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Reference as well as field strains of Malassezia furfur (30), M. sympodialis (49), M. globosa (52), M. obtusa (one), M. restricta (one), M. slooffiae (seven), and M. pachydermatis (373) were investigated for their ability to produce pigment and fluorochromes when tryptophan (Trp) is offered as the main nitrogen source. Only the M. furfur strains produced pigment on a pigment-inducing medium (p-medium). Remarkably, the optical activity of Trp was not significant for pigment synthesis. Other nitrogen sources that are structurally similar to Trp (gramine, tryptamine, serotonin) did not induce pigment formation. All lipophilic non- furfur species failed to grow and to form pigment on this agar. However, growth of all lipid-dependent species was achieved on a modified Dixon agar in which peptone had been substituted by an equal amount of l-Trp. Here, too, the M. furfur colonies were characterized by rapidly developing dark brown halos. Furthermore, about 11% of the M. pachydermatis strains tested produced pigment formation on the p-medium, which was enhanced by addition of d-glucose. In contrast to M. furfur, pigment formation occurred after a markedly longer incubation time (4 weeks unlike 3–5 days) with a lower yield and limited color spectrum (thin layer chromatography, TLC). The UV filter pityriacitrine recently described for M. furfur was also demonstrated for M. pachydermatis by extraction, high-performance liquid chromatography (HPLC) analysis with co-elution and mass spectroscopy. The phenotypic feature of pigment formation in some strains of M. pachydermatis may confirm recent molecular-genetic findings suggesting a relationship between some strains of M. pachydermatis and M. furfur. [ABSTRACT FROM AUTHOR]

Summary: A new species, Phialophora europaea, member of the P. verrucosa complex, is introduced. It is distinguished from existing species by reduced, flaring phialidic collarettes and inability to assimilate melibiose as sole source of carbon. Analysis of ITS1 and 2 rDNA of six strains attributed to the species show it to be clearly individualized. All strains originated from cutaneous and nail infections of humans in North-western Europe. A key to morphologically similar taxa is provided. [ABSTRACT FROM AUTHOR]

Background: Malassezia (M.) pachydermatis as a frequent reason for dermatological consultation in dogs and cats was recently shown to be lipid-dependent, too. Lipolytic activity is a prerequisite for activating antimicrobial effectivity of fatty acid esters., Objectives: It was therefore of interest whether it is possible to induce this mechanism in M. pachydermatis and to identify possible differences between minimal and strong lipid-dependent strains., Methods: In an agar dilution test, the minimal inhibitory concentrations of six fatty acid esters were determined for seventeen M. pachydermatis strains. GC analysis of parent compounds and liberated fatty acids was used to quantify ester cleavage., Results: Hydrolysis was observed in all test strains in a homogenous manner but was dependent on the chemical structure. Lowest MICs (500 ppm after 14 days of incubation) were obtained applying glyceryl monocaprylate and 3-hydroxylpropyl caprylate, while the corresponding esters of undecylenic acid showed nearly twice the value. As shown by GC analysis with the reference strains CBS 1879 and CBS 1892 and 3-hydroxypropyl caprylate, hydrolysis and caprylic acid formation starts immediately and was dependent on yeast density. Furthermore, nine azole-resistant strains isolated from dogs with treatment failures showed MIC values comparable to the other strains and no resistance to monohydric fatty acid esters., Conclusions: Medium-chain fatty acid esters may represent a new therapeutic option for veterinary use even in azole-resistant strains. The in vivo verification in M. pachydermatis-associated dermatitis in dogs and cats will be the next step for the successful development of new therapeutics., (© 2022 Wiley-VCH GmbH.)

Approximately 70-75% of women will have vulvovaginal candidosis (VVC) at least once in their lifetime. In premenopausal, pregnant, asymptomatic and healthy women and women with acute VVC, Candida albicans is the predominant species. The diagnosis of VVC should be based on clinical symptoms and microscopic detection of pseudohyphae. Symptoms alone do not allow reliable differentiation of the causes of vaginitis. In recurrent or complicated cases, diagnostics should involve fungal culture with species identification. Serological determination of antibody titres has no role in VVC. Before the induction of therapy, VVC should always be medically confirmed. Acute VVC can be treated with local imidazoles, polyenes or ciclopirox olamine, using vaginal tablets, ovules or creams. Triazoles can also be prescribed orally, together with antifungal creams, for the treatment of the vulva. Commonly available antimycotics are generally well tolerated, and the different regimens show similarly good results. Antiseptics are potentially effective but act against the physiological vaginal flora. Neither a woman with asymptomatic colonisation nor an asymptomatic sexual partner should be treated. Women with chronic recurrent Candida albicans vulvovaginitis should undergo dose-reducing maintenance therapy with oral triazoles. Unnecessary antimycotic therapies should always be avoided, and non-albicans vaginitis should be treated with alternative antifungal agents. In the last 6 weeks of pregnancy, women should receive antifungal treatment to reduce the risk of vertical transmission, oral thrush and diaper dermatitis of the newborn. Local treatment is preferred during pregnancy., (© 2021 The Authors.Mycoses published by Wiley-VCH GmbH.)

