Prevalence, Resistance Rates, and Risk Factors of Pathogens in Routine Bile Cultures Obtained during Endoscopic Retrograde Cholangiography.

INTRODUCTION AND OBJECTIVE: Acute cholangitis is a life-threatening condition. The early initiation of antibiotic therapy significantly impacts the course of disease. Only few data are available on distribution and resistance profiles of bile pathogens. Here, we report on an analysis of routinely acquired bile specimens and provide an overview of the prevalence, resistance rates, and risk factors for the presence of pathogens in bile. METHODS: Bile cultures obtained from 388 endoscopic retrograde cholangiographies (ERCs) with corresponding clinical data were analysed in 208 patients. RESULTS: The majority (84.8%) of cultures yielded positive for at least 1 organism. Abundance was highest for Enterococcus faecalis, Enterococcus faecium, and Escherichia coli. Multiresistant organisms were present in 14.9%. The initial antibiotic regimen was changed in 44.1%, which increased the length of hospital stay significantly (***p < 0.001). Pre-existing papillotomy (EPT) or biliary drainage was associated with higher frequency of bile pathogens (**p < 0.01) in a univariate analysis. Multivariate analysis confirmed these results for EPT and revealed significantly more positive results for pathogens, gram-negative bacteria, and fungi in patients with biliary drainage. Significant differences in the prevalence of pathogens were observed between relevant subgroups of ERC indications. The highest susceptibility rates were observed for linezolid and tigecycline in gram-positive bacteria and for meropenem and gentamicin in gram-negative bacteria. CONCLUSIONS: Our study provides a comprehensive analysis of the distribution, resistance profiles, and risk factors for the detection of bile pathogens. The frequent change in initial antibiotic treatment highlights the importance of routine bile culture and indicates that current schemas of empirical treatment might not cover the contemporary spectrum of pathogens in bile.

Under temperate climate, the conversion of grassland to arable land affects soil nutrient stocks and bacteria in a short term.

Projected population growth and climate change will make it inevitable to convert neglected and marginal land into productive arable land. We investigate the influence of agricultural management practices on nutrient stocks and soil functions during the conversion of former extensively used grassland to arable land. Effects of grassland removal, tillage, intercropping with faba bean (Vicia faba) and its later incorporation were studied with respect to soil properties and bacterial community structure. Therefore, composite samples were collected with a core sampler from the topsoil (0-20 cm) in (a) the initial grassland, (b) the transitional phase during the vegetation period of V. faba, (c) after ploughing the legume in, and (d) untreated controls. In all samples, nitrate-N, ammonium-N, dissolved organic carbon (DOC) and total nitrogen bound (TNb) were analyzed and comparisons of the bacterial community structure after 16S-amplicon sequencing were performed to assess soil functions. Mineralization after grassland conversion followed by the biological nitrogen fixation of broad beans enhanced the nitrate-N content in bulk soil from 4 to almost 50 µg N g-1dw. Bacterial community structure on phylum level in bulk soil was dominated by Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, and Bacteroidetes and remained almost stable. However, alpha and beta-diversity analysis revealed a change of the bacterial composition at the final state of the conversion. This change was primarily driven by increasing abundances of the genera Massilia and Lysobacter, both members of the Proteobacteria, after the decay of the leguminous plant residues. Furthermore, increasing abundances of the family Gaiellaceae and its genus Gaiella fostered this change and were related to the decreasing carbon to nitrogen ratio. In short, gentle management strategies could replace the input of mineral fertilizer with the aim to contribute to future sustainable and intensified production even on converted grassland.

Extreme climatic events down-regulate the grassland biomass response to elevated carbon dioxide.

Terrestrial ecosystems are considered as carbon sinks that may mitigate the impacts of increased atmospheric CO2 concentration ([CO2]). However, it is not clear what their carbon sink capacity will be under extreme climatic conditions. In this study, we used long-term (1998-2013) data from a C3 grassland Free Air CO2 Enrichment (FACE) experiment in Germany to study the combined effects of elevated [CO2] and extreme climatic events (ECEs) on aboveground biomass production. CO2 fertilization effect (CFE), which represents the promoted plant photosynthesis and water use efficiency under higher [CO2], was quantiffied by calculating the relative differences in biomass between the plots with [CO2] enrichment and the plots with ambient [CO2]. Down-regulated CFEs were found when ECEs occurred during the growing season, and the CFE decreases were statistically significant with p well below 0.05 (t-test). Of all the observed ECEs, the strongest CFE decreases were associated with intensive and prolonged heat waves. These findings suggest that more frequent ECEs in the future are likely to restrict the mitigatory effects of C3 grassland ecosystems, leading to an accelerated warming trend. To reduce the uncertainties of future projections, the atmosphere-vegetation interactions, especially the ECEs effects, are emphasized and need to be better accounted.

Compositional diversity of rehabilitated tropical lands supports multiple ecosystem services and buffers uncertainties.

High landscape diversity is assumed to increase the number and level of ecosystem services. However, the interactions between ecosystem service provision, disturbance and landscape composition are poorly understood. Here we present a novel approach to include uncertainty in the optimization of land allocation for improving the provision of multiple ecosystem services. We refer to the rehabilitation of abandoned agricultural lands in Ecuador including two types of both afforestation and pasture rehabilitation, together with a succession option. Our results show that high compositional landscape diversity supports multiple ecosystem services (multifunction effect). This implicitly provides a buffer against uncertainty. Our work shows that active integration of uncertainty is only important when optimizing single or highly correlated ecosystem services and that the multifunction effect on landscape diversity is stronger than the uncertainty effect. This is an important insight to support a land-use planning based on ecosystem services.