in the response of unrestricted yeast S. cerevisiae culture to changes in the temperature of cultivation is revealed experimentally. Yeast population, in the absence of environmental constraints on the functioning of cell chemosmotic bioenergetic system, demonstrates the ability of thermoresistance when the temperature of cultivation switches from the range of 12-36 degrees C to 37.5-40 degrees C. During the transient period that is associated with the temperature switching and lasts from 1 to 4 turnover cycles, yeast reproduction rate remains 1.5-2 times higher than under stationary conditions. This is due to evolutionary acquired adaptive activity of cell chemosmotic system. After the adaptive resources exhausting, yeast thermoresistance fully recovers at the temperature range of 12-36 degrees C within one generation time under conditions of both restricted and unrestricted nourishment. Adaptive significance of such thermoresistance seems obvious enough--it allows maintaining high reproduction rate in yeast when ambient temperature is reaching a brief maximum shortly after noon.

  4. Interaction Between Yeasts and Zinc

    NASA Astrophysics Data System (ADS)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  5. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis...

  6. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic acid...

  7. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic acid...

  8. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic acid...

  9. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic acid...

  10. Carbonic anhydrase activators: Activation of the β-carbonic anhydrase from Malassezia globosa with amines and amino acids.

    PubMed

    Vullo, Daniela; Del Prete, Sonia; Capasso, Clemente; Supuran, Claudiu T

    2016-03-01

    The β-carbonic anhydrase (CA, EC 4.2.1.1) from the dandruff producing fungus Malassezia globosa, MgCA, was investigated for its activation with amines and amino acids. MgCA was weakly activated by amino acids such as L-/D-His, L-Phe, D-DOPA, D-Trp, L-/D-Tyr and by the amine serotonin (KAs of 12.5-29.3μM) but more effectively activated by d-Phe, l-DOPA, l-Trp, histamine, dopamine, pyridyl-alkylamines, and 4-(2-aminoethyl)-morpholine, with KAs of 5.82-10.9μM. The best activators were l-adrenaline and 1-(2-aminoethyl)piperazine, with activation constants of 0.72-0.81μM. This study may help a better understanding of the activation mechanisms of β-CAs from pathogenic fungi as well as the design of tighter binding ligands for this enzyme which is a drug target for novel types of anti-dandruff agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Yeast flocculation: New story in fuel ethanol production.

    PubMed

    Zhao, X Q; Bai, F W

    2009-01-01

    Yeast flocculation has been used in the brewing industry to facilitate biomass recovery for a long time, and thus its mechanism of yeast flocculation has been intensively studied. However, the application of flocculating yeast in ethanol production garnered attention mainly in the 1980s and 1990s. In this article, updated research progress in the molecular mechanism of yeast flocculation and the impact of environmental conditions on yeast flocculation are reviewed. Construction of flocculating yeast strains by genetic approach and utilization of yeast flocculation for ethanol production from various feedstocks were presented. The concept of self-immobilized yeast cells through their flocculation is revisited through a case study of continuous ethanol fermentation with the flocculating yeast SPSC01, and their technical and economic advantages are highlighted by comparing with yeast cells immobilized with supporting materials and regular free yeast cells as well. Taking the flocculating yeast SPSC01 as an example, the ethanol tolerance of the flocculating yeast was also discussed.

  12. Brewing characteristics of piezosensitive sake yeasts

    NASA Astrophysics Data System (ADS)

    Nomura, Kazuki; Hoshino, Hirofumi; Igoshi, Kazuaki; Onozuka, Haruka; Tanaka, Erika; Hayashi, Mayumi; Yamazaki, Harutake; Takaku, Hiroaki; Iguchi, Akinori; Shigematsu, Toru

    2018-04-01

    Application of high hydrostatic pressure (HHP) treatment to food processing is expected as a non-thermal fermentation regulation technology that supresses over fermentation. However, the yeast Saccharomyces cerevisiae used for Japanese rice wine (sake) brewing shows high tolerance to HHP. Therefore, we aimed to generate pressure-sensitive (piezosensitive) sake yeast strains by mating sake with piezosensitive yeast strains to establish an HHP fermentation regulation technology and extend the shelf life of fermented foods. The results of phenotypic analyses showed that the generated yeast strains were piezosensitive and exhibited similar fermentation ability compared with the original sake yeast strain. In addition, primary properties of sake brewed using these strains, such as ethanol concentration, sake meter value and sake flavor compounds, were almost equivalent to those obtained using the sake yeast strain. These results suggest that the piezosensitive strains exhibit brewing characteristics essentially equivalent to those of the sake yeast strain.

  13. 21 CFR 172.898 - Bakers yeast glycan.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Bakers yeast glycan. 172.898 Section 172.898 Food... Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and dried cell walls of the yeast...

  14. Opportunistic Pathogenic Yeasts

    NASA Astrophysics Data System (ADS)

    Banerjee, Uma

    Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

  15. Yeast Droplets

    NASA Astrophysics Data System (ADS)

    Nguyen, Baochi; Upadhyaya, Arpita; van Oudenaarden, Alexander; Brenner, Michael

    2002-11-01

    It is well known that the Young's law and surface tension govern the shape of liquid droplets on solid surfaces. Here we address through experiments and theory the shape of growing aggregates of yeast on agar substrates, and assess whether these ideas still hold. Experiments are carried out on Baker's yeast, with different levels of expressions of an adhesive protein governing cell-cell and cell-substrate adhesion. Changing either the agar concentration or the expression of this protein modifies the local contact angle of a yeast droplet. When the colony is small, the shape is a spherical cap with the contact angle obeying Young's law. However, above a critical volume this structure is unstable, and the droplet becomes nonspherical. We present a theoretical model where this instability is caused by bulk elastic effects. The model predicts that the transition depends on both volume and contact angle, in a manner quantitatively consistent with our experiments.

  16. Not your ordinary yeast: non-Saccharomyces yeasts in wine production uncovered.

    PubMed

    Jolly, Neil P; Varela, Cristian; Pretorius, Isak S

    2014-03-01

    Saccharomyces cerevisiae and grape juice are 'natural companions' and make a happy wine marriage. However, this relationship can be enriched by allowing 'wild' non-Saccharomyces yeast to participate in a sequential manner in the early phases of grape must fermentation. However, such a triangular relationship is complex and can only be taken to 'the next level' if there are no spoilage yeast present and if the 'wine yeast' - S. cerevisiae - is able to exert its dominance in time to successfully complete the alcoholic fermentation. Winemakers apply various 'matchmaking' strategies (e.g. cellar hygiene, pH, SO2 , temperature and nutrient management) to keep 'spoilers' (e.g. Dekkera bruxellensis) at bay, and allow 'compatible' wild yeast (e.g. Torulaspora delbrueckii, Pichia kluyveri, Lachancea thermotolerans and Candida/Metschnikowia pulcherrima) to harmonize with potent S. cerevisiae wine yeast and bring the best out in wine. Mismatching can lead to a 'two is company, three is a crowd' scenario. More than 40 of the 1500 known yeast species have been isolated from grape must. In this article, we review the specific flavour-active characteristics of those non-Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments. We seek to present 'single-species' and 'multi-species' ferments in a new light and a new context, and we raise important questions about the direction of mixed-fermentation research to address market trends regarding so-called 'natural' wines. This review also highlights that, despite the fact that most frontier research and technological developments are often focussed primarily on S. cerevisiae, non-Saccharomyces research can benefit from the techniques and knowledge developed by research on the former. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  17. Lager Yeast Comes of Age

    PubMed Central

    2014-01-01

    Alcoholic fermentations have accompanied human civilizations throughout our history. Lager yeasts have a several-century-long tradition of providing fresh beer with clean taste. The yeast strains used for lager beer fermentation have long been recognized as hybrids between two Saccharomyces species. We summarize the initial findings on this hybrid nature, the genomics/transcriptomics of lager yeasts, and established targets of strain improvements. Next-generation sequencing has provided fast access to yeast genomes. Its use in population genomics has uncovered many more hybridization events within Saccharomyces species, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution within Saccharomyces species. This “web of life” recognizes the ability of closely related species to exchange DNA and thus drain from a combined gene pool rather than be limited to a gene pool restricted by speciation. Within the domesticated lager yeasts, two groups, the Saaz and Frohberg groups, can be distinguished based on fermentation characteristics. Recent evidence suggests that these groups share an evolutionary history. We thus propose to refer to the Saaz group as Saccharomyces carlsbergensis and to the Frohberg group as Saccharomyces pastorianus based on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement. PMID:25084862

  18. Yeast killer systems.

    PubMed Central

    Magliani, W; Conti, S; Gerloni, M; Bertolotti, D; Polonelli, L

    1997-01-01

    The killer phenomenon in yeasts has been revealed to be a multicentric model for molecular biologists, virologists, phytopathologists, epidemiologists, industrial and medical microbiologists, mycologists, and pharmacologists. The surprisingly widespread occurrence of the killer phenomenon among taxonomically unrelated microorganisms, including prokaryotic and eukaryotic pathogens, has engendered a new interest in its biological significance as well as its theoretical and practical applications. The search for therapeutic opportunities by using yeast killer systems has conceptually opened new avenues for the prevention and control of life-threatening fungal diseases through the idiotypic network that is apparently exploited by the immune system in the course of natural infections. In this review, the biology, ecology, epidemiology, therapeutics, serology, and idiotypy of yeast killer systems are discussed. PMID:9227858

  19. Yeasts as distinct life forms of fungi

    USDA-ARS?s Scientific Manuscript database

    This review describes all presently recognized genera of the Ascomycete yeasts (Saccharomycotina, budding yeasts, and the Taphrinomycotina, fission yeasts and related) as well as all currently recognized genera of the Basidiomycete yeasts. This update will be the lead chapter for a book entitled “Ye...

  20. Study of amyloids using yeast

    PubMed Central

    Wickner, Reed B.; Kryndushkin, Dmitry; Shewmaker, Frank; McGlinchey, Ryan; Edskes, Herman K.

    2012-01-01

    Summary Saccharomyces cerevisiae has been a useful model organism in such fields as the cell cycle, regulation of transcription, protein trafficking and cell biology, primarily because of its ease of genetic manipulation. This is no less so in the area of amyloid studies. The endogenous yeast amyloids described to date include prions, infectious proteins (Table 1), and some cell wall proteins (1). and amyloids of humans and a fungal prion have also been studied using the yeast system. Accordingly, the emphasis of this chapter will be on genetic, biochemical, cell biological and physical methods particularly useful in the study of yeast prions and other amyloids studied in yeast. We limit our description of these methods to those aspects which have been most useful in studying yeast prions, citing more detailed expositions in the literature. Volumes on yeast genetics methods (2–4), and on amyloids and prions (5, 6) are useful, and Masison has edited a volume of Methods on “Identification, analysis and characterization of fungal prions” which covers some of this territory (7). We also outline some useful physical methods, pointing the reader to more extensive and authoratative descriptions. PMID:22528100

  1. Evolutionary History of Ascomyceteous Yeasts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haridas, Sajeet; Riley, Robert; Salamov, Asaf

    2014-06-06

    Yeasts are important for many industrial and biotechnological processes and show remarkable diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. A comparison of these with several other previously published yeast genomes have added increased confidence to the phylogenetic positions of previously poorly placed species including Saitoella complicata, Babjeviella inositovora and Metschnikowia bicuspidata. Phylogenetic analysis also showed that yeasts with alternative nuclear codon usage where CUG encodes serine instead of leucine are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with amore » large fraction of single exon genes with Lipomyces starkeyi and the previously published Pneumocystis jirovecii being notable exceptions. Intron analysis suggests that early diverging species have more introns. We also observed a large number of unclassified lineage specific non-simple repeats in these genomes.« less

  2. Eighteen new oleaginous yeast species.

    PubMed

    Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Chandra, Idelia; Shi, Sandy; Lin, Ting; German, J Bruce; Fiehn, Oliver; Boundy-Mills, Kyria L

    2016-07-01

    Of 1600 known species of yeasts, about 70 are known to be oleaginous, defined as being able to accumulate over 20 % intracellular lipids. These yeasts have value for fundamental and applied research. A survey of yeasts from the Phaff Yeast Culture Collection, University of California Davis was performed to identify additional oleaginous species within the Basidiomycota phylum. Fifty-nine strains belonging to 34 species were grown in lipid inducing media, and total cell mass, lipid yield and triacylglycerol profiles were determined. Thirty-two species accumulated at least 20 % lipid and 25 species accumulated over 40 % lipid by dry weight. Eighteen of these species were not previously reported to be oleaginous. Triacylglycerol profiles were suitable for biodiesel production. These results greatly expand the number of known oleaginous yeast species, and reveal the wealth of natural diversity of triacylglycerol profiles within wild-type oleaginous Basidiomycetes.

  3. Oral yeast colonization throughout pregnancy

    PubMed Central

    Rio, Rute; Simões-Silva, Liliana; Garro, Sofia; Silva, Mário-Jorge; Azevedo, Álvaro

    2017-01-01

    Background Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. Material and Methods The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Results Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women. Conclusions Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment. Key words:Oral yeast, fungi, pregnancy, saliva pH. PMID:28160578

  4. Biomedical applications of yeast- a patent view, part one: yeasts as workhorses for the production of therapeutics and vaccines.

    PubMed

    Roohvand, Farzin; Shokri, Mehdi; Abdollahpour-Alitappeh, Meghdad; Ehsani, Parastoo

    2017-08-01

    Yeasts, as Eukaryotes, offer unique features for ease of growth and genetic manipulation possibilities, making it an exceptional microbial host. Areas covered: This review provides general and patent-oriented insights into production of biopharmaceuticals by yeasts. Patents, wherever possible, were correlated to the original or review articles. The review describes applications of major GRAS (generally regarded as safe) yeasts for the production of therapeutic proteins and subunit vaccines; additionally, immunomodulatory properties of yeast cell wall components were reviewed for use of whole yeast cells as a new vaccine platform. The second part of the review will discuss yeast- humanization strategies and innovative applications. Expert opinion: Biomedical applications of yeasts were initiated by utilization of Saccharomyces cerevisiae, for production of leavened (fermented) products, and advanced to serve to produce biopharmaceuticals. Higher biomass production and expression/secretion yields, more similarity of glycosylation patterns to mammals and possibility of host-improvement strategies through application of synthetic biology might enhance selection of Pichia pastoris (instead of S. cerevisiae) as a host for production of biopharmaceutical in future. Immunomodulatory properties of yeast cell wall β-glucans and possibility of intracellular expression of heterologous pathogen/tumor antigens in yeast cells have expanded their application as a new platform, 'Whole Yeast Vaccines'.

  5. Nutrient supplements boost yeast transformation efficiency

    PubMed Central

    Yu, Sheng-Chun; Dawson, Alexander; Henderson, Alyssa C.; Lockyer, Eloise J.; Read, Emily; Sritharan, Gayathri; Ryan, Marjah; Sgroi, Mara; Ngou, Pok M.; Woodruff, Rosie; Zhang, Ruifeng; Ren Teen Chia, Travis; Liu, Yu; Xiang, Yiyu; Spanu, Pietro D.

    2016-01-01

    Efficiency of yeast transformation is determined by the rate of yeast endocytosis. The aim of this study was to investigate the effect of introducing amino acids and other nutrients (inositol, adenine, or p-aminobenzoic acid) in the transformation medium to develop a highly efficient yeast transformation protocol. The target of rapamycin complex 1 (TORC1) kinase signalling complex influences the rate of yeast endocytosis. TORC signaling is induced by amino acids in the media. Here, we found that increasing the concentration of amino acids and other nutrients in the growth media lead to an increase yeast transformation efficiency up to 107 CFU per μg plasmid DNA and per 108 cells with a 13.8 kb plasmid DNA. This is over 130 times that of current published methods. This improvement may facilitate more efficient experimentation in which transformation efficiency is critical, such as yeast two-hybrid screening. PMID:27760994

  6. Virgin olive oil yeasts: A review.

    PubMed

    Ciafardini, Gino; Zullo, Biagi Angelo

    2018-04-01

    This review summarizes current knowledge on virgin olive oil yeasts. Newly produced olive oil contains solid particles and micro drops of vegetation water in which yeasts reproduce to become the typical microbiota of olive oil. To date, about seventeen yeast species have been isolated from different types of olive oils and their by-products, of which six species have been identified as new species. Certain yeast species contribute greatly to improving the sensorial characteristics of the newly produced olive oil, whereas other species are considered harmful as they can damage the oil quality through the production of unpleasant flavors and triacylglycerol hydrolysis. Studies carried out in certain yeast strains have demonstrated the presence of defects in olive oil treated with Candida adriatica, Nakazawaea wickerhamii and Candida diddensiae specific strains, while other olive oil samples treated with other Candida diddensiae strains were defect-free after four months of storage and categorized as extra virgin. A new acetic acid producing yeast species, namely, Brettanomyces acidodurans sp. nov., which was recently isolated from olive oil, could be implicated in the wine-vinegary defect of the product. Other aspects related to the activity of the lipase-producing yeasts and the survival of the yeast species in the flavored olive oils are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting from concentration of the solubles of mechanically ruptured cells of a selected strain of yeast, Saccharomyces...

  8. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b) The...

  9. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b) The...

  10. History of genome editing in yeast.

    PubMed

    Fraczek, Marcin G; Naseeb, Samina; Delneri, Daniela

    2018-05-01

    For thousands of years humans have used the budding yeast Saccharomyces cerevisiae for the production of bread and alcohol; however, in the last 30-40 years our understanding of the yeast biology has dramatically increased, enabling us to modify its genome. Although S. cerevisiae has been the main focus of many research groups, other non-conventional yeasts have also been studied and exploited for biotechnological purposes. Our experiments and knowledge have evolved from recombination to high-throughput PCR-based transformations to highly accurate CRISPR methods in order to alter yeast traits for either research or industrial purposes. Since the release of the genome sequence of S. cerevisiae in 1996, the precise and targeted genome editing has increased significantly. In this 'Budding topic' we discuss the significant developments of genome editing in yeast, mainly focusing on Cre-loxP mediated recombination, delitto perfetto and CRISPR/Cas. © 2018 The Authors. Yeast published by John Wiley & Sons, Ltd.