Background: For fatty acid esters of monohydric alcohols, cleavage by exo-enzymes of Malassezia (M.) spp. and release of fatty acids with antimicrobial activity have been shown recently. On skin surface, this selective activation of antimicrobial activity might result in a 'self-kill' targeted locally at the site with the highest M. density., Objectives: As for the disadvantage of strong odour, use of these esters for topical therapy is limited to low concentrations. Therefore, cleavage was also tested for monoesters of octanoic and undec-10-enoic acid with the bihydric alcohol propane-1,3-diol or the trihydric glycerol., Methods: In an agar dilution test, the minimal inhibitory concentrations of these compounds were determined for M. furfur, M. globosa, M. sympodialis and M. restricta, respectively. GC analysis of parent compounds and liberated fatty acids was used to reveal ester cleavage., Results: Ester cleavage started immediately. MICs for the test compounds ranged between ~1000-8000 ppm after 14 days of incubation. 1,3-propanediol esters, especially 3-hydroxypropyl octanoate and 3-hydroxypropyl undecylenate were most effective, binary combinations exerted synergistic effects., Conclusions: The new substances are advantageous in terms of odour and substantivity and have also beneficial skin caring properties if not hydrolysed by M. spp. As a different panel of hydrolases of each single M. species is responsible for variation in efficacy among the test substances, tailored products to treat preferentially single species or blends with a broader effectivity can be designed. In vivo verification will be the next step for the successful development of this new therapeutical concept for M.-associated diseases., (© 2020 Blackwell Verlag GmbH.)

In the late 1980's, the incidence of invasive fungal diseases (IFDs) in Germany was estimated with 36.000 IFDs per year. The current number of fungal infections (FI) occurring each year in Germany is still not known. In the actual analysis, data on incidence of fungal infections in various patients groups at risk for FI were calculated and mostly estimated from various (mostly national) resources. According to the very heterogenous data resources robust data or statistics could not be obtained but preliminary estimations could be made and compared with data from other areas in the world using a deterministic model that has consistently been applied in many countries by the LIFE program ( www.LIFE-worldwide.org). In 2012, of the 80.52 million population (adults 64.47 million; 41.14 million female, 39.38 million male), 20% are children (0-14 years) and 16% of population are ≥65 years old. Using local data and literature estimates of the incidence or prevalence of fungal infections, about 9.6 million (12%) people in Germany suffer from a fungal infection each year. These figures are dominated (95%) by fungal skin disease and recurrent vulvo-vaginal candidosis. In general, considerable uncertainty surrounds the total numbers because IFDs do not belong to the list of reportable infectious diseases in Germany and most patients were not hospitalised because of the IFD but a distinct underlying disease., (© 2015 Blackwell Verlag GmbH.)

Free medium and short chain fatty acids are known to have broad antimicrobial activity. However, their practical use in topical therapy is limited by their intensive smell and acidity. Surprisingly, a nearly identical antimicrobial effect was found with the ethyl ester derivatives of these fatty acids, but only against Malassezia (M.) yeast, not against Candida spp. Obviously, these esters are hydrolysed by M. enzymes, thus generating a selective activation of antimicrobial activity especially in areas well populated with these yeast ('targeting'). Octanoic acid ethyl ester (CAS 106-32-1) was found to be most suitable. In an agar dilution test, the minimal inhibitory concentrations against M. globosa, M. pachydermatis and M. sympodialis, respectively, ranged between ~5 and 10 mmol l(-1) after 10 days of incubation. The effect started immediately and was not delayed by other lipid sources applied simultaneously. Based on these data, fatty acid monoesters may represent a new therapeutic concept in M.-associated diseases., (© 2015 Blackwell Verlag GmbH.)

