[Show abstract][Hide abstract] ABSTRACT: During the study of bacteria associated with white-nose syndrome affected bats hibernating in caves in the Czech Republic, we isolated two facultative anaerobic, Gram-negative bacteria, designated strains 12(T) and 52(T). Strains 12(T) and 52(T) are motile, rod-like bacteria (0.5-0.6 µm in diameter; 1-1.3 µm long), with optimum growth at 20-35°C and pH 6-8. On the basis of the almost complete sequence of their 16S rDNA genes they are classified within the genus Serratia, the closest relatives to strains 12(T) and 52(T) were Serratia quinivorans DSM 4597(T) (99.5% similarity between their 16S rRNA gene sequences) and Serratia ficaria DSM 4569(T) (99.5% similarity between their 16S rRNA gene sequences), respectively. DNA-DNA relatedness between strain 12(T) and Serratia quinivorans DSM 4597(T) was only 37.1% and between strain 52(T) and Serratia ficaria DSM 4569(T) was only 56.2%. Both values are far below the 70% threshold value for species delineation. In view of this data, we propose the inclusion of the two isolates in the genus Serratia as Serratia myotis sp. nov. (type strain 12(T) = CECT 8594(T) = DSM 28726(T)) and Serratia vespertilionis sp. nov. (type strain 52(T) = CECT 8595(T) = DSM 28727(T)).
International journal of systematic and evolutionary microbiology. 10/2014;
[Show abstract][Hide abstract] ABSTRACT: Regulatory T cells (Tregs) have been well described and the factors regulating their development and function have been identified. Recently, a growing body of evidence documents the existence of IL-10-producing B cells which are called regulatory B10 cells. These cells attenuate autoimmune, inflammatory and transplantation reactions, and the main mechanism of their inhibitory action is the production of IL-10. We show that the production of IL-10 by LPS-stimulated B cells is significantly enhanced by IL-12 and IFN-γ and negatively regulated by IL-21 and TGF-β. In addition, exogenous IL-10 also inhibits B cell proliferation and the expression of the IL-10 gene in LPS-stimulated B cells. The negative autoregulation of IL-10 production is supported by the observation that the inclusion of anti-IL-10R mAb enhances IL-10 production and the proliferation of activated B cells. The effects of cytokines on IL-10 production by B10 cells did not correlate with their effects on B cell proliferation or on IL-10 production by T cells or macrophages. The cytokine-induced changes in IL-10 production occured on the level of IL-10 gene expression, as confirmed by increased or decreased IL-10 mRNA expression in the presence of a particular cytokine. The regulatory cytokines modulate the number of IL-10 producing cells rather than augment or decrease the secretion of IL-10 on a single cell level. Altogether these data show that the production of IL-10 by B cells is under the strict regulatory control of cytokines and that individual cytokines differentially regulate the development and activity of Tregs and IL-10-producing Bregs. This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Auxarthron is a genus within the Onygenales encompassing keratinophilic species with typical ascomata (gymnothecia) consisting of anastomosing network of thick-walled hyphae and small globose or oblate ascospores. No association of this genus with clinically relevant cases of human or animal infection has been reported. This paper describes the isolation of an undescribed Auxarthron species as an agent of proven onychomycosis affecting almost all ﬁ ngernails in a man with psoriasis. The causality of the isolated fungus was veriﬁ ed by repeated sampling and direct microscopy revealing irregular septate hyphae. Based on micro- and macromorphological features and unique sequence data (ITS region, benA and RPB2 gene), the isolated fungus is proposed as the new species A. ostraviense . The sibling species of A. ostraviense , A. umbrinum , was isolated from three patients with suspected onychomycosis and a detailed clinical history is provided for
one of these patients. All four isolates were tested for susceptibility to selected antifungal agents. Terbinaﬁ ne and clotrimazole appear to be effective in vitro . The morphological identiﬁ cation of Auxarthron spp. is non-trivial, time-consuming and requires cultivation media other than Sabouraud glucose agar which is routinely used in dermatomycology.