  11. Inventions on baker's yeast strains and specialty ingredients.

    PubMed

    Gélinas, Pierre

    2009-06-01

    Baker's yeast is one of the oldest food microbial starters. Between 1927 and 2008, 165 inventions on more than 337 baker's yeast strains were patented. The first generation of patented yeast strains claimed improved biomass yield at the yeast plant, higher gassing power in dough or better survival to drying to prepare active dry baker's yeast. Especially between 1980 and 1995, a major interest was given to strains for multiple bakery applications such as dough with variable sugar content and stored at refrigeration (cold) or freezing temperatures. During the same period, genetically engineered yeast strains became very popular but did not find applications in the baking industry. Since year 2000, patented baker's yeast strains claimed aroma, anti-moulding or nutritive properties to better meet the needs of the baking industry. In addition to patents on yeast strains, 47 patents were issued on baker's yeast specialty ingredients for niche markets. This review shows that patents on baker's yeast with improved characteristics such as aromatic or nutritive properties have regularly been issued since the 1920's. Overall, it also confirms recent interest for a very wide range of tailored-made yeast-based ingredients for bakery applications.

  12. 21 CFR 172.898 - Bakers yeast glycan.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Bakers yeast glycan. 172.898 Section 172.898 Food... Multipurpose Additives § 172.898 Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and...

  13. 21 CFR 172.898 - Bakers yeast glycan.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Bakers yeast glycan. 172.898 Section 172.898 Food... Multipurpose Additives § 172.898 Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and...

  14. The wine and beer yeast Dekkera bruxellensis

    PubMed Central

    Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

    2014-01-01

    Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:24932634

  15. The wine and beer yeast Dekkera bruxellensis.

    PubMed

    Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

    2014-09-01

    Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

  16. Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

    PubMed

    Johnson, Eric A

    2013-09-01

    Yeasts are the major producer of biotechnology products worldwide, exceeding production in capacity and economic revenues of other groups of industrial microorganisms. Yeasts have wide-ranging fundamental and industrial importance in scientific, food, medical, and agricultural disciplines (Fig. 1). Saccharomyces is the most important genus of yeast from fundamental and applied perspectives and has been expansively studied. Non-Saccharomyces yeasts (non-conventional yeasts) including members of the Ascomycetes and Basidiomycetes also have substantial current utility and potential applicability in biotechnology. In an earlier mini-review, "Biotechnology of non-Saccharomyces yeasts-the ascomycetes" (Johnson Appl Microb Biotechnol 97: 503-517, 2013), the extensive biotechnological utility and potential of ascomycetous yeasts are described. Ascomycetous yeasts are particularly important in food and ethanol formation, production of single-cell protein, feeds and fodder, heterologous production of proteins and enzymes, and as model and fundamental organisms for the delineation of genes and their function in mammalian and human metabolism and disease processes. In contrast, the roles of basidiomycetous yeasts in biotechnology have mainly been evaluated only in the past few decades and compared to the ascomycetous yeasts and currently have limited industrial utility. From a biotechnology perspective, the basidiomycetous yeasts are known mainly for the production of enzymes used in pharmaceutical and chemical synthesis, for production of certain classes of primary and secondary metabolites such as terpenoids and carotenoids, for aerobic catabolism of complex carbon sources, and for bioremediation of environmental pollutants and xenotoxicants. Notwithstanding, the basidiomycetous yeasts appear to have considerable potential in biotechnology owing to their catabolic utilities, formation of enzymes acting on recalcitrant substrates, and through the production of unique primary

  17. Between science and industry-applied yeast research.

    PubMed

    Korhola, Matti

    2018-03-01

    I was fortunate to enter yeast research at the Alko Research Laboratories with a strong tradition in yeast biochemistry and physiology studies. At the same time in the 1980s there was a fundamental or paradigm change in molecular biology research with discoveries in DNA sequencing and other analytical and physical techniques for studying macromolecules and cells. Since that time biotechnological research has expanded the traditional fermentation industries to efficient production of industrial and other enzymes and specialty chemicals. Our efforts were directed towards improving the industrial production organisms: minerals enriched yeasts (Se, Cr, Zn) and high glutathione content yeast, baker´s, distiller´s, sour dough and wine yeasts, and the fungal Trichoderma reesei platform for enzyme production. I am grateful for the trust of my colleagues in several leadership positions at the Alko Research Laboratories, Yeast Industry Platform and at the international yeast community.

  18. Yeast-based biosensors: design and applications.

    PubMed

    Adeniran, Adebola; Sherer, Michael; Tyo, Keith E J

    2015-02-01

    Yeast-based biosensing (YBB) is an exciting research area, as many studies have demonstrated the use of yeasts to accurately detect specific molecules. Biosensors incorporating various yeasts have been reported to detect an incredibly large range of molecules including but not limited to odorants, metals, intracellular metabolites, carcinogens, lactate, alcohols, and sugars. We review the detection strategies available for different types of analytes, as well as the wide range of output methods that have been incorporated with yeast biosensors. We group biosensors into two categories: those that are dependent upon transcription of a gene to report the detection of a desired molecule and those that are independent of this reporting mechanism. Transcription-dependent biosensors frequently depend on heterologous expression of sensing elements from non-yeast organisms, a strategy that has greatly expanded the range of molecules available for detection by YBBs. Transcription-independent biosensors circumvent the problem of sensing difficult-to-detect analytes by instead relying on yeast metabolism to generate easily detected molecules when the analyte is present. The use of yeast as the sensing element in biosensors has proven to be successful and continues to hold great promise for a variety of applications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  19. Oral yeast colonization throughout pregnancy.

    PubMed

    Rio, R; Simões-Silva, L; Garro, S; Silva, M-J; Azevedo, Á; Sampaio-Maia, B

    2017-03-01

    Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women. Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment.

  20. Biotechnological Applications of Dimorphic Yeasts

    NASA Astrophysics Data System (ADS)

    Doiphode, N.; Joshi, C.; Ghormade, V.; Deshpande, M. V.

    The dimorphic yeasts have the equilibrium between spherical growth (budding) and polarized (hyphal or pseudohyphal tip elongation) which can be triggered by change in the environmental conditions. The reversible growth phenomenon has made dimorphic yeasts as an useful model to understand fungal evolution and fungal differentiation, in general. In nature dimorphism is clearly evident in plant and animal fungal pathogens, which survive and most importantly proliferate in the respective hosts. However, number of organisms with no known pathogenic behaviour also show such a transition, which can be exploited for the technological applications due to their different biochemical make up under different morphologies. For instance, chitin and chitosan production using dimorphic Saccharomyces, Mucor, Rhizopus and Benjaminiella, oil degradation and biotransformation with yeast-form of Yarrowia species, bioremediation of organic pollutants, exopolysac-charide production by yeast-phase of Aureobasidium pullulans, to name a few. Myrothecium verrucaria can be used for seed dressing in its yeast form and it produces a mycolytic enzyme complex in its hyphal-form for the biocontrol of fungal pathogens, while Beauveria bassiana and other entomopathogens kill the insect pest by producing yeast- like cells in the insect body. The form-specific expression of protease, chitinase, lipase, ornithine decarboxylase, glutamate dehydrogenases, etc. make Benjaminiella poitrasii, Basidiobolus sp., and Mucor rouxii strains important in bioremediation, nanobiotechnology, fungal evolution and other areas.

  1. Yeasts of the soil – obscure but precious

    PubMed Central

    2018-01-01

    Abstract Pioneering studies performed in the nineteenth century demonstrated that yeasts are present in below‐ground sources. Soils were regarded more as a reservoir for yeasts that reside in habitats above it. Later studies showed that yeast communities in soils are taxonomically diverse and different from those above‐ground. Soil yeasts possess extraordinary adaptations that allow them to survive in a wide range of environmental conditions. A few species are promising sources of yeast oils and have been used in agriculture as potential antagonists of soil‐borne plant pathogens or as plant growth promoters. Yeasts have been studied mainly in managed soils such as vineyards, orchards and agricultural fields, and to a lesser extent under forests and grasslands. Our knowledge of soil yeasts is further biased towards temperate and boreal forests, whereas data from Africa, the Americas and Asia are scarce. Although soil yeast communities are often species‐poor in a single sample, they are more diverse on the biotope level. Soil yeasts display pronounced endemism along with a surprisingly high proportion of currently unidentified species. However, like other soil inhabitants, yeasts are threatened by habitat alterations owing to anthropogenic activities such as agriculture, deforestation and urbanization. In view of the rapid decline of many natural habitats, the study of soil yeasts in undisturbed or low‐managed biotopes is extremely valuable. The purpose of this review is to encourage researchers, both biologists and soil scientists, to include soil yeasts in future studies. PMID:29365211

  2. Electron transport chain in a thermotolerant yeast.

    PubMed

    Mejía-Barajas, Jorge A; Martínez-Mora, José A; Salgado-Garciglia, Rafael; Noriega-Cisneros, Ruth; Ortiz-Avila, Omar; Cortés-Rojo, Christian; Saavedra-Molina, Alfredo

    2017-04-01

    Yeasts capable of growing and surviving at high temperatures are regarded as thermotolerant. For appropriate functioning of cellular processes and cell survival, the maintenance of an optimal redox state is critical of reducing and oxidizing species. We studied mitochondrial functions of the thermotolerant Kluyveromyces marxianus SLP1 and the mesophilic OFF1 yeasts, through the evaluation of its mitochondrial membrane potential (ΔΨ m ), ATPase activity, electron transport chain (ETC) activities, alternative oxidase activity, lipid peroxidation. Mitochondrial membrane potential and the cytoplasmic free Ca 2+ ions (Ca 2+ cyt) increased in the SLP1 yeast when exposed to high temperature, compared with the mesophilic yeast OFF1. ATPase activity in the mesophilic yeast diminished 80% when exposed to 40° while the thermotolerant SLP1 showed no change, despite an increase in the mitochondrial lipid peroxidation. The SLP1 thermotolerant yeast exposed to high temperature showed a diminution of 33% of the oxygen consumption in state 4. The uncoupled state 3 of oxygen consumption did not change in the mesophilic yeast when it had an increase of temperature, whereas in the thermotolerant SLP1 yeast resulted in an increase of 2.5 times when yeast were grown at 30 o , while a decrease of 51% was observed when it was exposed to high temperature. The activities of the ETC complexes were diminished in the SLP1 when exposed to high temperature, but also it was distinguished an alternative oxidase activity. Our results suggest that the mitochondria state, particularly ETC state, is an important characteristic of the thermotolerance of the SLP1 yeast strain.

  3. Yeasts in floral nectar: a quantitative survey

    PubMed Central

    Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, María I.

    2009-01-01

    Background and Aims One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored. Methods The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated. Key Results Yeasts occurred regularly in the floral nectar of many species, where they sometimes reached extraordinary densities (up to 4 × 105 cells mm−3). Depending on the region, between 32 and 44 % of all nectar samples contained yeasts. Yeast cell densities in the order of 104 cells mm−3 were commonplace, and densities >105 cells mm−3 were not rare. About one-fifth of species at each site had mean yeast cell densities >104 cells mm−3. Across species, yeast frequency and abundance were directly correlated with the proportion of floral visits by bumble-bees, and inversely with the proportion of visits by solitary bees. Conclusions Incorporating nectar yeasts into the scenario of plant–pollinator interactions opens up a number of intriguing avenues for research. In addition, with yeasts being as ubiquitous and abundant in floral nectars as revealed by this study, and given their astounding metabolic versatility, studies focusing on nectar chemical features should carefully control for the presence

  4. Interactions between Drosophila and its natural yeast symbionts—Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

    PubMed Central

    Hoang, Don; Kopp, Artyom

    2015-01-01

    Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker’s yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host–microbe interactions can have profound effects on host biology, the results from D. melanogaster–S. cerevisiae laboratory experiments may not be fully representative of host–microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

  5. Interactions between Drosophila and its natural yeast symbionts-Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

    PubMed

    Hoang, Don; Kopp, Artyom; Chandler, James Angus

    2015-01-01

    Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker's yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host-microbe interactions can have profound effects on host biology, the results from D. melanogaster-S. cerevisiae laboratory experiments may not be fully representative of host-microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

  6. Evaluation of Automated Yeast Identification System

    NASA Technical Reports Server (NTRS)

    McGinnis, M. R.

    1996-01-01

    One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

  7. Genomics and the making of yeast biodiversity.

    PubMed

    Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P

    2015-12-01

    Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces cerevisiae; the common human commensal and opportunistic pathogen, Candida albicans; and over 1000 other known species (with more continuing to be discovered). Yeasts are found in every biome and continent and are more genetically diverse than angiosperms or chordates. Ease of culture, simple life cycles, and small genomes (∼10-20Mbp) have made yeasts exceptional models for molecular genetics, biotechnology, and evolutionary genomics. Here we discuss recent developments in understanding the genomic underpinnings of the making of yeast biodiversity, comparing and contrasting natural and human-associated evolutionary processes. Only a tiny fraction of yeast biodiversity and metabolic capabilities has been tapped by industry and science. Expanding the taxonomic breadth of deep genomic investigations will further illuminate how genome function evolves to encode their diverse metabolisms and ecologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Accelerating Yeast Prion Biology using Droplet Microfluidics

    NASA Astrophysics Data System (ADS)

    Ung, Lloyd; Rotem, Assaf; Jarosz, Daniel; Datta, Manoshi; Lindquist, Susan; Weitz, David

    2012-02-01

    Prions are infectious proteins in a misfolded form, that can induce normal proteins to take the misfolded state. Yeast prions are relevant, as a model of human prion diseases, and interesting from an evolutionary standpoint. Prions may also be a form of epigenetic inheritance, which allow yeast to adapt to stressful conditions at rates exceeding those of random mutations and propagate that adaptation to their offspring. Encapsulation of yeast in droplet microfluidic devices enables high-throughput measurements with single cell resolution, which would not be feasible using bulk methods. Millions of populations of yeast can be screened to obtain reliable measurements of prion induction and loss rates. The population dynamics of clonal yeast, when a fraction of the cells are prion expressing, can be elucidated. Furthermore, the mechanism by which certain strains of bacteria induce yeast to express prions in the wild can be deduced. Integrating the disparate fields of prion biology and droplet microfluidics reveals a more complete picture of how prions may be more than just diseases and play a functional role in yeast.

  9. [Groups and sources of yeasts in house dust].

    PubMed

    Glushakova, A M; Zheltikova, T M; Chernov, I Iu

    2004-01-01

    House dust contains bacteria, mycelial fungi, microarthropods, and yeasts. The house dust samples collected in 25 apartments in Moscow and the Moscow region were found to contain yeasts belonging to the genera Candida, Cryptococcus, Debaryomyces, Rhodotorula, Sporobolomyces, and Trichosporon. The most frequently encountered microorganisms were typical epiphytic yeasts, such as Cryptococcus diffluens and Rhodotorula mucilaginosa, which are capable of long-term preservation in an inactive state. The direct source of epiphytic yeasts occurring in the house dust might be the indoor plants, which were contaminated with these yeasts, albeit to a lesser degree than outdoor plants. Along with the typical epiphytic yeasts, the house dust contained the opportunistic yeast pathogens Candida catenulata, C. guillermondii, C. haemulonii, C. rugosa, and C. tropicalis, which are known as the causal agents of candidiasis. We failed to reveal any correlation between the abundance of particular yeast species in the house dust, residential characteristics, and the atopic dermatitis of the inhabitants.

  10. Isolation, screening and partial purification of antimicrobial antibiotics from soil Streptomyces sp. SCA 7.

    PubMed

    Saravana Kumar, P; Duraipandiyan, V; Ignacimuthu, S

    2014-09-01

    Thirty-seven actinomycetes strains were isolated from soil samples collected from an agriculture field in Vengodu, Thiruvannamalai District, Tamil Nadu, India (latitude: 12° 54' 0033″, North; longitude: 79° 78' 5216″, East; elevation: 228.6/70.0 ft/m). The isolates were assessed for antagonistic activity against five Gram-positive bacteria, seven Gram-negative bacteria, and two pathogenic fungi. During the initial screening, 43% of the strains showed weak activity, 16% showed moderate activity, 5% showed good activity, and 35% showed no antagonistic activity. Among the strains tested, SCA 7 showed strong antimicrobial activity. Maximum biological activity was obtained on modified nutrient glucose agar (MNGA) medium. The mycelia of SCA 7 were extracted with methanol and tested against microbial pathogens using the disc diffusion method. The crude extract was purified partially using column chromatography and assessed for antimicrobial activity. Fraction 10 showed good activity against Staphylococcus epidermidis (31.25 μg/mL) and Malassezia pachydermatis (500 μg/mL) and the active principle (fraction 10) was identified as 2,4-bis (1,1-dimethylethyl) phenol. Based on morphological, physiological, biochemical, cultural, and molecular characteristics (16S rDNA sequencing), this strain was identified as Streptomyces sp. SCA 7. It could be used in the development of new substances for pharmaceutical or agricultural purposes. Copyright © 2014. Published by Elsevier B.V.

  11. Genomics and the making of yeast biodiversity

    USDA-ARS?s Scientific Manuscript database

    Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces ...

  12. Atrophying pityriasis versicolor as an idiosyncratic T cell-mediated response to Malassezia: A case series.

    PubMed

    Levy, Jonathan Michael Stephen; Magro, Cynthia

    2017-04-01

    Atrophying pityriasis versicolor (PV), first described in 1971, is a rare variant in which lesions appear atrophic. We sought to determine the pathophysiology of atrophying PV. A retrospective chart review identified 6 cases of atrophying PV. In all cases, routine light microscopy, an elastic tissue stain, and immunohistochemical assessment for the expression of CD3, CD4, CD8, GATA3 and CXCR3 was performed. All cases demonstrated hyperkeratosis with intracorneal infiltration by pathogenic hyphal forms as well as epidermal attenuation and papillary dermal elastolysis. A supervening, mild-to-moderate, superficial lymphocytic infiltrate was noted and characterized by a focal CD8 + T cell-mediated interface dermatitis along with a mixed T-cell infiltrate composed of GATA3 + and CXCR3 + T cells. Small sample size and the loss of some patients to follow-up. Atrophying PV represents the sequelae of a mixed helper T-cell (T H 1 and T H 2) idiosyncratic immune response to Malassezia and can present as a protracted dermatosis that may clinically mimic an atypical lymphocytic infiltrate. T H 1 cytokines can recruit histiocytes, a source of elastases, and upregulate matrix metalloproteinase activity, which may contribute to epidermal atrophy. Copyright © 2016. Published by Elsevier Inc.

  13. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section, may... produced by partial hydrolysis of yeast extract (derived from Saccharomyces cereviseae, Saccharomyces...

  14. Yeasts Diversity in Fermented Foods and Beverages

    NASA Astrophysics Data System (ADS)

    Tamang, Jyoti Prakash; Fleet, Graham H.

