Structural modification of nanohydroxyapatite Ca10(PO4)6(OH)2 related to Eu3+ and Sr2+ ions doping and its spectroscopic and antimicrobial properties

The Eu3+ and Sr2+ ions co-doped hydroxyapatite nanopowders (Ca10(PO4)6(OH)2) were synthesized via a precipitation method and post heat-treated at 500 °C. The concentration of Eu3+ ions was established in the range of 0.5–5 mol% to investigate the site occupancy preference. The concentration of Sr2+ ions was set at 5 mol%. The structural and morphological properties of the obtained materials were studied by an X-ray powder diffraction, a transmission electron microscopy techniques and infrared spectroscopy. As synthesized nanoparticles were in the range of 11–17 nm and annealed particles were in the range of 20–26 nm. The luminescence properties in dependence of the dopant concentration and applied temperature were investigated. The 5D0 → 7F0 transition shown the abnormally strong intensity for annealed materials connected with the increase of covalency character of Eu3+–O2− bond, which arise as an effect of charge compensation mechanism. The Eu3+ ions occupied three possible crystallographic sites in these materials revealed in emission spectra: one Ca(1) site with C3 symmetry and two Ca(2) sites with Cs symmetry arranged as cis and trans symmetry. The antibacterial properties of Eu3+ and Sr2+ ions doped and co-doped hydroxyapatite nanopowders were also determined against Gram-negative pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. Obtained results suggest that both europium and strontium ions may implement antibacterial properties for hydroxyapatites. In the most cases, better antibacterial effect we noticed for dopants at 5 mol% ratio. However, the effect is strongly species- and strain-dependent feature

Soil and Sediments in Natural Underground Ecosystems as a Source of Culturable Micromycetes: A Case Study of the Brestovská Cave (Western Tatras, Slovakia)

Soil and sediment host microorganisms are able to survive in extremely resource-limited environments. Therefore, more and more attention is being paid to cave sediments as a reservoir of microbiota. The aim of this study is the speleomycological evaluation of the culturable soil and sediment fungal communities in the Brestovská Cave. To explore the origins of fungi, speleomycological studies were conducted both inside and outside the cave under investigation. Additionally, two incubation temperatures (5 and 24 °C) were used to increase the species spectrum of isolated fungi. To achieve the most accurate species identification, we combined an assessment of morphological characteristics of the isolates with molecular sequencing (ITS, internal transcribed spacer). Twenty different species were found and the most frequent was Penicillium commune, followed by Trichosporiella cerebriformis and Pseudogymnoascus pannorum. To our knowledge, our study has enabled the first identification of fungal species such as Penicillium swiecicki, Cephalotrichum hinnuleum, Cosmpospora berkeleyana, Lecythophora hoffmannii, Ambomucor seriatoinflatus, and Mortierella minutissima in underground sites. Our data showed that the abundance and composition of the fungal community varied between the indoor and outdoor samples and thus from the entrance and less visited sites deeper in the cave

Keratinophilic and Keratinolytic Fungi in Cave Ecosystems: A Culture-Based Study of Brestovská Cave and Demänovská Ľadová and Slobody Caves (Slovakia)

Despite speleomycological research going back to the 1960s, the biodiversity of many specific groups of micromycetes in underground sites still remains unknown, including keratinolytic and keratinophilic fungi. These fungi are a frequent cause of infections in humans and animals. Since subterranean ecosystems are inhabited by various animals and are a great tourist attraction, the goal of our research was to provide the first report of keratinophilic and keratinolytic fungal species isolated from three caves in Tatra Mts., Slovakia (Brestovská, Demänovská Ľadová and Demänovská Slobody). Speleomycological investigation was carried out inside and outside the explored caves by combining culture-based techniques with genetic and phenotypic identifications. A total of 67 fungal isolates were isolated from 24 samples of soil and sediment using Vanbreuseghem hair bait and identified as 18 different fungal species. The study sites located inside the studied caves displayed much more fungal species (17 species) than outside the underground (3 species), and the highest values of the Shannon diversity index of keratinophilic and keratinolytic fungi were noted for the study sites inside the Demänovská Slobody Cave. Overall, Arthroderma quadrifidum was the most common fungal species in all soil and/or sediment samples. To the best of our knowledge, our research has allowed for the first detection of fungal species such as Arthroderma eboreum, Arthrodermainsingulare, Chrysosporiumeuropae, Chrysosporiumsiglerae, Keratinophytonwagneri, and Penicillium charlesii in underground sites. We also showed that the temperature of soil and sediments was negatively correlated with the number of isolated keratinophilic and keratinolytic fungal species in the investigated caves

First Speleomycological Study on the Occurrence of Psychrophilic and Psychrotolerant Aeromycota in the Brestovská Cave (Western Tatras Mts., Slovakia) and First Reports for Some Species at Underground Sites

