Prevalence of Malassezia species on the skin of HIV-seropositive patients.
ABSTRACT: Malassezia is a genus of lipophilic yeasts residing on the skin of warm-blooded animals. The correlation between specific species and their involvement in skin diseases has been well researched. However, only very few studies have investigated the distribution of Malassezia spp. on the healthy skin of patients infected with human immunodeficiency virus (HIV). The purpose of this work was to analyze whether the composition of Malassezia spp. isolated from the skin of the HIV-infected patients differs from that of healthy individuals. The study included a total of 96 subjects, who were divided into two equally sized groups: HIV-seropositive and HIV-seronegative. The specimens were collected from the subjects by swabbing four anatomical sites (face, chest, back, and scalp). Species were identified using phenotype-based methods, and the identification of strains isolated from the HIV-seropositive patients was confirmed by PCR sequencing of the rDNA cluster. Malassezia spp. were isolated from 33 (69%) HIV-seropositive patients and 38 (79%) healthy volunteers. It was found that men were much more likely to have their heads colonized with Malassezia spp. than women. The most prevalent species on the skin of both HIV-seropositive and HIV-seronegative individuals were Malassezia sympodialis, M. globosa, and M. furfur, albeit at different proportions in the two populations. The diversity of Malassezia spp. was the highest on the face of the HIV-seropositive patients (Shannon-Weiner Index H?=?1.35) and lowest on the back of the healthy volunteers (H?=?0.16). The phenotype- and molecular-based identification methods were congruent at 94.9%. It was observed a tendency that the HIV-seropositive patients had higher CD4+ cell counts, indicating higher colonization with Malassezia spp.
Project description:We used Affymetix HG Focus GeneChip to measure the expression levels of HIV seronegative and seropositive individuals in human PBMCs in vivo. GSM39104 -GSM39115 are HIV seronegative samples; GSM39116-GSM39137 are HIV seropositive but drug naive samples; GSM39138-GSM39147 are HIV seropositive samples used to test serostatus biomarker; GSM39148-GSM39170 are HIV seropositive individuals whose CD4 cells decrease over time; GSM39171-GSM39187 are HIV seropositive individuals whose CD4 cells increase over time; GSM39188-GSM39190 are HIV seropositive samples used to test CD4 cell increase/decrease over time.
Project description:BACKGROUND: The Malassezia yeasts which belong to the physiological microflora of human skin have also been implicated in several dermatological disorders, including pityriasis versicolor (PV), atopic dermatitis (AD), and psoriasis (PS). The Malassezia genus has repeatedly been revised and it now accommodates 14 species, all but one being lipid-dependent species. The traditional, phenotype-based identification schemes of Malassezia species are fraught with interpretative ambiguities and inconsistencies, and are thus increasingly being supplemented or replaced by DNA typing methods. The aim of this study was to explore the species composition of Malassezia microflora on the skin of healthy volunteers and patients with AD and PS. METHODS: Species characterization was performed by conventional, culture-based methods and subsequently molecular techniques: PCR-RFLP and sequencing of the internal transcribed spacer (ITS) 1/2 regions and the D1/D2 domains of the 26S rRNA gene. The Chi-square test and Fisher's exact test were used for statistical analysis. RESULTS: Malassezia sympodialis was the predominant species, having been cultured from 29 (82.9%) skin samples collected from 17 out of 18 subjects under the study. Whereas AD patients yielded exclusively M. sympodialis isolates, M. furfur isolates were observed only in PS patients. The isolation of M. sympodialis was statistically more frequent among AD patients and healthy volunteers than among PS patients (P <?0.03). Whether this mirrors any predilection of particular Malassezia species for certain clinical conditions needs to be further evaluated. The overall concordance between phenotypic and molecular methods was quite high (65%), with the discordant results being rather due to the presence of multiple species in a single culture (co-colonization) than true misidentification. All Malassezia isolates were susceptible to cyclopiroxolamine and azole drugs, with M. furfur isolates being somewhat more drug tolerant than other Malassezia species. CONCLUSIONS: This study provides an important insight into the species composition of Malassezia microbiota in human skin. The predominance of M. sympodialis in both normal and pathologic skin, contrasts with other European countries, reporting M. globosa and M. restricta as the most frequently isolated Malassezia species.
