Dixon Agar Research Articles

Fungal dysbiosis following antibacterial monotherapy in canine otitis externa.

To evaluate evidence of Malassezia overgrowth following successful topical antibacterial monotherapy of refractory canine bacterial otitis using semi-quantitative cultures. Twenty-nine dogs with bacterial otitis were treated topically with either fluoro-quinolone [0.5% enrofloxacin (18 dogs, 19 treatment events, 25 ears) or 0.1% marbofloxacin (1 ear), with 0.1% dexamethasone] ("FQ") SID, or 143 mg/mL piperacillin/18 mg/mL tazobactam ("PT") BID (11 dogs, 14 treatment events, 19 ears) for 8 to 36 days (mean 20 days). At visits 1 (V1) and 2 (V2), ear swab tips were washed in PBS + Triton X-100 and serial dilutions spread-plated onto blood, MacConkey (37°C, 48 hours) and modified Dixon's agar (32°C, 14 days) to generate semiquantitative counts. Microbes were identified by phenotype and MALDI-TOF. Prior to treatment, Pseudomonas aeruginosa was isolated alone or in combination with other bacteria in 14 FQ-treated ears and 18 PT-treated ears; the next most frequent bacteria were Streptococcus canis (8 FQ, 2 PT) and Staphylococcus pseudintermedius (8 FQ, 1 PT). The proportions of dogs' ears (excluding cross-over treatments and contra-lateral affected ears) from which bacteria were isolated were significantly reduced by treatment with both FQ (V1, 13/15; V2, 5/15) and PT (V1, 14/14; V2, 2/14). The proportions of dogs' ears from which yeasts (Malassezia pachydermatis, Candida spp.) were isolated were significantly increased by treatment in dogs treated with PT (V1, 1/14; V2, 14/14) but not FQ (V1, 3/15; V2, 6/15). Otitis cases that receive potent antibacterial monotherapy must be monitored for yeast overgrowth.

Isolation of Malassezia yeasts from dogs with gastrointestinal disease undergoing duodenal endoscopy.

To culture Malassezia and other fungi from the duodenum of dogs with gastrointestinal signs undergoing routine endoscopic examination. Quantitative microbial culture was performed on duodenal juice aspirated from dogs with suspected enteropathy during routine upper gastrointestinal endoscopy; samples were cultured on Sabouraud's dextrose agar (30, 32 and 37°C) and modified Dixon agar (32°C) for 14 days. Isolates were identified phenotypically and by matrix-assisted laser desorption ionisation-time of flight, and internal transcribed spacer sequencing. Yeast presence was also evaluated by cytological and histopathological examination of smears and biopsy specimens. Forty-five dogs were recruited with chronic inflammatory enteropathy (n=38), granulomatous colitis (n=2), gastric adenocarcinoma (n=2), duodenal small cell lymphoma (n=1) and idiopathic severe gastrointestinal haemorrhage (n=2). Fungi were cultured from 14 dogs: Malassezia pachydermatis was isolated from eight [chronic inflammatory enteropathy (n=7) (along with Candida albicans n=1); granulomatous colitis (n=1)] and Malassezia sympodialis from another (gastric adenocarcinoma). Five dogs with chronic inflammatory enteropathy yielded other yeasts (C. albicans, Candida glabrata, Kazachstania slooffiae, Kazachstania telluris, Pichia kudriavzevii [syn. C. krusei]). Yeasts were never observed in histopathological specimens. Fluorescent microscopical examination of cytological specimens showed yeast in only one case, from which K. slooffiae was subsequently isolated. Based on a literature search, this is the first report of isolation of M. pachydermatis, M. sympodialis, K. slooffiae and K. telluris from the canine duodenum. Further studies are needed to determine whether these are resident or transient fungi in the canine duodenum and whether their presence has a pathogenic effect on the host.

