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P Mayser

Publications and source records attributed to P Mayser.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Yeasts of the genus Malassezia: taxonomic classification and significance in (veterinary and) clinical medicine].

The historical development of the taxonomic classification of Malassezia yeasts until today yielded the description of seven different species based upon molecularbiological, morphological and biochemical parameters (M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, M. slooffiae). Tests like Cremophor EL assimilation, esculin degradation, catalase test, pigment production and determination of polidocanol sensitivity appear to be suitable procedures for routine identification of the different species. Their colonization of clinically healthy humans (in particular M. sympodialis, M. globosa, M. obtusa) and animals (M. pachydermatis) skin renders interpretation difficulties, when isolating Malassezia spp. from clinical specimens. Out of the seven species, in man the clinical significance of M. furfur for pityriasis versicolor and systemic infections appears to be accepted largely. In dogs and cats M. pachydermatis has been regarded as cause of otitis externa and seborrhoeic dermatitis. But, due to geno- and phenotypic variabilities described for M. pachydermatis field isolates further investigations concerning the taxonomic uniformity of the species are necessary.

Animals↗
PubMed1999

Allergic fungal sinusitis caused by Bipolaris (Drechslera) hawaiiensis.

Depending on the aggressiveness of the pathogen and a patient's immunocompetence, fungal polypoid pansinusitis or allergic fungal sinusitis (AFS) may be a life-threatening disease. Apart from the clinical findings, its diagnosis is based on the demonstration of mucinous material with abundant eosinophils in the paranasal sinuses (indicating an allergic process), cultivation of the causative pathogen and immunocompetence of the patient. In a 20-year-old immigrant Sudanese woman, AFS due to Bipolaris (Drechslera) hawaiiensis was diagnosed. Because of intracranial extension, the disease had led to erosion of the cranial base and orbit with amaurosis on the right side and focal epilepsy. In addition to endonasal microsurgical pansinus operations, local irrigation therapy with amphothericin B was accompanied by systemic treatment with itraconazole after in vitro cultivation of the pathogen and determination of its sensitivities. Interdisciplinary management included a combination of endonasal surgery with debridement of infected tissues and wide drainage of the sinuses without removal of skull bone or the dural lesion in addition to specific antimycotic treatment. Injury to adjacent anatomical structures must be avoided in any case to prevent systemic or possibly lethal dissemination of infection.

Adult↗
PubMed1999

Efficacy and tolerability of terbinafine 1% topical solution used for 1 week compared with 4 weeks clotrimazole 1% topical solution in the treatment of interdigital tinea pedis: a randomized, double-blind, multi-centre, 8-week clinical trial.

In this double-blind clinical trial 429 patients (217 terbinafine and 212 clotrimazole) were randomized to receive twice daily terbinafine 1% topical solution for 1 week followed by a vehicle application for 3 weeks, or 1% clotrimazole solution for 4 weeks. Patients were evaluated clinically and mycologically at baseline and then at weeks one, two, four (end of treatment), and eight (end of follow-up). To be evaluable the patient needed to have a positive culture for a dermatophyte and positive KOH microscopy and a clinical diagnosis of tinea pedis (interdigital type) at baseline. Effective treatment of tinea pedis was recorded in 181 of 217 (83%) of patients treated for 1 week with terbinafine 1% solution and 174 of 212 (82%) of patients treated for 4 weeks with clotrimazole 1% solution. Mycological cure and disappearance of signs and symptoms were similar at each assessment visit in the two groups. In the subgroup of patients without any protocol violation the mycological cure rate was 95% (164 of 173) with terbinafine solution and 91% (159 of 174) with clotrimazole solution (P = 0.05). Adverse events believed to be drug-related occurred in 13 patients in the terbinafine group and 11 in the clotrimazole group (4 to 5% in each group). The events were primarily local skin reactions of mild to moderate intensity. It can be concluded that terbinafine 1% solution used for 1 week to treat tinea pedis is well tolerated and at least as effective as clotrimazole 1% solution used for 4 weeks.

Administration, Topical↗
PubMed1999

Mycotic infections of the penis.

