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A 28-year-old man diagnosed with triple positive antiphospholipid syndrome (APS) and undergoing warfarin experienced three separate admissions to the cardiac ward within a one-month period due to escalating chest pain. While the initial two admissions revealed normal results in cardiological investigations, such as blood tests, electrocardiogram, and echocardiography, the third admission unveiled signs of ST-elevation myocardial infarction (STEMI), despite the patient maintaining an INR (International Normalized Ratio) of 4. Subsequent percutaneous coronary intervention (PCI) exposed spontaneous coronary artery dissection (SCAD) of type 3. Faced with hemodynamic instability and worsening symptoms, the patient underwent stenting and was prescribed dual antiplatelet therapy in addition to warfarin. A follow-up evaluation one month later indicated a normalization of his condition. [ABSTRACT FROM AUTHOR]

Aims Vascular access site complications following transradial coronary procedures are less common and severe compared to femoral approach. Radial artery occlusion is considered the main adverse effect. As radial access is gaining more acknowledgement, complication awareness, and understanding is important. The aim was to assess complication rates following transradial coronary procedures and to compare two radial compression devices in a non-inferiority randomized controlled trial. Methods and results Four hundred and ninety-nine patients were randomized to radial compression with a new device (RY Stop, n = 248) or the reference device (TR Band, n = 251) following transradial coronary procedures. Radial artery occlusion persistent at 90 days was the primary endpoint. Discomfort and accounts of vascular complications at access site were secondary endpoints. Radial artery occlusion was observed in 5% (n = 26) for the entire cohort with no difference between groups (RY Stop 6% vs. TR Band 5%; P = 0.69). Patients overall reported low levels of discomfort and the median scores were similar in both groups; RY Stop: 7 vs. TR Band: 10 (P = 0.90). There were few incidents of bleeding (7%), however, they were significantly more frequent with the RY Stop (12%) than with the TR Band (3%; P = 0.001). Few patients (4%) developed access site haematomas, and the incidence was similar in the two groups (P = 0.98). Conclusion We observed a radial artery occlusion rate of 5% at 90 days post-procedure. Access site discomfort and vascular complication rates were low. Overall, the RY Stop compression device was not inferior to the TR Band except occurrences of bleeding. [ABSTRACT FROM AUTHOR]

Summary: Metal‐sulfides are wide‐spread in marine benthic habitats. At deep‐sea hydrothermal vents, they occur as massive sulfide chimneys formed by mineral precipitation upon mixing of reduced vent fluids with cold oxygenated sea water. Although microorganisms inhabiting actively venting chimneys and utilizing compounds supplied by the venting fluids are well studied, only little is known about microorganisms inhabiting inactive chimneys. In this study, we combined 16S rRNA gene‐based community profiling of sulfide chimneys from the Manus Basin (SW Pacific) with radiometric dating, metagenome (n = 4) and metaproteome (n = 1) analyses. Our results shed light on potential lifestyles of yet poorly characterized bacterial clades colonizing inactive chimneys. These include sulfate‐reducing Nitrospirae and sulfide‐oxidizing Gammaproteobacteria dominating most of the inactive chimney communities. Our phylogenetic analysis attributed the gammaproteobacterial clades to the recently described Woeseiaceae family and the SSr‐clade found in marine sediments around the world. Metaproteomic data identified these Gammaproteobacteria as autotrophic sulfide‐oxidizers potentially facilitating metal‐sulfide dissolution via extracellular electron transfer. Considering the wide distribution of these gammaproteobacterial clades in marine environments such as hydrothermal vents and sediments, microbially accelerated neutrophilic mineral oxidation might be a globally relevant process in benthic element cycling and a considerable energy source for carbon fixation in marine benthic habitats. [ABSTRACT FROM AUTHOR]

