Prevalence of Malassezia species in patients with pityriasis versicolor in Rosario, Argentina

BackgroundMalassezia species are considered opportunistic yeasts of increasing clinical importance. These lipophilic yeasts are associated with various human diseases, especially pityriasis versicolor (PV), a chronic superficial scaling dermatomycosis.AimsThe aim of this study was to isolate, identify and analyze the distribution of the different species of Malassezia in patients with PV in Rosario city (Argentina).MethodsA total of 264 clinical samples were studied. Isolates were identified on the basis of microscopic observation of cells, and physiological properties, such as the presence of catalase, ability to use Tween compounds, splitting of esculin, and morphology, color and precipitate production on chromogenic agar CHROMagar-Malassezia medium (CHROMM).ResultsThe highest prevalence of PV in this study was observed in the 25- to 45-year-old group. No differences were found in the development of PV between sexes. The most affected areas of body were the trunk and face. Malassezia sympodialis (51%) was the most commonly isolated species, followed in frequency by M. globosa (40%), Malassezia furfur (7%), Malassezia obtusa (1%) and Malassezia slooffiae (1%).ConclusionsThe success for a correct identification of these yeasts is important to improve our knowledge about their epidemiological role in PV and also to detect the appearance of strains which are resistant to the commonly used antifungal drugs.     

Two new lipid-dependent Malassezia species from domestic animals

During a study on the occurrence of lipid-dependent Malassezia spp. in domestic animals, some atypical strains, phylogenetically related to Malassezia sympodialis Simmons et Guého, were shown to represent novel species. In this study, we describe two new taxa, Malassezia caprae sp. nov. (type strain MA383=CBS 10434), isolated mainly from goats, and Malassezia equina sp. nov. (type strain MA146=CBS 9969), isolated mainly from horses, including their morphological and physiological characteristics. The validation of these new taxa is further supported by analysis of the D1/D2 regions of the 26S rRNA gene, the ITS1-5.8S-ITS2 rRNA, the RNA polymerase subunit 1 and chitin synthase nucleotide sequences, and the amplified fragment length polymorphism patterns, which were all consistent in separating these new species from the other species of the genus, and those of the M. sympodialis species cluster, specifically.     

Prevalence of Malassezia species in pityriasis versicolor lesions in northeast Argentina

BackgroundMalassezia species normally colonize the skin but they can change their saprophytic state and invade the stratum corneum as pathogens.AimsTo determine the prevalence of Malassezia species isolated from patients with pityriasis versicolor (PV) and to analyse their distribution according to the location of the lesion on the body.MethodsThis study included 218 patients with PV and positive Malassezia cultures who resided in the city of Resistencia, a subtropical area located in northeast Argentina. Age, gender, and the body site of lesions were recorded. Strains were identified by PCR-RFLP.ResultsMalassezia sympodialis (37.7%) and Malassezia globosa (37.2%) were the most prevalent species isolated alone or in association with other Malassezia species in 82% of the patients. Malassezia furfur (21.3%) was the third most common species, followed by Malassezia slooffiae (1.7%), and Malassezia restricta (1.3%), which was found only in combination with M. globosa and M. sympodialis. Malassezia dermatis (0.4%) and Malassezia pachydermatis (0.4%) were each isolated once. None of the species affected a body site with statistical significance. Significant difference between genders according to age was found only in the 31–40-year-age group.ConclusionsThis study suggests that M. sympodialis and M. globosa represent the main species implicated in the pathogenicity of PV. M. furfur appears to be the third agent of importance in this geographical area. Statistical analyses showed none of the species was particularly associated with any one of the body sites.     