The oestrogenised vagina is colonised by Candida species in at least 20% of women; in late pregnancy and in immunosuppressed patients, this increases to at least 30%. In most cases, Candida albicans is involved. Host factors, particularly local defence mechanisms, gene polymorphisms, allergies, serum glucose levels, antibiotics, psycho-social stress and oestrogens influence the risk of candidal vulvovaginitis. Non-albicans species, particularly Candida glabrata, and in rare cases also Saccharomyces cerevisiae, cause less than 10% of all cases of vulvovaginitis with some regional variation; these are generally associated with milder signs and symptoms than normally seen with a C. albicans-associated vaginitis. Typical symptoms include premenstrual itching, burning, redness and odourless discharge. Although itching and redness of the introitus and vagina are typical symptoms, only 35-40% of women reporting genital itching in fact suffer from vulvovaginal candidosis. Medical history, clinical examination and microscopic examination of vaginal content using 400× optical magnification, or preferably phase contrast microscopy, are essential for diagnosis. In clinically and microscopically unclear cases and in chronically recurring cases, a fungal culture for pathogen determination should be performed. In the event of non-C. albicans species, the minimum inhibitory concentration (MIC) should also be determined. Chronic mucocutaneous candidosis, a rarer disorder which can occur in both sexes, has other causes and requires different diagnostic and treatment measures. Treatment with all antimycotic agents on the market (polyenes such as nystatin; imidazoles such as clotrimazole; and many others including ciclopirox olamine) is easy to administer in acute cases and is successful in more than 80% of cases. All vaginal preparations of polyenes, imidazoles and ciclopirox olamine and oral triazoles (fluconazole, itraconazole) are equally effective (Table ); however, oral triazoles should not be administered during pregnancy according to the manufacturers. C. glabrata is not sufficiently sensitive to the usual dosages of antimycotic agents approved for gynaecological use. In other countries, vaginal suppositories of boric acid (600 mg, 1-2 times daily for 14 days) or flucytosine are recommended. Boric acid treatment is not allowed in Germany and flucytosine is not available. Eight hundred-milligram oral fluconazole per day for 2-3 weeks is therefore recommended in Germany. Due to the clinical persistence of C. glabrata despite treatment with high-dose fluconazole, oral posaconazole and, more recently, echinocandins such as micafungin are under discussion; echinocandins are very expensive, are not approved for this indication and are not supported by clinical evidence of their efficacy. In cases of vulvovaginal candidosis, resistance to C. albicans does not play a significant role in the use of polyenes or azoles. Candida krusei is resistant to the triazoles, fluconazole and itraconazole. For this reason, local imidazole, ciclopirox olamine or nystatin should be used. There are no studies to support this recommendation, however. Side effects, toxicity, embryotoxicity and allergies are not clinically significant. Vaginal treatment with clotrimazole in the first trimester of a pregnancy reduces the rate of premature births. Although it is not necessary to treat a vaginal colonisation of Candida in healthy women, vaginal administration of antimycotics is often recommended in the third trimester of pregnancy in Germany to reduce the rate of oral thrush and napkin dermatitis in healthy full-term newborns. Chronic recurrent vulvovaginal candidosis continues to be treated in intervals using suppressive therapy as long as immunological treatments are not available. The relapse rate associated with weekly or monthly oral fluconazole treatment over 6 months is approximately 50% after the conclusion of suppressive therapy according to current studies. Good results have been achieved with a fluconazole regimen using an initial 200 mg fluconazole per day on 3 days in the first week and a dosage-reduced maintenance therapy with 200 mg once a month for 1 year when the patient is free of symptoms and fungal infection (Table ). Future studies should include Candida autovaccination, antibodies to Candida virulence factors and other immunological experiments. Probiotics with appropriate lactobacillus strains should also be examined in future studies on the basis of encouraging initial results. Because of the high rate of false indications, OTC treatment (self-treatment by the patient) should be discouraged., (© 2015 Blackwell Verlag GmbH.)

