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

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 efficiently for the diagnosis of Malassezia species obtained directly from patient samples.

[Evaluation of Malassezia species by Fourier transform infrared (FT-IR) spectroscopy]. / Fourier Dönüsümlü Kizilötesi (FT-IR) Spektroskopisi ile Malassezia Türlerinin Degerlendirilmesi.

Malassezia species which are lipophilic exobasidiomycetes fungi, have been accepted as members of normal cutaneous flora as well as causative agent of certain skin diseases. In routine microbiology laboratory, species identification based on phenotypic characters may not yield identical results with taxonomic studies. Lipophilic and lipid-dependent Malassezia yeasts require lipid-enriched complex media. For this reason, Fourier transform infrared (FT-IR) spectroscopy analysis focused on lipid window may be useful for identification of Malassezia species. In this study, 10 different standard Malassezia species (M.dermatis CBS 9145, M.furfur CBS 7019, M.japonica CBS 9432, M.globosa CBS 7966, M.nana CBS 9561, M.obtusa CBS 7876, M.pachydermatis CBS 1879, M.slooffiae CBS 7956, M.sympodialis CBS 7222 and M.yamatoensis CBS 9725) which are human pathogens, have been analyzed by FT-IR spectroscopy following standard cultivation onto modified Dixon agar medium. Results showed that two main groups (M1; M.globosa, M.obtusa, M.sympodialis, M.dermatis, M.pachydermatis vs, M2; M.furfur, M.japonica, M.nana, M.slooffiae, M.yamatoensis) were discriminated by whole spectra analysis. M.obtusa in M1 by 1686-1606 cm-1 wavenumber ranges and M.japonicum in M2 by 2993-2812 cm-1 wavenumber ranges were identified with low level discrimination power. Discriminatory areas for species differentiation of M1 members as M.sympodialis, M.globosa and M.pachydermatis and M2 members as M.furfur and M.yamatoensis could not be identified. Several spectral windows analysis results revealed that FT-IR spectroscopy was not sufficient for species identification of culture grown Malassezia species.

Otomycosis in Turkey: predisposing factors, aetiology and therapy.

Otomycosis usually requires long-term treatment and tends to recur. This study was performed on 87 patients with the clinical diagnosis of otomycosis and 20 controls in order to determine the pathogenic agents, predisposing factors and a cost-effective treatment. The predisposing factors included wearing head clothes (74.7 per cent), presence of dermatomycoses (34.5 per cent) and swimming (27.6 per cent). The most common pathogenic fungus was Aspergillus niger (44.8 per cent) in the otomycosis group. The only isolate was Candida albicans in the control group (2.5 per cent). We concluded that administration of four per cent boric acid solution in alcohol and frequent suction cleaning of the ear canal might be a cost-effective treatment for otomycosis since 77 per cent of the patients were treated effectively this way. Eighty per cent of the resistant cases had mixed fungal-bacterial infections, and 50 per cent of them had dermatomycoses. These resistant cases were treated by administration of tioconazole ointment.

Concomitant otomycosis and dermatomycoses: a clinical and microbiological study.

Otomycosis tends to recur despite long-term treatment. To our knowledge, there is no study in the English literature concerning the clinical importance of concomitant otomycosis and dermatomycoses. We investigated the presence of dermatomycoses in 52 patients with otomycosis in order to document the clinical and microbiological importance of their coexistence. Dermatomycoses on the feet and/or hands were identified in 19 patients (36.5%). The most common pathogen for otomycosis was Aspergillus niger, while it was Candida albicans for the dermatomycoses. The same pathogenic fungi were isolated from the otomycosis and dermatomycoses in nine of the 19 patients (47.4%). Aspergillus niger was the most common shared pathogen. The pathogens isolated in concomitant dermatomycoses were common pathogens for the fungal infection of the ear ( Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Candida albicans). It was concluded that the autoinoculation of the ear canal by pathogenic fungi might be possible in the presence of the untreated dermatomycoses. Dermatomycoses must be investigated in patients with otomycosis and must be treated simultaneously in order to prevent the recurrence of both.