Methane and nitrous oxide annual emissions from an old eutrophic temperate reservoir.

Two greenhouse gases -methane (CH4) and nitrous oxide (N2O) - were monitored monthly during one year (2011) at the Eguzon Reservoir in France. The objective of the study was to quantify for the first time in a temperate area the total emissions of these gases through the main emission pathways (diffusion and bubbling from the reservoir, degassing and downstream diffusion). The reservoir was impounded in 1926 and had, in 2011, a eutrophic status promoting high organic matter degradation and nitrification-denitrification, all favouring CH4 and N2O production. CH4 and N2O emissions were dominated by diffusion from the reservoir surface (respectively 78.0% and 92.3%). Ebullition was only observed for CH4 and accounted for 14.0% of total CH4 emissions. Downstream degassing and diffusion represented 8.1% of the total CH4 emissions and 7.7% of the total N2O emissions.

Trait-based structure of invertebrates along a gradient of sediment colmation: benthos versus hyporheos responses.

Streambed colmation by fine sediment, e.g. the deposition, accumulation and storage of fines in the substrate, is known to have severe effects on invertebrate assemblages in both the benthic and hyporheic zones but the changes in biological attributes of invertebrate assemblages related to colmation have never been considered simultaneously for these two zones. We studied the effects of colmation on the invertebrate assemblages of three rivers, testing a priori hypotheses on the biological attributes that should be more selected in communities subjected to different levels of colmation in both zones. Only the proportion of organisms with high fecundity increased and the proportion of small-sized organisms decreased along the colmation gradient in both zones simultaneously. As expected, a higher number of traits were significantly modified with colmation in the benthic vs. hyporheic assemblages. Most of the biological attributes impaired were different in the two zones. In the benthic zone, colmation mainly selected particular physiological or trophic characteristics of species and features related to their resistance or resilience capacities. In contrast, the morphological attributes of species were much more impaired by colmation in the hyporheic zone than in the benthic zone. In clogged benthic habitats, traits seemed to be more impaired by an increase in physico-chemical constraints (e.g. the reduction of oxygen availability) and a reduction of potential exchanges (including exchanges of food resources) due to a decline in stream bed conductivity. The morphological attributes of the hyporheic species were probably more influenced by changes in interstitial space characteristics. A potential indicator of the effects of colmation on river health may be based on the functional traits of benthic communities because they (i) satisfy the WFD recommendations, (ii) respond consistently along a colmation gradient and (iii) are comparable among assemblages even across ecoregions that differ in their taxonomic composition.

Emergence of methicillin-resistant Staphylococcus pseudintermedius in Switzerland: three cases of urinary tract infections in cats.

Methicillin resistance has emerged in clinical isolates of Staphylococcus pseudintermedius from cats in Switzerland. Three cats suffering from urinary tract infections were infected with methicillin-resistant S. pseudintermedius (MRSP). Phenotypic and genotypic characterization of the resistance profile showed that the isolates displayed resistance to all beta-lactams and cephalosporins (blaZ, mecA), fluoroquinolones, tetracyclines [tet(K)], macrolides, lincosamides and streprogramins B [erm(B)], chloramphenicol (catpC221), trimethoprim [dfr(G)] and the aminoglycosides gentamicin [aac(6')-Ie-aph(2')-Ia], kanamycin and neomycin [aph(3')-III] and streptomycin [ant(6)-Ia]. They also harbor the leukocidin gene lukS-I. MRSP represents a new challenge for antibiotic therapy and this zoonotic bacteria may rapidly spread to animals and humans.