Deep-sea hydrothermal vents are highly dynamic habitats characterized by steep temperature and chemical gradients. The oxidation of reduced compounds dissolved in the venting fluids fuels primary production providing the basis for extensive life. Until recently studies of microbial vent communities have focused primarily on chemolithoautotrophic organisms. In our study, we targeted the change of microbial community compositions along mixing gradients, focusing on distribution and capabilities of heterotrophic microorganisms. Samples were retrieved from different venting areas within the Menez Gwen hydrothermal field, taken along mixing gradients, including diffuse fluid discharge points, their immediate surroundings and the buoyant parts of hydrothermal plumes. High throughput 16S rRNA gene amplicon sequencing, fluorescence in situ hybridization, and targeted metagenome analysis were combined with geochemical analyses. Close to diffuse venting orifices dominated by chemolithoautotrophic Epsilonproteobacteria, in areas where environmental conditions still supported chemolithoautotrophic processes, we detected microbial communities enriched for versatile heterotrophic Alpha- and Gammaproteobacteria. The potential for alkane degradation could be shown for several genera and yet uncultured clades. We propose that hotspots of chemolithoautotrophic life support a 'belt' of heterotrophic bacteria significantly different from the dominating oligotrophic microbiota of the deep sea. [ABSTRACT FROM AUTHOR]

Diffuse hydrothermal fluids often contain organic compounds such as hydrocarbons, lipids, and organic acids. Microorganisms consuming these compounds at hydrothermal sites are so far only known from cultivation-dependent studies. To identify potential heterotrophs without prior cultivation, we combined microbial community analysis with short-term incubations using 13C-labeled acetate at two distinct hydrothermal systems. We followed cell growth and assimilation of 13C into single cells by nanoSIMS combined with fluorescence in situ hybridization (FISH). In 55 °C-fluids from the Menez Gwen hydrothermal system/Mid-Atlantic Ridge, a novel epsilonproteobacterial group accounted for nearly all assimilation of acetate, representing the first aerobic acetate-consuming member of the Nautiliales. In contrast, Gammaproteobacteria dominated the 13C-acetate assimilation in incubations of 37 °C-fluids from the back-arc hydrothermal system in the Manus Basin/Papua New Guinea. Here, 16S rRNA gene sequences were mostly related to mesophilic Marinobacter, reflecting the high content of seawater in these fluids. The rapid growth of microorganisms upon acetate addition suggests that acetate consumers in diffuse fluids are copiotrophic opportunists, which quickly exploit their energy sources, whenever available under the spatially and temporally highly fluctuating conditions. Our data provide first insights into the heterotrophic microbial community, catalyzing an under-investigated part of microbial carbon cycling at hydrothermal vents. [ABSTRACT FROM AUTHOR]

Sulfide 'chimneys' characteristic of seafloor hydrothermal venting are diverse microbial habitats. 13 C/12 C ratios of microbial lipids have rarely been used to assess carbon assimilation pathways on these structures, despite complementing gene- and culture-based approaches. Here, we integrate analyses of the diversity of intact polar lipids ( IPL) and their side-chain δ13 C values (δ13 Clipid) with 16S r RNA gene-based phylogeny to examine microbial carbon flow on active and inactive sulfide structures from the Manus Basin. Surficial crusts of active structures, dominated by E psilonproteobacteria, yield bacterial δ13 Clipid values higher than biomass δ13 C (total organic carbon), implicating autotrophy via the reverse tricarboxylic acid cycle. Our data also suggest δ13 Clipid values vary on individual active structures without accompanying microbial diversity changes. Temperature and/or dissolved substrate effects - likely relating to variable advective-diffusive fluxes to chimney exteriors - may be responsible for differing 13 C fractionation during assimilation. In an inactive structure, δ13 Clipid values lower than biomass δ13 C and a distinctive IPL and 16S r RNA gene diversity suggest a shift to a more diverse community and an alternate carbon assimilation pathway after venting ceases. We discuss here the potential of IPL and δ13 Clipid analyses to elucidate carbon flow in hydrothermal structures when combined with other molecular tools. [ABSTRACT FROM AUTHOR]