Dermatomycosis is one of the most common dermatological infectious diseases. In recent years, the incidence of tinea pedum, a fungal infection of the feet, was increasing due to changing lifestyles. The risk of tinea pedum infections is associated with the use of sport shoes as well as contact with public sports facilities. Transmission of dermatomycosis occurs almost exclusively through indirect contacts, meaning that contagious material initially contaminates the patients' environment and subsequently facilitates the spread of infection to others. A suitable disinfection procedure for 'fungal reservoirs' is very important in order to reduce the risk of reinfection of tinea pedum. This study investigates the effect of microwave radiation on various dermatophytes- (Trichophyton rubrum, T. rubrum var. nigricans, T. interdigitale and Microsporum canis infected cork and polyethylene sponge shoe insoles. The contaminated insoles were irradiated with various intensities and durations of microwaves. In each case, 10 colonies on cork and polyethylene sponge insoles were irradiated with the same intensity and duration, and subsequently compared with those of corresponding non-irradiated control groups. Results of three independent experiments were statistically verified using Chi-squared test for significance. We found significant differences between the various dermatophytes on polyethylene sponge insoles and also partly on cork insoles for the same irradiation intensity and duration. We were also able to show that a complete growth inhibition of all four dermatophytes occurs on both types of insoles after a 30 s exposure at 560 W, including a maximum temperature of 60 °C., (© 2013 Blackwell Verlag GmbH.)

The effects of the addition of different amino nitrogens on growth, morphology and secondary metabolism of Malassezia furfur were investigated. After primary culture on Dixon agar, M. furfur CBS 1878 was transferred into a fluid medium together with the nitrogen sources, glycine (Gly) or tryptophan (Trp), or a combination of both. Growth was measured by means of a direct cell counting method and pigment synthesis was photometrically assessed. Addition of glycine resulted in an exponential increase in biomass, but not in pigment production. Tryptophan as the sole nitrogen source caused distinct brown staining of the medium, without increasing biomass. Simultaneous equimolar addition of both amino acids resulted in an initial increase in biomass as a sign of preferential metabolism of glycine, followed by a growth plateau and pigment production which, caused by higher biomass, occurred more rapidly than after addition of tryptophan alone. The yeast-cell morphology changed from round to oval. Addition of glycine to the tryptophan-containing liquid culture stopped pigment formation with simultaneous growth induction. These in vitro on-off phenomena depending on the nitrogen source might be significant in the pathogenesis of pityriasis versicolor: hyperhidrosis followed by preferential consumption of individual nitrogen sources such as glycine with exponential growth and thereafter transamination of tryptophan and TRP-dependent pigment synthesis., (© 2009 Blackwell Verlag GmbH.)

In Malassezia furfur, tryptophan as the main nitrogen source induces production of the potent ultraviolet-absorbing indole compound pityriacitrin. An in vitro study about the effects of pityriacitrin on other human skin microorganisms is presented, with special focus on Candida albicans and staphylococci in which its toxicity and UV-protective capacity were investigated. Candida albicans was irradiated with UVB light either in the presence or in the absence of pityriacitrin (11 mmol) and the growth rate was determined. A UVB dose of 1 J cm(-2) caused death of the fungi without pityriacitrin, whereas those in the presence of pityriacitrin showed almost unaffected growth. A diffusion test in staphylococci revealed no antibiotic effects of pityriacitrin. For testing of an ultraviolet-protective effect, staphylococci were either inoculated and irradiated in a plate model for visual assessment of growth or inoculated and irradiated in square quartz cylinders for quantitative measurement of cell density, each time in the absence or presence of pityriacitrin. Cell density of the bacterial suspensions exhibited nearly no influence of pityriacitrin on growth rates, while again a UV-protective effect was observed. In summary, pityriacitrin has an ultraviolet-protective effect on Candida albicans and staphylococci with no toxicity in the range tested.

The yeast Malassezia furfur is a part of the resident flora of human skin. It causes various diseases such as pityriasis versicolor, which hardly shows signs of inflammation despite marked clinical symptoms (e.g. hypopigmentation). The pathophysiology related morphological picture might give a clue to this phenomenon. As a part of the literature data are controversial, the present study compared the inflammatory infiltrate of pityriasis versicolor with that of tinea corporis in 40 human skin preparations each from diagnostic specimens. All preparations were stained with HE and PAS. Neutrophilic granulocytes were counted in the HE stain, and hyphae and spores in the PAS stain. The number of counted cells was related to the size of the respective area and the values were compared between pityriasis and tinea corporis. Significantly, more neutrophilic granulocytes were found with tinea corporis (P > 0.01), while they were virtually not demonstrable with pityriasis versicolor. It is surprising that fungal load in the stratum corneum is significantly higher with pityriasis versicolor (P > 0.01). Obviously the immune response involving neutrophilic granulocytes does not occur despite high bacterial load. This might be explained by reduced immunogenicity because of high content of lipids in the cell membrane. Furthermore, pityriarubins that are produced during tryptophan metabolism might be involved, which, in a stimulus-dependent manner, can suppress the ROS production of neutrophilic granulocytes in vivo.