MP15-14 INVESTIGATION OF FUNGAL FLORA OF THE GLANS PENIS AND THE CAUSES OF BALANITIS/BALANOPOSTHITIS IN DIABETIC PATIENTS

You have accessJournal of UrologyCME1 Apr 2023MP15-14 INVESTIGATION OF FUNGAL FLORA OF THE GLANS PENIS AND THE CAUSES OF BALANITIS/BALANOPOSTHITIS IN DIABETIC PATIENTS Ibrahim Atilla Aridogan, Nebil Akdogan, Hazal Kandemir, Ismail Onder Yilmaz, Tamer Tetiker, Fesih Ok, and Macit Ilkit Ibrahim Atilla AridoganIbrahim Atilla Aridogan More articles by this author , Nebil AkdoganNebil Akdogan More articles by this author , Hazal KandemirHazal Kandemir More articles by this author , Ismail Onder YilmazIsmail Onder Yilmaz More articles by this author , Tamer TetikerTamer Tetiker More articles by this author , Fesih OkFesih Ok More articles by this author , and Macit IlkitMacit Ilkit More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003235.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: This study aimed to examine glans penis samples from the diabetic population, whose prevalence is increasing worldwide, and to reveal the presence of both flora and fungal balanitis in these cases. METHODS: Glans penis samples taken by the imprint method from 151 patients followed up with the diagnosis of diabetes mellitus (DM), and a control group of 50 people without DM diagnosis were inoculated into modified Dixon agar (MDA) and CHROMagar™ Malassezia (CAM; Paris, France) media. Samples were incubated at 32°C for one week. RESULTS: The age distribution of the patients did not show a statistically significant difference between the control and diabetes groups (p=0.759). Again, there was no difference between the groups according to marital status (p>0.999). Fasting blood glucose (ACS), HbA1c, insulin, HOMA-IR, and BUN were distributed at higher levels in the diabetes group (p<0.001, p<0.001, p<0.001, p<0.001 and p=0.032, respectively). There was no statistically significant difference between the groups regarding creatinine values (p=0.633). When the growth of MDA or CAM in the patients included in the study was examined, Malassezia or Candida grew in 93 (62%) patients in the diabetes group and 36 (72%) patients in the control group, and no statistically significant difference was found (p=0.18). When MDA and CAM were compared in terms of their growth, there was no significant difference between the groups. (p=0.65/0.54). Balanitis was not observed in any of the patients included in the study. CONCLUSIONS: The high rate of Candida and Malassezia in the normal penile flora strengthens the idea that it may cause higher rates of balanitis in people prone to infections such as diabetes. Source of Funding: Balanitis, Balanoposthitis, Fungus, Candida, Malassezia © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e197 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ibrahim Atilla Aridogan More articles by this author Nebil Akdogan More articles by this author Hazal Kandemir More articles by this author Ismail Onder Yilmaz More articles by this author Tamer Tetiker More articles by this author Fesih Ok More articles by this author Macit Ilkit More articles by this author Expand All Advertisement PDF downloadLoading ...