Summary The ultramafic-hosted Logatchev hydrothermal field (LHF) is characterized by vent fluids, which are enriched in dissolved hydrogen and methane compared with fluids from basalt-hosted systems. Thick sediment layers in LHF are partly covered by characteristic white mats. In this study, these sediments were investigated in order to determine biogeochemical processes and key organisms relevant for primary production. Temperature profiling at two mat-covered sites showed a conductive heating of the sediments. Elemental sulfur was detected in the overlying mat and metal-sulfides in the upper sediment layer. Microprofiles revealed an intensive hydrogen sulfide flux from deeper sediment layers. Fluorescence in situ hybridization showed that filamentous and vibrioid, Arcobacter-related Epsilonproteobacteria dominated the overlying mats. This is in contrast to sulfidic sediments in basalt-hosted fields where mats of similar appearance are composed of large sulfur-oxidizing Gammaproteobacteria. Epsilonproteobacteria (7-21%) and Deltaproteobacteria (20-21%) were highly abundant in the surface sediment layer. The physiology of the closest cultivated relatives, revealed by comparative 16S rRNA sequence analysis, was characterized by the capability to metabolize sulfur components. High sulfate reduction rates as well as sulfide depleted in 34S further confirmed the importance of the biogeochemical sulfur cycle. In contrast, methane was found to be of minor relevance for microbial life in mat-covered surface sediments. Our data indicate that in conductively heated surface sediments microbial sulfur cycling is the driving force for bacterial biomass production although ultramafic-hosted systems are characterized by fluids with high levels of dissolved methane and hydrogen. [ABSTRACT FROM AUTHOR]

Anaerobic oxidation of methane (AOM) with sulfate is catalysed by microbial consortia of archaea and bacteria affiliating with methanogens and sulfate-reducing Deltaproteobacteria respectively. There is evidence that methane oxidation is catalysed by enzymes related to those in methanogenesis, but the enzymes for sulfate reduction coupled to AOM have not been examined. We collected microbial mats with high AOM activity from a methane seep in the Black Sea. The mats consisted mainly of archaea of the ANME-2 group and bacteria of the Desulfosarcina-Desulfococcus group. Cell-free mat extract contained activities of enzymes involved in sulfate reduction to sulfide: ATP sulfurylase (adenylyl : sulfate transferase; Sat), APS reductase (Apr) and dissimilatory sulfite reductase (Dsr). We partially purified the enzymes by anion-exchange chromatography. The amounts obtained indicated that the enzymes are abundant in the mat, with Sat accounting for 2% of the soluble mat protein. N-terminal amino acid sequences of purified proteins suggested similarities to the corresponding enzymes of known species of sulfate-reducing bacteria. The deduced amino acid sequence of PCR-amplified genes of the Apr subunits is similar to that of Apr of the Desulfosarcina/ Desulfococcus group. These results indicate that the major enzymes involved in sulfate reduction in the Back Sea microbial mats are of bacterial origin, most likely originating from the bacterial partner in the consortium. [ABSTRACT FROM AUTHOR]

The anaerobic oxidation of methane (AOM) with sulfate as terminal electron acceptor is mediated by consortia of methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB). Whereas three clades of ANME have been repeatedly studied with respect to phylogeny, key genes and genomic capabilities, little is known about their sulfate-reducing partner. In order to identify the partner of anaerobic methanotrophs of the ANME-2 clade, bacterial 16S rRNA gene libraries were constructed from cultures highly enriched for ANME-2a and ANME-2c in consortia with Deltaproteobacteria of the Desulfosarcina/Desulfococcus group (DSS). Phylogenetic analysis of those and publicly available sequences from AOM sites supported the hypothesis by Knittel and colleagues that the DSS partner belongs to the diverse SEEP-SRB1 cluster. Six subclusters of SEEP-SRB1, SEEP-SRB1a to SEEP-SRB1f, were proposed and specific oligonucleotide probes were designed. Using fluorescence in situ hybridization on samples from six different AOM sites, SEEP-SRB1a was identified as sulfate-reducing partner in up to 95% of total ANME-2 consortia. SEEP-SRB1a cells exhibited a rod-shaped, vibrioid, or coccoid morphology and were found to be associated with subgroups ANME-2a and ANME-2c. Moreover, SEEP-SRB1a was also detected in 8% to 23% of ANME-3 consortia in Haakon Mosby Mud Volcano sediments, previously described to be predominantly associated with SRB of the Desulfobulbus group. SEEP-SRB1a contributed to only 0.3% to 0.7% of all single cells in almost all samples indicating that these bacteria are highly adapted to a symbiotic relationship with ANME-2. [ABSTRACT FROM AUTHOR]