Balanitis/balanoposthitis caused by Candida albicans is the most frequent mycotic infection of the penis. Its incidence is increasing and it seems to be primarily transmitted by sexual intercourse. Although the groin is a common site for tinea, dermatophytic infections of the penis are rare. Penile involvement in systemic mycosis is usually a sign of severe disease. In immunocompromised individuals, nearly every fungal agent may cause the disease. It normally presents as ulceration, and biopsy and culture can help to confirm the diagnosis. In most cases, superficial infections of the penis respond satisfactorily to local antifungal treatment, especially if provovatice factors and the possibility of sexual transmission are considered. Systemic treatment is recommended in cases of widespread dermatophytic infection, candidosis or systemic mycosis.

Balanitis↗
PubMed1998

Growth requirements and nitrogen metabolism of Malassezia furfur.

Investigations on the nutrient requirements of Malassezia yeasts led to the preparation of a new minimal medium consisting of an amino nitrogen and a lipid source, which only allowed the growth of the species M. furfur. Carbohydrates, electrolytes, vitamins and trace elements were not required. Using the basal medium, a nitrogen auxanogram for M. furfur was developed, which allowed investigation of the assimilation of 22 amino acids and 9 further nitrogen sources. With the exception of cysteine, all amino acids were metabolized, as were ammonium salts, urea, creatine, creatinine, uric acid and allantoin. KNO3, however, failed to support growth. Depending on the source used, the yeast cells changed micromorphologically: both oval and round forms were induced. Assimilation of several amino acids resulted in dimorphism, especially in the case of glycine and serine. The cell yield differed significantly depending on the nitrogen source; short-chain unbranched amino acids were utilized most readily. Thus, M. furfur can be characterized as a relatively undemanding yeast species which is optimally adapted to the superficial skin environment. All other lipid-dependent Malassezia species seem to require more complex media.

Allantoin↗
PubMed1998

Omega-3 fatty acid-based lipid infusion in patients with chronic plaque psoriasis: results of a double-blind, randomized, placebo-controlled, multicenter trial.

BACKGROUND: Profound changes in the metabolism of eicosanoids with increased concentrations of free arachidonic acid (AA) and its proinflammatory metabolites have been observed in psoriatic lesions. Free eicosapentaenoic acid (EPA) may compete with liberated AA and result in an antiinflammatory effect. OBJECTIVE: Our purpose was to assess the efficacy and safety of intravenously administered fish-oil-derived lipid emulsion on chronic plaque-type psoriasis. METHODS: A double-blind, randomized, parallel group study was performed in eight European centers. Eighty-three patients hospitalized for chronic plaque-type psoriasis with a severity score of at least 15 according to the Psoriasis Area and Severity Index (PASI) participated in a 14-day trial. They were randomly allocated to receive daily infusions with either a omega-3 fatty acid-based lipid emulsion (Omegavenous; 200 ml/day with 4.2 gm of both EPA and docosahexaenoic acid (DHA); 43 patients) or a conventional omega-6-lipid emulsion (Lipovenous; EPA+DHA < 0.1 gm/100 ml; 40 patients). The groups were well matched with respect to demographic data and psoriasis-specific medical history. Efficacy of therapy was evaluated by changes in PASI, in an overall assessment of psoriasis by the investigator, and a self-assessment by the patient. In one center neutrophil 4- versus 5-series leukotriene (LT) generation and platelet 2- versus 3- thromboxane generation were investigated and plasma-free fatty acids were determined. RESULTS: The total PASI score decreased by 11.2 +/- 9.8 in the omega-3 group and by 7.5 +/- 8.8 in the omega-6 group (p = 0.048). In addition, the omega-3 group was superior to the omega-6 group with respect to change in severity of psoriasis per body area, change in overall erythema, overall scaling and overall infiltration, as well as change in overall assessment by the investigator and self-assessment by the patient. Response (defined as decrease in total PASI of at least 50% between admission and last value) was seen in 16 of 43 patients (37%) receiving the omega-3 emulsion and 9 of 40 patients (23%) receiving omega-6 fatty acid-based lipid emulsion. No serious side effects were observed. Within the first few days of omega-3 lipid administration, but not in the omega-6 supplemented patients, a manifold increase in plasma-free EPA concentration, neutrophil leukotriene B5 and platelet thromboxane B3 generation occurred. CONCLUSION: Intravenous omega-3-fatty acid administration is effective in the treatment of chronic plaque-type psoriasis. This effect may be related to changes in inflammatory eicosanoid generation.