P105 In vitro interaction of Malassezia and commensal Staphylococcus species

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM Objective Malassezia is the most abundant fungal skin commensal organism, representing 50%–80% of total fungi present on the skin. It has been associated with many skin disorders such as pityriasis versicolor (PV) and seborrheic dermatitis/dandruff (SD/D). The role of Malassezia in disease manifestation is not discerned. It is important to understand its interaction with bacterial flora such as Staphylococcus epidermidis and S. capitis in vitro. We have studied the interaction of Malassezia and Staphylococcus species isolated from skin flora.Methods Malassezia restricta, M. globosa (n = 5) isolated from patients with SD and M. furfur (n = 5) isolated from PV were sub-cultured on Modified Dixon's agar (MDA). Staphylococcus epidermidis and S. capitis were isolated from patients with SD and sub-cultured on brain heart infusion (BHI) agar. Malassezia species requires media supplemented with lipids (MDA) for its growth. Bacteria and Malassezia were quantified on MDA and BHI agar by Miles and Mishra method to perform interaction between them. For direct interaction, suspensions (100 μl) of M. restricta, M. globose, and M. furfur were prepared in normal saline and added to wells on the plates of lawn cultures containing S. epidermidis and S. capitis (107 CFU/ml). Plates were incubated for 12 h at 35°C and observed for zone of inhibition. To investigate the release of antibacterial compounds into the extracellular environment, M. furfur was inoculated in modified Dixon's broth (MDB) and incubated at 35°C for 5 days. Supernatant was collected at 12 h, 24 h, 48 h, 72 h, 96 h, and 120 h of incubation and evaluated for antibacterial activity by agar-well diffusion assay. Effect of cell-free supernatant of Malassezia on growth of bacteria was also monitored by growth kinetics of S. epidermidis for 24 h in the absence and presence of M. furfur supernatant using Epoch-2 microplate spectrophotometer.ResultsMDA supported the growth of bacteria at different cell densities (107-103 CFU/ml count) and incubation time of S. epidermidis and S. capitis was similar on MDA and BHI. Zone of inhibition (ZOI) was witnessed with M. restricta (20.6 ± 3 mm, 21 ± 3 mm), M. globosa (21 ±1 mm, 22.6 ±2 mm) and M. furfur isolates (16.5 ± 1 mm, 18 ± 2 mm) against S. capitis and S. epidermidis respectively by direct interaction. Inhibition of bacteria by M. furfur was noted from 48-120 h as ZOI (21.7 ±5.1 mm) was observed on bacterial lawn cultured plate. When growth kinetics of S. epidermidis was monitored in presence of M. furfur supernatant, maximum value reached upto 0.26 ± 0.019 only from 0.01 ± 0.001 at OD600 in 9 h including lag phase of 4 h (Fig. 1). However, OD600 value reached upto 0.97 ± 0.005 in 8 h including lag phase of 1.5 h in absence of supernatant. Doubling time calculated from logistic growth equation was 76.6 ± 4.4 and 65.2 ± 2.9 minutes in the presence and absence of supernatant respectively.ConclusionInhibition of bacteria by Malassezia species noted in our study has not been reported earlier. The possible production of antibacterial compounds by Malassezia might be responsible for dysbiosis leading to disease.

P226 Malassezia hyphae play possible roles in the pathogenesis of androgenetic alopecia

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMBackgroundAndrogenetic alopecia (AGA) is the most common type of hair loss that seriously affects the appearance and psychology of patients. Some studies show that Malassezia seems to participate in the development of AGA, but there is still debate on this because of absent hyphae in the alopecia area. Interestingly, M. hyphae were found in scalp alopecia area of AGA patients. Thus, we speculate that the hyphae form of Malassezia may be not causal in AGA patients, and the M. hyphae may play a possible role in AGA.ObjectiveThe present study aims to elucidate the correlation of M. mycelia with hair loss in AGA patients and compare the species distribution of Malassezia in scalp between AGA patients and healthy individuals.MethodsWe sampled scales from scalp alopecia area from the patients diagnosed with AGA. The specimen was stained with calcofluor white staining (CFW) and observed for Malassezia structure under light microscopy and fluorescence microscopy. In the meanwhile, the scales were used for DNA direct extraction and sequencing. The other part of the specimen was inoculated onto Modified Dixon agar and culture at 37°C for 7 days. The isolates were identified by morphological and molecular sequencing (ITS1 and ITS4).ResultsThe fungal load of Malassezia was significantly increased and short club-shaped mycelia exist in AGA patients, accounting for 48.89%, The fungal load was positively correlated with the skin inflammation of the hair loss area. The skin inflammation on the hair loss scalp was relieved after the treatment with antifungal agents, accompanying the disappearance of M. hyphae and decreasing of fungal load. There is no difference in species distribution of Malassezia in both AGA patients and healthy individuals. M. globosa and M. restricta are the two most common species isolated from the hair loss area.Conclusion Malassezia mycelia exist in patients with mild to moderate AGA, accounting for a certain percentage. The hair loss stopped accompanied with the disappearance of M. hyphae and decreasing of fungal burden. Our data suggest that the presence of M. hyphae may contribute to the pathogenesis of AGA.

