The [FeFe] hydrogenase of Nyctotherus ovalis has a chimeric origin

BACKGROUND: The hydrogenosomes of the anaerobic ciliate Nyctotherus ovalis show how mitochondria can evolve into hydrogenosomes because they possess a mitochondrial genome and parts of an electron-transport chain on the one hand, and a hydrogenase on the other hand. The hydrogenase permits direct reoxidation of NADH because it consists of a [FeFe] hydrogenase module that is fused to two modules, which are homologous to the 24 kDa and the 51 kDa subunits of a mitochondrial complex I. RESULTS: The [FeFe] hydrogenase belongs to a clade of hydrogenases that are different from well-known eukaryotic hydrogenases. The 24 kDa and the 51 kDa modules are most closely related to homologous modules that function in bacterial [NiFe] hydrogenases. Paralogous, mitochondrial 24 kDa and 51 kDa modules function in the mitochondrial complex I in N. ovalis. The different hydrogenase modules have been fused to form a polyprotein that is targeted into the hydrogenosome. CONCLUSION: The hydrogenase and their associated modules have most likely been acquired by independent lateral gene transfer from different sources. This scenario for a concerted lateral gene transfer is in agreement with the evolution of the hydrogenosome from a genuine ciliate mitochondrion by evolutionary tinkering

Making use of comparable health data to improve quality of care and outcomes in diabetes : The EUBIROD review of diabetes registries and data sources in Europe

Background: Registries and data sources contain information that can be used on an ongoing basis to improve quality of care and outcomes of people with diabetes. As a specific task of the EU Bridge Health project, we carried out a survey of diabetes-related data sources in Europe. Objectives: We aimed to report on the organization of different sources of diabetes information, including their governance, information infrastructure and dissemination strategies for quality control, service planning, public health, policy and research. Methods: Survey using a structured questionnaire to collect targeted data from a network of collaborating institutions managing registries and data sources in 17 countries in the year 2017. Results: The 18 data sources participating in the study were most frequently academic centres (44.4%), national (72.2%), targeting all types of diabetes (61.1%) covering no more than 10% of the target population (44.4%). Although population-based in over a quarter of cases (27.8%), sources relied predominantly on provider-based datasets (38.5%), fewer using administrative data (16.6%). Data collection was continuous in the majority of cases (61.1%), but 50% could not perform data linkage. Public reports were more frequent (72.2%) as well as quality reports (77.8%), but one third did not provide feedback to policy and only half published ten or more peer reviewed papers during the last 5 years. Conclusions: The heterogeneous implementation of diabetes registries and data sources hampers the comparability of quality and outcomes across Europe. Best practices exist but need to be shared more effectively to accelerate progress and deliver equitable results for people with diabetes.publishedVersionPeer reviewe

Interplay Between Bacteriophages and Restriction-Modification Systems in Enterococci

The complete genomes of Enterococcus faecalis bacteriophages were analyzed for tetranucleotide words avoidance. Very similar tetranucleotide composition was found in all tested genomes with strong underrepresentation of palindromic GATC and GGCC words. This avoidance could be explained as a protection mechanism against host restriction-modification systems as a clear correlation was found between avoidance of palindromic words and the specificity of E. faecalis restriction and modification systems. No similar avoidance of tetranucleotide words was observed for non-palindromic words. A weak correlation was observed between avoidance of tetranucleotide palindromes in bacteriophage genomes and the possession of phage encoded DNA methyltransferases confirming the interrelation between bacteriophage genomes composition and restriction and modification systems in enterococc

Badanie mechanizmów stosowanych przez glony w celu zmniejszenia toksyczności srebra w środowisku wodnym