Description of three novel Lagenidium (Oomycota) species causing infection in mammals

BackgroundRecent molecular phylogenetic analysis of Lagenidium strains recovered from subcutaneous lesions in cats, dogs, and a human with lagenidiosis resolved into four clades; one of them was Lagenidium giganteum, but three others were novel.AimsDue to the recent increase in L. giganteum infections from mammals, we studied 21 Lagenidium strains isolated from dogs and a human available in our collection.MethodsMolecular phylogenetic studies and phenotypic characteristics were used to characterize the strains.ResultsWe report the finding of three novel species, herein designated as Lagenidium ajelloi, sp. nov., Lagenidium albertoi sp. nov, and Lagenidium vilelae sp. nov. Their morphological and growth features are also presented.ConclusionsOur study revealed the presence of three novel Lagenidium species infecting mammals.     

Five novel species of the anamorphic genus Candida in the Cyberlindnera clade isolated from natural substrates in Taiwan

Twelve strains representing five novel yeast species were isolated from natural samples distributed in mountain areas in Taiwan during 2007 and 2009. Sequence analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene revealed that these species are members of the Cyberlindnera clade. These five new species have a greater than 1% difference from their closest relatives in the sequences of the D1/D2 domain of the LSU rRNA gene and were well separated from their closest relatives in terms of physiological characteristics. Moreover, a sexual state could not be found in these five novel yeast species. Therefore, the scientific names of Candida maesa sp. nov. (type strain GJ8L01^T), Candida takata sp. nov. (type strain EN25S01^T), Candida taoyuanica sp. nov. (type strain GY15S07^T), Candida hungchunana sp. nov. (type strain NC3W71^T) and Candida stauntonica sp. nov. (type strain GY13L05^T) were proposed to accommodate these yeasts.     

Atypical non-lipid-dependent strains of <Emphasis Type="Italic">Malassezia furfur</Emphasis>

Members of the yeast genus Malassezia, including atypical strains, are lipophilic except for Malassezia pachydermatis. New physiological features that characterize atypical Malassezia strains are mainly associated with alteration in Tween assimilation pattern — such isolates still require lipids for growth. We isolated three non-lipid-dependent strains of Malassezia from patients with diagnosed atopic dermatitis (AD). These isolates could not be identified to the species level via their physiological properties. Phylogenetic trees, based on the D1/D2 regions of the 26S rDNA gene sequences and nucleotide sequences of the ITS1-5.8S-ITS2 rRNA region, showed the isolates to belong to Malassezia furfur. Three non-lipid dependent isolates from AD skin were conspecific, and sequences analysis proved them to be M. furfur.     

Identification of Malassezia species isolated from patients with extensive forms of pityriasis versicolor in Siena,Italy

BackgroundPityriasis versicolor (PV) is an infection caused by various species of Malassezia yeast. There is no agreement in the literature concerning the species of Malassezia and the demographic, clinical, and mycological data.AimsTo prospectively identify Malassezia species isolated from lesions of patients with extensive, long standing and recurrent forms of PV and to estimate the relationship between Malassezia species and the demographic and clinical data of the patients.MethodsAll patients with PV were enrolled over a four-year period. Malassezia species were isolated in cultures and identified by morphological features and physiological tests. In the last 2 years a PCR-based technique was used to confirm the species’ identification.ResultsA total of 74 patients (43 males and 31 females, mean age 39.5 years) were enrolled. Only one species was isolated in 45 patients, and more than one species were identified in the remaining 28 patients (38%). M. globosa was the most frequently isolated (60.3%) species. There was a significant association between the isolation of 2 or more species and the presence of at least one predisposing factor. In the last 29 cases, which were subjected to PCR, there were no differences in the identification of isolated species as compared to traditional methods.ConclusionsThe isolation of more than one species in a single lesion is not infrequent in PV and is related to the presence of one predisposing factor. The isolated species isolated were not influenced by demographic and clinical features. The traditional and more recent (PCR) procedures gave the same results in the isolated species.     