Adult↗
PubMed1998

Decreased susceptibility of Malassezia furfur to UV light by synthesis of tryptophane derivatives.

Recently, tryptophane (Trp)-dependent synthesis of pigments and fluorochromes in Malassezia furfur was described. The possible significance of this metabolic pathway for the microorganism remains to be explored. Since the upper parts of the human epidermis are a natural habitat of M. furfur, increased exposure to UV light may be hazardous. Five reference strains and one wild type strain of M. furfur were grown on m-Dixon agar, in which the nitrogen source peptone had been substituted either by pigment-inducing tryptophane or arginine. The yeast cells thus obtained were harvested after 6 days, washed with physiological saline and inoculated on to the modified Dixon medium. Immediately after inoculation, the yeast cells were irradiated with UVA (100, 150 and 200 Jcm-2, single dose) or UVB (100, 500, 1000, 1500, 2000 mJcm-2, single dose; 500, 1500, 2500 mJcm-2 cumulative dose). Irrespective of the primary nitrogen source (Trp or Arg), unexposed controls showed nearly identical cell yield after 5 days. In the case of irradiation, however, growth reduction of cells cultured on Trp was lesser than that of cells fed with arginine. High significance (p < 0.0001) was found especially with the upper UVA and UVB doses. Differences were also found among the individual test strains, the wild strain being most sensitive. One strain (CBS 6094) failed to produce pigment on Trp medium, and there were no differences in the growth behavior of subcultures of this strain fed with either arginine or tryptophane under irradiation. In conclusion, synthesis of pigments and fluorochromes by M. furfur implies the generation of potent UV filters in the UVA and UVB spectrum.

Arginine↗
PubMed1998

[Synthesis of fluorochromes and pigments in Malassezia furfur by using tryptophan as the single source of nitrogen].

A new minimal medium consisting only of L-tryptophan (L-trp) and a lipid source induced formation of brown pigmentation only in the species Malassezia furfur. Strains of the species M. sympodialis and M. pachydermatis failed to grow on this medium. Pigmentogenesis was already induced in M. furfur by 0.01 g% tryptophan, the pH optimum was pH = 5. Alternative amino nitrogen sources given concurrently with trp suppressed pigmentogenesis. The extract of the culture exhibited remarkable fluorescence, and several indole derivatives with a broad spectrum of colors were detected by means of mass spectroscopy and NMR. This finding may have an impact on the clinical appearance of pityriasis versicolor, a very common skin disease caused by lipophilic yeasts of the genus Malassezia. We hypothesize that in pityriasis versicolor metabolic adaptation of Malassezia yeasts to altered nitrogen conditions on superficial skin might be of pathophysiological importance. Tryptophan as inductor of pigmentogenesis probably cumulates during excessive sweating, a well known manifestation factor of pityriasis versicolor.

Dermatomycoses↗
PubMed1998

Demonstration of Malassezia furfur and M. sympodialis together with M. pachydermatis in veterinary specimens.

