The use of copper isotopes for understanding metal transfer mechanisms within the continuum mine-river-dam (Huelva Region, Spain).

Mining areas and in particular those containing massive sulfides have left a heavy environmental legacy with soils and hydrographic networks highly contaminated with metals and metalloids as for example in the Iberian Pyrite Belt (Huelva, Spain). Here, we present new data on copper (Cu) isotopic composition of waters and solids collected along a continuum Mine (Tharsis)-River (Meca)-Lake (Sancho) in the Iberian Pyrite Belt. Our results show that the isotopic signature of pit lakes is spatially variable, but remains stable over the seasons; this signature seems to be controlled by water-rock interaction processes. The data obtained on the Meca River imply a number of attenuation processes such as decrease in the metal concentration by precipitation of secondary minerals. This is accompanied by preferential retention of the heavy isotope (65Cu) with a possibility of living organisms (e.g., algae) participation. The terminal Sancho lake demonstrated constant isotopic signature over the entire depth of the water column despite sizable variations in Cu concentrations, which can be tentatively explained by a superposition of counter-interacting biotic and abiotic processes of Cu fractionation. Overall, the understanding of the isotopic variations along the hydrological continuum is useful for a better understanding of metal element transfer within mining environments and surrounding surface waters.

Collaborative determination of trace element mass fractions and isotope ratios in AQUA-1 drinking water certified reference material.

The Isotrace CNRS workgroup in collaboration with National Research Council of Canada has characterized a number of trace element mass fractions and isotope ratios currently not certified in AQUA-1 natural drinking water reference material (NRC Canada). This survey further expands the use of this material as a tool for environmental quality control, method validation, and method development tool for the international community. Simultaneously, the SLRS-6 river water was analyzed as quality control and also in order to compare both water characteristics, which were sampled in the same area but having undergone different treatment. Mass fractions for B, Cs, Li, Ga, Ge, Hf, Nb, P, Rb, Rh, Re, S, Sc, Se, Si, Sn, Th, Ti, Tl, W, Y, Zr, REEs, and six isotopic ratios are proposed for Sr and Pb. Measurements were mostly performed using ICP-MS with various calibration approaches. The results are reported as consensus or indicative values depending on the number of available datasets, with their associated uncertainties.

Is There an Association Between Use of Amoxicillin-Clavulanate and Resistance to Third-Generation Cephalosporins in Klebsiella pneumoniae and Escherichia coli at the Hospital Level?

AIMS: Amoxicillin-clavulanate is extensively used in European hospitals. Whether the hospital use of amoxicillin-clavulanate is associated with nonsusceptibility to third-generation cephalosporins (3GC) in Klebsiella pneumoniae is unknown. Our aim was to assess the relationship between the hospital use of amoxicillin-clavulanate and 3GC nonsusceptibility in K. pneumoniae and Escherichia coli. METHODS: Yearly data of antibiotic use and 3GC nonsusceptibility in K. pneumoniae and E. coli were obtained from 33 French hospitals between 2011 and 2016. Decreased susceptibility to 3GC and Extended-Spectrum Beta-Lactamase (ESBL) production were modelled from antibiotic use with linear mixed models on years 2011 to 2015, and validated on year 2016. RESULTS: Nonsusceptibility to 3GC increased in K. pneumoniae and E. coli. In a multivariable model that included year and use of 3GC and fluoroquinolones as explanatory variables, amoxicillin-clavulanate use was protective against 3GC nonsusceptibility in K. pneumoniae (incidence rate ratio [IRR], 0.992 [0.988-0.997]), and with ESBL production in K. pneumoniae (IRR, 0.989 [0.985-0.992]). The correlation coefficient between observed and predicted numbers of 3GC-nonsusceptible K. pneumoniae in 2016 was 0.95 (95% confidence interval, 0.89-0.98). There was no significant association between amoxicillin-clavulanate use and 3GC nonsusceptibility in E. coli. CONCLUSION: Amoxicillin-clavulanate hospital use was protective against nonsusceptibility to 3GC in K. pneumoniae. Conversely, it was not associated with susceptibility to 3GC in E. coli. To decrease the hospital use of 3GC and fluoroquinolones, and 3GC nonsusceptibility in K. pneumoniae, it may be acceptable to increase the hospital use of amoxicillin-clavulanate. Interventional studies are necessary to confirm this hypothesis.

[Antimicrobial in nursing homes in a French region: point prevalence survey and consumption in 2012]. / Antibiotiques en établissements d'hébergement pour personnes âgées dépendantes dans une région française : prévalence et consommations en 2012.

Infectious diseases and bacterial resistance are gaining importance in nursing homes. A few studies about antibiotic (AB) consumption in nursing homes (NHs) already exist. A national survey was performed by the European surveillance of antimicrobial consumption with the aim of gaining insight in NHs care to all European countries. This study shows that the surveillance of AB use is not organised in continuous for many countries and have shown that the prevalence of infections in French nursing homes was 4.8%. In France, there is no national data collection system of AB consumption for NHs. Data were obtained from a point prevalence survey conducted in 2012 in 80 NHs. In total, 1.366 residents were included and 48 residents were treated with antimicrobials (3.5%). Antimicrobials were most frequently prescribed for the treatment of respiratory (45.8%) and urinary tract infections (27.1%). For 4 prescriptions, the indication was not found. Consumption datas for 52 NHs were collected. The AB consumption mediane was 39 defined daily dose/1.000 PD (DDD/1.000 PD). The mediane of AB consumption for the region was 39.4 DDD/1.000 PD. Coamoxi-clav is the main AB consumed (39%) followed by amoxicillin with 30%.