    People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

  15. Genetics of Yeasts

    NASA Astrophysics Data System (ADS)

    Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

    The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

  16. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

  17. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

  18. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

  19. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

  20. Yeasts in sustainable bioethanol production: A review.

    PubMed

    Mohd Azhar, Siti Hajar; Abdulla, Rahmath; Jambo, Siti Azmah; Marbawi, Hartinie; Gansau, Jualang Azlan; Mohd Faik, Ainol Azifa; Rodrigues, Kenneth Francis

    2017-07-01

    Bioethanol has been identified as the mostly used biofuel worldwide since it significantly contributes to the reduction of crude oil consumption and environmental pollution. It can be produced from various types of feedstocks such as sucrose, starch, lignocellulosic and algal biomass through fermentation process by microorganisms. Compared to other types of microoganisms, yeasts especially Saccharomyces cerevisiae is the common microbes employed in ethanol production due to its high ethanol productivity, high ethanol tolerance and ability of fermenting wide range of sugars. However, there are some challenges in yeast fermentation which inhibit ethanol production such as high temperature, high ethanol concentration and the ability to ferment pentose sugars. Various types of yeast strains have been used in fermentation for ethanol production including hybrid, recombinant and wild-type yeasts. Yeasts can directly ferment simple sugars into ethanol while other type of feedstocks must be converted to fermentable sugars before it can be fermented to ethanol. The common processes involves in ethanol production are pretreatment, hydrolysis and fermentation. Production of bioethanol during fermentation depends on several factors such as temperature, sugar concentration, pH, fermentation time, agitation rate, and inoculum size. The efficiency and productivity of ethanol can be enhanced by immobilizing the yeast cells. This review highlights the different types of yeast strains, fermentation process, factors affecting bioethanol production and immobilization of yeasts for better bioethanol production.

  1. Yeast and Mammalian Metallothioneins Functionally Substitute for Yeast Copper-Zinc Superoxide Dismutase

    NASA Astrophysics Data System (ADS)

    Tamai, Katherine T.; Gralla, Edith B.; Ellerby, Lisa M.; Valentine, Joan S.; Thiele, Dennis J.

    1993-09-01

    Copper-zinc superoxide dismutase catalyzes the disproportionation of superoxide anion to hydrogen peroxide and dioxygen and is thought to play an important role in protecting cells from oxygen toxicity. Saccharomyces cerevisiae strains lacking copper-zinc superoxide dismutase, which is encoded by the SOD1 gene, are sensitive to oxidative stress and exhibit a variety of growth defects including hypersensitivity to dioxygen and to superoxide-generating drugs such as paraquat. We have found that in addition to these known phenotypes, SOD1-deletion strains fail to grow on agar containing the respiratory carbon source lactate. We demonstrate here that expression of the yeast or monkey metallothionein proteins in the presence of copper suppresses the lactate growth defect and some other phenotypes associated with SOD1-deletion strains, indicating that copper metallothioneins substitute for copper-zinc superoxide dismutase in vivo to protect cells from oxygen toxicity. Consistent with these results, we show that yeast metallothionein mRNA levels are dramatically elevated under conditions of oxidative stress. Furthermore, in vitro assays demonstrate that yeast metallothionein, purified or from whole-cell extracts, exhibits copper-dependent antioxidant activity. Taken together, these data suggest that both yeast and mammalian metallothioneins may play a direct role in the cellular defense against oxidative stress by functioning as antioxidants.

  2. Experimental Systems to Study Yeast Pexophagy.

    PubMed

    Yamashita, Shun-Ichi; Oku, Masahide; Sakai, Yasuyoshi; Fujiki, Yukio

    2017-01-01

    Peroxisome abundance is tightly regulated according to the physiological contexts, through regulations of both proliferation and degradation of the organelles. Here, we describe detailed methods to analyze processes for autophagic degradation of peroxisomes, termed pexophagy, in yeast organisms. The assay systems include a method for biochemical detection of pexophagy completion, and one for microscopic visualization of specialized membrane structures acting in pexophagy. As a model yeast organism utilized in studies of pexophagy, the methylotrophic yeast Komagataella phaffii (Pichia pastoris) is referred to in this chapter and related information on the studies with baker's yeast (Saccharomyces cerevisiae) is also included. The described techniques facilitate elucidation of molecular machineries for pexophagy and understanding of peroxisome-selective autophagic pathways.

  3. [Distiller Yeasts Producing Antibacterial Peptides].

    PubMed

    Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

    2015-01-01

    A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

  4. Differential Adsorption of Ochratoxin A and Anthocyanins by Inactivated Yeasts and Yeast Cell Walls during Simulation of Wine Aging

    PubMed Central

    Petruzzi, Leonardo; Baiano, Antonietta; De Gianni, Antonio; Sinigaglia, Milena; Corbo, Maria Rosaria; Bevilacqua, Antonio

    2015-01-01

    The adsorption of ochratoxin A (OTA) by yeasts is a promising approach for the decontamination of musts and wines, but some potential competitive or interactive phenomena between mycotoxin, yeast cells, and anthocyanins might modify the intensity of the phenomenon. The aim of this study was to examine OTA adsorption by two strains of Saccharomyces cerevisiae (the wild strain W13, and the commercial isolate BM45), previously inactivated by heat, and a yeast cell wall preparation. Experiments were conducted using Nero di Troia red wine contaminated with 2 μg/L OTA and supplemented with yeast biomass (20 g/L). The samples were analyzed periodically to assess mycotoxin concentration, chromatic characteristics, and total anthocyanins over 84 days of aging. Yeast cell walls revealed the highest OTA-adsorption in comparison to thermally-inactivated cells (50% vs. 43% toxin reduction), whilst no significant differences were found for the amount of adsorbed anthocyanins in OTA-contaminated and control wines. OTA and anthocyanins adsorption were not competitive phenomena. Unfortunately, the addition of yeast cells to wine could cause color loss; therefore, yeast selection should also focus on this trait to select the best strain. PMID:26516913

  5. Made for Each Other: Ascomycete Yeasts and Insects.

    PubMed

    Blackwell, Meredith

    2017-06-01

    Fungi and insects live together in the same habitats, and many species of both groups rely on each other for success. Insects, the most successful animals on Earth, cannot produce sterols, essential vitamins, and many enzymes; fungi, often yeast-like in growth form, make up for these deficits. Fungi, however, require constantly replenished substrates because they consume the previous ones, and insects, sometimes lured by volatile fungal compounds, carry fungi directly to a similar, but fresh, habitat. Yeasts associated with insects include Ascomycota (Saccharomycotina, Pezizomycotina) and a few Basidiomycota. Beetles, homopterans, and flies are important associates of fungi, and in turn the insects carry yeasts in pits, specialized external pouches, and modified gut pockets. Some yeasts undergo sexual reproduction within the insect gut, where the genetic diversity of the population is increased, while others, well suited to their stable environment, may never mate. The range of interactions extends from dispersal of yeasts on the surface of insects (e.g., cactus- Drosophila -yeast and ephemeral flower communities, ambrosia beetles, yeasts with holdfasts) to extremely specialized associations of organisms that can no longer exist independently, as in the case of yeast-like symbionts of planthoppers. In a few cases yeast-like fungus-insect associations threaten butterflies and other species with extinction. Technical advances improve discovery and identification of the fungi but also inform our understanding of the evolution of yeast-insect symbioses, although there is much more to learn.

  6. The growth of solar radiated yeast

    NASA Technical Reports Server (NTRS)

    Kraft, Tyrone

    1995-01-01

    This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

  7. The growth of solar radiated yeast

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kraft, T.

    This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containersmore » with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.« less

  8. Freeze-drying of yeast cultures.

    PubMed

    Bond, Chris

    2007-01-01

    A method is described that allows yeast species to be stored using a variation on the standard freeze-drying method, which employs evaporative cooling in a two-stage process. Yeast cultures are placed in glass ampoules after having been mixed with a lyoprotectant. Primary drying is carried out using a centrifuge head connected to a standard freeze-dryer. Once the centrifuge head is running, air is removed and evaporated liquid is captured in the freeze-dryer. Centrifugation continues for 15 min and primary drying for a further 3 h. The ampoules are constricted using a glass blowing torch. They are then placed on the freeze-dryer manifold for secondary drying under vacuum overnight, using phosphorus pentoxide as a desiccant. The ampoules are sealed and removed from the manifold by melting the constricted section. Although the process causes an initial large drop in viability, further losses after storage are minimal. Yeast strains have remained viable for more than 30 yr when stored using this method and sufficient cells are recovered to produce new working stocks. Although survival rates are strain specific, nearly all National Collection of Yeast Cultures strains covering most yeast genera, have been successfully stored with little or no detectable change in strain characteristics.

  9. Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

    PubMed

    Johnson, Eric A

    2013-01-01

    Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described.

  10. Yeast proteome map (last update).

    PubMed

    Perrot, Michel; Moes, Suzette; Massoni, Aurélie; Jenoe, Paul; Boucherie, Hélian

    2009-10-01

    The identification of proteins separated on 2-D gels is essential to exploit the full potential of 2-D gel electrophoresis for proteomic investigations. For this purpose we have undertaken the systematic identification of Saccharomyces cerevisiae proteins separated on 2-D gels. We report here the identification by mass spectrometry of 100 novel yeast protein spots that have so far not been tackled due to their scarcity on our standard 2-D gels. These identifications extend the number of protein spots identified on our yeast 2-D proteome map to 716. They correspond to 485 unique proteins. Among these, 154 were resolved into several isoforms. The present data set can now be expanded to report for the first time a map of 363 protein isoforms that significantly deepens our knowledge of the yeast proteome. The reference map and a list of all identified proteins can be accessed on the Yeast Protein Map server (www.ibgc.u-bordeaux2.fr/YPM).

  11. Septin Organization and Functions in Budding Yeast

    PubMed Central

    Glomb, Oliver; Gronemeyer, Thomas

    2016-01-01

    The septins are a conserved family of GTP-binding proteins present in all eukaryotic cells except plants. They were originally discovered in the baker's yeast Saccharomyces cerevisiae that serves until today as an important model organism for septin research. In yeast, the septins assemble into a highly ordered array of filaments at the mother bud neck. The septins are regulators of spatial compartmentalization in yeast and act as key players in cytokinesis. This minireview summarizes the recent findings about structural features and cell biology of the yeast septins. PMID:27857941

  12. Taming wild yeast: potential of conventional and nonconventional yeasts in industrial fermentations.

    PubMed

    Steensels, Jan; Verstrepen, Kevin J

    2014-01-01

    Yeasts are the main driving force behind several industrial food fermentation processes, including the production of beer, wine, sake, bread, and chocolate. Historically, these processes developed from uncontrolled, spontaneous fermentation reactions that rely on a complex mixture of microbes present in the environment. Because such spontaneous processes are generally inconsistent and inefficient and often lead to the formation of off-flavors, most of today's industrial production utilizes defined starter cultures, often consisting of a specific domesticated strain of Saccharomyces cerevisiae, S. bayanus, or S. pastorianus. Although this practice greatly improved process consistency, efficiency, and overall quality, it also limited the sensorial complexity of the end product. In this review, we discuss how Saccharomyces yeasts were domesticated to become the main workhorse of food fermentations, and we investigate the potential and selection of nonconventional yeasts that are often found in spontaneous fermentations, such as Brettanomyces, Hanseniaspora, and Pichia spp.

  13. Yeast: A Research Organism for Teaching Genetics.

    ERIC Educational Resources Information Center

    Manney, Thomas R.; Manney, Monta L.

    1992-01-01

    Explains why laboratory strains of bakers yeast, Saccharomyces cerevisiae, are particularly suited for classroom science activities. Describes the sexual life cycle of yeast and the genetic system with visible mutations. Presents an overview of activities that can be done with yeast and gives a source for teachers to obtain more information. (PR)

  14. Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

    PubMed

    Bellon, Jennifer R; Schmid, Frank; Capone, Dimitra L; Dunn, Barbara L; Chambers, Paul J

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

  15. Yeast fuel cell: Application for desalination

    NASA Astrophysics Data System (ADS)

    Mardiana, Ummy; Innocent, Christophe; Cretin, Marc; Buchari, Buchari; Gandasasmita, Suryo

    2016-02-01

    Yeasts have been implicated in microbial fuel cells as biocatalysts because they are non-pathogenic organisms, easily handled and robust with a good tolerance in different environmental conditions. Here we investigated baker's yeast Saccharomyces cerevisiae through the oxidation of glucose. Yeast was used in the anolyte, to transfer electrons to the anode in the presence of methylene blue as mediator whereas K3Fe(CN)6 was used as an electron acceptor for the reduction reaction in the catholyte. Power production with biofuel cell was coupled with a desalination process. The maximum current density produced by the cell was 88 mA.m-2. In those conditions, it was found that concentration of salt was removed 64% from initial 0.6 M after 1-month operation. This result proves that yeast fuel cells can be used to remove salt through electrically driven membrane processes and demonstrated that could be applied for energy production and desalination. Further developments are in progress to improve power output to make yeast fuel cells applicable for water treatment.

  16. Yeasts for Global Happiness: report of the 14th International Congress on Yeasts (ICY14) held in Awaji Island.

    PubMed

    Watanabe, Daisuke; Takagi, Hiroshi

    2017-02-01

    The 14th International Congress on Yeasts (ICY14) was held at Awaji Yumebutai International Conference Center (Awaji, Hyogo) in Japan from 11 to 15 September 2016. The main slogan of ICY14 was 'Yeasts for Global Happiness', which enabled us to acknowledge the high-potential usefulness of yeasts contributing to the global happiness in terms of food/beverage, health/medicine and energy/environment industries, as well as to basic biosciences. In addition, two more concepts were introduced: 'from Japan to the world' and 'from senior to junior'. As it was the first ICY meeting held in Japan or other Asian countries, ICY14 provided a good opportunity to widely spread the great achievements by Japanese and Asian yeast researchers, such as those by the 2016 Nobel Laureate Dr. Yoshinori Ohsumi, and also, to convey the fun and importance of yeasts to the next generation of researchers from Asia and all over the world. As a result, a total of 426 yeast lovers from 42 countries (225 overseas and 201 domestic participants) with different generations attended ICY14 to share the latest knowledge of a wide range of yeast research fields and to join active and constructive scientific discussions. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  17. The secretory pathway: exploring yeast diversity.

    PubMed

    Delic, Marizela; Valli, Minoska; Graf, Alexandra B; Pfeffer, Martin; Mattanovich, Diethard; Gasser, Brigitte

    2013-11-01

    Protein secretion is an essential process for living organisms. In eukaryotes, this encompasses numerous steps mediated by several hundred cellular proteins. The core functions of translocation through the endoplasmic reticulum membrane, primary glycosylation, folding and quality control, and vesicle-mediated secretion are similar from yeasts to higher eukaryotes. However, recent research has revealed significant functional differences between yeasts and mammalian cells, and even among diverse yeast species. This review provides a current overview of the canonical protein secretion pathway in the model yeast Saccharomyces cerevisiae, highlighting differences to mammalian cells as well as currently unresolved questions, and provides a genomic comparison of the S. cerevisiae pathway to seven other yeast species where secretion has been investigated due to their attraction as protein production platforms, or for their relevance as pathogens. The analysis of Candida albicans, Candida glabrata, Kluyveromyces lactis, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, and Schizosaccharomyces pombe reveals that many - but not all - secretion steps are more redundant in S. cerevisiae due to duplicated genes, while some processes are even absent in this model yeast. Recent research obviates that even where homologous genes are present, small differences in protein sequence and/or differences in the regulation of gene expression may lead to quite different protein secretion phenotypes. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  18. Yeasts are essential for cocoa bean fermentation.

    PubMed

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  19. Yeast Genetics and Biotechnological Applications

    NASA Astrophysics Data System (ADS)

    Mishra, Saroj; Baranwal, Richa

    Yeast can be recognized as one of the very important groups of microorganisms on account of its extensive use in the fermentation industry and as a basic eukaryotic model cellular system. The yeast Saccharomyces cerevisiae has been extensively used to elucidate the genetics and regulation of several key functions in the cell such as cell mating, electron transport chain, protein trafficking, cell cycle events and others. Even before the genome sequence of the yeast was out, the structural organization and function of several of its genes was known. With the availability of the origin of replication from the 2 μm plasmid and the development of transformation system, it became the host of choice for expression of a number of important proteins. A large number of episomal and integrative shuttle vectors are available for expression of mammalian proteins. The latest developments in genomics and micro-array technology have allowed investigations of individual gene function by site-specific deletion method. The application of metabolic profiling has also assisted in understanding the cellular network operating in this yeast. This chapter is aimed at reviewing the use of this system as an experimental tool for conducting classical genetics. Various vector systems available, foreign genes expressed and the limitations as a host will be discussed. Finally, the use of various yeast enzymes in biotechnology sector will be reviewed.

  20. Functional adaptation between yeast actin and its cognate myosin motors.

    PubMed

    Stark, Benjamin C; Wen, Kuo-Kuang; Allingham, John S; Rubenstein, Peter A; Lord, Matthew

    2011-09-02

    We employed budding yeast and skeletal muscle actin to examine the contribution of the actin isoform to myosin motor function. While yeast and muscle actin are highly homologous, they exhibit different charge density at their N termini (a proposed myosin-binding interface). Muscle myosin-II actin-activated ATPase activity is significantly higher with muscle versus yeast actin. Whether this reflects inefficiency in the ability of yeast actin to activate myosin is not known. Here we optimized the isolation of two yeast myosins to assess actin function in a homogenous system. Yeast myosin-II (Myo1p) and myosin-V (Myo2p) accommodate the reduced N-terminal charge density of yeast actin, showing greater activity with yeast over muscle actin. Increasing the number of negative charges at the N terminus of yeast actin from two to four (as in muscle) had little effect on yeast myosin activity, while other substitutions of charged residues at the myosin interface of yeast actin reduced activity. Thus, yeast actin functions most effectively with its native myosins, which in part relies on associations mediated by its outer domain. Compared with yeast myosin-II and myosin-V, muscle myosin-II activity was very sensitive to salt. Collectively, our findings suggest differing degrees of reliance on electrostatic interactions during weak actomyosin binding in yeast versus muscle. Our study also highlights the importance of native actin isoforms when considering the function of myosins.

  1. [Superficial mycoses: casuistry of the Mycology Department of the Instituto Nacional de Higiene "Rafael Rangel", Caracas, Venezuela (2001-2014)].