Project description:We used Affymetix HG Focus GeneChip to measure the expression levels of HIV seronegative and seropositive individuals in human PBMCs in vivo. GSM39104 -GSM39115 are HIV seronegative samples; GSM39116-GSM39137 are HIV seropositive but drug naive samples; GSM39138-GSM39147 are HIV seropositive samples used to test serostatus biomarker; GSM39148-GSM39170 are HIV seropositive individuals whose CD4 cells decrease over time; GSM39171-GSM39187 are HIV seropositive individuals whose CD4 cells increase over time; GSM39188-GSM39190 are HIV seropositive samples used to test CD4 cell increase/decrease over time. Keywords: other
Project description:BACKGROUND & OBJECTIVES: Malassezia species implicated with dandruff vary at different geographical locations. The present study was conducted to determine the spectrum and distribution of Malassezia species in dandruff patients and healthy individuals. METHODS: Patients with dandruff from northern (Chandigarh) and southern (Manipal, Karnataka) parts of India (50 each) and healthy individuals (20) were included in the study. Dandruff severity was graded as mild, moderate and severe. Malassezia spp. isolated were quantified and identified by phenotypic characters and molecular methods including PCR-RFLP and DNA sequencing. RESULTS: Number of Malassezia spp. retrieved was significantly higher (P<0.001) in dandruff cases (84%) as compared to healthy individuals (30%). Isolation of Malassezia spp. was significantly higher (P<0.01) in patients from southern India. In moderately severe cases M. restricta was single most predominant (37.8%) isolate from patients of northern part of India and M. furfur (46.4%) from patients of southern part of India. Malassezia density was significantly associated with the severity of dandruff (P<0.001). INTERPRETATION & CONCLUSIONS: Our results on a limited number of individuals show that Malassezia spp. associated with dandruff varies in different regions of the country and the density of yeasts increases with severity of disease.
Project description:Members of the genus Malassezia, lipophilic yeasts, are considered to be one of the exacerbating factors in atopic dermatitis (AD). We examined variation in cutaneous colonization by Malassezia species in AD patients and compared it with variation in healthy subjects. Samples were collected by applying transparent dressings to the skin lesions of AD patients. DNA was extracted directly from the dressings and amplified in a specific nested PCR assay. Malassezia-specific DNA was detected in all samples obtained from 32 AD patients. In particular, Malassezia globosa and M. restricta were detected in approximately 90% of the AD patients and M. furfur and M. sympodialis were detected in approximately 40% of the cases. The detection rate was not dependent on the type of skin lesion. In healthy subjects, Malassezia DNA was detected in 78% of the samples, among which M. globosa, M. restricta, and M. sympodialis were detected at frequencies ranging from 44 to 61%, with M. furfur at 11%. The diversity of Malassezia species found in AD patients was greater (2.7 species detected in each individual) than that found in healthy subjects (1.8 species per individual). Our results suggest that M. furfur, M. globosa, M. restricta, and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of AD patients shows more diversity than that of healthy subjects. To our knowledge, this is the first report of the use of a nested PCR as an alternative to fungal culture for analysis of the distribution of cutaneous Malassezia spp.
Project description:BACKGROUND:Lack of a gold standard for latent TB infection has precluded direct measurement of test characteristics of the tuberculin skin test and interferon-? release assays (QuantiFERON Gold In-Tube and T-SPOT.TB). OBJECTIVE:We estimated test sensitivity/specificity and latent TB infection prevalence in a prospective, US-based cohort of 10?740 participants at high risk for latent infection. METHODS:Bayesian latent class analysis was used to estimate test sensitivity/specificity and latent TB infection prevalence among subgroups based on age, foreign birth outside the USA and HIV infection. RESULTS:Latent TB infection prevalence varied from 4.0% among foreign-born, HIV-seronegative persons aged <5 years to 34.0% among foreign-born, HIV-seronegative persons aged ?5 years. Test sensitivity ranged from 45.8% for the T-SPOT.TB among foreign-born, HIV-seropositive persons aged ?5 years to 80.7% for the tuberculin skin test among foreign-born, HIV-seronegative persons aged ?5 years. The skin test was less specific than either interferon-? release assay, particularly among foreign-born populations (eg, the skin test had 70.0% specificity among foreign-born, HIV-seronegative persons aged ?5 years vs 98.5% and 99.3% specificity for the QuantiFERON and T-SPOT.TB, respectively). The tuberculin skin test's positive predictive value ranged from 10.0% among foreign-born children aged <5 years to 69.2% among foreign-born, HIV-seropositive persons aged ?5 years; the positive predictive values of the QuantiFERON (41.4%) and T-SPOT.TB (77.5%) were also low among US-born, HIV-seropositive persons aged ?5 years. CONCLUSIONS:These data reinforce guidelines preferring interferon-? release assays for foreign-born populations and recommending against screening populations at low risk for latent TB infection. TRIAL REGISTRATION NUMBER:NCT01622140.