Presence of Malassezia Hyphae Is Correlated with Pathogenesis of Seborrheic Dermatitis.

ABSTRACTSeborrheic dermatitis (SD) is a common, chronic, and relapsing skin disease. The roles of Malassezia spp. in the pathogenesis of SD are still not clear due to the lack of direct evidence for the existence of hyphae within affected skin tissues. We set out to elucidate if Malassezia mycelium contributes to the onset and development of SD and if Malassezia mycelium is correlated with the clinical severity of SD patients. We detected Malassezia hyphae in patients with SD using potassium hydroxide (KOH) and calcofluor white (CFW) staining. Fluorescent microscopy was performed for the analysis of fungal cell wall and morphological characteristics of Malassezia under CFW staining. Culture growth in modified Dixon agar was used for DNA extraction and sequencing, and Malassezia species were confirmed by a sequencing data BLAST search against the NCBI database. We demonstrated that Malassezia hyphae were positively correlated with the clinical severity of SD patients (P = 3.1738 × 10−11). All the patients responded well to antifungal treatment. There is no significant difference for species dominance across the variant groups. However, the exact molecular mechanisms of how Malassezia spp. affect SD need to be further explored. The results show that Malassezia spp. in the hyphal stage are restricted to SD patients compared with healthy controls, suggesting that the presence of Malassezia hyphae contributes to the pathogenesis of SD. The results highlight the importance of the antifungal therapy for the future treatment of SD patients.IMPORTANCE Our results support the proposal that the hyphal form of Malassezia could be one of the pathogenic factors that contribute to SD, which has been previously less well studied. This clinical observation paves the way for further investigations of the molecular mechanisms of Malassezia hyphal pathogenicity in SD.

Molecular identification of Malassezia species isolated from neonates hospitalized in Neonatal intensive care units and their mothers.

Background and Purpose: Given the important role of Malassezia spp. in skin diseases and other associated infections in neonates, this study aimed to investigate the presence and frequency of Malassezia spp. in the skin of neonates hospitalized in neonatal intensive care units and their mothers using culture and accurate molecular-based methods.Materials and Methods: In total, 205 samples were collected from 130 neonates (>4-day-old) and 75 mothers. Isolation of Malassezia spp. from the skin was performed using Leeming-Notman agar and modified Dixon agar media. To compare the Malassezia microflora on the skin of the neonates and their mothers, a polymerase chain reaction-sequencing method was performed for spp. identification of 92 isolates obtained from neonates and their mothers. Moreover, possible associated risk factors for the colonization of Malassezia spp. on the skin were recorded.Results: Cultures from 62.3% of neonates and 77.3% of mothers were positive for Malassezia spp. growth. Malassezia globosa was the most prevalent isolated spp. found in the skin of the study population. It is noteworthy that a rare Malassezia spp., Malassezia arunalokei, was isolated from the skin of one neonate. There was a 76% similarity between the mother-neonate isolate sequences results. The statistical analysis showed that the type of feeding is a significant (P<0.001) associated factor for Malassezia skin colonization.Conclusion: The findings support the hypothesis that the colonization of Malassezia in neonates is significantly influenced by that of the mother, and this may be associated with breastfeeding.