<Emphasis Type="Italic">Malassezia</Emphasis> spp. in Acoustic Meatus of Bats (<Emphasis Type="Italic">Molossus molossus</Emphasis>) of the Amazon Region,Brazil

The yeasts of the Malassezia genus are opportunistic microorganisms and can cause human and animal infections. They are commonly isolated from the skin and auricular canal of mammalians, mainly dogs and cats. The present study was aimed to isolate Malassezia spp. from the acoustic meatus of bats (Molossus molossus) in the Montenegro region, “Rondônia”, Brazil. From a total of 30 bats studied Malassezia spp. were isolated in 24 (80%) animals, the breakdown by species being as follows (one Malassezia sp. per bat, N = 24): 15 (62.5%) M. pachydermatis, 5 (20.8%) M. furfur, 3 (12.5%) M. globosa and 1 (4.2%) M. sympodialis. This study establishes a new host and anatomic place for Malassezia spp., as it presents the first report ever of the isolation of this genus of yeasts in the acoustic meatus of bats.     

Molecular Epidemiology of Malassezia globosa and Malassezia restricta in Sudanese Patients with Pityriasis Versicolor

Pityriasis versicolor is a superficial infection of the stratum corneum caused by Malassezia yeasts. The cutaneous Malassezia globosa and Malassezia restricta in Sudanese patients with pityriasis versicolor were elucidated using a molecular-based, culture-independent method and compared with that in healthy individuals. Scale samples were collected by applying an Opsite? transparent dressing to lesional and non-lesional sites on 29 Sudanese patients with pityriasis versicolor and 54 healthy individuals. Malassezia DNA was extracted directly from the samples. The overall level of colonization by Malassezia globosa and Malassezia restricta was analyzed by real-time PCR using a TaqMan probe. The overall level of colonization by Malassezia at the lesional sites was higher than that at the non-lesional sites for all body sites, including the face, neck, cheeks, and trunk (2.7- to 6.0-fold increase). Both M. globosa and M. restricta were detected in patients and healthy individuals. However, M. globosa predominated at lesional sites, whereas the level of colonization by both species was similar in healthy individuals.     

Isolation of a new heterolobosean amoeba from a rice field soil: Vrihiamoeba italica gen. nov., sp. nov.

A heterolobosean amoeba strain 6_5F was isolated from an Italian rice field soil. Although 18S rRNA gene sequence analysis demonstrated that the new isolate was closely related to Stachyamoeba sp. ATCC 50324, further molecular analysis and morphological observation showed distinct differences amongst the two. The 5.8S rRNA gene was successfully amplified and sequenced for strain 6_5F but not for strain ATCC 50324. Trophozoites of strain ATCC 50324 transform into flagellate forms in the late stage of incubation before encystment, while strain 6_5F do not show flagellate forms under different conditions of the flagellation test. Light and electron microscopic observation showed the structural difference of cysts of strain 6_5F from strain ATCC 50324 and also from the type strain Stachyamoeba lipophora. The results show that the strain 6_5F is distinct from Stachyamoeba spp. and we propose a new genus and species for this isolate, Vrihiamoeba italica gen. nov., sp. nov.     

Malassezia Intra-Specific Diversity and Potentially New Species in the Skin Microbiota from Brazilian Healthy Subjects and Seborrheic Dermatitis Patients

Malassezia yeasts are part of the resident cutaneous microbiota, and are also associated with skin diseases such as seborrheic dermatitis (SD). The role these fungi play in skin diseases and why they are pathogenic for only some individuals remain unclear. This study aimed to characterize Malassezia microbiota from different body sites in healthy and SD subjects from Brazil. Scalp and forehead samples from healthy, mild SD and severe SD subjects were collected. Non-scalp lesions from severe SD patients were also sampled. 5.8S rDNA/ITS2 amplicons from Malassezia sp. were analyzed by RFLP and sequencing. Results indicate that Malassezia microbiota did not group according to health condition or body area. Phylogenetic analysis revealed that three groups of sequences did not cluster together with any formally described species, suggesting that they might belong to potential new species. One of them was found in high proportions in scalp samples. A large variety of Malassezia subtypes were detected, indicating intra-specific diversity. Higher M. globosa proportions were found in non-scalp lesions from severe SD subjects compared with other areas, suggesting closer association of this species with SD lesions from areas other than scalp. Our results show the first panorama of Malassezia microbiota in Brazilian subjects using molecular techniques and provide new perspectives for further studies to elucidate the association between Malassezia microbiota and skin diseases.     