In the study SEM, EDS, TEM and UV-vis analysis were used to investigate the biosorption, bioaccumulation and bioprecipitation/bioreduction of silver by freshwater green alga Parachlorella kessleri and to shed light on the reasons of biological silver nanoparticle production. When dead biomass of P. kessleri was used for silver removal, majority of silver (75%) was removed within 2 min. Biosorption was probably the main mechanisms responsible for Ag+ ions removal from aqueous solutions. However, when behaviour of living biomass in the presence of silver ions was studied, the decrease of silver concentration was slower (68% within 24 hours) with subsequent increase of silver concentration in the solution and extracellular formation of silver nanoparticles. The formed AgNPs exhibited a lower toxicity against tested organisms. Algal cells probably used the formation of nanoparticles combined with rapid biosorption as detoxification mechanisms against silver toxicity. Bioaccumulation inside the cells played only a minor role in the detoxification process.W badaniu wykorzystano analizę SEM, EDS, TEM i UV-vis do zbadania biosorpcji, bioakumulacji i bioprecypitacji/bioredukcji srebra przez słodkowodną zieloną algę Parachlorella kessleri i rzucenia światła na przyczyny biologicznej produkcji nanocząstek srebra. Gdy do usunięcia srebra użyto martwej biomasy P. kessleri, większość srebra (75%) usunięto w ciągu 2 minut. Biosorpcja była prawdopodobnie głównym mechanizmem odpowiedzialnym za usuwanie jonów Ag+ z roztworów wodnych. Jednakże, gdy badano zachowanie żywej biomasy w obecności jonów srebra, spadek stężenia srebra był wolniejszy (68% w ciągu 24 godzin) z późniejszym wzrostem stężenia srebra w roztworze i zewnątrzkomórkowym tworzeniem nanocząstek srebra. Utworzone AgNP wykazywały mniejszą toksyczność wobec badanych organizmów. Komórki glonów prawdopodobnie wykorzystywały tworzenie nanocząstek połączonych z szybką biosorpcją jako mechanizmów detoksykacji przeciwko toksyczności srebra. Bioakumulacja wewnątrz komórek odgrywała tylko niewielką rolę w procesie detoksykacji

Deep Subsurface Hypersaline Environment as a Source of Novel Species of Halophilic Sulfur-Oxidizing Bacteria

The sulfur cycle participates significantly in life evolution. Some facultatively autotrophic microorganisms are able to thrive in extreme environments with limited nutrient availability where they specialize in obtaining energy by oxidation of reduced sulfur compounds. In our experiments focused on the characterization of halophilic bacteria from a former salt mine in Solivar (Presov, Slovakia), a high diversity of cultivable bacteria was observed. Based on ARDRA (Amplified Ribosomal DNA Restriction Analysis), at least six groups of strains were identified with four of them showing similarity levels of 16S rRNA gene sequences lower than 98.5% when compared against the GenBank rRNA/ITS database. Heterotrophic sulfur oxidizers represented ~34% of strains and were dominated by Halomonas and Marinobacter genera. Autotrophic sulfur oxidizers represented ~66% and were dominated by Guyparkeria and Hydrogenovibrio genera. Overall, our results indicate that the spatially isolated hypersaline deep subsurface habitat in Solivar harbors novel and diverse extremophilic sulfur-oxidizing bacteria

Thiothrix and Sulfurovum genera dominate bacterial mats in Slovak cold sulfur springs

Abstract Microbiota of sulfur-rich environments has been extensively studied due to the biotechnological potential of sulfur bacteria, or as a model of ancient life. Cold terrestrial sulfur springs are less studied compared to sulfur-oxidizing microbiota of hydrothermal vents, volcanic environments, or soda lakes. Despite that, several studies suggested that sulfur springs harbor diverse microbial communities because of the unique geochemical conditions of upwelling waters. In this study, the microbiota of five terrestrial sulfur springs was examined using a 16 S rRNA gene sequencing. The clear dominance of the Proteobacteria and Campylobacterota phyla of cold sulfur springs microbiota was observed. Contrary to that, the microbiota of the hot sulfur spring was dominated by the Aquificota and Firmicutes phylum respectively. Sulfur-oxidizing genera constituted a dominant part of the microbial populations with the Thiothrix and Sulfurovum genera identified as the core microbiota of cold sulfur terrestrial springs in Slovakia. Additionally, the study emphasizes that sulfur springs in Slovakia support unique, poorly characterized bacterial communities of sulfur-oxidizing bacteria