Most underground ecosystems are heterotrophic, fungi in these objects are dispersed in the air in the form of spores, and they may be potentially hazardous to mammals. Research in underground sites has focused on mesophilic airborne fungi and only a few concerned cold-adapted species. Therefore, the goal of our research was the first report of psychrophilic and psychrotolerant aeromycota in the Brestovská Cave using culture-based techniques with genetic and phenotypic identification. Plates with PDA medium containing sampled biological material were incubated at 8 ± 0.5 °C. The density of mycobiota inside the cave ranged from 37.4 to 71 CFU 1 m−3 of air and 63.3 CFU 1 m−3 of air outside the cave. Thus, the level of fungal spores did not exceed the standards for the mycological quality of the air. A total of 18 species were isolated during the study, and some species may be potentially dangerous to people with weakened immune system. All fungal species were present inside the cave and only seven of them were outside. Cladosporium cladosporioides dominated in the external air samples and Mortierella parvispora was cultured most frequently from internal air samples. To our knowledge, this is the first discovery of the fungal species such as Coniothyrium pyrinum, Cystobasidium laryngis, Filobasidium wieringae, Leucosporidium drummii, M. parvispora, Mrakia blollopis, Nakazawaea holstii, and Vishniacozyma victoriae in the air inside the underground sites. Moreover, C. pyrinum, C. laryngis, L. drummii, M. blollopis, and N. holstii have never been detected in any component of the underground ecosystems. There are possible reasons explaining the detection of those species, but global warming is the most likely

Epicoccum nigrum link as a potential biocontrol agent against selected dermatophytes

Epicoccum nigrum Link is well known for producing biologically-active substances with activities against prokaryotic and eukaryotic cells. The major goal of this study was to assess E. nigrum as a potential in vitro agent against selected species of dermatophytes. The effects of the types of media used in this study on the interactions between the microscopic fungi were also examined. Epicoccum nigrum’s bioactive metabolites exhibited a strong growth inhibitory effect against the dermatophytes, suggesting its potential as a biocontrol agent. Notably, the strength of these interactions was dependent on the type of the medium. These secondary metabolites are not toxic against the higher eukaryotic organisms, which was further demonstrated by using the Galleria mellonella model

Eutanazja w Belgii – 16 lat po legalizacji

INTRODUCTION: Euthanasia is generally defined as an act or negligence that causes death, and consequently, interruption of the suffering of an incurably ill person. MATERIAL AND METHODS: The analysis was based on the data of the European Institute of Bioethics. The main source of information was the Reports of the Belgian Federal Committee for Euthanasia Control and Evaluation Nos. 1–8. RESULTS: Just a year after legalizing this practice in Belgium, 235 people were subjected to ‘assisted death’. In 2017, the number of euthanasia procedures exceeded 2300. In the years 2002–2017 a total of 17,063 euthanasia procedures were performed. In recent years, the age structure of people undergoing euthanasia has changed. The number of people from the age of 80 and up is ncreasing, and it decreases at the age of 40–59. The main places of the death of patients remain the home and hospital. CONCLUSIONS: 1. Since the legalization of euthanasia in Belgium, the number of people submitting to this procedure has been steadily increasing. 2. In recent years, euthanasia in the patient’s home and in nursing homes is more often observed. 3. The most common reasons for euthanasia include neoplastic diseases.WSTĘP: Eutanazja to pojęcie ogólnie definiowane jako czyn bądź zaniedbanie powodujące śmierć, a w konsekwencji przerwanie dotychczasowego cierpienia osoby nieuleczalnie chorej. MATERIAŁ I METODY: Analizę przeprowadzono na podstawie danych Europejskiego Instytutu Bioetyki. Główne źródło informacji stanowiły Raporty Belgijskiego Federalnego Komitetu ds. Kontroli i Oceny Eutanazji nr 1–8. WYNIKI: Już rok po zalegalizowaniu eutanazji w Belgii 235 osób zostało poddanych „wspomaganej śmierci”. W roku 2017 liczba eutanazji przekroczyła 2300. W latach 2002–2017 wykonano łącznie 17 063 eutanazje. Na przełomie ostatnich lat zmieniała się struktura wieku osób poddających się eutanazji. Zwiększa się liczba osób od 80 roku życia wzwyż, a zmniejsza w wieku 40–59 lat. Głównym miejscem śmierci pacjentów pozostaje dom i szpital. WNIOSKI: 1. Od momentu legalizacji eutanazji w Belgii liczba osób poddających się temu działaniu stale wzrasta. 2. W ostatnich latach częściej obserwuje się przeprowadzanie eutanazji w domu pacjenta oraz w domach opieki. 3. Spośród najczęstszych przyczyn eutanazji wymienia się choroby nowotworowe