Biodiversity and monitoring of colorless filamentous bacteitrtn sulfide aquatic systems of North Caucasus region

Bacterial mats in sulfide aquatic systems of North Caucasus are basically composed by the species of genera Thiothrix and Sphaerotilus. Additionally, several non-filamentous sulfur-oxidizing bacteria were isolated from the mats and several minor 16S rRNA phylotypes were found in clone libraries from these mats. The minor components were affiliated with Proteobacteria, Chlorobia, Cyanobacteria and Firmicutes. Even in an individual mat population heterogeneity of Thiothrix spp. was revealed by analysis of 16S rRNA gene and RAPD-PCR. Five Thiothrix isolates were described as new species Thiothrix caldifontis sp. nov. and Thiothrix lacustris sp. nov. In the Thiothrix-Sphaerotilus type of bacterial mat the proportion of dominant organisms might be influenced by sulfide concentration in the spring water. The higher sulfide concentration (more than 10 mg/1) in the spring water is more favorable for the development of bacterial mats with dominant Thiothrix organisms than for Thiothrix-Sphaerotilus type of sulfur mat.     

Eleven new species of Sugiyamaella and Candida from forest habitats

Eleven new yeasts from forest habitats are described from nucleotide sequence analysis of the nearly entire large subunit rRNA gene, ITS1-5.8S-ITS2 rRNA gene, mitochondrial small subunit rRNA gene, and the cytochrome oxidase II gene. All are members of the Sugiyamaella clade. Three are heterothallic species of Sugiyamaella and eight species are assigned to Candida. The Sugiyamaella species are: Su. americana sp. nov., type strain NRRL YB-2067 (CBS 10352), mating type a, and isotype NRRL YB-4197 (CBS 10353), mating type alpha; Su. chiloensis sp. nov., type strain NRRL Y-17646 (CBS 8168), mating type a, and isotype NRRL Y-27101 (CBS 5927), mating type alpha, anamorph Ca. bertae; Su. japonica sp. nov., type strain NRRL YB-2788 (CBS 10354), diploid, NRRL YB-2764 (CBS 10355), mating type a, and NRRL YB-2799 (CBS 10356), mating type alpha. The Candida species with type strains are: Ca. boreocaroliniensis sp. nov. NRRL YB-1835 (CBS 10344), Ca. floridensis sp. nov. NRRL YB-3827 (CBS 10350), Ca. grinbergsii sp. nov. NRRL Y-27117 (CBS 5924), Ca. lignohabitans sp. nov. NRRL YB-1473 (CBS 10342), Ca. marilandica sp. nov. NRRL YB-1847 (CBS 10346), Ca. marionensis sp. nov. NRRL YB-1336 (CBS 10341), Ca. neomexicana sp. nov. NRRL YB-2450 (CBS 10349), and Ca. pinicola sp. nov. NRRL YB-2263 (CBS 10348).     