Microbial consortia mediating the anaerobic oxidation of methane with sulfate are composed of methanotrophic Archaea (ANME) and Bacteria related to sulfate-reducing Deltaproteobacteria. Cultured representatives are not available for any of the three ANME clades. Therefore, a metagenomic approach was applied to assess the genetic potential of ANME-1 archaea. In total, 3.4 Mbp sequence information was generated based on metagenomic fosmid libraries constructed directly from a methanotrophic microbial mat in the Black Sea. These sequence data represent, in 30 contigs, about 82–90% of a composite ANME-1 genome. The dataset supports the hypothesis of a reversal of the methanogenesis pathway. Indications for an assimilatory, but not for a dissimilatory sulfate reduction pathway in ANME-1, were found. Draft genome and expression analyses are consistent with acetate and formate as putative electron shuttles. Moreover, the dataset points towards downstream electron-accepting redox components different from the ones known from methanogenic archaea. Whereas catalytic subunits of [NiFe]-hydrogenases are lacking in the dataset, genes for an [FeFe]-hydrogenase homologue were identified, not yet described to be present in methanogenic archaea. Clustered genes annotated as secreted multiheme c-type cytochromes were identified, which have not yet been correlated with methanogenesis-related steps. The genes were shown to be expressed, suggesting direct electron transfer as an additional possible mode to shuttle electrons from ANME-1 to the bacterial sulfate-reducing partner. [ABSTRACT FROM AUTHOR]

Sulfate-reducing bacteria (SRB) belonging to the metabolically versatile Desulfobacteriaceae are abundant in marine sediments and contribute to the global carbon cycle by complete oxidation of organic compounds. Desulfobacterium autotrophicum HRM2 is the first member of this ecophysiologically important group with a now available genome sequence. With 5.6 megabasepairs (Mbp) the genome of Db. autotrophicum HRM2 is about 2 Mbp larger than the sequenced genomes of other sulfate reducers (SRB). A high number of genome plasticity elements (> 100 transposon-related genes), several regions of GC discontinuity and a high number of repetitive elements (132 paralogous genes Mbp−1) point to a different genome evolution when comparing with Desulfovibrio spp. The metabolic versatility of Db. autotrophicum HRM2 is reflected in the presence of genes for the degradation of a variety of organic compounds including long-chain fatty acids and for the Wood–Ljungdahl pathway, which enables the organism to completely oxidize acetyl-CoA to CO2 but also to grow chemolithoautotrophically. The presence of more than 250 proteins of the sensory/regulatory protein families should enable Db. autotrophicum HRM2 to efficiently adapt to changing environmental conditions. Genes encoding periplasmic or cytoplasmic hydrogenases and formate dehydrogenases have been detected as well as genes for the transmembrane TpII- c3, Hme and Rnf complexes. Genes for subunits A, B, C and D as well as for the proposed novel subunits L and F of the heterodisulfide reductases are present. This enzyme is involved in energy conservation in methanoarchaea and it is speculated that it exhibits a similar function in the process of dissimilatory sulfate reduction in Db. autotrophicum HRM2. [ABSTRACT FROM AUTHOR]

Hypersaline environments, such as crystallizer ponds of solar salterns, show one of the highest concentration of viruses reported for aquatic systems. All the halophages characterized so far are isolates obtained by cultivation from described haloarchaeal species that have only low abundance in the environment. We employed a culture-independent metagenomic approach to analyse for the first time complete genomes in the halophage community and explored the in situ diversity by transmission electron microscopy and pulsed-field gel electrophoresis. We report the genomic sequence of a not yet isolated halophage (named as nvironmental alo hage 1 ‘EHP-1′) whose DNA was obtained from crystallizer samples with a salinity of 31%. The sequenced genome has a size of 35 kb and a G + C content around 51%. The G + C content is lower than that of previously characterized halophages. However, G + C content and codon usage in EHP-1 are similar to the recently cultivated and sequenced Haloquadratum walsbyi, the major prokaryotic component in solar salterns around the world. Forty open reading frames have been predicted, including genes that putatively code for proteins involved in DNA replication (ribonucleotide reductases, thymidylate kinase) normally found in lytic viruses. [ABSTRACT FROM AUTHOR]