    PubMed

    Capote, Ana María; Ferrara, Giuseppe; Panizo, María Mercedes; García, Nataly; Alarcón, Víctor; Reviakina, Vera; Dolande, Maribel

    2016-03-01

    The superficial mycoses are very common infectious diseases and therefore are a frequent reason for medical consultation. The aim of this study was to determine the diagnostic frequency of superficial mycoses in the Mycology Department of the Instituto Nacional de Higiene "Rafael Rangel" during 14 years (2001-2014). A retrospective cross-sectional study was performed to review the mycological records of patients with presumptive diagnosis of superficial mycosis. Nails, hairs and epidermal scales were the processed samples. The identification of fungi was performed by macro and microscopic observation of colonies and biochemical and physiological tests, as required of the isolated agent. For the investigation of Malassezia spp. only direct examination was performed. Of the 3 228 samples processed, 1 098 (34%) were positive and their distribution according to the etiological agent was: dermatophytes 79.5%; 10.9% yeasts; non-dermatophytes fungi 5.1% and 4.5% Malassezia spp. The most frequently isolated dermatophyte was Trichophyton rubrum Complex (70.1%), followed by T mentagrophytes complex (15.1%), Microsporum canis (9.4%) and Epidermophyton floccosum (4%). The most frequent ringworms Were: Tinea unguium (66.8%), followed by Tineapedis (16.4%) and Tinea capitis (8.1%). Candida parapsilosis complex (37.5%) was the most frequently isolated yeast and Fusarium spp. (53.6%) was the most isolated among non-dermatophyte fungi, followed by Aspergillus spp. (19.6%) and Acremonium spp. (10.7%). The identification of the etiological agent is essential to guide appropriate treatment. This study constitutes an important contribution to the knowledge of the epidemiology of superficial mycoses in our country.

  2. Genomic Evolution of the Ascomycete Yeasts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Riley, Robert; Haridas, Sajeet; Salamov, Asaf

    2015-03-16

    Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. Phylogenetic analysis of these and previously published yeast genomes helped resolve the placement of species including Saitoella complicata, Babjeviella inositovora, Hyphopichia burtonii, and Metschnikowia bicuspidata. Moreover, we find that alternative nuclear codon usage, where CUG encodes serine instead of leucine, are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes, and amore » tendency towards more introns in early-diverging species. Analysis of enzyme phylogeny gives insights into the evolution of metabolic capabilities such as methanol utilization and assimilation of alternative carbon sources.« less

  3. Specialist nectar-yeasts decline with urbanization in Berlin

    NASA Astrophysics Data System (ADS)

    Wehner, Jeannine; Mittelbach, Moritz; Rillig, Matthias C.; Verbruggen, Erik

    2017-03-01

    Nectar yeasts are common inhabitants of insect-pollinated flowers but factors determining their distribution are not well understood. We studied the influence of host identity, environmental factors related to pollution/urbanization, and the distance to a target beehive on local distribution of nectar yeasts within Robinia pseudoacacia L. and Tilia tomentosa Moench in Berlin, Germany. Nectar samples of six individuals per species were collected at seven sites in a 2 km radius from each target beehive and plated on YM-Agar to visualise the different morphotypes, which were then identified by sequencing a section of the 26S rDNA gene. Multivariate linear models were used to analyze the effects of all investigated factors on yeast occurrence per tree. Yeast distribution was mainly driven by host identity. The influence of the environmental factors (NO2, height of construction, soil sealing) strongly depended on the radius around the tree, similar to the distance of the sampled beehive. Incidence of specialist nectar-borne yeast species decreased with increasing pollution/urbanization index. Given that specialist yeast species gave way to generalist yeasts that have a reduced dependency on pollinators for between-flower dispersal, our results indicate that increased urbanization may restrict the movement of nectar-specialized yeasts, via limitations of pollinator foraging behavior.

  4. Accumulation and metabolism of selenium by yeast cells.

    PubMed

    Kieliszek, Marek; Błażejak, Stanisław; Gientka, Iwona; Bzducha-Wróbel, Anna

    2015-07-01

    This paper examines the process of selenium bioaccumulation and selenium metabolism in yeast cells. Yeast cells can bind elements in ionic from the environment and permanently integrate them into their cellular structure. Up to now, Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica yeasts have been used primarily in biotechnological studies to evaluate binding of minerals. Yeast cells are able to bind selenium in the form of both organic and inorganic compounds. The process of bioaccumulation of selenium by microorganisms occurs through two mechanisms: extracellular binding by ligands of membrane assembly and intracellular accumulation associated with the transport of ions across the cytoplasmic membrane into the cell interior. During intracellular metabolism of selenium, oxidation, reduction, methylation, and selenoprotein synthesis processes are involved, as exemplified by detoxification processes that allow yeasts to survive under culture conditions involving the elevated selenium concentrations which were observed. Selenium yeasts represent probably the best absorbed form of this element. In turn, in terms of wide application, the inclusion of yeast with accumulated selenium may aid in lessening selenium deficiency in a diet.

  5. Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

    PubMed Central

    Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

  6. Yeast Can Affect Behavior and Learning.

    ERIC Educational Resources Information Center

    Crook, William G.

    1984-01-01

    A pediatrician recounts his experiences in diagnosing and treating allergies to common yeast germs that may result in behavior and learning problems. He lists characteristics that may predispose children to yeast-connected health problems. (CL)

  7. Chemical signaling and insect attraction is a conserved trait in yeasts.

    PubMed

    Becher, Paul G; Hagman, Arne; Verschut, Vasiliki; Chakraborty, Amrita; Rozpędowska, Elżbieta; Lebreton, Sébastien; Bengtsson, Marie; Flick, Gerhard; Witzgall, Peter; Piškur, Jure

    2018-03-01

    Yeast volatiles attract insects, which apparently is of mutual benefit, for both yeasts and insects. However, it is unknown whether biosynthesis of metabolites that attract insects is a basic and general trait, or if it is specific for yeasts that live in close association with insects. Our goal was to study chemical insect attractants produced by yeasts that span more than 250 million years of evolutionary history and vastly differ in their metabolism and lifestyle. We bioassayed attraction of the vinegar fly Drosophila melanogaster to odors of phylogenetically and ecologically distinct yeasts grown under controlled conditions. Baker's yeast Saccharomyces cerevisiae , the insect-associated species Candida californica , Pichia kluyveri and Metschnikowia andauensis , wine yeast Dekkera bruxellensis , milk yeast Kluyveromyces lactis , the vertebrate pathogens Candida albicans and Candida glabrata , and oleophilic Yarrowia lipolytica were screened for fly attraction in a wind tunnel. Yeast headspace was chemically analyzed, and co-occurrence of insect attractants in yeasts and flowering plants was investigated through a database search. In yeasts with known genomes, we investigated the occurrence of genes involved in the synthesis of key aroma compounds. Flies were attracted to all nine yeasts studied. The behavioral response to baker's yeast was independent of its growth stage. In addition to Drosophila , we tested the basal hexapod Folsomia candida (Collembola) in a Y-tube assay to the most ancient yeast, Y. lipolytica, which proved that early yeast signals also function on clades older than neopteran insects. Behavioral and chemical data and a search for selected genes of volatile metabolites underline that biosynthesis of chemical signals is found throughout the yeast clade and has been conserved during the evolution of yeast lifestyles. Literature and database reviews corroborate that yeast signals mediate mutualistic interactions between insects and yeasts

  8. Yeast as a model for Ras signalling.

    PubMed

    Tisi, Renata; Belotti, Fiorella; Martegani, Enzo

    2014-01-01

    For centuries yeast species have been popular hosts for classical biotechnology processes, such as baking, brewing, and wine making, and more recently for recombinant proteins production, thanks to the advantages of unicellular organisms (i.e., ease of genetic manipulation and rapid growth) together with the ability to perform eukaryotic posttranslational modifications. Moreover, yeast cells have been used for few decades as a tool for identifying the genes and pathways involved in basic cellular processes such as the cell cycle, aging, and stress response. In the budding yeast S. cerevisiae the Ras/cAMP/PKA pathway is directly involved in the regulation of metabolism, cell growth, stress resistance, and proliferation in response to the availability of nutrients and in the adaptation to glucose, controlling cytosolic cAMP levels and consequently the cAMP-dependent protein kinase (PKA) activity. Moreover, Ras signalling has been identified in several pathogenic yeasts as a key controller for virulence, due to its involvement in yeast morphogenesis. Nowadays, yeasts are still useful for Ras-like proteins investigation, both as model organisms and as a test tube to study variants of heterologous Ras-like proteins.

  9. Flor Yeast: New Perspectives Beyond Wine Aging

    PubMed Central

    Legras, Jean-Luc; Moreno-Garcia, Jaime; Zara, Severino; Zara, Giacomo; Garcia-Martinez, Teresa; Mauricio, Juan C.; Mannazzu, Ilaria; Coi, Anna L.; Bou Zeidan, Marc; Dequin, Sylvie; Moreno, Juan; Budroni, Marilena

    2016-01-01

    The most important dogma in white-wine production is the preservation of the wine aroma and the limitation of the oxidative action of oxygen. In contrast, the aging of Sherry and Sherry-like wines is an aerobic process that depends on the oxidative activity of flor strains of Saccharomyces cerevisiae. Under depletion of nitrogen and fermentable carbon sources, these yeast produce aggregates of floating cells and form an air–liquid biofilm on the wine surface, which is also known as velum or flor. This behavior is due to genetic and metabolic peculiarities that differentiate flor yeast from other wine yeast. This review will focus first on the most updated data obtained through the analysis of flor yeast with -omic tools. Comparative genomics, proteomics, and metabolomics of flor and wine yeast strains are shedding new light on several features of these special yeast, and in particular, they have revealed the extent of proteome remodeling imposed by the biofilm life-style. Finally, new insights in terms of promotion and inhibition of biofilm formation through small molecules, amino acids, and di/tri-peptides, and novel possibilities for the exploitation of biofilm immobilization within a fungal hyphae framework, will be discussed. PMID:27148192

  10. Physiological and environmental control of yeast prions

    PubMed Central

    Chernova, Tatiana A.; Wilkinson, Keith D.; Chernoff, Yury O.

    2014-01-01

    Prions are self-perpetuating protein isoforms that cause fatal and incurable neurodegenerative disease in mammals. Recent evidence indicates that a majority of human proteins involved in amyloid and neural inclusion disorders possess at least some prion properties. In lower eukaryotes, such as yeast, prions act as epigenetic elements, which increase phenotypic diversity by altering a range of cellular processes. While some yeast prions are clearly pathogenic, it is also postulated that prion formation could be beneficial in variable environmental conditions. Yeast and mammalian prions have similar molecular properties. Crucial cellular factors and conditions influencing prion formation and propagation were uncovered in the yeast models. Stress-related chaperones, protein quality control deposits, degradation pathways and cytoskeletal networks control prion formation and propagation in yeast. Environmental stresses trigger prion formation and loss, supposedly acting via influencing intracellular concentrations of the prion-inducing proteins, and/or by localizing prionogenic proteins to the prion induction sites via heterologous ancillary helpers. Physiological and environmental modulation of yeast prions points to new opportunities for pharmacological intervention and/or prophylactic measures targeting general cellular systems rather than the properties of individual amyloids and prions. PMID:24236638

  11. Isolation and characterization of ethanol tolerant yeast strains

    PubMed Central

    Tikka, Chiranjeevi; Osuru, Hari Prasad; Atluri, Navya; Raghavulu, Praveen Chakravarthi Veera; yellapu, Nanda Kumar; Mannur, Ismail Shaik; Prasad, Uppu Venkateswara; Aluru, Sudheer; K, Narasimha Varma; Bhaskar, Matcha

    2013-01-01

    Yeast strains are commonly associated with sugar rich environments. Various fruit samples were selected as source for isolating yeast cells. The isolated cultures were identified at Genus level by colony morphology, biochemical characteristics and cell morphological characters. An attempt has been made to check the viability of yeast cells under different concentrations of ethanol. Ethanol tolerance of each strain was studied by allowing the yeast to grow in liquid YEPD (Yeast Extract Peptone Dextrose) medium having different concentrations of ethanol. A total of fifteen yeast strains isolated from different samples were used for the study. Seven strains of Saccharomyces cerevisiae obtained from different fruit sources were screened for ethanol tolerance. The results obtained in this study show a range of tolerance levels between 7%-12% in all the stains. Further, the cluster analysis based on 22 RAPD (Random Amplified polymorphic DNA) bands revealed polymorphisms in these seven Saccharomyces strains. PMID:23750092

  12. Phylogenetics of Saccharomycetales, the ascomycete yeasts.

    PubMed

    Suh, Sung-Oui; Blackwell, Meredith; Kurtzman, Cletus P; Lachance, Marc-André

    2006-01-01

    Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial and biotechnological processes, including baking, brewing and synthesis of recombinant proteins. Species such as Saccharomyces cerevisiae are model organisms in research, some of which led to a Nobel Prize. Yeasts usually reproduce asexually by budding, and their sexual states are not enclosed in a fruiting body. The group also is well defined by synapomorphies visible at the ultrastructural level. Yeast identification and classification changed dramatically with the availability of DNA sequencing. Species identification now benefits from a constantly updated sequence database and no longer relies on ambiguous growth tests. A phylogeny based on single gene analyses has shown the order to be remarkably divergent despite morphological similarities among members. The limits of many previously described genera are not supported by sequence comparisons, and multigene phylogenetic studies are under way to provide a stable circumscription of genera, families and orders. One recent multigene study has resolved species of the Saccharomycetaceae into genera that differ markedly from those defined by analysis of morphology and growth responses, and similar changes are likely to occur in other branches of the yeast tree as additional sequences become available.

  13. Yeast species associated with wine grapes in China.

    PubMed

    Li, Shuang-Shi; Cheng, Chao; Li, Zheng; Chen, Jing-Yu; Yan, Bin; Han, Bei-Zhong; Reeves, Malcolm

    2010-03-31

    Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine

  14. Antimicrobial activity of yeasts against some pathogenic bacteria

    PubMed Central

    Younis, Gamal; Awad, Amal; Dawod, Rehab E.; Yousef, Nehal E.

    2017-01-01

    Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR) for detection of khs (kievitone hydratase) and pelA (pectate degrading enzyme)genes. Results: The recovery rate of yeasts from sausage was 20% (2/10) followed by kareish cheese, processed cheese, and butter 10% (1/10) each as well as raw milk 9% (9/100), and fruit yoghurt 30% (6/20). Different yeast species were recovered, namely, Candida kefyr (5 isolates), Saccharomyces cerevisiae (4 isolates), Candida intermedia (3 isolates), Candida tropicalis (2 isolates), Candida lusitaniae (2 isolates), and Candida krusei (1 isolate). khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa. Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food. PMID:28919693

  15. Genomic evolution of the ascomycetous yeasts

    USDA-ARS?s Scientific Manuscript database

    Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphr...

  16. Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis

    PubMed Central

    Chatterjee, Gautam; Sankaranarayanan, Sundar Ram; Guin, Krishnendu; Thattikota, Yogitha; Padmanabhan, Sreedevi; Siddharthan, Rahul; Sanyal, Kaustuv

    2016-01-01

    The centromere, on which kinetochore proteins assemble, ensures precise chromosome segregation. Centromeres are largely specified by the histone H3 variant CENP-A (also known as Cse4 in yeasts). Structurally, centromere DNA sequences are highly diverse in nature. However, the evolutionary consequence of these structural diversities on de novo CENP-A chromatin formation remains elusive. Here, we report the identification of centromeres, as the binding sites of four evolutionarily conserved kinetochore proteins, in the human pathogenic budding yeast Candida tropicalis. Each of the seven centromeres comprises a 2 to 5 kb non-repetitive mid core flanked by 2 to 5 kb inverted repeats. The repeat-associated centromeres of C. tropicalis all share a high degree of sequence conservation with each other and are strikingly diverged from the unique and mostly non-repetitive centromeres of related Candida species—Candida albicans, Candida dubliniensis, and Candida lusitaniae. Using a plasmid-based assay, we further demonstrate that pericentric inverted repeats and the underlying DNA sequence provide a structural determinant in CENP-A recruitment in C. tropicalis, as opposed to epigenetically regulated CENP-A loading at centromeres in C. albicans. Thus, the centromere structure and its influence on de novo CENP-A recruitment has been significantly rewired in closely related Candida species. Strikingly, the centromere structural properties along with role of pericentric repeats in de novo CENP-A loading in C. tropicalis are more reminiscent to those of the distantly related fission yeast Schizosaccharomyces pombe. Taken together, we demonstrate, for the first time, fission yeast-like repeat-associated centromeres in an ascomycetous budding yeast. PMID:26845548

  17. Seborrheic dermatitis: an update.

    PubMed

    Bukvić Mokos, Zrinka; Kralj, Martina; Basta-Juzbašić, Aleksandra; Lakoš Jukić, Ines

    2012-01-01

    Seborrheic dermatitis is a chronic relapsing inflammatory skin disorder clinically characterized by scaling and poorly defined erythematous patches. The prevalence of adult seborrheic dermatitis is estimated at 5%. Although the exact cause of seborrheic dermatitis has yet to be understood, Malassezia yeasts, hormones (androgens), sebum levels and immune response are known to play important roles in its development. Additional factors including drugs, winter temperatures and stress may exacerbate seborrheic dermatitis. A variety of treatment modalities are available, including antifungal agents, topical low-potency steroids and calcineurin inhibitors (immunomodulators). This review summarizes current knowledge on the etiopathogenesis and therapy of adult seborrheic dermatitis.

  18. Comparative genomics of biotechnologically important yeasts

    USDA-ARS?s Scientific Manuscript database

    Ascomycete yeasts are metabolically diverse, with great potential for biotechnology. Here, we report the comparative genome analysis of 29 taxonomically and biotechnologically important yeasts, including 16 newly sequenced. We identify a genetic code change, CUG-Ala, in Pachysolen tannophilus in the...

  19. Counting Yeast.

    ERIC Educational Resources Information Center

    Bealer, Jonathan; Welton, Briana

    1998-01-01

    Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)

  20. Comprehensive analysis of the skin fungal microbiota of astronauts during a half-year stay at the International Space Station.

