Malassezia skin diseases in humans

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.

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

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.

Disseminated Scedosporium Apiospermum Infection in Renal Transplant Recipient: Long-Term Successful Treatment With Voriconazole: A Case Report

Scedosporium apiospermum, the asexual form of Pseudallescheria boydii, is a ubiquitous fungus that represents an unfrequent complication of immune suppression. It accounts for 20% of all non-Aspergillus mold infections in organ transplant recipients. The infection can be localized or disseminated in multiple organs, including lungs, brain, joints, tendons, and skin, and is difficult to treat, due to resistance of S apiospermum to amphotericin B and other antifungal agents. The mortality rate is about 50%. To our knowledge, there are no prospective studies or registries of transplant recipients to guide diagnosis and there are no evidence-based recommendations for the optimal management of this infection. We report a case of S apiospermum infection in a woman with renal transplantation. The first occurrence of infection was a solitary nodule on the forearm, which was surgically excised. Two following relapses were disseminated to the knee, the Achilles tendon, and the skin of the left leg. The infection was successfully treated with voriconazole, but due to the severe iatrogenic immune suppression, a strong reduction in immunosuppressant drugs was needed.

Detection of Candida dubliniensis in oropharyngeal samples from human immunodeficiency virus infected and non-infected patients and in a yeast culture collection

The incidence of Candida dubliniensis in oropharyngeal swabs of 132 human immunodeficiency virus (HIV)-positive and 89 HIV-negative patients was determined. The samples were plated onto CHROMagar Candida medium and 82 strains, presumptively identified as C. albicans or C. dubliniensis, were further investigated (temperature test, chlamydoconidia production, specific primer PCR). In addition, 487 collection strains (isolated from clinical samples and previously identified as C. albicans on the basis of a positive germ tube test) were screened in order to identify C. dubliniensis isolates. Two C. dubliniensis strains were isolated from two HIV-positive patients without oral candidiasis. Candida dubliniensis was not isolated from 89 HIV-negative patients nor was it identified among the collection strains.

Use of magnetic beads to extract fungal DNA

Authors compare two methods of extracting DNA from different fungi: the classic method with phenol/chloroform (P/C) and that with magnetic beads. Both were tested on Candida albicans and Cryptococcus neoformans var. neoformans, belonging to the yeast group and Microsporum canis, M. gypseum, Trichophyton rubrum, T. interdigitale, T. ajelloi, Epidermophyton floccosum, belonging to the dermatophytes group. Extraction products underwent polymerase chain reaction (PCR) fingerprinting with the appropriate primers to point out any disagreement in the genomic profiles. After having determined that the genomic profiles obtained from the DNA extracted from the same strain with the two methods correspond perfectly, the authors concluded that the extraction method with magnetic beads from fungal cells is simpler and quicker than with P/C extraction, greatly facilitating the obtainment of fungal DNA.

Comparative evaluation of SensititreR YeastOne vs. the NCCLS M27A protocol and E-test for antifungal susceptibility testing of yeasts. Vergleichende Bewertung des SensititreR YeastOne vs. NCCLS M27A-Protokoll und E-test zur Empfindlichkeitsprufung von Hefen gegenuber Antimykotika

A recently developed microdilution method (Sensititre) YeastOne) may represent a valid alternative to the National Committee for Clinical Laboratory Standards (NCCLS) method for routine testing. The Medical Mycology Committee of the Associazione Microbiologi Clinici Italiani (AMCLI) decided to evaluate its reproducibility and reliability compared with the NCCLS M27A protocol and the E-test. Nineteen strains each of Candida albicans and Ca. parapsilosis, isolated from systemic infections, were tested against amphotericin B, flucytosine, ketoconazole, itraconazole, and fluconazole. All the participating laboratories tested the YeastOne panels, while the E-test and the NCCLS method were performed by two laboratories each. Interlaboratory reproducibility showed a good correlation (from 95% for amphotericin B to 92.5% for flucytosine). The agreement between NCCLS and YeastOne ranged from 95 (ketoconazole and itraconazole) to 100% (amphotericin B and flucytosine), whereas the agreement between E-test and YeastOne ranged from 72.5 (fluconazole) to 100% (amphotericin B and flucytosine). The Sensititre YeastOne panels appear to be an excellent alternative to both the E-test and the NCCLS protocol for antifungal susceptibility testing.

Investigation in Central Italy of the possible association between Cryptococcus neoformans var. Gattii and Eucalyptus camaldulensis

The authors present a worldwide review of isolations of Cryptococcus neoformans, var. neoformans and C. neoformans var. gattii from animals and vegetation, referring in particular to the already well-known association of the former variety with Eucalyptus camaldulensis. They then review the Italian situation relative to this association and their studies carried out in Central Italy: in Latina (Lazio), Pisa, Viareggio and Lake Massaciuccoli (Tuscany). From the 256 E. camaldulensis trees examined C. neoformans var. gattii was not isolated. An E. camaldulensis tree situated in the nature reserve on Lake Massaciuccoli proved to be positive for C. neoformans var. neoformans. This variety was isolated from the leaves, flowers, bark and the debris at the foot of the tree, suggesting that it had colonized the entire tree and that it was capable of developing not only on its usual habitat (bird guano, soil rich with guano) but also on Eucalyptus trees. The identity of the isolates was confirmed by their genomic profiles obtained by random amplification polymorphic DNA (RAPD) with the primer (GACA)4. The presence of a single genotype indicates a sole source of contamination, perhaps brought by a bird coming from a contaminated environment.

