AbstractBackground Listeria monocytogenes is an opportunistic gram-positive, facultative intracellular bacterium that causes invasive diseases mostly in pregnant women and immunosuppressed patients. Despite the predilection toward the central nervous system (CNS), it usually causes meningitis and meningoencephalitis, whereas brain abscesses are very uncommon.Case presentation We describe the case of a 69-year-old homeless patient with a brain abscess due to L. monocytogenes who was successfully treated surgically by a guided stereotactic aspiration and antibiotic therapy with ampicillin and gentamicin. Our patient was discharged after 4 weeks of therapy without neurologic deficits. Additionally, we provide a review of the literature of brain abscesses caused by L. monocytogenes.Conclusions This case highlights the need to drain cerebral abscesses and culture pus to correctly treat patients with antibiotics, especially given the high mortality rate of this infectious entity.
The Arctic environments constitute rich and dynamic ecosystems, dominated by microorganisms extremely well adapted to survive and function under severe conditions. A range of physiological adaptations allow the microbiota in these habitats to withstand low temperatures, low water and nutrient availability, high levels of UV radiation, etc. In addition, other adaptations of clear competitive nature are directed at not only surviving but thriving in these environments, by disrupting the metabolism of neighboring cells and affecting intermicrobial communication. Since Arctic microbes are bioindicators which amplify climate alterations in the environment, the Arctic region presents the opportunity to study local microbiota and carry out research about interesting, potentially virulent phenotypes that could be dispersed into other habitats around the globe as a consequence of accelerating climate change. In this context, exploration of Arctic habitats as well as descriptions of the microbes inhabiting them are abundant but microbial ...
'Zwei Untersuchungen wurden durchgeführt, in denen Berichte über das eigene subjektive Wohlbefinden beeinflußt werden a) durch die Augenfälligkeit eines Vergleichsstandards und b) durch die Aktivierung einer sozialen Norm im Kontext der Urteilsabgabe. Wir fanden, daß sich die Versuchspersonen in Anwesenheit einer anderen Person, der es vergleichsweise schlechter ging, als glücklicher einschätzten. Dieser Kontrasteffekt trat verstärkt auf, wenn die Aufmerksamkeit der Vpn beim Ausfüllen des Fragebogens durch ein natürliches Sitzarrangement auf die Vergleichsperson gerichtet war. Die Ergebnisse des zweiten Experiments, in dem die Darbietungsform der Befragung (anonym vs. offen) und der offensichtliche Gesundheitszustand der Vergleichsperson (körperbehindert oder nicht) variiert wurde, zeigen, daß solche vergleichende Urteile nicht geäußert werden, wenn die Antworten dem körperbehinderten Versuchsteilnehmer gegenüber offen geäußert werden müssen. Zusammengenommen machen beide Untersuchungen deutlich, daß kognitive und kommunikative Prozesse gleichermaßen beachtet werden müssen, um die Determinanten von Urteilen des subjektiven Wohlbefindens zu verstehen.' (Autorenreferat)
Selver, Ayça Doğrul (Balikesir Author) ; The Siberian Arctic contains a globally significant pool of organic carbon (OC) vulnerable to enhanced warming and subsequent release by both fluvial and coastal erosion processes. However, the rate of release, its behaviour in the Arctic Ocean and vulnerability to remineralisation is poorly understood. Here we combine new measurements of microbial biohopanoids including adenosylhopane, a lipid associated with soil microbial communities, with published glycerol dialkyl glycerol tetraethers (GDGTs) and bulk delta C-13 measurements to improve knowledge of the fate of OC transported to the East Siberian Arctic Shelf (ESAS). The microbial hopanoid-based soil OC proxy R'(soil) ranges from 0.0 to 0.8 across the ESAS, with highest values nearshore and decreases offshore. Across the shelf R'(soil) displays a negative linear correlation with bulk delta C-13 measurements (r(2) = -0.73, p = < 0 : 001). When compared to the GDGT-based OC proxy, the branched and isoprenoid tetraether (BIT) index, a decoupled (non-linear) behaviour on the shelf was observed, particularly in the Buor-Khaya Bay, where the R'(soil) shows limited variation, whereas the BIT index shows a rapid decline moving away from the Lena River outflow channels. This reflects a balance between delivery and removal of OC from different sources. The good correlation between the hopanoid and bulk terrestrial signal suggests a broad range of hopanoid sources, both fluvial and via coastal erosion, whilst GDGTs appear to be primarily sourced via fluvial transport. Analysis of ice complex deposits (ICDs) revealed an average R'(soil) of 0.5 for the Lena Delta, equivalent to that of the Buor-Khaya Bay sediments, whilst ICDs from further east showed higher values (0.6-0.85). Although R'(soil) correlates more closely with bulk OC than the BIT, our understanding of the endmembers of this system is clearly still incomplete, with variations between the different East Siberian Arctic regions potentially reflecting differences in environmental conditions (e.g. temperature, pH), but other physiological controls on microbial bacteriohopanepolyol (BHP) production under psychrophilic conditions are as yet unknown. ; NERC Natural Environment Research Council NE/I024798/1 NE/I027967/1 Ministry of National Education - Turkey Swedish Royal Academy of Sciences through Knut and Alice Wallenberg Foundation Government of the Russian Federation 14 Z50.31.0012/03.19.2014 Russian Science Foundation (RSF) 15-17-20032 National Science Foundation (NSF) ANT-1203885/PLR-1500169 Knut & Alice Wallenberg Foundation Russian Academy of Sciences Swedish Research Council National Oceanic Atmospheric Admin (NOAA) - USA Russian Foundation for Basic Research (RFBR) Swedish Polar Research Secretariat Nordic Council of Ministers National Science Foundation (NSF) NERC Natural Environment Research Council NE/I024798/1 NE/I027967/1
Abstract Desert environments constitute one of the largest and yet most fragile ecosystems on Earth. Under the absence of regular precipitation, microorganisms are the main ecological component mediating nutrient fluxes by using soil components, like minerals and salts, and atmospheric gases as a source for energy and water. While most of the previous studies on microbial ecology of desert environments have focused on surface environments, little is known about microbial life in deeper sediment layers. Our study is extending the limited knowledge about microbial communities within the deeper subsurface of the hyperarid core of the Atacama Desert. By employing intracellular DNA extraction and subsequent 16S rRNA sequencing of samples collected from a soil pit in the Yungay region of the Atacama Desert, we unveiled a potentially viable microbial subsurface community residing at depths down to 4.20 m. In the upper 80 cm of the playa sediments, microbial communities were dominated by Firmicutes taxa showing a depth-related decrease in biomass correlating with increasing amounts of soluble salts. High salt concentrations are possibly causing microbial colonization to cease in the lower part of the playa sediments between 80 and 200 cm depth. In the underlying alluvial fan deposits, microbial communities reemerge, possibly due to gypsum providing an alternative water source. The discovery of this deeper subsurface community is reshaping our understanding of desert soils, emphasizing the need to consider subsurface environments in future explorations of arid ecosystems.