    PubMed

    Sugita, Takashi; Yamazaki, Takashi; Makimura, Koichi; Cho, Otomi; Yamada, Shin; Ohshima, Hiroshi; Mukai, Chiaki

    2016-03-01

    The International Space Station (ISS) is a huge manned construct located approximately 400 km above the earth and is inhabited by astronauts performing space experiments. Because the station is within a closed microgravity environment, the astronauts are subject to consistent stress. This study analyzed the temporal changes in the skin fungal microbiota of 10 astronauts using pyrosequencing and quantitative PCR assay before, during, and after their stay in the ISS. Lipophilic skin fungi, Malassezia predominated most samples regardless of the collection period, body site (cheek or chest), or subject. During their stay in the ISS, the level of Malassezia colonization changed by 7.6- ± 7.5-fold (mean ± standard deviation) and 9.5- ± 24.2-fold in cheek and chest samples, respectively. At the species level, M. restricta, M. globosa, and M. sympodialis were more abundant. In the chest samples, the ratio of M. restricta to all Malassezia species increased, whereas it did not change considerably in cheek samples. Fungal diversity was reduced, and the ratio of Malassezia to all fungal colonization increased during the astronauts' stay at the ISS. The ascomycetous yeast Cyberlindnera jadinii was detected in abundance in the in-flight sample of 5 of the 10 astronauts. The microorganism may have incidentally adhered to the skin during the preflight period and persisted on the skin thereafter. This observation suggests the ability of a specific or uncommon microorganism to proliferate in a closed environment. Our study is the first to reveal temporal changes in the skin fungal microbiota of ISS astronauts. These findings will provide information useful for maintaining the health of astronauts staying in the space environment for long periods and for preventing infection due to the human skin microbiota. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e

  1. Yeast diversity and native vigor for flavor phenotypes.

    PubMed

    Carrau, Francisco; Gaggero, Carina; Aguilar, Pablo S

    2015-03-01

    Saccharomyces cerevisiae, the yeast used widely for beer, bread, cider, and wine production, is the most resourceful eukaryotic model used for genetic engineering. A typical concern about using engineered yeasts for food production might be negative consumer perception of genetically modified organisms. However, we believe the true pitfall of using genetically modified yeasts is their limited capacity to either refine or improve the sensory properties of fermented foods under real production conditions. Alternatively, yeast diversity screening to improve the aroma and flavors could offer groundbreaking opportunities in food biotechnology. We propose a 'Yeast Flavor Diversity Screening' strategy which integrates knowledge from sensory analysis and natural whole-genome evolution with information about flavor metabolic networks and their regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Making Sense of the Yeast Sphingolipid Pathway.

    PubMed

    Megyeri, Márton; Riezman, Howard; Schuldiner, Maya; Futerman, Anthony H

    2016-12-04

    Sphingolipids (SL) and their metabolites play key roles both as structural components of membranes and as signaling molecules. Many of the key enzymes and regulators of SL metabolism were discovered using the yeast Saccharomyces cerevisiae, and based on the high degree of conservation, a number of mammalian homologs were identified. Although yeast continues to be an important tool for SL research, the complexity of SL structure and nomenclature often hampers the ability of new researchers to grasp the subtleties of yeast SL biology and discover new modulators of this intricate pathway. Moreover, the emergence of lipidomics by mass spectrometry has enabled the rapid identification of SL species in yeast and rendered the analysis of SL composition under various physiological and pathophysiological conditions readily amenable. However, the complex nomenclature of the identified species renders much of the data inaccessible to non-specialists. In this review, we focus on parsing both the classical SL nomenclature and the nomenclature normally used during mass spectrometry analysis, which should facilitate the understanding of yeast SL data and might shed light on biological processes in which SLs are involved. Finally, we discuss a number of putative roles of various yeast SL species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Novel brewing yeast hybrids: creation and application.

    PubMed

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2017-01-01

    The natural interspecies Saccharomyces cerevisiae × Saccharomyces eubayanus hybrid yeast is responsible for global lager beer production and is one of the most important industrial microorganisms. Its success in the lager brewing environment is due to a combination of traits not commonly found in pure yeast species, principally low-temperature tolerance, and maltotriose utilization. Parental transgression is typical of hybrid organisms and has been exploited previously for, e.g., the production of wine yeast with beneficial properties. The parental strain S. eubayanus has only been discovered recently and newly created lager yeast strains have not yet been applied industrially. A number of reports attest to the feasibility of this approach and artificially created hybrids are likely to have a significant impact on the future of lager brewing. De novo S. cerevisiae × S. eubayanus hybrids outperform their parent strains in a number of respects, including, but not restricted to, fermentation rate, sugar utilization, stress tolerance, and aroma formation. Hybrid genome function and stability, as well as different techniques for generating hybrids and their relative merits are discussed. Hybridization not only offers the possibility of generating novel non-GM brewing yeast strains with unique properties, but is expected to aid in unraveling the complex evolutionary history of industrial lager yeast.

  4. Improving industrial yeast strains: exploiting natural and artificial diversity

    PubMed Central

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

    2014-01-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as ‘global transcription machinery engineering’ (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

  5. MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

    PubMed

    Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

    2018-02-02

    Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value<1.7. Two strains could not be identified at first as they represented a mix of two different species. These mixes were Rhodotorula babjevae with Meyerozyma caribbica and Clavispora lusitaniae with Debaryomyces hansenii. After separation, all four species could be correctly identified with scores>1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Comparative genomics of biotechnologically important yeasts

    USDA-ARS?s Scientific Manuscript database

    Saccharomyces cerevisiae, is used in the vast majority of the world’s bioprocesses, and its economic significance is unchallenged. It, however, represents only a small slice of yeast physiological diversity. Many other yeasts, are used in lesser known, but commercially important processes that take ...

  7. The yeast Golgi apparatus: insights and mysteries

    PubMed Central

    Papanikou, Effrosyni; Glick, Benjamin S.

    2009-01-01

    The Golgi apparatus is known to modify and sort newly synthesized secretory proteins. However, fundamental mysteries remain about the structure, operation, and dynamics of this organelle. Important insights have emerged from studying the Golgi in yeasts. For example, yeasts have provided direct evidence for Golgi cisternal maturation, a mechanism that is likely to be broadly conserved. Here, we highlight features of the yeast Golgi as well as challenges that lie ahead. PMID:19879270

  8. Evolution and variation of the yeast (Saccharomyces) genome.

    PubMed

    Mortimer, R K

    2000-04-01

    In this review we describe the role of the yeast Saccharomyces in the development of human societies including the use of this organism in the making of wine, bread, beer, and distilled beverages. We also discuss the tremendous diversity of yeast found in natural (i.e., noninoculated) wine fermentations and the scientific uses of yeast over the past 60 years. In conclusion, we present ideas on the model of "genome renewal" and the use of this model to explain the mode by which yeast has evolved and how diversity can be generated.

  9. Brewer's/baker's yeast (Saccharomyces cerevisiae) and preventive medicine: Part II.

    PubMed

    Moyad, Mark A

    2008-02-01

    Yeast is the term generally applied to a unicellular fungus, and there are hundreds of species now identified. One of the most notable and well-known species of yeast in health and wellness is known as Saccharomyces cerevisiae, which is also known by its more common names, brewer's yeast or baker's yeast. Typically, brewer's yeast is used as a protein supplement, energy booster, immune enhancer, or other vehicle where other compounds can be inserted to create a commercialized health product. For example, one of the most notable positive findings was the encouraging results from a large randomized trial of adults recently vaccinated for seasonal influenza who also received an over-the-counter daily adjuvant modified brewer's yeast-based product (EpiCor) to prevent colds and flu symptoms. The modified yeast-based product significantly reduced the incidence and duration of this common condition. Yeast-based technology is also being used as a molecular mechanistic model of caloric restriction (CR) with the goal of improving the human life span. The current and potential impact of yeast-based technology in medicine is encouraging and should receive more attention, but the recent preliminary positive results of CR in humans may be in part due to what has been already learned from brewer's yeast.

  10. The yeast spectrum of the 'tea fungus Kombucha'.

    PubMed

    Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

    1995-01-01

    The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably

  11. [Yeast species in vulvovaginitis candidosa].

    PubMed

    Nemes-Nikodém, Éva; Tamási, Béla; Mihalik, Noémi; Ostorházi, Eszter

    2015-01-04

    Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

  12. 21 CFR 172.381 - Vitamin D2 bakers yeast.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... conventional bakers yeast. (c) The additive may be used in yeast-leavened baked goods and baking mixes and yeast-leavened baked snack foods at levels not to exceed 400 International Units of vitamin D2 per 100...

  13. Anaerobic digestion of food waste using yeast.

    PubMed

    Suwannarat, Jutarat; Ritchie, Raymond J

    2015-08-01

    Fermentative breakdown of food waste seems a plausible alternative to feeding food waste to pigs, incineration or garbage disposal in tourist areas. We determined the optimal conditions for the fermentative breakdown of food waste using yeast (Saccharomyces cerevisiae) in incubations up to 30days. Yeast efficiently broke down food waste with food waste loadings as high as 700g FW/l. The optimum inoculation was ≈46×10(6)cells/l of culture with a 40°C optimum (25-40°C). COD and BOD were reduced by ≈30-50%. Yeast used practically all the available sugars and reduced proteins and lipids by ≈50%. Yeast was able to metabolize lipids much better than expected. Starch was mobilized after very long term incubations (>20days). Yeast was effective in breaking down the organic components of food waste but CO2 gas and ethanol production (≈1.5%) were only significant during the first 7days of incubations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Nectar yeasts: a natural microcosm for ecology.

    PubMed

    Chappell, Callie R; Fukami, Tadashi

    2018-06-01

    The species of yeasts that colonize floral nectar can modify the mutualistic relationships between plants and pollinators by changing the chemical properties of nectar. Recent evidence supporting this possibility has led to increased interest among ecologists in studying these fungi as well as the bacteria that interact with them in nectar. Although not fully explored, nectar yeasts also constitute a promising natural microcosm that can be used to facilitate development of general ecological theory. We discuss the methodological and conceptual advantages of using nectar yeasts from this perspective, including simplicity of communities, tractability of dispersal, replicability of community assembly, and the ease with which the mechanisms of species interactions can be studied in complementary experiments conducted in the field and the laboratory. To illustrate the power of nectar yeasts as a study system, we discuss several topics in community ecology, including environmental filtering, priority effects, and metacommunity dynamics. An exciting new direction is to integrate metagenomics and comparative genomics into nectar yeast research to address these fundamental ecological topics. Copyright © 2018 John Wiley & Sons, Ltd.

  15. Kinetics of growth and sugar consumption in yeasts.

    PubMed

    van Dijken, J P; Weusthuis, R A; Pronk, J T

    1993-01-01

    An overview is presented of the steady- and transient state kinetics of growth and formation of metabolic byproducts in yeasts. Saccharomyces cerevisiae is strongly inclined to perform alcoholic fermentation. Even under fully aerobic conditions, ethanol is produced by this yeast when sugars are present in excess. This so-called 'Crabtree effect' probably results from a multiplicity of factors, including the mode of sugar transport and the regulation of enzyme activities involved in respiration and alcoholic fermentation. The Crabtree effect in S. cerevisiae is not caused by an intrinsic inability to adjust its respiratory activity to high glycolytic fluxes. Under certain cultivation conditions, for example during growth in the presence of weak organic acids, very high respiration rates can be achieved by this yeast. S. cerevisiae is an exceptional yeast since, in contrast to most other species that are able to perform alcoholic fermentation, it can grow under strictly anaerobic conditions. 'Non-Saccharomyces' yeasts require a growth-limiting supply of oxygen (i.e. oxygen-limited growth conditions) to trigger alcoholic fermentation. However, complete absence of oxygen results in cessation of growth and therefore, ultimately, of alcoholic fermentation. Since it is very difficult to reproducibly achieve the right oxygen dosage in large-scale fermentations, non-Saccharomyces yeasts are therefore not suitable for large-scale alcoholic fermentation of sugar-containing waste streams. In these yeasts, alcoholic fermentation is also dependent on the type of sugar. For example, the facultatively fermentative yeast Candida utilis does not ferment maltose, not even under oxygen-limited growth conditions, although this disaccharide supports rapid oxidative growth.

  16. The ecology of the Drosophila-yeast mutualism in wineries

    PubMed Central

    2018-01-01

    The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila. PMID:29768432

  17. The ecology of the Drosophila-yeast mutualism in wineries.

    PubMed

    Quan, Allison S; Eisen, Michael B

    2018-01-01

    The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila.

  18. Improving industrial yeast strains: exploiting natural and artificial diversity.

    PubMed

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Picca Nicolino, Martina; Voordeckers, Karin; Verstrepen, Kevin J

    2014-09-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. © 2014 The Authors. FEMS Microbiology Reviews published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

  19. Chromosomal Aneuploidy Improves the Brewing Characteristics of Sake Yeast.

    PubMed

    Kadowaki, Masafumi; Fujimaru, Yuki; Taguchi, Seiga; Ferdouse, Jannatul; Sawada, Kazutaka; Kimura, Yuta; Terasawa, Yohei; Agrimi, Gennaro; Anai, Toyoaki; Noguchi, Hideki; Toyoda, Atsushi; Fujiyama, Asao; Akao, Takeshi; Kitagaki, Hiroshi

    2017-12-15

    The effect of chromosomal aneuploidy on the brewing characteristics of brewery yeasts has not been studied. Here we report that chromosomal aneuploidy in sake brewery yeast ( Saccharomyces cerevisiae ) leads to the development of favorable brewing characteristics. We found that pyruvate-underproducing sake yeast, which produces less off-flavor diacetyl, is aneuploid and trisomic for chromosomes XI and XIV. To confirm that this phenotype is due to aneuploidy, we obtained 45 haploids with various chromosomal additions and investigated their brewing profiles. A greater number of chromosomes correlated with a decrease in pyruvate production. Especially, sake yeast haploids with extra chromosomes in addition to chromosome XI produced less pyruvate than euploids. Mitochondrion-related metabolites and intracellular oxygen species in chromosome XI aneuploids were higher than those in euploids, and this effect was canceled in their "petite" strains, suggesting that an increase in chromosomes upregulated mitochondrial activity and decreased pyruvate levels. These findings suggested that an increase in chromosome number, including chromosome XI, in sake yeast haploids leads to pyruvate underproduction through the augmentation of mitochondrial activity. This is the first report proposing that aneuploidy in brewery yeasts improves their brewing profile. IMPORTANCE Chromosomal aneuploidy has not been evaluated in development of sake brewing yeast strains. This study shows the relationship between chromosomal aneuploidy and brewing characteristics of brewery yeast strains. High concentrations of pyruvate during sake storage give rise to α-acetolactate and, in turn, to high concentrations of diacetyl, which is considered an off-flavor. It was demonstrated that pyruvate-underproducing sake yeast is trisomic for chromosome XI and XIV. Furthermore, sake yeast haploids with extra chromosomes produced reduced levels of pyruvate and showed metabolic processes characteristic of

  20. Chromosomal Aneuploidy Improves the Brewing Characteristics of Sake Yeast

    PubMed Central

    Kadowaki, Masafumi; Fujimaru, Yuki; Taguchi, Seiga; Ferdouse, Jannatul; Sawada, Kazutaka; Kimura, Yuta; Terasawa, Yohei; Agrimi, Gennaro; Anai, Toyoaki; Noguchi, Hideki; Toyoda, Atsushi; Fujiyama, Asao; Akao, Takeshi

    2017-01-01

    ABSTRACT The effect of chromosomal aneuploidy on the brewing characteristics of brewery yeasts has not been studied. Here we report that chromosomal aneuploidy in sake brewery yeast (Saccharomyces cerevisiae) leads to the development of favorable brewing characteristics. We found that pyruvate-underproducing sake yeast, which produces less off-flavor diacetyl, is aneuploid and trisomic for chromosomes XI and XIV. To confirm that this phenotype is due to aneuploidy, we obtained 45 haploids with various chromosomal additions and investigated their brewing profiles. A greater number of chromosomes correlated with a decrease in pyruvate production. Especially, sake yeast haploids with extra chromosomes in addition to chromosome XI produced less pyruvate than euploids. Mitochondrion-related metabolites and intracellular oxygen species in chromosome XI aneuploids were higher than those in euploids, and this effect was canceled in their “petite” strains, suggesting that an increase in chromosomes upregulated mitochondrial activity and decreased pyruvate levels. These findings suggested that an increase in chromosome number, including chromosome XI, in sake yeast haploids leads to pyruvate underproduction through the augmentation of mitochondrial activity. This is the first report proposing that aneuploidy in brewery yeasts improves their brewing profile. IMPORTANCE Chromosomal aneuploidy has not been evaluated in development of sake brewing yeast strains. This study shows the relationship between chromosomal aneuploidy and brewing characteristics of brewery yeast strains. High concentrations of pyruvate during sake storage give rise to α-acetolactate and, in turn, to high concentrations of diacetyl, which is considered an off-flavor. It was demonstrated that pyruvate-underproducing sake yeast is trisomic for chromosome XI and XIV. Furthermore, sake yeast haploids with extra chromosomes produced reduced levels of pyruvate and showed metabolic processes characteristic

  1. 21 CFR 172.325 - Bakers yeast protein.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

  2. 21 CFR 172.325 - Bakers yeast protein.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

  3. 21 CFR 172.325 - Bakers yeast protein.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

  4. 21 CFR 172.325 - Bakers yeast protein.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

  5. Mammalian amyloidogenic proteins promote prion nucleation in yeast.

    PubMed

    Chandramowlishwaran, Pavithra; Sun, Meng; Casey, Kristin L; Romanyuk, Andrey V; Grizel, Anastasiya V; Sopova, Julia V; Rubel, Aleksandr A; Nussbaum-Krammer, Carmen; Vorberg, Ina M; Chernoff, Yury O

    2018-03-02

    Fibrous cross-β aggregates (amyloids) and their transmissible forms (prions) cause diseases in mammals (including humans) and control heritable traits in yeast. Initial nucleation of a yeast prion by transiently overproduced prion-forming protein or its (typically, QN-rich) prion domain is efficient only in the presence of another aggregated (in most cases, QN-rich) protein. Here, we demonstrate that a fusion of the prion domain of yeast protein Sup35 to some non-QN-rich mammalian proteins, associated with amyloid diseases, promotes nucleation of Sup35 prions in the absence of pre-existing aggregates. In contrast, both a fusion of the Sup35 prion domain to a multimeric non-amyloidogenic protein and the expression of a mammalian amyloidogenic protein that is not fused to the Sup35 prion domain failed to promote prion nucleation, further indicating that physical linkage of a mammalian amyloidogenic protein to the prion domain of a yeast protein is required for the nucleation of a yeast prion. Biochemical and cytological approaches confirmed the nucleation of protein aggregates in the yeast cell. Sequence alterations antagonizing or enhancing amyloidogenicity of human amyloid-β (associated with Alzheimer's disease) and mouse prion protein (associated with prion diseases), respectively, antagonized or enhanced nucleation of a yeast prion by these proteins. The yeast-based prion nucleation assay, developed in our work, can be employed for mutational dissection of amyloidogenic proteins. We anticipate that it will aid in the identification of chemicals that influence initial amyloid nucleation and in searching for new amyloidogenic proteins in a variety of proteomes. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Inventions on baker's yeast storage and activation at the bakery plant.