In the present study, 47 wild-type isolates of the genus Malassezia were isolated from dog and cat specimens by means of a simple differentiating system recently published. The purpose was to determine whether any of the other seven Malassezia spp. apart from M. pachydermatis occur in carnivores. Of the 47 isolates, three had been obtained from cats (ear 2, skin 1) and 44 from dogs (ear 37, skin 3, faeces 2, claw and paw 2). After primary isolation, they were subcultured on mDixon agar and then purified and differentiated by means of assimilation of Cremophor EL, splitting of esculin, growth on lipid-free medium and formation of tryptophan-dependent pigments and fluorochromes. Thus, a total of 100 strains could be obtained from the 47 primary isolates. Referring to the source material, M. pachydermatis was found in 83%, M. furfur in 45% and M. sympodialis in 75%. More than 80% of cultures were mixed, comprising two or all three species; a single species was isolated in only nine cases. This shows that animals are not colonized by M. pachydermatis alone, as has been thought until now, but in nearly all cases by mixed cultures. Thus, (domestic) animals could well be a reservoir for other Malassezia species such as M. furfur and M. sympodialis. Surprisingly, Malassezia yeasts were also isolated from dog faeces, indicating that they apparently pass through the gastrointestinal tract in unchanged form after having been taken up by licking colonized areas. The survivability of Malassezia yeasts in highly acid milieu was also demonstrated in vitro. The study confirms the usefulness of the new test procedures and allows new statements concerning the epidemiology of Malassezia yeasts.

Animals↗
PubMed1998

Different utilization of neutral lipids by Malassezia furfur and Malassezia sympodialis.

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

Agar↗
PubMed1997

Differentiation of Malassezia species: selectivity of cremophor EL, castor oil and ricinoleic acid for M. furfur.

In recent years, the genus Malassezia has been reclassified based on molecular data. In addition to M. furfur, M. pachydermatis and M. sympodialis, four new species, M. globosa, M. obtusa, M. restricta and M. slooffiiae, have been described. However, apart from their lipid dependence, little is known about the metabolism and nutritional requirements of all the seven species. Further to recent studies, 10 hydrophilic emulsifiers (HLB > 10) were examined in an agar diffusion test to determine their growth-promoting effect on reference strains of the different Malassezia species. Polyethylene glycol (PEG) 7 glyceryl monoalcanoate (Cetiol HE). PEG-glyceryl stearate (Tagat S2) and macrogol-50 stearate (Myrj 53) were metabolized by all strains, while PEG-35 castor oil (Cremophor EL) was metabolized only by M. furfur. The latter observation is due to a different metabolism of castor oil and its main component, ricinoleic acid (12-hydroxy oleic acid), which may also give an insight into the pathogenesis of diseases that are associated with Malassezia spp. As hydroxy fatty acids are important in maintaining the epidermal structure and function, their metabolism specifically by M. furfur might clarify some clinical aspects of pityriasis versicolor. Apart from this speculation, use of Cremophor EL, with splitting of esculin as an additional key character, improves the distinction of the species M. furfur, M. slooffiae and M. sympodialis.

Castor Oil↗
PubMed1997

Polidocanol sensitivity--a possible tool in the differentiation of Malassezia spp.

In recent years, the genus Malassezia was reclassified based on molecular data; in addition to M. furfur, M. pachydermatis and M. sympodialis, four new species (M. globosa, M. obtusa, M. restricta, M. slooffiae) were described. Primary keys for routine identification have recently been presented. Polidocanol was shown to have specific inhibitory effects against Malassezia spp. In an agar diffusion test, type strains of all Malassezia species were incubated with polidocanol concentrations between 0.01% and 10%. M. furfur strains were most resistant, with minimal inhibitory concentrations (MIC) ranging from 7.5% to 10%. Inhibitory concentrations of the other strains were lower by at least one factor of ten. Most sensitive were strains of M. pachydermatis (0.05%). In a further test, polidocanol-containing olive oil was used to determine the sensitivity of Malassezia furfur and M. sympodialis. Again, the inhibitory concentrations for strains of M. sympodialis were one tenth of those found for M. furfur. In addition to its antifungal effects, polidocanol might therefore be a useful tool in differentiating Malassezia species.

Agar↗
PubMed1996

Detection of extracellular phospholipase activity in Candida albicans and Rhodotorula rubra.