First Report on the Occurence of Dermatophytes of Microsporum Cookei Clade and Close Affinities to Paraphyton Cookei in the Harmanecká Cave (Veľká Fatra Mts., Slovakia)

Keratinolytic and keratinophilic fungi, such as dermatophytes, are frequently a cause of infections in humans and animals. Underground ecosystems are inhabited by various animals and are of interest for tourists. Therefore, the main goal of our research was the first evaluation of sediment and soil samples taken inside and outside the Harmanecká Cave in Slovakia for the occurrence of keratinolytic and keratinophilic fungi. Tests with Vanbreuseghema bait, as well as phenotyping and molecular methods, showed that all of the sampling sites contained ten isolates, all of the same species of keratinophilic fungi, belonging to the Microsporum cookei clade and with close affinities to Paraphyton cookei (Ajello) Y. Gräser, Dukik & de Hoog. Our research showed that, dependent on the medium, its mycelium varied in color and showed different growth rates. It also produced metabolites alkalizing DTM (dermatophyte test medium) medium. It dissolved keratin in in vitro hair perforation tests and was able to utilize most substrates in the API® 20C AUX, except for MDG (α-methyl-D-glucoside). In addition, the vegetative structures of mycelium were viable after storage at temperatures from −72 to −5 °C for 56 days, and actively grew after 28 days at a temperature range from 15 to 37 °C, with 25 °C being optimal. It showed weak, but active, growth at 5 and 10 °C after 56 days. We can assume that due to the low temperature in the caves, this fungus will not be able to actively grow rapidly on keratin substrates, but the contact with mammals, along with other favorable factors, might lead to an infection

The Study of Nanosized Silicate-Substituted Hydroxyapatites Co-Doped with Sr2+ and Zn2+ Ions Related to Their Influence on Biological Activities

Nanosized silicate-substituted hydroxyapatites, characterized by the general formula Ca9.8−x−nSrnZnx(PO4)6−y(SiO4)y(OH)2 (where: n = 0.2 [mol%]; x = 0.5–3.5 [mol%]; y = 4–5 [mol%]), co-doped with Zn2+ and Sr2+ ions, were synthesized with the help of a microwave-assisted hydrothermal technique. The structural properties were determined using XRD (X-ray powder diffraction) and Fourier-transformed infrared spectroscopy (FT-IR). The morphology, size and shape of biomaterials were detected using scanning electron microscopy techniques (SEM). The reference strains of Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa were used to assess bacterial survivability and the impact on biofilm formation in the presence of nanosilicate-substituted strontium-hydroxyapatites. Safety evaluation was also performed using the standard cytotoxicity test (MTT) and hemolysis assay. Moreover, the mutagenic potential of the materials was assessed (Ames test). The obtained results suggest the dose-dependent antibacterial activity of nanomaterials, especially observed for samples doped with 3.5 mol% Zn2+ ions. Moreover, the modification with five SiO4 groups enhanced the antibacterial effect; however, a rise in the toxicity was observed as well. No harmful activity was detected in the hemolysis assay as well as in the mutagenic assay (Ames test)

A Culture-Based Study of Micromycetes Isolated from the Urban Nests of Grey Heron (<i>Ardea cinerea</i>) in SW Poland

There are many positive relationships between micromycetes and birds: They can spread fungal spores, and fungi facilitate cavity woodpecker excavation by preparing and modifying excavation sites. In turn, bird nests are mainly a source of potentially zoopathogenic fungi. The Wrocław city centre hosts the biggest grey heron breeding colony in Poland with at least 240 breeding birds pairs. To assess the possible public health risks associated with bird nests, the goal of the present study was to identify cultivable fungi present in the nests of grey herons (Ardea cinerea) in Wrocław. Additionally, attempts were made to determine whether the obtained species of fungi may pose a potential threat to animal health. Fungi were cultured at 23 and 37 ± 0.5 °C, and identified based on phenotypic and genotypic traits. Moreover, during routine inspection, visible fungal growth in some of the nests was found. Overall, 10 different fungal species were obtained in the study (Alternaria alternata, Aspergillus fumigatus, Botryotrichum piluliferum, Cladosporium cladosporioides, Epicoccum layuense, Mucor circinelloides, M.hiemalis, Penicillium atramentosum, P.coprophilum, and P.griseofulvum). They are both cosmopolitan species and a source of potential threat to humans, homoiothermous animals and plants. The greatest number of fungal species was obtained from the nest fragments with visible fungal growth incubated at 23 °C, and the least from western conifer seed bugs (Leptoglossus occidentalis) inhabiting the nests. The species such as A. fumigatus, P. coprophilum, and P.griseofulvum can be directly related to the occurrence of visible fungal growth on plant fragments of grey heron’s nests