Malassezia Species Distribution in Cases of Pityriasis Versicolor and Dandruff in a Tertiary Care Rural Hospital: A Cross-sectional Study

Introduction: Pityriasis Versicolor (PV) a commonly encountered superficial mycosis is a mild, chronic infection of the stratum corneum. Malassezia species are lipid dependent yeast that are commonly found on human skin and associated with PV and dandruff. Aim: To study the distribution of Malassezia species in cases of PV and Dandruff. Materials and Methods: A tertiary care rural hospital based cross-sectional study was undertaken. Skin scrapings were collected and cultured on Sabouraud’s Dextrose Agar (SDA) overlaid with olive oil and modified Dixon agar (mDA). The isolates were identified by biochemical tests. Data was analysed using the Chi-square test. The p-value of &lt;0.05 was considered statistically significant. Results: Out of the 127 samples of PV, 38.2% were 10% KOH positive. A total of 76 yielded growth. The most common isolate was M.sympodialis (53.06%), followed by M.furfur (26.53%), M.globosa (16.33%) and M.slooffiae (4.08%). Of the 51 cases of dandruff cases, 27 samples yielded growth and the most common isolate was M.sympodialis (62.96%), followed by M.furfur (25.93%), M.globosa (11.11%). Conclusion: PV and dandruff are the common surface infections in this rural region and Malassezia sympodialis is the commonest species associated with these conditions.

Comparison of Three Skin Sampling Methods and Two Media for Culturing Malassezia Yeast.

Malassezia is a lipid-dependent commensal yeast of the human skin. The different culture media and skin sampling methods used to grow these fastidious yeasts are a source of heterogeneity in culture-based epidemiological study results. This study aimed to compare the performances of three methods of skin sampling, and two culture media for the detection of Malassezia yeasts by culture from the human skin. Three skin sampling methods, namely sterile gauze, dry swab, and TranswabTM with transport medium, were applied on 10 healthy volunteers at 5 distinct body sites. Each sample was further inoculated onto either the novel FastFung medium or the reference Dixon agar for the detection of Malassezia spp. by culture. At least one colony of Malassezia spp. grew on 93/300 (31%) of the cultures, corresponding to 150 samplings. The positive culture rate was 67%, 18%, and 15% (P < 10−3), for samples collected with sterile gauze, TranswabTM, and dry swab, respectively. The positive culture rate was 62% and 38% (P < 0.003) by using the FastFung and the Dixon media, respectively. Our results showed that sterile gauze rubbing skin sampling followed by inoculation on FastFung medium should be implemented in the routine clinical laboratory procedure for Malassezia spp. cultivation.

Epidemiological characterization of pityriasis versicolor and distribution of Malassezia species among students in Hai Phong city, Vietnam.

Background and Purpose: Pityriasis versicolor (PV) is a common fungal skin infection caused by Malassezia species. Previous studies have shown that the prevalence of PV is influenced by geographic factors. The aim of the current study was to find the epidemiological characteristics of PV and distribution of Malassezia species in the secondary school students living in Hai Phong city, Vietnam.Materials and Methods: This study was conducted on 1357 students within the age range of 10 - 16 years selected from four secondary schools in Hai Phong city. The students were screened for PV skin lesions from August 2016 to December 2017. The isolates of Malassezia from PV patients were analyzed by performing direct microscopy and culturing on modified Dixon agar plates, containing gentamicin, at 32oC for 7 days. In the next stage, the fungal strains obtained from patients with positive fungal cultures were identified using the CHROMagarTM Malassezia medium, polymerase chain reaction-restriction fragment length polymorphism techniques, and D1/D2 rDNA genome sequencing.Results: Pityriasis versicolor was diagnosed in 305 (22.48%) students and confirmed by clinical appearance and direct examination. A total of 293 (96.07%) samples grew on modified Dixon agar. With regard to demographic characteristics, 50.49% of the PV cases were female, and 57.38% of cases resided in urban areas. Furthermore, 88.52% of the subjects had the illness duration of more than 6 months. Hypopigmented and erythematous skin lesions were also observed in the research participants, with hypopigmentation being the most frequent condition (97.05%). Most of the Malassezia fungal strains were isolated from the back (39.56%), face (23.99%), and chest (16.51%). Malassezia furfur and M. japonica accounted for PV in 96.25% and 3.75% of the cases, respectively. Furthermore, Malassezia furfur was distributed in both rural and urban areas, while M. japonica was found only in the urban areas.Conclusion: The findings of the present study were indicative of the high prevalence of Malassezia yeasts, mostly M. furfur, among the students in Hai Phong city, Vietnam