    PubMed

    Gélinas, Pierre

    2010-01-01

    Baker's yeast is the gas-forming ingredient in bakery products. Methods have been invented to properly handle baker's yeast and optimize its activity at the bakery plant. Over the years, incentives for inventions on yeast storage and activation have greatly changed depending on trends in the baking industry. For example, retailer's devices for cutting bulk pressed yeast and techniques for activating dry yeast have now lost their importance. Review of patents for invention indicates that activation of baker's yeast activity has been a very important issue for bakers, for example, with baking ingredients called yeast foods. In the recent years and especially for highly automated bakeries, interest has moved to equipments and processes for optimized storage of liquid cream yeast to thoroughly control dough fermentation and bread quality.

  7. Guidelines and recommendations on yeast cell death nomenclature.

    PubMed

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J; Breitenbach, Michael; Burhans, William C; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W; Grant, Chris M; Greenwood, Michael T; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D; Outeiro, Tiago F; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F; Sharon, Amir; Sigrist, Stephan J; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B; Tuite, Mick; Vögtle, F-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J; Zhao, Richard Y; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

    2018-01-01

    Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cel-lular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the defi-nition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differ-ential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death rou-tines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the au-thors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the pro-gress of this vibrant field of research.

  8. Guidelines and recommendations on yeast cell death nomenclature

    PubMed Central

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J.; Breitenbach, Michael; Burhans, William C.; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F.; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B.; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W.; Grant, Chris M.; Greenwood, Michael T.; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M.; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P.; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A.; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D.; Outeiro, Tiago F.; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F.; Sharon, Amir; Sigrist, Stephan J.; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M.; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B.; Tuite, Mick; Vögtle, F.-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J.; Zhao, Richard Y.; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

    2018-01-01

    Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research. PMID:29354647

  9. Applications of yeast surface display for protein engineering

    PubMed Central

    Cherf, Gerald M.; Cochran, Jennifer R.

    2015-01-01

    The method of displaying recombinant proteins on the surface of Saccharomyces cerevisiae via genetic fusion to an abundant cell wall protein, a technology known as yeast surface display, or simply, yeast display, has become a valuable protein engineering tool for a broad spectrum of biotechnology and biomedical applications. This review focuses on the use of yeast display for engineering protein affinity, stability, and enzymatic activity. Strategies and examples for each protein engineering goal are discussed. Additional applications of yeast display are also briefly presented, including protein epitope mapping, identification of protein-protein interactions, and uses of displayed proteins in industry and medicine. PMID:26060074

  10. The primary structures of two yeast enolase genes. Homology between the 5' noncoding flanking regions of yeast enolase and glyceraldehyde-3-phosphate dehydrogenase genes.

    PubMed

    Holland, M J; Holland, J P; Thill, G P; Jackson, K A

    1981-02-10

    Segments of yeast genomic DNA containing two enolase structural genes have been isolated by subculture cloning procedures using a cDNA hybridization probe synthesized from purified yeast enolase mRNA. Based on restriction endonuclease and transcriptional maps of these two segments of yeast DNA, each hybrid plasmid contains a region of extensive nucleotide sequence homology which forms hybrids with the cDNA probe. The DNA sequences which flank this homologous region in the two hybrid plasmids are nonhomologous indicating that these sequences are nontandemly repeated in the yeast genome. The complete nucleotide sequence of the coding as well as the flanking noncoding regions of these genes has been determined. The amino acid sequence predicted from one reading frame of both structural genes is extremely similar to that determined for yeast enolase (Chin, C. C. Q., Brewer, J. M., Eckard, E., and Wold, F. (1981) J. Biol. Chem. 256, 1370-1376), confirming that these isolated structural genes encode yeast enolase. The nucleotide sequences of the coding regions of the genes are approximately 95% homologous, and neither gene contains an intervening sequence. Codon utilization in the enolase genes follows the same biased pattern previously described for two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes (Holland, J. P., and Holland, M. J. (1980) J. Biol. Chem. 255, 2596-2605). DNA blotting analysis confirmed that the isolated segments of yeast DNA are colinear with yeast genomic DNA and that there are two nontandemly repeated enolase genes per haploid yeast genome. The noncoding portions of the two enolase genes adjacent to the initiation and termination codons are approximately 70% homologous and contain sequences thought to be involved in the synthesis and processing messenger RNA. Finally there are regions of extensive homology between the two enolase structural genes and two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes within the 5

  11. [The yeast biofilm in human medicine].

    PubMed

    Růzicka, Filip; Holá, Veronika; Votava, Miroslav

    2007-08-01

    In recent years, the role of Candida yeasts as causative agents of nosocomial infections has increased. One of the important virulence factors contributing to the development of such infections is biofilm production. This virulence factor enables yeast to colonize both native surfaces and artificial implants. The most common sources of infection are patients themselves, in particular the gastrointestinal tract and skin. The vectors of exogenous yeast infections are predominantly the hands of the health personnel and contaminated medical instruments. The adhesion of yeasts to the implant surfaces is determined both by implant surface and yeast characteristics. This is followed by proliferation and production of microcolonies and extracellular matrix. The final biofilm structure is also influenced by the production of hyphae and pseudohyphae. The entire process of biofilm production is controlled by numerous regulatory systems, with the key role being played by the quorum sensing system. Like the adhered bacterial cultures, candidas growing in the form of a biofilm are highly resistant to antimicrobial therapy. Resistance of yeast biofilms to antifungals is a complex process with multiple contributing factors. These are especially increased gene expression (e.g. genes encoding the so called multidrug efflux pumps), limited penetration of substances through the extracellular matrix, inhibited cell growth and altered microenvironment in deeper biofilm layers. The concentrations of antifungals able to effectively affect the biofilm cells exceed, by several orders of magnitude, the values of conventionally determined MICs. High biofilm resistance results in ineffective antifungal therapy of biofilm infections. Therefore, if possible, the colonized implant should be removed. Conservative therapy should involve antifungals with a proven effect on the biofilm (e.g. caspofungin). The most effective measure in fighting biofilm infections is prevention, especially adhering to

  12. Heavy metal removal by caustic-treated yeast immobilized in alginate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lu, Y.; Wilkins, E.

    1995-12-31

    Saccharomyces cerevisiae yeast biomass was treated with hot alkali to increase its biosorption capacity for heavy metals and then was immobilized in alginate gel. Biosorption capacities for Cu{sup 2+}, Cd{sup 2+}, and Zn{sup 2+} on alginate gel, native yeast, native yeast immobilized in alginate gel, and caustic-treated yeast immobilized in alginate gel were all compared. Immobilized yeasts could be reactivated and reused in a manner similar to the ion exchange resins. Immobilized caustic-treated yeast has high heavy metal biosorption capacity and high metal removal efficiency in a rather wide acidic pH region. The biosorption isotherm of immobilized caustic-treated yeast wasmore » studied, and empirical equations were obtained. The initial pH of polluted water affected the metal removal efficiency significantly, and the equilibrium biosorption capacity seemed to be temperature independent at lower initial metal concentrations.« less

  13. A Proteome-wide Fission Yeast Interactome Reveals Network Evolution Principles from Yeasts to Human.

    PubMed

    Vo, Tommy V; Das, Jishnu; Meyer, Michael J; Cordero, Nicolas A; Akturk, Nurten; Wei, Xiaomu; Fair, Benjamin J; Degatano, Andrew G; Fragoza, Robert; Liu, Lisa G; Matsuyama, Akihisa; Trickey, Michelle; Horibata, Sachi; Grimson, Andrew; Yamano, Hiroyuki; Yoshida, Minoru; Roth, Frederick P; Pleiss, Jeffrey A; Xia, Yu; Yu, Haiyuan

    2016-01-14

    Here, we present FissionNet, a proteome-wide binary protein interactome for S. pombe, comprising 2,278 high-quality interactions, of which ∼ 50% were previously not reported in any species. FissionNet unravels previously unreported interactions implicated in processes such as gene silencing and pre-mRNA splicing. We developed a rigorous network comparison framework that accounts for assay sensitivity and specificity, revealing extensive species-specific network rewiring between fission yeast, budding yeast, and human. Surprisingly, although genes are better conserved between the yeasts, S. pombe interactions are significantly better conserved in human than in S. cerevisiae. Our framework also reveals that different modes of gene duplication influence the extent to which paralogous proteins are functionally repurposed. Finally, cross-species interactome mapping demonstrates that coevolution of interacting proteins is remarkably prevalent, a result with important implications for studying human disease in model organisms. Overall, FissionNet is a valuable resource for understanding protein functions and their evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Actin and Endocytosis in Budding Yeast

    PubMed Central

    Goode, Bruce L.; Eskin, Julian A.; Wendland, Beverly

    2015-01-01

    Endocytosis, the process whereby the plasma membrane invaginates to form vesicles, is essential for bringing many substances into the cell and for membrane turnover. The mechanism driving clathrin-mediated endocytosis (CME) involves > 50 different protein components assembling at a single location on the plasma membrane in a temporally ordered and hierarchal pathway. These proteins perform precisely choreographed steps that promote receptor recognition and clustering, membrane remodeling, and force-generating actin-filament assembly and turnover to drive membrane invagination and vesicle scission. Many critical aspects of the CME mechanism are conserved from yeast to mammals and were first elucidated in yeast, demonstrating that it is a powerful system for studying endocytosis. In this review, we describe our current mechanistic understanding of each step in the process of yeast CME, and the essential roles played by actin polymerization at these sites, while providing a historical perspective of how the landscape has changed since the preceding version of the YeastBook was published 17 years ago (1997). Finally, we discuss the key unresolved issues and where future studies might be headed. PMID:25657349

  15. Organoleptic Analysis of Doughs Fermented with Yeasts From A Nigerian Palm Wine (Elaeis guineensis) and Certain Commercial Yeasts

    PubMed Central

    B, Boboye; I, Dayo-Owoyemi; F. A, Akinyosoye

    2008-01-01

    Yeasts isolated from a freshly tapped palm wine obtained from Akure, Nigeria were identified as Schizosaccharomyces pombe, Saccharomyces cerevisiae, Debaryomyces hansenii, Geotrichum lactis and Zygosaccharomyces rouxii. Each of the isolates was used to ferment wheat flour dough and baked. Sensory analysis of the doughs was carried out on leavening, texture, aroma, taste and appearance. Saccharomyces cerevisiae performed best in leavening the dough while Debaryomyces hansenii produced doughs with the best taste and aroma. Appearances of the doughs made with all the isolated yeasts did not differ significantly (P<0.05) from that of the dough that lacked yeast. PMID:19088921

  16. Yeast as a tool to identify anti-aging compounds

    PubMed Central

    Zimmermann, Andreas; Hofer, Sebastian; Pendl, Tobias; Kainz, Katharina; Madeo, Frank; Carmona-Gutierrez, Didac

    2018-01-01

    Abstract In the search for interventions against aging and age-related diseases, biological screening platforms are indispensable tools to identify anti-aging compounds among large substance libraries. The budding yeast, Saccharomyces cerevisiae, has emerged as a powerful chemical and genetic screening platform, as it combines a rapid workflow with experimental amenability and the availability of a wide range of genetic mutant libraries. Given the amount of conserved genes and aging mechanisms between yeast and human, testing candidate anti-aging substances in yeast gene-deletion or overexpression collections, or de novo derived mutants, has proven highly successful in finding potential molecular targets. Yeast-based studies, for example, have led to the discovery of the polyphenol resveratrol and the natural polyamine spermidine as potential anti-aging agents. Here, we present strategies for pharmacological anti-aging screens in yeast, discuss common pitfalls and summarize studies that have used yeast for drug discovery and target identification. PMID:29905792

  17. Yeast Genomics for Bread, Beer, Biology, Bucks and Breath

    NASA Astrophysics Data System (ADS)

    Sakharkar, Kishore R.; Sakharkar, Meena K.

    The rapid advances and scale up of projects in DNA sequencing dur ing the past two decades have produced complete genome sequences of several eukaryotic species. The versatile genetic malleability of the yeast, and the high degree of conservation between its cellular processes and those of human cells have made it a model of choice for pioneering research in molecular and cell biology. The complete sequence of yeast genome has proven to be extremely useful as a reference towards the sequences of human and for providing systems to explore key gene functions. Yeast has been a ‘legendary model’ for new technologies and gaining new biological insights into basic biological sciences and biotechnology. This chapter describes the awesome power of yeast genetics, genomics and proteomics in understanding of biological function. The applications of yeast as a screening tool to the field of drug discovery and development are highlighted and the traditional importance of yeast for bakers and brewers is discussed.

  18. [Treatment of oil-manufacturing wastewater by yeast-SBR system].

    PubMed

    Lü, Wen-zhou; Liu, Ying; Huang, Yi-zhen

    2008-04-01

    Eight yeast strains were applied to a sequencing batch reactor (SBR) to treat high-strength oil-containing wastewater. The removal performance, yeast cultivation method and key factors affecting the stability of system were discussed. The results show yeast sludge with MLSS of 19 g/L and SVI of 35 mL/g can be obtained in 6 d in an open system without any molds and bacteria inhibitor addition; In 30 d continuous wastewater treatment, COD and oil removal rate achieve 86.8%-96.9% and above 99.5% respectively under the influent conditions of the COD of 9000-23000 mg/L and oil of 4500-16000 mg/L; Short period of pH impact brings reversible effects on the system and the sludge retention time can affect the SVI of the yeast; Absence of nitrogen induces morphology conversion of some yeast cells from single cell to filamentous one and impairs the settling capability of the yeast.

  19. The Yeast Deletion Collection: A Decade of Functional Genomics

    PubMed Central

    Giaever, Guri; Nislow, Corey

    2014-01-01

    The yeast deletion collections comprise >21,000 mutant strains that carry precise start-to-stop deletions of ∼6000 open reading frames. This collection includes heterozygous and homozygous diploids, and haploids of both MATa and MATα mating types. The yeast deletion collection, or yeast knockout (YKO) set, represents the first and only complete, systematically constructed deletion collection available for any organism. Conceived during the Saccharomyces cerevisiae sequencing project, work on the project began in 1998 and was completed in 2002. The YKO strains have been used in numerous laboratories in >1000 genome-wide screens. This landmark genome project has inspired development of numerous genome-wide technologies in organisms from yeast to man. Notable spinoff technologies include synthetic genetic array and HIPHOP chemogenomics. In this retrospective, we briefly describe the yeast deletion project and some of its most noteworthy biological contributions and the impact that these collections have had on the yeast research community and on genomics in general. PMID:24939991

  20. Triacetic acid lactone production in industrial Saccharomyces yeast strains

    USDA-ARS?s Scientific Manuscript database

    Triacetic acid lactone (TAL) is a potential platform chemical that can be produced in yeast. To evaluate the potential for industrial yeast strains to produce TAL, the g2ps1 gene encoding 2-pyrone synthase was transformed into thirteen industrial yeast strains of varied genetic background. TAL produ...

  1. Astaxanthinogenesis in the yeast Phaffia rhodozyma - optimization of low-cost culture media and yeast cell-wall lysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fontana, J.D.; Baron, M.; Guimaraes, M.F.

    Astaxanthin is a diketo-dihydroxy-carotenoid produced by Phaffia rhodozyma, a basidiomicetous yeast. A low-cost fermentation medium consisting of raw sugarcane juice and urea was developed to exploit the active sucrolytic/urelolytic enzyme apparatus inherent to the yeast. As compared to the beneficial effect of 0.1 g% urea, a ready nitrogen source, mild phosphoric pre inversion of juice sucrose to glucose and fructose, promptly fermentable carbon sources, resulted in smaller benefits. Corn steep liquor (CSL) was found to be a valuable supplement for both yeast biomass yield (9.2 g dry cells/L) and astaxanthin production (1.3 mg/g cells). Distillery effluent (vinace), despite only amore » slightly positive effect on yeast growth, allowed for the highest pigment productivity (1.9 mg/g cells). Trace amounts of Ni{sup 2} (1 mg/L, as a cofactor for urease) resulted in controversial effects, namely, biomass decrease and astaxanthin increase, with no effect on the release (and uptake) of ammonium ion from urea. 13 refs., 6 figs.« less

  2. The yeast replicative aging model.

    PubMed

    He, Chong; Zhou, Chuankai; Kennedy, Brian K

    2018-03-08

    It has been nearly three decades since the budding yeast Saccharomyces cerevisiae became a significant model organism for aging research and it has emerged as both simple and powerful. The replicative aging assay, which interrogates the number of times a "mother" cell can divide and produce "daughters", has been a stalwart in these studies, and genetic approaches have led to the identification of hundreds of genes impacting lifespan. More recently, cell biological and biochemical approaches have been developed to determine how cellular processes become altered with age. Together, the tools are in place to develop a holistic view of aging in this single-celled organism. Here, we summarize the current state of understanding of yeast replicative aging with a focus on the recent studies that shed new light on how aging pathways interact to modulate lifespan in yeast. Copyright © 2018. Published by Elsevier B.V.

  3. New lager yeast strains generated by interspecific hybridization.

    PubMed

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2015-05-01

    The interspecific hybrid Saccharomyces pastorianus is the most commonly used yeast in brewery fermentations worldwide. Here, we generated de novo lager yeast hybrids by mating a domesticated and strongly flocculent Saccharomyces cerevisiae ale strain with the Saccharomyces eubayanus type strain. The hybrids were characterized with respect to the parent strains in a wort fermentation performed at temperatures typical for lager brewing (12 °C). The resulting beers were analysed for sugar and aroma compounds, while the yeasts were tested for their flocculation ability and α-glucoside transport capability. These hybrids inherited beneficial properties from both parent strains (cryotolerance, maltotriose utilization and strong flocculation) and showed apparent hybrid vigour, fermenting faster and producing beer with higher alcohol content (5.6 vs 4.5 % ABV) than the parents. Results suggest that interspecific hybridization is suitable for production of novel non-GM lager yeast strains with unique properties and will help in elucidating the evolutionary history of industrial lager yeast.

  4. Interactions between yeast lees and wine polyphenols during simulation of wine aging. II. Analysis of desorbed polyphenol compounds from yeast lees.

    PubMed

    Mazauric, Jean-Paul; Salmon, Jean-Michel

    2006-05-31

    In the first part of this work, the analysis of the polyphenolic compounds remaining in the wine after different contact times with yeast lees during simulation of red wine aging was undertaken. To achieve a more precise view of the wine polyphenols adsorbed on lees during red wine aging and to establish a clear balance between adsorbed and remnant polyphenol compounds, the specific analysis of the chemical composition of the adsorbed polyphenolic compounds (condensed tannins and anthocyanins) after their partial desorbtion from yeast lees by denaturation treatments was realized in the second part of the study. The total recovery of polyphenol compounds from yeast lees was not complete, since a rather important part of the initial wine colored polyphenols, especially those with a dominant blue color component, remained strongly adsorbed on yeast lees, as monitored by color tristimulus and reflectance spectra measurements. All anthocyanins were recovered at a rather high percentage (about 62%), and it was demonstrated that they were not adsorbed in relation with their sole polarity. Very few monomeric phenolic compounds were extracted from yeast lees. With the use of drastic denaturing treatments, the total recovery of condensed tannins reached 83%. Such tannins extracted from yeast lees exhibited very high polymeric size and a rather high percentage of galloylated residues by comparison with initial wine tannins, indicating that nonpolar tannins were preferentially desorbed from yeast lees by the extraction treatments.