Heterotrophic bacteria associated with Varroa destructor mite

International audienceVarroa bee hive attack is a serious and common problem in bee keeping. In our work, an ecto-microflora of Varroa destructor mites was characterised as a potential source of bacterial bee diseases. Using a cultivation approach, a variable population of bacteria was isolated from the body surface of Varroa mites with frequency of about 150 cfu per mite individual. Nine studied isolates were classified to four genera and six species by a combination of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF)- and 16S ribosomal RNA (rRNA)-based methods, suggesting relatively low diversity of Varroa mite-associated ecto-microflora. The Varroa mite-associated bacterial population was found to be dominated by Gram-positive bacteria of Bacillus and Microbacterium genera. Gram-negative bacteria were represented by members of Brevundimonas and Rhizobium genera. Most of the identified species are not known to be associated with Varroa mite, either honey bee or honey up until now and some of them are probably representatives of new bacterial taxa

Wpływ metali ciężkich na rozwój odporności na zawartość metali w mikroflorze w glebie

Heavy metal pollution caused by anthropogenic activity is a great concern of the present days. Widespread use of substances containing metals inevitably lead to their deposition in soil affecting soil microbiota, which plays important role in maintaining soil functions. The aim of our study was to determine number of heavy metal resistant isolates acquired from the soil from heavy metal polluted area of dump near Hnúšťa. Soil samples were obtained from two collection sites (48° 36´ 4,47502´´ N, 19° 57´32,654´´ E and 48° 36´ 4,4634´´ N, 19° 57´ 32,67´´ E) and mixed together. The microorganisms used in this study were routinely cultivated and screened for resistance to different concentrations of four heavy metals – Zn (2–500 mg/l), Cu, Ni, Pb (all three metals tested at concentrations from 0,5 to 125 mg/l). Very high resistance against Cu, Ni and Pb even at the highest tested concentrations was found at majority of tested bacterial strains. Almost all 89 from 89 isolates show resistance against these metals at tested concentrations. Only in case of Zn we determined the MIC (minimal inhibitory concentration) – 125 mg/l. The results point out very high resistance pattern in soil bacteria.Zanieczyszczenie metalami ciężkimi wywołane działalnością antropogeniczną jest wielkim problemem współczesności. Powszechne stosowanie substancji zawierających metale nieuchronnie prowadzi do ich odkładania się w glebie co wpływa na mikroflorę glebową, która odgrywa ważną rolę w utrzymywaniu funkcji gleby. Celem badań było określenie liczby izolatów odpornych na metale ciężkie pozyskanych z gleby z zanieczyszczonego obszaru składowiska metali ciężkich w pobliżu Hnúšťa. Próbki gleby pobrano z dwóch miejsc (48° 36' 4,47502'' N, 19° 57'32,654'' E i 48° 36' 4,4634''bN, 19° 57'32,67'' E) i wymieszano razem. Mikroorganizmy wykorzystane w tym badaniu były rutynowo hodowane i badane pod kątem odporności na różne stężenia czterech metali ciężkich: Zn (2–500 mg/l), Cu, Ni, Pb (wszystkie trzy badane metale w stężeniach od 0,5 do 125 mg/l). Bardzo wysoką odporność na Cu, Ni i Pb nawet przy najwyższych testowanych stężeniach stwierdzono w większości badanych szczepów bakteryjnych. Prawie wszystkie z 89 izolatów wykazują odporność na te metale w testowanych stężeniach. Tylko w przypadku Zn określiliśmy MIC (minimalne stężenie hamujące) = 125 mg/l. Wyniki wskazują na bardzo wysoki wzór oporności w bakteriach glebowych