Malassezia species causative of pityriasis versicolor in Paraguay

Pityriasis versicolor is a frequent pathology in Paraguay; however, its epidemiology is unknown. To determine the frequency of Malassezia species causing pityriasis versicolor and the epidemiological characteristics of the population. Samples from patients with a presumptive diagnosis of pityriasis versicolor were collected. Laboratory diagnosis was carried out by fresh examination and culture in modified Dixon agar and chromogenic Chromagar Malassezia®, incubated at 32° C, and identification by macro and micromorphological features, biochemical and physiological tests. 102 patients were included (51% female) from 1 month to 63 years of age, the predominant age group was 11-20 years (35.3%). The most frequent location was on the back (60.8%). Hipocromic clinical forms (48%) predominated. The most frequent species was M. globosa (52.9%), followed by M. furfur (24.5%), M. sympodialis (18.6%) and M. slooffiae (6.9%). The observed epidemiology is similar to other South American studies, with no sex distinction, predominantly hypochromic clinical form and as primary responsible species appears M. globosa. This is the first report on species causing pityriasis versicolor in Paraguay and the characteristics of the affected population.

Evaluation of otoscope cone disinfection techniques on contamination by Malassezia pachydermatis

Summary Background Otoscope cones (OCs) are used in veterinary medical practices to examine healthy or infected ears in dogs and cats. Since OCs are reusable equipment, they can be vectors of cross contamination/infection between patients. Objectives The objective was to evaluate the efficacy of different disinfection procedures applied on OCs contaminated by Malassezia pachydermatis. Material and methods OCs were soaked for 10 min in a suspension of yeasts 2.5 McFarland and then allowed to air dry. OCs were soaked for 10 min either in ethanol, chlorhexidine, hydrogen peroxide, peracetic acid disinfectant, enilconazole or water (positive control). They were then paper wiped or left to air dry. Each OC was sampled with two swabs that were inoculated on modified Dixon's agar and incubated at 32 °C. On day 3, the number of Colony Forming Unit (CFU) was counted. Results Ninety-six cultures were performed and the growth of Malassezia could be seen in all cultures from positive controls/water (over 200 CFU in 6 from 12 tests). Similar results were observed when enilconazole was used at 0.2% concentration (over 200 CFU in 3 from 12 tests). In rest, all the cultures were negative. Conclusions Enilconazole should be used at minimal concentration of 0.4%.

Diagnostics of Malassezia Species: A Review

Abstract Yeasts from the genus Malassezia belongs to normal commensal skin flora of warm-blooded vertebrates. These yeasts may act as opportunistic pathogens and cause skin diseases in humans and animals under certain conditions. The identification of Malassezia species is based on the phenotypic or genotypic diagnostics. The methods used for the phenotypic identification is determined by: the growth on Sabouraud agar, growth on selective media (Leeming-Notman agar, Dixon agar, Chrom Malassezia agar), the ability to utilise different concentrations of Tween, monitoring of the growth on CEL agar (soil enriched with castor oil) and TE agar (Tween-esculine agar), and the catalase test. The genotypic identification uses molecular methods like: the pulsed field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), amplified fragment lenght polymorphism (AFLP), denaturing gradient gel electrophoresis (DGGE), and the DNA sequence analysis.

Identification of Malassezia species from suspected Pityriasis (versicolor) patients.

Pityriasis versicolor is a chronic, superficial fungal infection affecting the superficial layer of a stratum corneum. Malassezia furfur is the major species involved in pityriasis versicolor. Currently many researchers reported increase in the incidence of other species as a causative agent of pityriasis versicolor. Isolation and identification of Malassezia species from suspected Pityriasis versicolor patients was conducted in the Department of Microbiology and immunology Bangabandhu Sheikh Mujib Medical University (BSMMU) from September 2013 to August 2014. Ninety two clinically diagnosed patients of Pityriasis versicolor were studied and samples from skin lesion were processed for direct microscopy and culture. Species of Malassezia were identified by cultural characteristics in Dixon's agar media by macro and microscopic observation of the colonies and by catalase test, urease test, esculin test and tween assimilation test. A totalof 92 cases 70(70.08%) were positive by direct microscopy and 50(54.34%) were positive by culture. Malassezia globosa was found in 38(76%) cases as the commonest etiological agent and Malassezia furfur was found in 10(20%) cases and Malassezia obtusa in 2 (4%) cases respectively.Bangladesh J Med Microbiol 2015; 9 (2): 17-19

English

Yeasts of the Malassezia genus are linked to seborrheic dermatitis (SD) in humans; however, etiological species causing this disease can vary according to their geographical location. M. globosa and M. restricta are the most often isolated microorganisms and can be found in the skin of patients with SD. Nevertheless, species identification by molecular methods and the relationship among etiological agents and the clinical severity of the disease have not been determined in Mexican patients. The goal of this study was to analyze the prevalence of Malassezia species in the skin of SD patients by molecular methods in order to establish their distribution according to the severity of the disease in Monterrey, Nuevo Leon, Mexico. Skin samples from patients with SD (n = 60) were obtained by scraping and were cultured on modified Dixon agar. The Malassezia colonies were identified by amplification of the D1/D2 regions of 26S rDNA by polymerase chain reaction (PCR) and subsequent sequencing and BLAST analysis in GenBank. The positive Malassezia culture rate was 48.3%. The most commonly isolated species were Malassezia furfur (20%), Malassezia globosa (16.7%), Malassezia sympodialis (6.7%), Malassezia restricta (3.3%) and Malassezia slooffiae (1.7%). No significant difference was found in the distribution of Malassezia species according to disease severity. Key words: Seborrheic dermatitis, Malassezia, LSU rDNA D1/D2, yeasts, Malassezia furfur; M. globosa.

Efficacy of medicinal essential oils against pathogenic Malassezia sp. isolates

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.

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

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.

Characterization of Normal and Dandruff Causing Micro-Flora from Human Scalp of Various Age Groups

Dandruff is the most common problem that affects many people leading to an embarrassing condition. It results from three main factors namely: Malassezia fungi, sebaceous secretion and individual sensitivity. To study the characterization of dandruff causing micro-flora from healthy and affected scalp sample according various age groups (1–10, 10–30, 30–60 and above 60) scalp sample of healthy and affected scalp sample were cultured in appropriate media like Nutrient agar, Sabouraud's dextrose and Dixon's agar. The normal micro-flora (including Yeast and Bacteria) from the scalp with dandruff was compared to the flora from people without dandruff. The bacterial and fungal communities associated with dandruff were investigated using culture-dependent Method. Normal Bacterial count of healthy and dandruff-affected scalp sample of various age group (1–10, 10–30, 30–60 and above 60) were 0.003, 0.2549, 2.0082, 1.1800 and 1.17, 1.0909, 1.2554, 0.7729 respectively. Normal Yeast count of healthy and dandruff-affected scalp sample of various age group (1–10, 10–30, 30–60 and above 60) were 0.03, 0.0014, 1.3202, 0.8987 and 0.016, 0.0034, 0.6692, 0.9117 respectively. Malassezia count of healthy and dandruff-affected scalp sample of age group (1–10, 10–30, 30–60 and above 60) were 6.6, 100.2, 62.6 and 61.4, 300, 63.2 respectively. Malassezia count was absent in age group (1–10) of both scalp sample. Bacterial and Yeast count of dandruff affected scalp were increases in age group (1–10, 10–30) as compare to healthy scalp sample. But in age group (30–60 and above 60) normal Bacterial and Yeast count was decrease in dandruffaffected scalp sample. Malassezia furfur and Malassezia dermatis were identified by Biochemical test method. A comparative study on the efficacy of chemical and herbal anti-dandruff ingredients on basis and their performance in market shampoos was done in vitro against normal micro-flora including (Bacteria, Fungi and Malassezia Species.) which found on healthy and dandruff-affected scalp sample. Banana extract (Musa Acuminata) were also tested against normal micro-flora and Malasssezia Species. Banana extract showed excellent anti-malassezia activity against Malassezia Species. But failed to show antibacterial and anti-fungal activities. Zone of inhibition of herbal and banana extract showed lower value than synthetic (Chemical shampoo) ingredients containing ZnPTC and Ketoconozole recorded higher in vitro activities than shampoos containing herbal AD ingredients and Banana extract.