  5. Vaginal Yeast Infections

    MedlinePlus

    ... for sure if yogurt with Lactobacillus or other probiotics can prevent or treat vaginal yeast infections. If ... Chen, H., et al. (2013). Impact of eating probiotic yogurt on colonization by Candida species of the ...

  6. Prevalence of external ear disorders in Belgian stray cats.

    PubMed

    Bollez, Anouck; de Rooster, Hilde; Furcas, Alessandra; Vandenabeele, Sophie

    2018-02-01

    Objectives Feline otitis externa is a multifactorial dermatological disorder about which very little is known. The objective of this study was to map the prevalence of external ear canal disorders and the pathogens causing otitis externa in stray cats roaming around the region of Ghent, Belgium. Methods One hundred and thirty stray cats were randomly selected during a local trap-neuter-return programme. All cats were European Shorthairs. This study included clinical, otoscopic and cytological evaluation of both external ears of each cat. Prospective data used as parameters in this study included the sex, age and body condition score of each cat, as well as the presence of nasal and/or ocular discharge, and the results of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) Snap tests. Results Remarkably, very few (sub)clinical problems of the external ear canal were found in the stray cat population. Malassezia species was by far the most common organism found in the external ear canals of the 130 stray cats. A total of 96/130 (74%) cats were found to have Malassezia species organisms present in one or both ears based on the cytological examination. No correlation was found between the parameters of sex, age, body condition score, the presence of nasal and/or ocular discharge and FIV and FeLV status, and the presence of parasites, bacteria or yeasts. Conclusions and relevance This study provides more information about the normal state of the external ear canal of stray cats. The ears of most stray cats are relatively healthy. The presence of Malassezia species organisms in the external ear canal is not rare among stray cats.

  7. Oxidative Stress and Programmed Cell Death in Yeast

    PubMed Central

    Farrugia, Gianluca; Balzan, Rena

    2012-01-01

    Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed. PMID:22737670

  8. [Yeast microbiota in artisanal cheeses from Corrientes, Argentina].

    PubMed

    Cardozo, Marina C; Fusco, Ángel J V; Carrasco, Marta S

    The artisanal cheese from Corrientes (from the Spanish acronym QAC-Queso Artesanal de Corrientes/Artisanal Cheese from Corrientes) is a soft cheese elaborated with raw cow milk and an artisanal coagulant agent. Lactic bacteria contitute the main flora of this cheese although yeasts are also present in high quantities as secondary microbiota and might play a relevant role in cheese ripening. The aim of this work was to evaluate yeast occurrence during QAC elaboration and ripening, and the effect of seasonal variation. Yeasts were isolated and purified from raw materials and cheese at different ripening stagesl elaborated during the different seasons. Yeast sample counts were in the order of 10 3 - 10 7 UFC/ml o UFC/g. Ninety yeast strains were classified: 9 from milk, 28 from the coagulant agent, 10 from curd and 43 from cheese. Candida predominated in milk samples while other yeast genera had low incidence. Candida also predominated in the coagulant agent samples, followed by genera Myxozyma and Debaryomyces. The isolates obtained from cheese belonged to the same genera predominating in the coagulant agent, and showed the same order of prevalence. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker's Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast.

    PubMed

    Ran, Chao; Huang, Lu; Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker's yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker's yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  10. The impact of yeast fermentation on dough matrix properties.

    PubMed

    Rezaei, Mohammad N; Jayaram, Vinay B; Verstrepen, Kevin J; Courtin, Christophe M

    2016-08-01

    Most studies on dough properties are performed on yeastless dough to exclude the complicating, time-dependent effect of yeast. Baker's yeast, however, impacts dough matrix properties during fermentation, probably through the production of primary (CO2 and ethanol) and secondary (glycerol, acetic acid and succinic acid) metabolites. The aim of this study is to obtain a better understanding of the changes in yeasted dough behavior introduced by fermentation, by investigating the impact of yeast fermentation on Farinograph dough consistency, dough spread, Kieffer rig dough extensibility and gluten agglomeration behavior in a fermented dough-batter gluten starch separation system. Results show that fermentation leads to a dough with less flow and lower extensibility that breaks more easily under stress and strain. The dough showed less elastic and more plastic deformation behavior. Gluten agglomerates were smaller for yeasted dough than for the unyeasted control. These changes probably have to be attributed to metabolites generated during fermentation. Indeed, organic acids and also ethanol in concentrations produced by yeast were previously shown to have similar effects in yeastless dough. These findings imply the high importance of yeast fermentation metabolites on dough matrix properties in industrial bread production. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  11. Yeast as a model system for mammalian seven-transmembrane segment receptors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jeansonne, N.E.

    1994-05-01

    Investigators have used the budding yeast Saccharomyces cerevisiae as a model system in which to study the {beta}-adrenergic receptor, the T-cell receptor pathway, initiation of mammalian DNA replication, initiation of mammalian transcription, secretion, the CDC2 kinase system, cell cycle control, and aging, as well as the function of oncogenes. This list continues to growth with the discovery of an immunoglobulin heavy-chain binding homologue in yeast, an Rb binding protein homologue, and a possible yeast arrestin. Yeast is relatively easy to maintain, to grow, and to genetically manipulate. A single gene can be overexpressed, selectively mutated or deleted from its chromosomalmore » location. In this way, the in vivo function of a gene can be studied. It has become reasonable to consider yeast as a model system for studying the seven transmembrane segments (7-TMS) receptor family. Currently, subtypes of the {beta}-adrenergic receptor are being studied in yeast. The receptor and its G{sub {alpha}}-G-protein, trigger the mating pheromone receptor pathway. This provides a powerful assay for determining receptor function. Studies expressing the muscarinic cholinergic receptor in yeast are underway. The yeast pheromone receptor belongs to this receptor family, sharing sequences and secondary structure homology. An effective strategy has been to identify a yeast pathway or process which is homologous to a mammalian system. The pathway is delineated in yeast, identifying other genetic components. Then yeast genes are used to screen for human homologues of these components. The putative human homologues are then expressed in yeast and in mammalian cells to determine function. When this type of {open_quotes}mixing and matching{close_quotes} works, yeast genetics can be a powerful tool. 115 refs.« less

  12. Nonlinear Dielectric Properties of Yeast Cells Cultured in Different Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Kawanishi, Gomon; Fukuda, Naoki; Muraji, Masafumi

    The harmonics of the electric current through yeast suspensions, the nonlinear dielectric properties of yeast cells, have particular patterns according to the biological activity of the cells and the measurement of these patterns is a technique for determining the activity of living cells. The concentration of glucose and oxygen in yeast culture medium influences the manifestation of fermentation or respiration of yeast cells. Measurements were made with yeast cells (Saccharomyces cerevisiae) cultured aerobically and anaerobically in sufficient glucose concentration, aerobic fermentation and anaerobic fermentation, and aerobically in limited glucose concentration, respiration. The results showed that the harmonics were barely apparent for yeast cells in aerobic fermentation and respiratory; however, cells in the anaerobic fermentation displayed substantial third and fifth harmonics. We can say that environmental condition affects the yeast cells' nonlinear properties, from another viewpoint, the measurements of the nonlinear properties are available to determine the activity of yeast cells adjusted to the conditions of their cultivation.

  13. Diversity and killer activity of yeasts in Malaysian fermented food samples.

    PubMed

    Lim, S L; Tay, S T

    2011-08-01

    The biodiversity and the killer activity of yeasts isolated from various types of fermented food in Malaysia were investigated in this study. Of 252 yeasts isolated from 48 fermented food samples in this study, 19 yeast species were identified based on sequence analysis of the ITS1-5.8S-ITS2 partial fragments of the yeasts. A total of 29 (11.5%) of the yeast isolates demonstrated killer activity to at least one Candida species tested in this study; including 22 isolates of Trichosporon asahii, 4 isolates of Pichia anomala, and one isolate each of Pichia norvegensis, Pichia fermentans and Issatchenkia orientalis, respectively. The presence of killer yeasts reflects antagonism that occurs during microbial interaction in the fermented food, whereby certain yeasts produce killer toxins and possibly other toxic substances in competition for limited nutrients and space. The anti-Candida activity demonstrated by killer yeasts in this study should be further explored for development of alternative therapy against candidiasis.

  14. Yeast Infection Test

    MedlinePlus

    ... infections of the skin and genitals. Serious yeast infections occur more often in hospital patients and in people with weakened immune systems. References Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health ...

  15. Biocavity laser spectroscopy of genetically altered yeast cells and isolated yeast mitochondria

    NASA Astrophysics Data System (ADS)

    Gourley, Paul L.; Hendricks, Judy K.; McDonald, Anthony E.; Copeland, R. Guild; Naviaux, Robert K.; Yaffe, Michael P.

    2006-02-01

    We report an analysis of 2 yeast cell mutants using biocavity laser spectroscopy. The two yeast strains differed only by the presence or absence of mitochondrial DNA. Strain 104 is a wild-type (ρ +) strain of the baker's yeast, Saccharomyces cerevisiae. Strain 110 was derived from strain 104 by removal of its mitochondrial DNA (mtDNA). Removal of mtDNA causes strain 110 to grow as a "petite" (ρ -), named because it forms small colonies (of fewer cells because it grows more slowly) on agar plates supplemented with a variety of different carbon sources. The absence of mitochondrial DNA results in the complete loss of all the mtDNA-encoded proteins and RNAs, and loss of the pigmented, heme-containing cytochromes a and b. These cells have mitochondria, but the mitochondria lack the normal respiratory chain complexes I, III, IV, and V. Complex II is preserved because its subunits are encoded by genes located in nuclear DNA. The frequency distributions of the peak shifts produced by wild-type and petite cells and mitochondria show striking differences in the symmetry and patterns of the distributions. Wild-type ρ + cells (104) and mitochondria produced nearly symmetric, Gaussian distributions. The ρ - cells (110) and mitochondria showed striking asymmetry and skew that appeared to follow a Poisson distribution.

  16. Site-directed mutagenesis studies of the aromatic residues at the active site of a lipase from Malassezia globosa.

    PubMed

    Gao, Chongliang; Lan, Dongming; Liu, Lu; Zhang, Houjin; Yang, Bo; Wang, Yonghua

    2014-07-01

    The lipase from Malassezia globosa (SMG1) has specific activity on mono- and diacylglycerol but not on triacylglycerol. The structural analysis of SMG1 structure shows that two bulky aromatic residues, W116 and W229, lie at the entrance of the active site. To study the functions of these two residues in the substrate recognition and the catalytic reaction, they were mutated to a series of amino acids. Subsequently, biochemical properties of these mutants were investigated. Although the activities decrease, W229L and W116A show a significant shift in substrate preference. W229L has an increased preference for short-chain substrates whereas W116A has preference for long-chain substrates. Besides, the half-lives of W116A and W116H at 45 °C are 346.6 min and 115.5 min respectively, which improve significantly compared to that of native enzyme. Moreover, the optimum substrate of W116A, W116F and W229F mutants shifted from p-nitrophenyl caprylate to p-nitrophenyl myristate. These findings not only shed light onto the lipase structure/function relationship but also lay the framework for the potential industrial applications. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Efforts to make and apply humanized yeast

    PubMed Central

    Laurent, Jon M.; Young, Jonathan H.; Kachroo, Aashiq H.

    2016-01-01

    Despite a billion years of divergent evolution, the baker’s yeast Saccharomyces cerevisiae has long proven to be an invaluable model organism for studying human biology. Given its tractability and ease of genetic manipulation, along with extensive genetic conservation with humans, it is perhaps no surprise that researchers have been able to expand its utility by expressing human proteins in yeast, or by humanizing specific yeast amino acids, proteins or even entire pathways. These methods are increasingly being scaled in throughput, further enabling the detailed investigation of human biology and disease-specific variations of human genes in a simplified model organism. PMID:26462863

  18. The Influence of Heating Mains on Yeast Communities in Urban Soils

    NASA Astrophysics Data System (ADS)

    Tepeeva, A. N.; Glushakova, A. M.; Kachalkin, A. V.

    2018-04-01

    The number and species diversity of yeasts in urban soils (urbanozems) affected by heating mains and in epiphytic yeast complexes of grasses growing above them were studied. The number of yeasts in the soil reached 103-104 CFU/g; on the plants, 107 CFU/g. Significant (by an order of magnitude) increase in the total number of soil yeasts in the zone of heating mains in comparison with the surrounding soil was found in winter period. Overall, 25 species of yeasts were isolated in our study. Yeast community of studied urbanozems was dominated by the Candida sake, an eurybiont of the temperate zone and other natural ecotopes with relatively low temperatures, but its share was minimal in the zone of heating mains. In general, the structure of soil and epiphytic yeast complexes in the zones of heating mains differed from that in the surrounding area by higher species diversity and a lower share of pigmented species among the epiphytic yeasts. The study demonstrated that the number and species structure of soil yeast communities in urban soils change significantly under the influence of the temperature factor and acquire a mosaic distribution pattern.

  19. Genetic Polymorphism in Wine Yeasts: Mechanisms and Methods for Its Detection

    PubMed Central

    Guillamón, José M.; Barrio, Eladio

    2017-01-01

    The processes of yeast selection for using as wine fermentation starters have revealed a great phenotypic diversity both at interspecific and intraspecific level, which is explained by a corresponding genetic variation among different yeast isolates. Thus, the mechanisms involved in promoting these genetic changes are the main engine generating yeast biodiversity. Currently, an important task to understand biodiversity, population structure and evolutionary history of wine yeasts is the study of the molecular mechanisms involved in yeast adaptation to wine fermentation, and on remodeling the genomic features of wine yeast, unconsciously selected since the advent of winemaking. Moreover, the availability of rapid and simple molecular techniques that show genetic polymorphisms at species and strain levels have enabled the study of yeast diversity during wine fermentation. This review will summarize the mechanisms involved in generating genetic polymorphisms in yeasts, the molecular methods used to unveil genetic variation, and the utility of these polymorphisms to differentiate strains, populations, and species in order to infer the evolutionary history and the adaptive evolution of wine yeasts, and to identify their influence on their biotechnological and sensorial properties. PMID:28522998

  20. Nectar yeasts warm the flowers of a winter-blooming plant

    PubMed Central

    Herrera, Carlos M.; Pozo, María I.

    2010-01-01

    Yeasts are ubiquitous in terrestrial and aquatic microbiota, yet their ecological functionality remains relatively unexplored in comparison with other micro-organisms. This paper formulates and tests the novel hypothesis that heat produced by the sugar catabolism of yeast populations inhabiting floral nectar can increase the temperature of floral nectar and, more generally, modify the within-flower thermal microenvironment. Two field experiments were designed to test this hypothesis for the winter-blooming herb Helleborus foetidus (Ranunculaceae). In experiment 1, the effect of yeasts on the within-flower thermal environment was tested by excluding them from flowers, while in experiment 2 the test involved artificial inoculation of virgin flowers with yeasts. Nectary temperature (Tnect), within-flower air temperature (Tflow) and external air temperature (Tair) were measured on experimental and control flowers in both experiments. Experimental exclusion of yeasts from the nectaries significantly reduced, and experimental addition of yeasts significantly increased, the temperature excess of nectaries (ΔTnect = Tnect − Tair) and the air space inside flowers in relation to the air just outside the flowers. In non-experimental flowers exposed to natural pollinator visitation, ΔTnect was linearly related to log yeast cell density in nectar, and reached +6°C in nectaries with the densest yeast populations. The warming effect of nectar-dwelling yeasts documented in this study suggests novel ecological mechanisms potentially linking nectarivorous microbes with winter-blooming plants and their insect pollinators. PMID:20147331

  1. Glycosylceramide modifies the flavor and metabolic characteristics of sake yeast.

    PubMed

    Ferdouse, Jannatul; Yamamoto, Yuki; Taguchi, Seiga; Yoshizaki, Yumiko; Takamine, Kazunori; Kitagaki, Hiroshi

    2018-01-01

    In the manufacture of sake, Japanese traditional rice wine, sake yeast is fermented with koji, which is steamed rice fermented with the non-pathogenic fungus Aspergillus oryzae . During fermentation, sake yeast requires lipids, such as unsaturated fatty acids and sterols, in addition to substances provided by koji enzymes for fermentation. However, the role of sphingolipids on the brewing characteristics of sake yeast has not been studied. In this study, we revealed that glycosylceramide, one of the sphingolipids abundant in koji, affects yeast fermentation. The addition of soy, A. oryzae , and Grifola frondosa glycosylceramide conferred a similar effect on the flavor profiles of sake yeast. In particular, the addition of A. oryzae and G. frondosa glycosylceramide were very similar in terms of the decreases in ethyl caprylate and ethyl 9-decenoate. The addition of soy glycosylceramide induced metabolic changes to sake yeast such as a decrease in glucose, increases in ethanol and glycerol and changes in several amino acids and organic acids concentrations. Tricarboxylic acid (TCA) cycle, pyruvate metabolism, starch and sucrose metabolism, and glycerolipid metabolism were overrepresented in the cultures incubated with sake yeast and soy glycosylceramide. This is the first study of the effect of glycosylceramide on the flavor and metabolic profile of sake yeast.

  2. Brewer's/baker's yeast (Saccharomyces cerevisiae) and preventive medicine: part I.

    PubMed

    Moyad, Mark A

    2007-12-01

    Yeast is the term generally applied to a unicellular fungus, and there are hundreds of species now identified. One of the most notable and well-known species of yeast in health and wellness is known as Saccharomyces cerevisiae, which is also known by its more common names, brewer's yeast or baker's yeast. It is usually grown on hops or another substrate similar to the plant utilized in the beer-making industry, after which it is harvested and killed. The final product is generally half composed of protein, as well as a large amount of B vitamins and minerals, and depending on the technology, a diverse number of other healthy compounds. Typically, brewer's yeast is used as a protein supplement, energy booster, immune enhancer, or other vehicle where other compounds can be inserted to create a commercialized health product. A more extensive review of the preventive medical aspects of yeast will be covered in Part 2 of this article to be published in a future issue of Urologic Nursing. Yeast-based technology is also being used as a molecular mechanistic model of caloric restriction with the goal of improving the human life span. The current and potential impact of yeast-based technology in medicine is encouraging.