Medical Mycology 03/2013; 51(6):614-624. · 1.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Limbal stem cells (LSC), which reside in the basal layer of the limbus, are thought to be responsible for corneal epithelial healing after injury. When the cornea is damaged, LSC start to proliferate, differentiate, and migrate to the site of injury. To characterize the signaling molecules ensuring communication between the cornea and LSC, we established a mouse model of mechanical corneal damage. The central cornea or limbal tissue was excised at different time intervals after injury, and the expression of genes in the explants was determined. It was observed that a number of genes for growth and differentiation factors were significantly upregulated in the cornea rapidly after injury. The ability of these factors to regulate the differentiation and proliferation of limbal cells was tested. It was found that the insulin-like growth factor-I (IGF-I), which is rapidly overexpressed after injury, enhances the expression of IGF receptor in limbal cells and induces the differentiation of LSC into cells expressing the corneal cell marker, cytokeratin K12, without any effect on limbal cell proliferation. In contrast, the epidermal growth factor (EGF) and fibroblast growth factor-β (FGF-β), which are also produced by the damaged corneal epithelium, supported limbal cell proliferation without any effect on their differentiation. Other factors did not affect limbal cell differentiation or proliferation. Thus, IGF-I was identified as the main factor stimulating the expression of IGF receptors in limbal cells and inducing the differentiation of LSC into cells expressing corneal epithelial cell markers. The proliferation of these cells was supported by EGF and FGF.
Stem cells and development 08/2012; · 4.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A collection of 178 Aspergillus isolates, recovered from Czech patients, mostly from 2007-2011, was subjected to multilocus DNA sequence typing using the ITS region, β-tubulin, and calmodulin genes. An unusually wide spectrum of etiologic agents that included 36 species of Aspergillus is discussed in the context of recent taxonomic and clinical reports. Invasive aspergillosis (IA), onychomycosis, and otitis externa were the predominant clinical entities. Five cases due to species newly proven as etiologic agents of human mycoses, as well as cases with unique clinical manifestations caused by unusual agents are discussed in more detail. Three species (i.e., A. insulicola, A. westerdijkiae and A. tritici) were identified as the confirmed etiologic agents of non-dermatophytic onychomycosis. Emericella rugulosa was recovered from a premature newborn with a fatal necrotising disseminated infection and is reported for only the second time as the cause of IA. Furthermore, we document the first infection due to A. calidoustus in a patient with chronic granulomatous disease. The infection manifested as a latent brain aspergilloma with an unusual clinical-laboratory finding. In addition to the well-known agents of human mycosis, several rarely isolated or poorly documented species were identified. An undescribed cryptic species related to A. versicolor was found to be common among isolates linked to proven and probable onychomycosis. An isolate representing A. fresenii, or an unnamed sister species, were causal agents of otomycosis. Three well defined, and tentative new species belonging to section Cervini, Candidi and Aspergillus (Eurotium spp.), were associated with cases of probable onychomycosis.
Medical mycology: official publication of the International Society for Human and Animal Mycology 03/2012; 50(6):601-10. · 2.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During a study of endophytic and saprotrophic fungi in the sapwood and phloem of broadleaf trees (Salix alba, Quercus robur, Ulmus laevis, Alnus glutinosa, Betula pendula) fungi belonging to an anamorphic coelomycetous genus not attributable to a described taxon were detected and isolated in pure culture. The new genus, Liberomyces, with two species, L. saliciphilus and L. macrosporus, is described. Both species have subglobose conidiomata containing holoblastic sympodial conidiogenous cells. The conidiomata dehisce irregularly or by ostiole and secrete a slimy suspension of conidia. The conidia are hyaline, narrowly allantoid with a typically curved distal end. In L. macrosporus simultaneous production of synanamorph with thin filamentous conidia was observed occasionally. The genus has no known teleomorph. Related sequences in the public databases belong to endophytes of angiosperms. Phylogenetic analysis revealed a position close to the Xylariales (Sordariomycetes), but family and order affiliation remained unclear.
[Show abstract][Hide abstract] ABSTRACT: A new polyene macrolide family, closely related to the pentaene macrolide antibiotic roflamycoin, was isolated from the both fermentation broth and biomass of Streptomyces durmitorensis wild-type strain MS405. The main compound was identified by NMR and Fourier transform ion cyclotron resonance mass spectrometry as 32,33-didehydroroflamycoin (1; DDHR). Additional four structurally related compounds were determined solely by MS analysis. DDHR induces cell death by apoptosis in various cancer cell lines as demonstrated by DNA fragmentation. Striking feature of DDHR is its internal fluorescence allowing visualization of labeled plasma membranes and internal membrane structures.