The Prevalence and Species Composition of Malassezia yeasts in Patients with Clinically Suspected Onychomycosis.

Introduction:There are limited numbers of studies which focused on the identification of Malassezia yeasts to a species level in onychomycosis. Therefore, the aim of our study was to determine the prevalence and species composition of Malassezia yeasts in patients with clinically suspected onychomycosis and to examine if the range of species varies with patient gender, age, site of involvement and clinical pattern of onychomycosis.Methods:Specimens were taken from 785 patients presenting signs of onychomycosis and then incubated on Sabouraud dextrose agar and modified Dixon agar. The yeasts isolated were identified according to their macroscopic and microscopic features and physiological characteristics.Results:Malassezia species were diagnosed both by microscopy and culture in fourteen (1.8%) patients. M. globosa was the predominant, if not only, species identified from nail samples. Mixed cultures were observed in five cases: in 4 cases Malassezia was co-isolated with Candida albicans and in one case with dermatophyte. Fingernails were affected more frequently than toenails (85.7%) and distolateral subungual onychomycosis was the most common clinical type (78.6%).Conclusion:No significant differences were found in the distribution of Malassezia species isolated according to demographic parameters.

Study of the Distribution of Malassezia Species in Patients with Pityriasis Versicolor in Kolar Region, Karnataka.

Context:Pityriasis versicolor is a superficial, chronically recurring fungal infection caused by Malassezia species. Recently it has been revised taxanomically into 14 species, in that only 7 species have been well studied in relation to pityriasis versicolor.Aims:To identify Malassezia species isolated from patients with pityriasis versicolor and to find out any correlation between the species with clinical presentation of lesions.Settings and Design:Prospective study comprising of 100 clinically diagnosed cases of pityriasis versicolor attending Dermatology Outpatient Department over a period of 1 year.Materials and Methods:The clinical specimens were collected under aseptic precautions and subjected to culture on Sabouraud's Dextrose Agar overlaid with olive oil and modified Dixon agar. The isolates were identified by biochemical tests.Statistical Analysis Used:Statistical analysis was done using proportion, mean and chi-square test.Results:Of the 100 cases, 73% were males, 26% were females and predominant age group was 21-30 years. Out of 100 samples, 70 yielded growth. The most common isolate was M. sympodialis (50%), followed by M. furfur (32.86%), M. globosa (14.28%) and M. slooffiae (2.86%). Among 100 cases, 74% had hypopigmented and 26% had hyperpigmented lesions. M. sympodialis and M. furur were predominantly isolated from hypopigmented lesions and M. globosa and M. slooffiae were found to be more common in hyperpigmented lesions.Conclusions:M. sympodialis was the most common isolate, followed by M. furfur, M. globosa and M. slooffiae. There was no significant difference in distribution of different species in patients with hypo or hyper pigmented lesions