  3. Glycosylceramide modifies the flavor and metabolic characteristics of sake yeast

    PubMed Central

    Taguchi, Seiga; Yoshizaki, Yumiko; Takamine, Kazunori

    2018-01-01

    In the manufacture of sake, Japanese traditional rice wine, sake yeast is fermented with koji, which is steamed rice fermented with the non-pathogenic fungus Aspergillus oryzae. During fermentation, sake yeast requires lipids, such as unsaturated fatty acids and sterols, in addition to substances provided by koji enzymes for fermentation. However, the role of sphingolipids on the brewing characteristics of sake yeast has not been studied. In this study, we revealed that glycosylceramide, one of the sphingolipids abundant in koji, affects yeast fermentation. The addition of soy, A. oryzae, and Grifola frondosa glycosylceramide conferred a similar effect on the flavor profiles of sake yeast. In particular, the addition of A. oryzae and G. frondosa glycosylceramide were very similar in terms of the decreases in ethyl caprylate and ethyl 9-decenoate. The addition of soy glycosylceramide induced metabolic changes to sake yeast such as a decrease in glucose, increases in ethanol and glycerol and changes in several amino acids and organic acids concentrations. Tricarboxylic acid (TCA) cycle, pyruvate metabolism, starch and sucrose metabolism, and glycerolipid metabolism were overrepresented in the cultures incubated with sake yeast and soy glycosylceramide. This is the first study of the effect of glycosylceramide on the flavor and metabolic profile of sake yeast. PMID:29761062

  4. Dielectric modelling of cell division for budding and fission yeast

    NASA Astrophysics Data System (ADS)

    Asami, Koji; Sekine, Katsuhisa

    2007-02-01

    The frequency dependence of complex permittivity or the dielectric spectrum of a system including a cell in cell division has been simulated by a numerical technique based on the three-dimensional finite difference method. Two different types of cell division characteristic of budding and fission yeast were examined. The yeast cells are both regarded as a body of rotation, and thus have anisotropic polarization, i.e. the effective permittivity of the cell depends on the orientation of the cell to the direction of an applied electric field. In the perpendicular orientation, where the rotational axis of the cell is perpendicular to the electric field direction, the dielectric spectra for both yeast cells included one dielectric relaxation and its intensity depended on the cell volume. In the parallel orientation, on the other hand, two dielectric relaxations appeared with bud growth for budding yeast and with septum formation for fission yeast. The low-frequency relaxation was shifted to a lower frequency region by narrowing the neck between the bud and the mother cell for budding yeast and by increasing the degree of septum formation for fission yeast. After cell separation, the low-frequency relaxation disappeared. The simulations well interpreted the oscillation of the relative permittivity of culture broth found for synchronous cell growth of budding yeast.

  5. A new methodology to obtain wine yeast strains overproducing mannoproteins.

    PubMed

    Quirós, Manuel; Gonzalez-Ramos, Daniel; Tabera, Laura; Gonzalez, Ramon

    2010-04-30

    Yeast mannoproteins are highly glycosylated proteins that are covalently bound to the beta-1,3-glucan present in the yeast cell wall. Among their outstanding enological properties, yeast mannoproteins contribute to several aspects of wine quality by protecting against protein haze, reducing astringency, retaining aroma compounds and stimulating growth of lactic-acid bacteria. The development of a non-recombinant method to obtain enological yeast strains overproducing mannoproteins would therefore be very useful. Our previous experience on the genetic determinants of the release of these molecules by Saccharomyces cerevisiae has allowed us to propose a new methodology to isolate and characterize wine yeast that overproduce mannoproteins. The described methodology is based on the resistance of the killer 9 toxin produced by Williopsis saturnus, a feature linked to an altered biogenesis of the yeast cell wall. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Biosorption of nickel by yeasts in an osmotically unsuitable environment.

    PubMed

    Breierová, Emilia; Certík, Milan; Kovárová, Annamaria; Gregor, Tomas

    2008-01-01

    The tolerance, sorption of nickel(II) ions, and changes in the production and composition of exopolymers of eight yeast strains grown under nickel presence with/without NaCl were studied. Strains of Pichia anomala and Candida maltosa known as the most resistant yeasts against nickel tolerated up to 3 mM Ni2+. NaCl addition decreased both the resistance of the yeast strains toward nickel ions and the sorption of metal ions into cells. All yeasts absorbed nickel predominantly into exopolymers (glycoproteins) and on the surface of cells. However, while the amount of polysaccharide moieties of exoglycoproteins of most of the resistant yeasts was induced by stress conditions, the ratio polysaccharide/protein in the exopolymers remained unchanged in the sensitive species Cystofilobasidium. The exopolymer composition might play a key role in yeast adaptation to stress conditions caused by heavy metal ions.

  7. Cellodextrin transport in yeast for improved biofuel production.

    PubMed

    Galazka, Jonathan M; Tian, Chaoguang; Beeson, William T; Martinez, Bruno; Glass, N Louise; Cate, Jamie H D

    2010-10-01

    Fungal degradation of plant biomass may provide insights for improving cellulosic biofuel production. We show that the model cellulolytic fungus Neurospora crassa relies on a high-affinity cellodextrin transport system for rapid growth on cellulose. Reconstitution of the N. crassa cellodextrin transport system in Saccharomyces cerevisiae promotes efficient growth of this yeast on cellodextrins. In simultaneous saccharification and fermentation experiments, the engineered yeast strains more rapidly convert cellulose to ethanol when compared with yeast lacking this system.

  8. Yeast: An Experimental Organism for Modern Biology.

    ERIC Educational Resources Information Center

    Botstein, David; Fink, Gerald R.

    1988-01-01

    Discusses the applicability and advantages of using yeasts as popular and ideal model systems for studying and understanding eukaryotic biology at the cellular and molecular levels. Cites experimental tractability and the cooperative tradition of the research community of yeast biologists as reasons for this success. (RT)

  9. Characterization of Hyaluronan-Degrading Enzymes from Yeasts.

    PubMed

    Smirnou, Dzianis; Krčmář, Martin; Kulhánek, Jaromír; Hermannová, Martina; Bobková, Lenka; Franke, Lukáš; Pepeliaev, Stanislav; Velebný, Vladimír

    2015-10-01

    Hyaluronidases (HAases) from yeasts were characterized for the first time. The study elucidated that hyaluronate 4-glycanohydrolase and hyaluronan (HA) lyase can be produced by yeasts. Six yeasts producing HAases were found through express screening of activities. The extracellular HAases from two of the yeast isolates, Pseudozyma aphidis and Cryptococcus laurentii, were characterized among them. P. aphidis HAase hydrolyzed β-1,4 glycosidic bonds of HA, yielding even-numbered oligosaccharides with N-acetyl-D-glucosamine at the reducing end. C. laurentii produced hyaluronan lyase, which cleaved β-1,4 glycosidic bonds of HA in β-elimination reaction, and the products of HA degradation were different-sized even-numbered oligosaccharides. The shortest detected HA oligomer was dimer. The enzymes' pH and temperature optima were pH 3.0 and 37-45 °C (P. aphidis) and pH 6.0 and 37 °C (C. laurentii), respectively. Both HAases showed good thermostability.

  10. Nuclear Magnetic Resonance Spectroscopy-Based Identification of Yeast.

    PubMed

    Himmelreich, Uwe; Sorrell, Tania C; Daniel, Heide-Marie

    2017-01-01

    Rapid and robust high-throughput identification of environmental, industrial, or clinical yeast isolates is important whenever relatively large numbers of samples need to be processed in a cost-efficient way. Nuclear magnetic resonance (NMR) spectroscopy generates complex data based on metabolite profiles, chemical composition and possibly on medium consumption, which can not only be used for the assessment of metabolic pathways but also for accurate identification of yeast down to the subspecies level. Initial results on NMR based yeast identification where comparable with conventional and DNA-based identification. Potential advantages of NMR spectroscopy in mycological laboratories include not only accurate identification but also the potential of automated sample delivery, automated analysis using computer-based methods, rapid turnaround time, high throughput, and low running costs.We describe here the sample preparation, data acquisition and analysis for NMR-based yeast identification. In addition, a roadmap for the development of classification strategies is given that will result in the acquisition of a database and analysis algorithms for yeast identification in different environments.

  11. Responses of Yeast Biocontrol Agents to Environmental Stress

    PubMed Central

    Sui, Yuan; Wisniewski, Michael; Droby, Samir

    2015-01-01

    Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeast species, is a research topic that has received considerable attention in the literature over the past 30 years. In principle, it represents a promising alternative to chemical fungicides for the management of postharvest decay of fruits, vegetables, and grains. A yeast-based biocontrol system is composed of a tritrophic interaction between a host (commodity), a pathogen, and a yeast species, all of which are affected by environmental factors such as temperature, pH, and UV light as well as osmotic and oxidative stresses. Additionally, during the production process, biocontrol agents encounter various severe abiotic stresses that also impact their viability. Therefore, understanding the ecological fitness of the potential yeast biocontrol agents and developing strategies to enhance their stress tolerance are essential to their efficacy and commercial application. The current review provides an overview of the responses of antagonistic yeast species to various environmental stresses, the methods that can be used to improve stress tolerance and efficacy, and the related mechanisms associated with improved stress tolerance. PMID:25710368

  12. Oxygen requirements of yeasts. [Saccharomyces cerevisiae; Candida tropicalis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Visser, W.; Scheffers, W.A.; Batenburg-Van Der Vegte, W.H.

    1990-12-01

    Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, suchmore » as Torulaspora delbrueckii and Candida tropicalis, grew poorly ({mu}{sub max}, 0.03 and 0.05 h{sup {minus}1}, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth.« less

  13. Vegemite Beer: yeast extract spreads as nutrient supplements to promote fermentation.

    PubMed

    Kerr, Edward D; Schulz, Benjamin L

    2016-01-01

    Vegemite is an iconic Australian food spread made from spent brewers' yeast extract, which has been reported to be used as an ingredient in illegal home brewing. In this study, we tested the utility of Vegemite and the similar spread Marmite in promoting fermentation. We could not culture microorganisms from either Vegemite or Marmite, consistent with these food-grade spreads being essentially sterile. To test if the addition of Vegemite or Marmite could assist in fermentation when additional viable yeast was also present, solutions containing glucose and a range of concentrations of either Vegemite or Marmite were inoculated with brewers' yeast. No fermentation occurred in any condition without addition of extra brewer's yeast. Fermentation did not occur when yeast was inoculated into solutions containing only glucose, but progressed efficiently with when Vegemite or Marmite was also added. Gas Chromatography confirmed that ethanol was present at ∼3% v/v post-fermentation in all samples which contained glucose, Vegemite or Marmite, and brewers' yeast. Trace amounts of methanol were also detected. Mass spectrometry proteomics identified abundant intracellular yeast proteins and barley proteins in Vegemite and Marmite, and abundant secreted yeast proteins from actively growing yeast in those samples to which extra brewers' yeast had been added. We estimate that the real-world cost of home brewed "Vegemite Beer" would be very low. Our results show that Vegemite or other yeast extract spreads could provide cheap and readily available sources of nutrient supplementation to increase the efficiency of fermentation in home brewing or other settings.

  14. Fungi in the healthy human gastrointestinal tract

    PubMed Central

    Hallen-Adams, Heather E.; Suhr, Mallory J.

    2017-01-01

    ABSTRACT Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are common on fermented foods but cannot grow at human body temperature), while still others have dietary or environmental sources (Saccharomyces cerevisiae, a fermentation agent and sometime probiotic; Aspergillus species, ubiquitous molds) yet are likely to impact gut ecology. The gut mycobiome appears less stable than the bacterial microbiome, and is likely subject to environmental factors. PMID:27736307

  15. Fungi in the healthy human gastrointestinal tract.

    PubMed

    Hallen-Adams, Heather E; Suhr, Mallory J

    2017-04-03

    Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are common on fermented foods but cannot grow at human body temperature), while still others have dietary or environmental sources (Saccharomyces cerevisiae, a fermentation agent and sometime probiotic; Aspergillus species, ubiquitous molds) yet are likely to impact gut ecology. The gut mycobiome appears less stable than the bacterial microbiome, and is likely subject to environmental factors.

  16. Yeast Biomass Production in Brewery's Spent Grains Hemicellulosic Hydrolyzate

    NASA Astrophysics Data System (ADS)

    Duarte, Luís C.; Carvalheiro, Florbela; Lopes, Sónia; Neves, Ines; Gírio, Francisco M.

    Yeast single-cell protein and yeast extract, in particular, are two products which have many feed, food, pharmaceutical, and biotechnological applications. However, many of these applications are limited by their market price. Specifically, the yeast extract requirements for culture media are one of the major technical hurdles to be overcome for the development of low-cost fermentation routes for several top value chemicals in a biorefinery framework. A potential biotechnical solution is the production of yeast biomass from the hemicellulosic fraction stream. The growth of three pentose-assimilating yeast cell factories, Debaryomyces hansenii, Kluyveromyces marxianus, and Pichia stipitis was compared using non-detoxified brewery's spent grains hemicellulosic hydrolyzate supplemented with mineral nutrients. The yeasts exhibited different specific growth rates, biomass productivities, and yields being D. hansenii as the yeast species that presented the best performance, assimilating all sugars and noteworthy consuming most of the hydrolyzate inhibitors. Under optimized conditions, D. hansenii displayed a maximum specific growth rate, biomass yield, and productivity of 0.34 h-1, 0.61 g g-1, and 0.56 g 1-1 h-1, respectively. The nutritional profile of D. hansenii was thoroughly evaluated, and it compares favorably to others reported in literature. It contains considerable amounts of some essential amino acids and a high ratio of unsaturated over saturated fatty acids.

  17. Formulation and evaluation of dried yeast tablets using different techniques.

    PubMed

    Al-Mohizea, Abdullah M; Ahmed, Mahrous O; Al-jenoobi, Fahad I; Mahrous, Gamal M; Abdel-Rahman, Aly A

    2007-08-01

    The aim of this study was to prepare and evaluate dried yeast tablets using both direct compression and dry granulation techniques in comparison with the conventional wet granulation as well as commercial product. Wet granulation technique is not favorable for producing the yeast tablets due to the problems of color darkening and the reduction of the fermentation power of the yeast as a result of the early start of the fermentation process due to the presence of moisture. Twenty six formulae of dried yeast tablets were prepared and evaluated. Certain directly compressible vehicles were employed for preparing these tablets. The quality control tests (weight uniformity, friability, disintegration time and hardness) of the prepared dried yeast tablets were performed according to B.P. 1998 limits. All batches of the prepared tablets complied with the B.P. limits of weight uniformity. Moreover, small values of friability % (1% or less) were obtained for all batches of dried yeast tablets with acceptable hardness values, indicating good mechanical properties which can withstand handling. On the other hand, not all batches complied with the limit of disintegration test which may be attributed to various formulation component variables. Therefore, four disintegrating agents were investigated for their disintegrating effect. It was found that the method of preparation, whether it is direct compression, dry granulation or wet granulation, has an effect on disintegration time of these dried yeast tablets and short disintegration times were obtained for some of the formulae. The shortest disintegration time was obtained with those tablets prepared by direct compression among the other techniques. Therefore, the direct compression is considered the best technique for preparation of dried yeast tablets and the best formula (which showed shorter disintegration time and better organoleptic properties than the available commercial yeast tablets) was chosen. Drug content for dried

  18. Cross-referencing yeast genetics and mammalian genomes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hieter, P.; Basset, D.; Boguski, M.

    1994-09-01

    We have initiated a project that will systematically transfer information about yeast genes onto the genetic maps of mice and human beings. Rapidly expanding human EST data will serve as a source of candidate human homologs that will be repeatedly searched using yeast protein sequence queries. Search results will be automatically reported to participating labs. Human cDNA sequences from which the ESTs are derived will be mapped at high resolution in the human and mouse genomes. The comparative mapping information cross-references the genomic position of novel human cDNAs with functional information known about the cognate yeast genes. This should facilitatemore » the initial identification of genes responsible for mammalian mutant phenotypes, including human disease. In addition, the identification of mammalian homologs of yeast genes provides reagents for determining evolutionary conservation and for performing direct experiments in multicellular eukaryotes to enhance study of the yeast protein`s function. For example, ESTs homologous to CDC27 and CDC16 were identified, and the corresponding cDNA clones were obtained from ATTC, completely sequenced, and mapped on human and mouse chromosomes. In addition, the CDC17hs cDNA has been used to raise antisera to the CDC27Hs protein and used in subcellular localization experiments and junctional studies in mammalian cells. We have received funding from the National Center for Human Genome Research to provide a community resource which will establish comprehensive cross-referencing among yeast, human, and mouse loci. The project is set up as a service and information on how to communicate with this effort will be provided.« less

  19. 21 CFR 172.381 - Vitamin D2 bakers yeast.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Vitamin D2 bakers yeast. 172.381 Section 172.381... CONSUMPTION Special Dietary and Nutritional Additives § 172.381 Vitamin D2 bakers yeast. Vitamin D2 bakers yeast may be used safely in foods as a source of vitamin D2 and as a leavening agent in accordance with...

  20. Yeast Modulation of Human Dendritic Cell Cytokine Secretion: An In Vitro Study

    PubMed Central

    Smith, Ida M.; Christensen, Jeffrey E.; Arneborg, Nils; Jespersen, Lene

    2014-01-01

    Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The concept of individual microorganisms influencing the makeup of T cell subsets via interactions with intestinal dendritic cells (DCs) appears to constitute the foundation for immunoregulatory effects of probiotics, and several studies have reported probiotic strains resulting in reduction of intestinal inflammation through modulation of DC function. Consequent to a focus on Saccharomyces boulardii as the fundamental probiotic yeast, very little is known about hundreds of non-Saccharomyces yeasts in terms of their interaction with the human gastrointestinal immune system. The aim of the present study was to evaluate 170 yeast strains representing 75 diverse species for modulation of inflammatory cytokine secretion by human DCs in vitro, as compared to cytokine responses induced by a S. boulardii reference strain with probiotic properties documented in clinical trials. Furthermore, we investigated whether cytokine inducing interactions between yeasts and human DCs are dependent upon yeast viability or rather a product of membrane interactions regardless of yeast metabolic function. We demonstrate high diversity in yeast induced cytokine profiles and employ multivariate data analysis to reveal distinct clustering of yeasts inducing similar cytokine profiles in DCs, highlighting clear species distinction within specific yeast genera. The observed differences in induced DC cytokine profiles add to the currently very limited knowledge of the cross-talk between yeasts and human immune cells and provide a foundation for selecting yeast strains for further characterization and development toward potentially novel yeast probiotics. Additionally, we present data to support a hypothesis that the interaction between yeasts and human DCs does not solely depend on yeast viability, a concept which may suggest a need for further classifications beyond the current