Project description:Background:Pityriasis versicolor (PV) is the most common chronic superficial infection of the stratum corneum, reported in 40-60% of the tropical population. After the description of the new Malassezia species, only a few studies have been conducted from India. Aims:Molecular identification, quantification of Malassezia species implicated with PV and correlation to its clinical presentation. Materials and Methods:The subjects include 50 PV patients, who attended the dermatology outpatient department of our hospital and 50 healthy individuals. Same size area of the skin was sampled from lesional and non-lesional sites in the patient group and from forehead, cheek, and chest of healthy individuals. Malassezia spp. isolated were identified by conventional method and confirmed by ITS2 PCR-RFLP and sequencing of D1/D2 region of 26S rDNA. Results:Eighty percent of patients presented with hypopigmented lesions and 20% with hyperpigmented lesions. From PV lesions, the most frequently isolated species was M. furfur (50%), followed by M. globosa (27.3%), mixture of M. furfur and M. globosa (15.9%), M. sympodialis (4.5%), and M. slooffiae (2.3%). Higher Malassezia density was found in lesional area as compared to non-lesional area of PV patients and in healthy individuals (P 0.0001). Conclusion:Although M. furfur was the most prevalent species isolated from both patients and controls, significantly higher isolation of M. globosa from the lesional area compared to non-lesional area indicates its possible role along with M. furfur in causing PV.
Project description:Seborrheic dermatitis (SD) is a common, chronic, and relapsing skin disease. The roles of <i>Malassezia</i> 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 <i>Malassezia</i> mycelium contributes to the onset and development of SD and if <i>Malassezia</i> mycelium is correlated with the clinical severity of SD patients. We detected <i>Malassezia</i> 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 <i>Malassezia</i> under CFW staining. Culture growth in modified Dixon agar was used for DNA extraction and sequencing, and <i>Malassezia</i> species were confirmed by a sequencing data BLAST search against the NCBI database. We demonstrated that <i>Malassezia</i> hyphae were positively correlated with the clinical severity of SD patients (<i>P </i>= 3.1738 × 10<sup>-11</sup>). 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 <i>Malassezia</i> spp. affect SD need to be further explored. The results show that <i>Malassezia</i> spp. in the hyphal stage are restricted to SD patients compared with healthy controls, suggesting that the presence of <i>Malassezia</i> hyphae contributes to the pathogenesis of SD. The results highlight the importance of the antifungal therapy for the future treatment of SD patients. <b>IMPORTANCE</b> Our results support the proposal that the hyphal form of <i>Malassezia</i> 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 <i>Malassezia</i> hyphal pathogenicity in SD.
Project description:We determined the effect of HIV infection on deaths among persons >18 months of age with culture-confirmed candidemia at 29 sentinel hospitals in South Africa during 2012-2017. Of 1,040 case-patients with documented HIV status and in-hospital survival data, 426 (41%) were HIV-seropositive. The in-hospital case-fatality rate was 54% (228/426) for HIV-seropositive participants and 37% (230/614) for HIV-seronegative participants (crude odds ratio [OR] 1.92, 95% CI 1.50-2.47; p<0.001). After adjusting for relevant confounders (n = 907), mortality rates were 1.89 (95% CI 1.38-2.60) times higher among HIV-seropositive participants than HIV-seronegative participants (p<0.001). Compared with HIV-seronegative persons, the stratum-specific adjusted mortality OR was higher among HIV-seropositive persons not managed in intensive care units (OR 2.27, 95% CI 1.47-3.52; p<0.001) than among persons who were (OR 1.56, 95% CI 1.00-2.43; p = 0.05). Outcomes among HIV-seropositive persons with candidemia might be improved with intensive care.
Project description:Dandruff is a skin condition that affects the scalp of up to half the world's population, it is characterised by an itchy, flaky scalp and is associated with colonisation of the skin by Malassezia spp. Management of this condition is typically via antifungal therapies, however the precise role of microbes in the aggravation of the condition are incompletely characterised. Here, a combination of 454 sequencing and qPCR techniques were used to compare the scalp microbiota of dandruff and non-dandruff affected Chinese subjects. Based on 454 sequencing of the scalp microbiome, the two most abundant bacterial genera found on the scalp surface were Cutibacterium (formerly Propionibacterium) and Staphylococcus, while Malassezia was the main fungal inhabitant. Quantitative PCR (qPCR) analysis of four scalp taxa (M. restricta, M. globosa, C. acnes and Staphylococcus spp.) believed to represent the bulk of the overall population was additionally carried out. Metataxonomic and qPCR analyses were performed on healthy and lesional buffer scrub samples to facilitate assessment of whether the scalp condition is associated with differential microbial communities on the sampled skin. Dandruff was associated with greater frequencies of M. restricta and Staphylococcus spp. compared with the healthy population (p<0.05). Analysis also revealed the presence of an unclassified fungal taxon that could represent a novel Malassezia species.