The Journal of Antibiotics 09/2011; 64(11):717-22. · 2.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose Purpose. To prepare nanofibers containing the immunosuppressive drug cyclosporine A (CsA) and to assess the potential of these nanofibers to inhibit allotransplantation and inflammatory reactions in vitro and in vivo.Methods Methods. Nanofibers containing 10 weight percent of CsA were prepared from biocompatible polymer poly(L-lactid) by electrospinning procedure. The kinetics of drug release was characterized in aqueous solutions in vitro and in vivo. The growth of mouse limbal stem cells (LSC) on CsA-loaded nanofibers was evaluated. The ability of CsA-loaded nanofibers to inhibit allotransplantion reactions in vitro and inflammatory reactions in vivo was characterized.Results Results. The incorporation of CsA into PLA polymer did not influence the pharmacological activity of CsA nor affected the diameter, shape or architecture of nanofibers. The addition of CsA-containing nanofibers into mixed lymphocyte culture significantly inhibited in a dose-dependent manner cell proliferation and production of proinflammatory cytokines IL-2, IL-17 and IFN- Mouse LSC grew on CsA-loaded nanofibers comparably as on CsA-free nanofibers. The covering of inflammatory sites with CsA-loaded nanofibers significantly attenuated the local inflammatory reaction.Conclusion Conclusion. The CsA-loaded and LSC-seeded electrospun nanofibers can be used as scaffolds for LSC transfer and simultaneously as drug carriers for the local suppression of transplantation and inflammatory reactions.
[Show abstract][Hide abstract] ABSTRACT: Cyclosporine A (CsA), a potent immunosuppressive drug with low water solubility, was dissolved in poly(L-lactic acid) (PLA) solution, and nanofibers were fabricated from this mixture by electrospinning technology. The addition of CsA into the PLA solution and the conditions of the electrospinning process did not influence the structure of the nanofibers nor affect the pharmacological activity of CsA. Study of the CsA release behavior in culture medium showed a release for at least 96 h. After the topical application of CsA-loaded nanofibers on skin allografts in vivo, the release was significantly slower and about 35% of the drug was still retained in the nanofibers on day 8. The addition of CsA-loaded nanofibers into cultures of mouse spleen cells stimulated with Concanavalin A selectively inhibited T cell functions; the activity of stimulated macrophages or the growth of non-T-cell populations was not suppressed in the presence of CsA-loaded nanofibers. The covering of skin allografts with CsA-loaded nanofibers significantly attenuated the local production of the proinflammatory cytokines IL-2, IFN-γ and IL-17. These results suggest that CsA-loaded electrospun nanofibers can serve as effective drug carriers for the local/topical suppression of an inflammatory reaction and simultaneously could be used as scaffolds for cell-based therapy.
Journal of Controlled Release 07/2011; 156(3):406-12. · 7.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Eight undescribed species of Claviceps were recognized from the combinations of molecular and morphological characters. The teleomorph was observed only for Claviceps setariicola. Phylogenetic affinities of the new species inside the genus were revealed by a 5.8S-ITS-28S nrDNA analysis. Claviceps chloridicola, C. tenuispora, C. setariicola and C. setariiphila are related to C. maximensis; C. truncatispora is a sister species to C. pusilla. Claviceps clavispora and C. langdonii cluster with species colonizing maize and sorghum. The position of C. loudetiae is unclear. Comparisons with herbarium specimens showed C. setariicola as a well-established species on Setaria spp. in the southern USA. C. tenuispora was recorded on Cenchrus and Pennisetum in Brazil, USA, and Zimbabwe. C. setariiphila was found on S. geniculata in Brazil. C. chloridicola, C. loudetiae and C. truncatispora occurred in African savannas on Chloris, Loudetia, and Hyparrhenia spp., respectively. C. clavispora was found on Paspalum sp. and Urochloa sp. in Mexico and C. langdonii colonized Dichanthium spp. in the southern USA and probably in Mexico. The occurrence of C. pusilla on pearl millet in the USA (Texas) is reported and the record of C. sulcata on Urochloa brizantha in Brazil is confirmed by nrDNA sequence comparison with an African herbarium specimen. No alkaloids were detected in sclerotia
and/or sphacelia of the new species.