Phospholipases are important pathogenicity determinants in Candida albicans. They play a significant role in damaging cell membranes and invading host cells. High phospholipase production is correlated with an increased ability of adherence and a higher mortality rate in animal models. By means of an egg yolk-containing agar and the Pz (= phospholipase activity zone) value according to Price, the present study investigated phospholipase production in 170 strains of C. albicans. At an incubation temperature of 37 degrees C, Pz values ranged from 0.395 to 1; no clear relationship was found between clinical origin of the isolates and severity of the disease. In addition to C. albicans, a total of 110 strains of 16 other yeast species were investigated for possible phospholipase production. Only yeasts of the species Rhodotorula rubra showed phospholipase activity, with mean values exceeding those observed in C. albicans. This result was confirmed by an assay using sterile culture filtrates and phosphatidyl-[3H-methyl]-choline-dipalmitoyl as a substrate. Since Rh. rubra has only rarely been demonstrated as a pathogen in humans, we believe that factors such as reduced growth at 37 degrees C, absence of dimorphism and low ability of adherence lessen the importance of high phospholipase activity in Rh. rubra as a pathogenicity determinant. Therefore, potential virulence factors should always be considered in the context of the whole spectrum of pathogenic determinants.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1996

[Diagnosis, clinical aspects and therapy of early chromoblastomycosis in a case example].

Despite the availability of modern antimycotics, which produce high cure rates in early infections, the therapy of advanced chromoblastomycosis is still unsatisfactory. An initial chromoblastomycosis caused by a hitherto unidentified species of the genus Phialophora was diagnosed in a 46-year-old teacher. The organism was isolated twice at an interval of 6 weeks from a partly psoriasiform, partly verrucous lesion on the 4th toe. The infection was apparently acquired 4 years ago during a holiday at Cape Verde. Treatment with itraconazole (Sempera). 200 mg/day, and amphotericin B (Ampho-Moronal) cream for 6 weeks initially resulted in rapid regression. However, 4 weeks after cessation of therapy, the Phialophora species was cultured again from skin scrapings. Complete healing was achieved after re-treatment with itraconazole for 20 weeks at the same dosage in combination with topical amorolfine and local hyperthermia. Until now, no relapse has occurred. The present case demonstrates that this rare disease, which mainly occurs as a traumatic mycosis in the rural population of tropical regions, must be included in the differential diagnosis of psoriasiform or verrucous skin lesions and also included in the list of diseases which may be acquired while on vacation in exotic locations.

Administration, Topical↗
PubMed1996

[Skin infections caused by Mycobacterium gordonae. Case report and review of the literature].

Mycobacterium gordonae is an atypical mycobacterium of very low pathogenic potential. It is widely distributed in soil and water and often detected on the mucous membranes of healthy persons. In recent years, there have been numerous reports of infections by M. gordonae in immunocompromised patients. In contrast, only four cases of skin infections by M. gordonae in immunocompetent patients have been published. We report on another patient without evidence of immunodeficiency who developed an atypical mycobacteriosis after a thorn injury during gardening. M. gordonae was isolated by tissue culture. The skin lesion cleared completely after treatment with doxycycline for three months.

Bacteriological Techniques↗
PubMed1996

[Fungi of the Trichosporon genus. Identification, epidemiology and significance of dermatologic disease pictures].

Based on molecular data, the genus Trichosporon was recently reclassified. Six human pathogenic species, which are closely related to specific types of infections can be differentiated. By means of commercial test systems and simple key criteria according to Gueho et al. [15], 44 isolates that had been identified as Tr. cutaneum between 7/92 and 1/96, were reclassified. The evaluation of clinical data also included 66 isolates that had not been preserved, and 27 strains of Tr. inkin. Trichosporon species were found in 4.8% of all yeast isolates (3.8% Tr. cutaneum, 1% Tr. inkin). Nearly every other isolate of Tr. cutaneum was cultivated from nail material, while Tr. inkin was mainly isolated from skin in the anogenital region. In 38 cases, reclassification revealed Tr. mucoides; Tr. ovoides and Tr. asteroides were identified in 3 cases each, while Tr. asahii, an especially remarkable pathogen in systemic mycoses, was not found. Clinically, isolates of Tr. mucoides were predominant in toenail mycoses which might be considered in the therapy of onychomycosis. Furthermore, isolates from the skin should be evaluated with respect to the increasing incidence of systemic Trichopsoron mycoses.

Adolescent↗