Pseudocitrobacter gen. nov., a novel genus of the Enterobacteriaceae with two new species Pseudocitrobacter faecalis sp. nov., and Pseudocitrobacter anthropi sp. nov,isolated from fecal samples from hospitalized patients in Pakistan

Four isolates of Gram-negative facultatively anaerobic bacteria, three of them producing NDM-1 carbapenemase, were isolated from hospitalized patients and outpatients attending two military hospitals in Rawalpindi, Pakistan, and studied for their taxonomic position. Initially the strains were phenotypically identified as Citrobacter species. Comparative analysis of 16S rRNA gene sequences then showed that the four strains shared >97%, but in no case >98.3%, 16S rRNA gene sequence similarities to members of the genera Citrobacter, Kluyvera, Pantoea, Enterobacter and Raoultella, but always formed a separate cluster in respective phylogenetic trees. Based on multilocus sequence analysis (MLSA) including partial recN, rpoA, thdF and rpoB gene sequence and respective amino acid sequence analysis it turned out that the strains also here always formed separate clusters. Based on further comparative analyses including DNA–DNA hybridizations, genomic fingerprint analysis using rep- and RAPD-PCRs and physiological tests, it is proposed to classify these four strains into the novel genus Pseudocitrobacter gen. nov. with a new species Pseudocitrobacter faecalis sp. nov. with strain 25 CIT^T (= CCM 8479^T = LMG 27751^T) and Pseudocitrobacter anthropi sp. nov. with strain C138^T (= CCM 8478^T = LMG 27750^T), as the type strains, respectively.     

Kocuria uropygioeca sp. nov. and Kocuria uropygialis sp. nov., isolated from the preen glands of Great Spotted Woodpeckers (Dendrocopos major)

Two new species of Gram-positive cocci were isolated from the uropygial glands of wild woodpeckers (Dendrocopos major) originating from different locations in Germany. A polyphasic approach confirmed the affiliation of the isolates to the genus Kocuria. Phylogenetic analysis based on the 16S rRNA gene showed high degree of similarity to Kocuria koreensis DSM 23367^T (99.0% for both isolates). However, low ANIb values of <80% unequivocally separated the new species from K. koreensis. This finding was further corroborated by DNA fingerprinting and analysis of polar lipid profiles. Furthermore, growth characteristics, biochemical tests, MALDI-TOF MS analysis, and G + C contents clearly differentiated the isolates from their known relatives. Besides, the woodpecker isolates significantly differed from each other in their whole-cell protein profiles, DNA fingerprints, and ANIb values. In conclusion, the isolated microorganisms constitute members of two new species, for which the names Kocuria uropygioeca sp. nov. and Kocuria uropygialis sp. nov. are proposed. The type strains are 36^T (DSM 101740^T = LMG 29265^T) and 257^T (=DSM 101741^T = LMG 29266^T) for K. uropygialis sp. nov. and K. uropygioeca sp. nov., respectively.     

Cryptococcus nanyangensis sp. nov., A New Basidiomycetous Yeast Isolated from the Gut of Wood-Boring Larvae

Two strains of a novel basidiomycetous yeast species were isolated from the gut of wood-boring larvae collected in the Baotianman Nature Reserve, the central China. Sequence analysis of the D1/D2 domains of the large subunit (LSU) rRNA gene and internal transcribed spacer (ITS) regions showed that these yeasts belong to the Bulleromyces clade and formed a cluster together with eleven undescribed Cryptococcus species. The novel species differed from its closest known species, Cryptococcus rajasthanensis, by 3.3 % divergence (15 substitutions and 6 gaps over 630 bases) in the D1/D2 domains, and by 13.4 % divergence (41 substitutions and 27 gaps over 508 bases) in the ITS regions. Physiologically, the fermentation of glucose, galactose, sucrose, trehalose, and raffinose in Durham tubes was observed for the strains of this new yeast. Based on the phenotypical and molecular characteristics presented, the two strains are proposed as a new species, Cryptococcus nanyangensis sp. nov., with the type strain KCY-1^T (=CICC 1976^T = CBS 12474^T).     

<Emphasis Type="SmallCaps">d</Emphasis>-Xylose fermentation,xylitol production and xylanase activities by seven new species of <Emphasis Type="Italic">Sugiyamaella</Emphasis>

Sixteen yeast isolates identified as belonging to the genus Sugiyamaella were studied in relation to D-xylose fermentation, xylitol production, and xylanase activities. The yeasts were recovered from rotting wood and sugarcane bagasse samples in different Brazilian regions. Sequence analyses of the internal transcribed spacer (ITS) region and the D1/D2 domains of large subunit rRNA gene showed that these isolates belong to seven new species. The species are described here as Sugiyamaella ayubii f.a., sp. nov. (UFMG-CM-Y607^T = CBS 14108^T), Sugiyamaella bahiana f.a., sp. nov. (UFMG-CM-Y304^T = CBS 13474^T), Sugiyamaella bonitensis f.a., sp. nov. (UFMG-CM-Y608^T = CBS 14270^T), Sugiyamaella carassensis f.a., sp. nov. (UFMG-CM-Y606^T = CBS 14107^T), Sugiyamaella ligni f.a., sp. nov. (UFMG-CM-Y295^T = CBS 13482^T), Sugiyamaella valenteae f.a., sp. nov. (UFMG-CM-Y609^T = CBS 14109^T) and Sugiyamaella xylolytica f.a., sp. nov. (UFMG-CM-Y348^T = CBS 13493^T). Strains of the described species S. boreocaroliniensis, S. lignohabitans, S. novakii and S. xylanicola, isolated from rotting wood of Brazilian ecosystems, were also compared for traits relevant to xylose metabolism. S. valenteae sp. nov., S. xylolytica sp. nov., S. bahiana sp. nov., S. bonitensis sp. nov., S. boreocarolinensis, S. lignohabitans and S. xylanicola were able to ferment d-xylose to ethanol. Xylitol production was observed for all Sugiyamaella species studied, except for S. ayubii sp. nov. All species studied showed xylanolytic activity, with S. xylanicola, S. lignohabitans and S. valenteae sp. nov. having the highest values. Our results suggest these Sugiyamaella species have good potential for biotechnological applications.     

New anamorphic yeast species: Candida infanticola sp. nov., Candida polysorbophila sp. nov., Candida transvaalensis sp. nov. and Trigonopsis californica sp. nov

Three new species of Candida and a new species of Trigonopsis are described based on their recognition from phylogenetic analysis of gene sequences from large subunit ribosomal RNA, ITS1/ITS2 rRNA, mitochondrial small subunit rRNA and cytochrome oxidase II. Candida infanticola sp. nov. (type strain NRRL Y-17858, CBS 7922) was isolated from the ear of an infant in Germany and is closely related to Candida sorbophila. Candida polysorbophila sp. nov. (type strain NRRL Y-27161, CBS 7317) is a member of the Zygoascus clade and was isolated in South Africa as a contaminant from an emulsion of white oil and polysorbate. Candida transvaalensis sp. nov. (type strain NRRL Y-27140, CBS 6663) was obtained from forest litter, the Transvaal, South Africa, and forms an isolated clade with Candida santjacobensis. Trigonopsis californica sp. nov. (type strain NRRL Y-27307, CBS 10351) represents a contaminant from wine in California, and forms a well-supported clade with Trigonopsis cantarellii, Trigonopsis variabilis and Trigonopsis vinaria.     

Identification of two cyanobacterial strains isolated from the Kotel’nikovskii hot spring of the Baikal rift

Two cyanobacterial strains, Pseudanabaena sp. 0411 and Synechococcus sp. 0431, were isolated from a sample collected in the Kotel’nikovskii hot spring of the Baikal rift. According to the results of light and transmission electron microscopy, as well as of the phylogenetic analysis of the 16S rRNA gene, these cyanobacteria were classified as Pseudanabaena sp. nov. and Synechococcus bigranulatus Skuja. The constructed phylogenetic tree shows that the studied strains are positioned in the clades of cyanobacteria isolated from hydrothermal vents of Asia and New Zealand, separately from marine and freshwater members of these genera, including those isolated from Lake Baikal.