The anaerobic oxidation of methane is a globally significant process which is mediated by consortia of yet uncultivated methanotrophic archaea (ANME) and sulfate-reducing bacteria. In order to gain deeper insights into genome characteristics of the different ANME groups, large-insert genomic libraries were constructed using DNA extracted from a methanotrophic microbial mat growing in the anoxic part of the Black Sea, and from sediments above gas hydrates at the Hydrate Ridge off the coast of Oregon. Analysis of these fosmid libraries with respect to archaeal 16S rRNA gene diversity revealed a single ANME-1b ribotype for the Black Sea libraries, whereas the sequences derived from the Hydrate Ridge library phylogenetically affiliated with the ANME-2a, ANME-2c and ANME-3 group. Genome walking for ANME-1b resulted in a contiguous 155 kb composite genome fragment. The comparison of a set of four genomic fragments belonging to the different ANME groups revealed differences in the rRNA operon structure and the average G+C content, with the ANME-2c contig showing the highest divergence within the set. A detailed analysis of the ANME contigs with respect to genes putatively involved in the anaerobic oxidation of methane led to the identification of: (i) a putative N 5 ,N 10-methenyltetrahydromethanopterin cyclohydrolase gene, (ii) a gene cluster supposedly encoding a novel type of heterodisulfide reductase/dehydrogenase complex and (iii) a gene cluster putatively encoding a new type of CO dehydrogenase/acetyl-CoA synthase enzyme complex. [ABSTRACT FROM AUTHOR]

A basic problem of the metagenomic approach in microbial ecology is the assignment of genomic fragments to a certain species or taxonomic group, when suitable marker genes are absent. Currently, the (G + C)-content together with phylogenetic information and codon adaptation for functional genes is mostly used to assess the relationship of different fragments. These methods, however, can produce ambiguous results. In order to evaluate sequence-based methods for fragment identification, we extensively compared (G + C)-contents and tetranucleotide usage patterns of 9054 fosmid-sized genomic fragments generated in silico from 118 completely sequenced bacterial genomes (40 982 931 fragment pairs were compared in total). The results of this systematic study show that the discriminatory power of correlations of tetranucleotide-derived z-scores is by far superior to that of differences in (G + C)-content and provides reasonable assignment probabilities when applied to metagenome libraries of small diversity. Using six fully sequenced fosmid inserts from a metagenomic analysis of microbial consortia mediating the anaerobic oxidation of methane (AOM), we demonstrate that discrimination based on tetranucleotide-derived z-score correlations was consistent with corresponding data from 16S ribosomal RNA sequence analysis and allowed us to discriminate between fosmid inserts that were indistinguishable with respect to their (G + C)-contents. [ABSTRACT FROM AUTHOR]

Anaerobic oxidation of methane (AOM) in marine sediments is an important microbial process in the global carbon cycle and in control of greenhouse gas emission. The responsible organisms supposedly reverse the reactions of methanogenesis, but cultures providing biochemical proof of this have not been isolated. Here we searched for AOM-associated cell components in microbial mats from anoxic methane seeps in the Black Sea. These mats catalyse AOM rather than carry out methanogenesis. We extracted a prominent nickel compound displaying the same absorption spectrum as the nickel cofactor F430 of methyl-coenzyme M reductase, the terminal enzyme of methanogenesis; however, the nickel compound exhibited a higher molecular mass than F430. The apparent variant of F430 was part of an abundant protein that was purified from the mat and that consists of three different subunits. Determined amino-terminal amino acid sequences matched a gene locus cloned from the mat. Sequence analyses revealed similarities to methyl-coenzyme M reductase from methanogenic archaea. The abundance of the nickel protein (7% of extracted proteins) in the mat suggests an important role in AOM. [ABSTRACT FROM AUTHOR]