The basidiomycete fungus is a useful model for investigating mechanisms of fungal pathogenesis in mammalian hosts. This pathogen is the causative agent of cryptococcal meningitis in immunocompromised patients and is in the critical priority group of the World Health Organization fungal priority pathogens list. In this study, we employed a mutant lacking the gene encoding a methylene-fatty-acyl-phospholipid synthase to characterize the role of phosphatidylcholine (PC) and lipid homeostasis in the virulence of .
View Article and Find Full Text PDFCandida albicans is the most common human fungal pathogen that can cause superficial and deep-seated infections in susceptible individuals. Despite its medical importance, the vast majority of C. albicans genes remain of unknown function.
View Article and Find Full Text PDFThe bark beetle genus Dendroctonus contains some of the most economically important pests of conifers worldwide. Despite many attempts, there is no agreement today on the phylogenetic relationships within the genus, which limits our understanding of its evolutionary history. Here, using restriction-site associated DNA (RAD) markers from 70 specimens representing 17 species (85% of the known diversity) we inferred the phylogeny of the genus, its time of origin and biogeographic history, as well as the evolution of key ecological traits (host plants, larval behavior and adults' attack strategies).
View Article and Find Full Text PDFis a major fungal pathogen that infects immunocompromised people and causes life-threatening meningoencephalitis. does not occur in isolation either in the environment or in the human host, but is surrounded by other microorganisms. Bacteria are ubiquitously distributed in nature, including soil, and make up the dominant part of the human microbiota.
View Article and Find Full Text PDFPathogenic microorganisms employ specialized virulence factors to cause disease. Biofilm formation and the production of a polysaccharide capsule are two important virulence factors in the fungal pathogen that causes meningoencephalitis. Here, we show that the bipolar disorder drug lithium inhibits formation of both virulence factors by a mechanism involving dysregulation of the ubiquitin/proteasome system.
View Article and Find Full Text PDFFungal pathogens rely on the production of specific virulence factors during infection. Inhibiting such factors generally results in reduced fungal pathogenicity. Most studies in the past have focused on understanding the molecular mechanisms of fungal virulence factor expression during mono-culture, or during interaction with the host.
View Article and Find Full Text PDFBacteria interact with each other in nature and often compete for limited nutrient and space resources. However, it is largely unknown whether and how bacteria also interact with human fungal pathogens naturally found in the environment. Here, we identified a soil bacterium, , which potently blocked several key virulence factors, including formation of the antioxidant pigment melanin and production of the antiphagocytic polysaccharide capsule.
View Article and Find Full Text PDFHuman fungal pathogens cause over 2 million infections per year and are major drivers of morbidity and mortality. and are two of the most common fungal pathogens of humans, together accounting for a staggering 1.4 million infections annually, with very high mortality rates.
View Article and Find Full Text PDFThe ability of the pathogenic fungus Cryptococcus neoformans to cause life-threatening meningoencephalitis in immunocompromised individuals is due in large part to elaboration of a capsule consisting of polysaccharide fibers. The size of the cell-associated capsule is remarkably responsive to a variety of environmental and host conditions, but the mechanistic details of the regulation, synthesis, trafficking, and attachment of the polysaccharides are poorly understood. Recent studies reveal a complex network of transcription factors that influence capsule elaboration in response to several different signals of relevance to disease (e.
View Article and Find Full Text PDFWhile phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species-specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree-killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser.
View Article and Find Full Text PDFHuman fungal pathogens are distributed throughout their kingdom, suggesting that pathogenic potential evolved independently. Candida albicans is the most virulent member of the CUG clade of yeasts and a common cause of both superficial and invasive infections. We therefore hypothesized that C.
View Article and Find Full Text PDFIps typographus and Pityogenes chalcographus are two sympatric Palearctic bark beetle species with wide distribution ranges. As both species are comparable in biology, life history, and habitat, including sharing the same host, Picea abies, they provide excellent models for applying a comparative approach in which to identify common historical patterns of population differentiation and the influence of species-specific ecological characteristics. We analysed patterns of genetic diversity, genetic structure and demographic history of ten I.
View Article and Find Full Text PDFSystemic infections of humans with the fungal pathogen Candida albicans are associated with a high mortality rate. Currently, efficient treatment of these infections is hampered by the relatively low number of available antifungal drugs. We recently identified the small heat shock protein Hsp21 in C.
View Article and Find Full Text PDFThe polymorphic fungus Candida albicans is a member of the normal human microbiome. In most individuals, C. albicans resides as a lifelong, harmless commensal.
View Article and Find Full Text PDFSmall heat shock proteins (sHsps) have multiple cellular functions. However, the biological function of sHsps in pathogenic microorganisms is largely unknown. In the present study we identified and characterized the novel sHsp Hsp21 of the human fungal pathogen Candida albicans.
View Article and Find Full Text PDFCandida albicans is the most frequent cause of oral fungal infections. However, the exact pathogenicity mechanisms that this fungus employs are largely unknown and many of the genes expressed during oral infection are uncharacterized. In this study we sought to functionally characterize 12 previously unknown function genes associated with oral candidiasis.
View Article and Find Full Text PDFThe human pathogenic yeast Candida albicans can cause an unusually broad range of infections reflecting a remarkable potential to adapt to various microniches within the human host. The exceptional adaptability of C. albicans is mediated by rapid alterations in gene expression in response to various environmental stimuli and this transcriptional flexibility can be monitored with tools such as microarrays.
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