Dataset Information

Molecular analysis of Malassezia sympodialis-related strains from domestic animals.

ABSTRACT: Recently, several new lipid-dependent species belonging to the genus Malassezia have been described. Some of them, such as Malassezia dermatis, Malassezia nana, and the tentatively named "Malassezia equi," have similar phenotypes and are genetically close to Malassezia sympodialis Simmons et Gueho 1990. DNA characterization by D1/D2 26S rRNA gene and internal transcribed spacer (ITS)-5.8S rRNA gene sequencing analysis of lipid-dependent strains from different animal species close to M. sympodialis is described and illustrated. Phylogenetic analysis of both the D1/D2 regions of 26S rRNA gene and ITS-5.8S rRNA gene sequences showed four distinct clusters. Cluster I included isolates from different animal species (horse, pig, and lamb) and the type culture of M. sympodialis. Cluster II included isolates from horses grouping close to the "M. equi" AJ305330 sequence. Cluster III comprised isolates mainly from goats. Cluster IV contained isolates mainly from cats grouping together with the M. nana AB075224 sequence. This last cluster included isolates from healthy and external otitic ears. All of these strains had identical 26S rRNA gene and ITS regions. It is not clear whether the value of these genetic differences is for the definition of species or whether they only demonstrate genetic variation among strains from different origins within M. sympodialis, which are in the course of differentiation and probably adaptation to specific animal hosts.

SUBMITTER: Cabanes FJ

PROVIDER: S-EPMC540166 | biostudies-literature | 2005 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Molecular analysis of Malassezia sympodialis-related strains from domestic animals.

Cabañes F J FJ Hernández J J JJ Castellá G G

Journal of clinical microbiology 20050101 1

Recently, several new lipid-dependent species belonging to the genus Malassezia have been described. Some of them, such as Malassezia dermatis, Malassezia nana, and the tentatively named "Malassezia equi," have similar phenotypes and are genetically close to Malassezia sympodialis Simmons et Gueho 1990. DNA characterization by D1/D2 26S rRNA gene and internal transcribed spacer (ITS)-5.8S rRNA gene sequencing analysis of lipid-dependent strains from different animal species close to M. sympodial ...[more]

PMID: 15634983

Similar Datasets

Project description:UNLABELLED:Malassezia commensal yeasts are associated with a number of skin disorders, such as atopic eczema/dermatitis and dandruff, and they also can cause systemic infections. Here we describe the 7.67-Mbp genome of Malassezia sympodialis, a species associated with atopic eczema, and contrast its genome repertoire with that of Malassezia globosa, associated with dandruff, as well as those of other closely related fungi. Ninety percent of the predicted M. sympodialis protein coding genes were experimentally verified by mass spectrometry at the protein level. We identified a relatively limited number of genes related to lipid biosynthesis, and both species lack the fatty acid synthase gene, in line with the known requirement of these yeasts to assimilate lipids from the host. Malassezia species do not appear to have many cell wall-localized glycosylphosphatidylinositol (GPI) proteins and lack other cell wall proteins previously identified in other fungi. This is surprising given that in other fungi these proteins have been shown to mediate interactions (e.g., adhesion and biofilm formation) with the host. The genome revealed a complex evolutionary history for an allergen of unknown function, Mala s 7, shown to be encoded by a member of an amplified gene family of secreted proteins. Based on genetic and biochemical studies with the basidiomycete human fungal pathogen Cryptococcus neoformans, we characterized the allergen Mala s 6 as the cytoplasmic cyclophilin A. We further present evidence that M. sympodialis may have the capacity to undergo sexual reproduction and present a model for a pseudobipolar mating system that allows limited recombination between two linked MAT loci. IMPORTANCE:Malassezia commensal yeasts are associated with a number of skin disorders. The previously published genome of M. globosa provided some of the first insights into Malassezia biology and its involvement in dandruff. Here, we present the genome of M. sympodialis, frequently isolated from patients with atopic eczema and healthy individuals. We combined comparative genomics with sequencing and functional characterization of specific genes in a population of clinical isolates and in closely related model systems. Our analyses provide insights into the evolution of allergens related to atopic eczema and the evolutionary trajectory of the machinery for sexual reproduction and meiosis. We hypothesize that M. sympodialis may undergo sexual reproduction, which has important implications for the understanding of the life cycle and virulence potential of this medically important yeast. Our findings provide a foundation for the development of genetic and genomic tools to elucidate host-microbe interactions that occur on the skin and to identify potential therapeutic targets.

Project description:BackgroundEscherichia coli is an important pathogen that causes diarrhea in both humans and animals. To determine the relationships between putative virulence factors and pathotypes or host taxa, many molecular studies on diarrhea-associated E. coli have been reported. However, little is known regarding genome-wide variation of E. coli from animal hosts. In this study, we performed whole genome sequencing of 127 E. coli isolates from sheep and swine with diarrhea in China. We compared isolates to explore the phylogenomic relatedness based on host origin. We explored the relationships of putative virulence factors across host taxa and pathotypes. Antimicrobial resistance was also tested.ResultsThe E. coli genomes in this study were diverse with clear differences in the SNP, MLST, and O serotypes. Seven putative virulence factors (VFs) were prevalent (> 95%) across the isolates, including Hcp, csgC, dsdA, feoB, fepA, guaA, and malX. Sixteen putative VFs showed significantly different distributions (P < 0.05) in strains from sheep and swine and were primarily adhesion- and toxin-related genes. Some putative VFs were co-occurrent in some specific pathotypes and O serotypes. The distribution of 4525 accessory genes of the 127 strains significantly differed (P < 0.05) between isolates obtained from the two animal species. The 127 animal isolates sequenced in this study were each classified into one of five pathotypes: EAEC, ETEC, STEC, DAEC, and EPEC, with 66.9% of isolates belonging to EAEC. Analysis of stx subtypes and a minimum spanning tree based on MLST revealed that STEC isolates from sheep and EAEC isolates from sheep and swine have low potential to infect humans. Antibiotic resistance analysis showed that the E. coli isolates were highly resistant to ampicillin and doxycycline. Isolates from southeast China were more resistant to antibiotics than isolates from northwest China. Additionally, the plasmid-mediated colist in resistance gene mcr-1 was detected in 15 isolates, including 4 from sheep in Qinghai and 11 from swine in Jiangsu.ConclusionsOur study provides insight into the genomes of E. coli isolated from animal sources. Distinguishable differences between swine and sheep isolates at the genomic level provides a baseline for future investigations of animal E. coli pathogens.

Dataset Information

Molecular analysis of Malassezia sympodialis-related strains from domestic animals.

Publications

Molecular analysis of Malassezia sympodialis-related strains from domestic animals.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure