11 research outputs found
Microbial communities in the nepheloid layers and hypoxic zones of the Canary Current upwelling system
Selective enrichment and molecular characterization of a previously uncultured Nitrospira-like bacterium from activated sludge
Previously uncultured nitrite-oxidizing bacteria affiliated to the genus Nitrospira have for the first time been successfully enriched from activated sludge from a municipal wastewater treatment plant. During the enrichment procedure, the abundance of the Nitrospira-like bacteria increased to approximately 86% of the total bacterial population. This high degree of purification was achieved by a novel enrichment protocol, which exploits physiological features of Nitrospira-like bacteria and includes the selective repression of coexisting Nitrobacter cells and heterotrophic contaminants by application of ampicillin in a final concentration of 50 µg ml−1. The enrichment process was monitored by electron microscopy, fluorescence in situ hybridization (FISH) with rRNA-targeted probes and fatty acid profiling. Phylogenetic analysis of 16S rRNA gene sequences revealed that the enriched bacteria represent a novel Nitrospira species closely related to uncultured Nitrospira-like bacteria previously found in wastewater treatment plants and nitrifying bioreactors. The enriched strain is provisionally classified as ‘Candidatus Nitrospira defluvii’
Methane fluxes in permafrost habitats of the Lena Delta: effects of microbial community structure and organic matter quality
For the understanding and assessment of recent and future carbon dynamics of arctic permafrost soils the processes of CH4 production and oxidation, the community structure and the quality of DOM were studied in two soils of a polygonal tundra. Activities of methanogens and methanotrophs differed significantly in their rates and distribution patterns among the two investigated profiles. Community structure analysis showed similarities between both soils for esterlinked PLFAs and differences in the fraction of unsaponifiable PLFAs and PLELs. Furthermore, a shift of the overall composition of the microbiota with depth at both sites was indicated by an increasing portion of iso- and anteiso-branched fatty acids related to the amount of straight chain fatty acids. Although permafrost soils represent a large carbon pool, it was shown, that the reduced quality of organic matter leads to a substrate limitation of the microbial metabolism. It can be concluded from our and previous findings firstly that microbial communities in the active layer of an Arctic polygon tundra are composed by members of all three domains of life, with a total biomass comparable to temperate soil ecosystems. And secondly that these microorganisms are well adapted to the extreme temperature gradient of their environment
Microbial communities in the nepheloid layers and hypoxic zones of the Canary Current upwelling system
Eastern boundary upwelling systems (EBUSs) are among the most productive marine
environments in the world. The Canary Current upwelling system off the coast of
Mauritania and Morocco is the second most productive of the four EBUS, where
nutrient-rich
waters fuel perennial phytoplankton blooms, evident by high chlorophyll
a concentrations off Cape Blanc, Mauritania. High primary production leads to
eutrophic waters in the surface layers, whereas sinking phytoplankton debris and
horizontally dispersed particles form nepheloid layers (NLs) and hypoxic waters at
depth. We used Catalyzed Reporter Deposition Fluorescence In Situ Hybridization
(CARD-FISH)
in combination with fatty acid (measured as methyl ester; FAME) profiles
to investigate the bacterial and archaeal community composition along transects
from neritic to pelagic waters within the “giant Cape Blanc filament” in two
consecutive years (2010 and 2011), and to evaluate the usage of FAME data for microbial
community studies. We also report the first fatty acid profile of Pelagibacterales
strain HTCC7211 which was used as a reference profile for the SAR11 clade.
Unexpectedly, the reference profile contained low concentrations of long chain fatty
acids 18:1 cis11, 18:1 cis11 11methyl, and 19:0 cyclo11–12 fatty acids, the main compounds
in other Alphaproteobacteria. Members of the free-living
SAR11 clade were
found at increased relative abundance in the hypoxic waters in both years. In contrast,
the depth profiles of Gammaproteobacteria (including Alteromonas and
Pseudoalteromonas), Bacteroidetes, Roseobacter, and Synechococcus showed high
abundances of these groups in layers where particle abundance was high, suggesting
that particle attachment or association is an important mechanisms of dispersal for
these groups. Collectively, our results highlight the influence of NLs, horizontal particle
transport, and low oxygen on the structure and dispersal of microbial communities
in upwelling systems
Role of laparoscopy in the management of visceral injuries following abdominal stab wounds
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Gadolinium modifies the cell membrane to inhibit permeabilization by nanosecond electric pulses
Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR): a multicentre, prospective observational study
Background Results from retrospective studies suggest that use of neuromuscular blocking agents during general
anaesthesia might be linked to postoperative pulmonary complications. We therefore aimed to assess whether the use
of neuromuscular blocking agents is associated with postoperative pulmonary complications.
Methods We did a multicentre, prospective observational cohort study. Patients were recruited from 211 hospitals in
28 European countries. We included patients (aged ≥18 years) who received general anaesthesia for any in-hospital
procedure except cardiac surgery. Patient characteristics, surgical and anaesthetic details, and chart review at discharge
were prospectively collected over 2 weeks. Additionally, each patient underwent postoperative physical examination
within 3 days of surgery to check for adverse pulmonary events. The study outcome was the incidence of postoperative
pulmonary complications from the end of surgery up to postoperative day 28. Logistic regression analyses were
adjusted for surgical factors and patients’ preoperative physical status, providing adjusted odds ratios (ORadj) and
adjusted absolute risk reduction (ARRadj). This study is registered with ClinicalTrials.gov, number NCT01865513.
Findings Between June 16, 2014, and April 29, 2015, data from 22803 patients were collected. The use of neuromuscular
blocking agents was associated with an increased incidence of postoperative pulmonary complications in patients who
had undergone general anaesthesia (1658 [7·6%] of 21694); ORadj 1·86, 95% CI 1·53–2·26; ARRadj –4·4%, 95% CI
–5·5 to –3·2). Only 2·3% of high-risk surgical patients and those with adverse respiratory profiles were anaesthetised
without neuromuscular blocking agents. The use of neuromuscular monitoring (ORadj 1·31, 95% CI 1·15–1·49;
ARRadj –2·6%, 95% CI –3·9 to –1·4) and the administration of reversal agents (1·23, 1·07–1·41; –1·9%, –3·2 to –0·7)
were not associated with a decreased risk of postoperative pulmonary complications. Neither the choice of sugammadex
instead of neostigmine for reversal (ORadj 1·03, 95% CI 0·85–1·25; ARRadj –0·3%, 95% CI –2·4 to 1·5) nor extubation at
a train-of-four ratio of 0·9 or more (1·03, 0·82–1·31; –0·4%, –3·5 to 2·2) was associated with better pulmonary outcomes.
Interpretation We showed that the use of neuromuscular blocking drugs in general anaesthesia is associated with an
increased risk of postoperative pulmonary complications. Anaesthetists must balance the potential benefits of
neuromuscular blockade against the increased risk of postoperative pulmonary complications