An unusual case of tinea capitis due to Trichophyton soudanense

A case of tinea capitis due to Trichophyton soudanense observed in a 4-year-old African girl is described. The infection manifested with diffuse pustular lesions of the scalp. Diagnosis was based on culture. Genome study by single primer PCR fingerprinting was also performed. A younger sister, aged 10 months, was the healthy carrier of the mycete.

Application of PCR to distinguish common species of dermatophytes

This report describes the application of PCR fingerprinting for the identification of species and varieties of common dermatophytes and related fungi utilizing as a single primer the simple repetitive oligonucleotide (GACA)(4). The primer was able to amplify all the strains, producing species-specific profiles for Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Trichophyton ajelloi, and Epidermophyton floccosum. Intraspecific variability was not observed for these species. Instead, three different profiles were observed in the Trichophyton mentagrophytes group.

Anti-Malassezia furfur antibodies in the population

The authors carried out research into anti-Malassezia precipitating antibodies in the population, specifying the distribution by age and sex. A total of 868 serum specimens from subjects of both sexes, aged between 0 and 80 years, were studied. An immunoelectroprecipitation reaction was used using a M. furfur culture filtrate as antigen. No antibodies were found in children under 11 years, whereas they were present after that age and reached maximum frequency in subjects between 31 and 40 years of age. In subjects up to 50 years of age they were more frequent in women, but in subjects over the age of 50 years they were more frequent in men. Globally, antibodies were found in 31% (270/868) of the subjects examined. The presence of antibodies correlates with data from the literature regarding the isolation of this yeast in relation to age.

Two cases of cutaneous phaeohyphomycosis by Alternaria alternata and Alternaria tenuissima

Two cases of cutaneous phaeohyphomycosis, one with a nodular appearance and the other with an erythematous infiltrating patch, are reported in immunocompromised patients. Diagnosis was based on histological examination, which revealed hyphae and round-shaped fungal cells in a granulomatous dermal infiltrate, and on identification of the moulds when biopsy fragments were cultured on Sabouraud-dextrose agar without cycloheximide. The pathogens were Alternaria tenuissima in the first case and A. alternata in the second. The fungi were examined by scanning electron microscopy. The patients were checked for bone and lung involvement and were then treated with surgical excision and itraconazole, and itraconazole only, respectively, with clinical and mycological resolution.

Cutaneous phaeohyphomycosis due to Alternaria tenuissima

A 50-year-old gardener with a 3-year history of pemphigus vulgaris and steroid-induced diabetes complained of various papulonodular lesions on the left elbow. The lesions had appeared 11 months previously. Skin biopsy showed chronic granulomatous inflammation of the dermis which contained septate hyphae and large spores mainly free. Fragments of the biopsy specimen, cultured on Sabouraud glucose agar without cycloheximide, for 4 days, produced soft white colonies which later turned blackish brown, especially on the underside. On the basis of the microscopic characters of the conidiophores and conidia, Alternaria tenuissima was identified. This phaeohyphomycete has only been isolated previously in two other cases in Italy.

Cryptococcosis in domestic mammals

After a brief review of cryptococcosis in dogs and cats from the literature from 1980 to 92, three cases in dogs (two epidemiologically strictly connected) and two in cats are reported. In the three dogs and in one of the two cats lesions were seen in many sites, but only one dog and one cat had a central nervous system localization. The cutis was affected in the three dogs and in one cat; in two of the dogs it was probably the primary lesion, and in the cat it was the only lesion. An unidentified genetic defect was probably the predisposing factor in two of the dogs of the same litter, exposed to soil cryptococcal contamination (from pigeon guano); a third dog, of different breeding, was not infected. Steroid treatment was predisposing in one cat. Flucytosine treatment was initially successful in two dogs, but in both relapses were reported; in one dog fluconazole treatment was successful. The isolates, before and after treatment, demonstrated a large increase in flucytosine MIC, strictly connected with the relapse.

[A case of mycotic endocarditis. Clinical, diagnostic and therapeutic considerations]

A case of endocarditis in 17 year old female with a psychomotor and neurovegetative disorder is presented. Serum and cultural data as well as the excellent response to treatment with 5-flucytosine seems to confirm the diagnosis of candida infection.

Fungal infections in hematological neoplastic disease: the possibility of chemoprophylaxis

Immunoelectrosmophoresis (IEOP) was used to detect antigens of Candida albicans in the sera of 90 patients with hemolymphoblastosis. A higher percentage of sensitive results occurred in patients with acute myeloid leukemia; moreover, most of the serologically positive patients showed severe leukopenia and neutropenia (WBC less than 1000/microliter; neutrophils less than 200/microliter). According to the results of IEOP assays, a prophylactic treatment with standard dosages of amphotericin B or myconazole was instituted in positive cases. Treatment schedules were randomized in order to assess the effect of each drug. The therapy resulted in serological negativity in 60% of the patients treated with amphotericin B and 57% of those who were given myconazole.