[Show abstract][Hide abstract] ABSTRACT: Siricid woodwasps live in obligatory nutritional symbiosis with fungi. Screening of symbionts from mycetangia of emerging Xiphydria females (X. longicollis, X. prolongata, X. camelus, X. picta) from 28 locations and four tree genera yielded 1 389 isolates. Each female carried a pure culture of a single fungus. In X. longicollis (Quercus), Daldinia childiae was either the only fungus or a highly dominant one in the samples from moderately dry oak-hornbeam (Quercus–Carpinus betula) forests. Females from the alluvial sites harboured D. childiae and Daldinia decipiens (approx. 1:1). X. camelus and X. picta (Alnus) shared the dominant symbiont D. decipiens whereas X. camelus from Betula carried D. decipiens and D. petriniae (approx. 1:1). In X. prolongata, D. childiae was the dominant species followed by an undescribed Daldinia sp. (0–20 % of isolates); D. decipiens was rare and in three females Hypoxylon macrocarpum was found. No symbiont occurred in a significant number among endophytes from the host trees.
[Show abstract][Hide abstract] ABSTRACT: The inconspicuous inner-bark parasite Obolarina dryophila is reported from wood of Quercus petraea and as an endophyte of Salix alba. In addition, viable ascospores of O. dryophila have been found in the gut of the oak bark weevil Gasterocercus depressirostris, suggesting a possible dissemination mechanism for the fungus. A phylogenetic analysis based on three genes (nrDNA, actin,
β-tubulin) placed Obolarina inside the genus Biscogniauxia as a close relative of the oak pathogens B. atropunctata and B. mediterranea.
KeywordsXylariales-Biscogniauxia-Camillea-RAxML analysis-Ascospore dissemination
[Show abstract][Hide abstract] ABSTRACT: Geosmithia fungi are little known symbionts of bark beetles. Secondary metabolites of lilac colored species G. lavendula and other nine Geosmithia species were investigated in order to elucidate their possible role in the interactions of the fungi with environment. Hydroxylated anthraquinones (yellow, orange, and red pigments), were found to be the most abundant compounds produced into the medium during the submerged cultivation. Three main compounds were identified as 1,3,6,8-tetrahydroxyanthraquinone (1), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone; 2), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (3). Compounds 2 and 3 (representing the majority of produced metabolites) inhibited the growth of G+-bacteria Staphylococcus aureus and Bacillus subtilis with minimum inhibitory concentration of 64-512 microg/mL. Anti-inflammatory activity detected as inhibition of cyclooxygenase-2 was found only for compound 3 at 1 and 10 microg/mL. Compound 2 interfered with the morphology, compound 3 with cell-cycle dynamics of adherent mammalian cell lines.
[Show abstract][Hide abstract] ABSTRACT: Claviceps purpurea, C. grohii, C. zizaniae, C. cyperi, and C. nigricans are closely related ergot fungi and form a monophyletic clade inside the genus Claviceps. Analysis of alkaloid content in C. nigricans sclerotia using UPLC detected ergocristine (1), ergosine (2), alpha-ergocryptine (3), and ergocristam (4). Alkaloids 1, 3, and 4 were found in the sclerotia of C. grohii. The content of 4 in the mixture of alkaloids from C. nigricans and C. grohii (over 8% and over 20%, respectively) was unusually high. Submerged shaken cultures of C. nigricans produced no alkaloids, whereas C. grohii culture formed small amounts (15 mg L (-1)) of extracellular clavines and 1. In the previously used HPLC method the ergocristam degradation product could have been obscured by the ergosine peak. Therefore sclerotia of a C. purpurea habitat-specific population G2 with the dominant production of 1 and 2 have been reanalyzed, but no 4 was detected. The phylogeny of the C. purpurea-related species group is discussed with regard to alkaloid-specific nonribosomal peptide synthetase duplication leading to the production of two main ergopeptines instead of a single product.
Journal of Natural Products 07/2008; 71(6):1085-8. · 3.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During 2003–2005, the diversity of culturable filamentous soil microfungi in saline and acidic soils of the Soos National
Natural Reserve (Czech Republic) was studied. Altogether, 28 soil samples were collected from four sampling sites and were
processed by various approaches. In total, 92 fungal taxa were identified using classical and molecular markers. Several detected
species were known from similar substrata worldwide; however, the overall fungal spectrum was distinct, as shown by comparison
to similar studies. All methodological approaches increased the observed fungal diversity. The different fungal communities
observed on the four sampling sites were influenced by the complex effects of environmental factors. The growth response of
selected strains to different salinities and pH values was determined. The results of the growth tests showed high adaptability
of all tested species to the extreme conditions of the studied substrate. Two acidophilic species (Acidomyces acidophilus, Sporothrix sp.) were isolated.