Modern and fossil non-pollen palynomorphs from the Basque mountains (western Pyrenees, France): the use of coprophilous fungi to reconstruct pastoral activity

International audienceThis paper presents results from a modern dataset of non-pollen palynomorphs and its application to aca. 2,000 year peat record from the same area in the western Pyrenees (Basque Country, France). The modern dataset is composed of 35 surface samples (moss polsters) from a mountainous pasture-woodland landscape. Airborne fungal spores (ascospores and conidia), found dominant in the dataset, are linked to the degree of landscape openness and grazing pressure. The complete spectrum of 13 selected spore-types of dung-related Ascomycetes is positively linked with grazing pressure. However, different dung affinities between the spore-types have been identified. These are types clearly related to high grazing pressure and types with no or unclear dung indicative value. The modern dataset is used to aid interpretation of the local fossil pollen record as an independent 'proxy' to assess past pastoral dynamics. This study confirms the utility of modern nonpollen palynomorphs from terrestrial ecosystems in the reconstruction of historical local pastoral activities but also shows their limitation. It may be necessary to extend such study to wetland ecosystems and to investigate the spatial dimension of some fungal spores

Pharmacodynamic evaluation of commonly prescribed oral antibiotics against respiratory bacterial pathogens

<p>Abstract</p> <p>Background</p> <p>Upper and lower respiratory tract infections (RTIs) account for a substantial portion of outpatient antibiotic utilization. However, the pharmacodynamic activity of commonly used oral antibiotic regimens has not been studied against clinically relevant pathogens. The objective of this study was to assess the probability of achieving the requisite pharmacodynamic exposure for oral antibacterial regimens commonly prescribed for RTIs in adults against bacterial isolates frequently involved in these processes (<it>S. pneumoniae</it>, <it>H. influenzae</it>, and <it>M. catharralis</it>).</p> <p>Methods</p> <p>Using a 5000-subject Monte Carlo simulation, the cumulative fractions of response (CFR), (i.e., probabilities of achieving requisite pharmacodynamic targets) for the most commonly prescribed oral antibiotic regimens, as determined by a structured survey of medical prescription patterns, were assessed against local respiratory bacterial isolates from adults in São Paulo collected during the same time period. Minimal inhibitory concentration (MIC) of 230 isolates of <it>Streptococcus pneumoniae </it>(103), <it>Haemophilus influenzae </it>(98), and <it>Moraxella catharralis </it>(29) from a previous local surveillance were used.</p> <p>Results</p> <p>The most commonly prescribed antibiotic regimens were azithromycin 500 mg QD, amoxicillin 500 mg TID, and levofloxacin 500 mg QD, accounting for 58% of the prescriptions. Varied doses of these agents, plus gatifloxacin, amoxicillin-clavulanate, moxifloxacin, and cefaclor made up the remaining regimens. Utilizing aggressive pharmacodynamic exposure targets, the only regimens to achieve greater than 90% CFR against all three pathogens were amoxicillin/amoxicillin-clavulanate 500 mg TID (> 91%), gatifloxacin 400 mg QD (100%), and moxifloxacin 400 mg QD (100%). Considering <it>S. pneumoniae </it>isolates alone, azithromycin 1000 mg QD also achieved greater than 90% CFR (91.3%).</p> <p>Conclusions</p> <p>The only regimens to achieve high CFR against all three pathogen populations in both scenarios were gatifloxacin 400 mg QD, moxifloxacin 400 mg QD, and amoxicillin-clavulanate 500 mg TID. These data suggest the need for reconsideration of empiric antibiotic regimen selection among adult patients with RTIs in the São Paulo area. Additionally, this type of study could be used to optimize prescribing patterns in specific regions in light of emerging resistance.</p

Multicenter, Prospective Validation of a Phenotypic Algorithm to Guide Carbapenemase Testing in Carbapenem-Resistant Pseudomonas aeruginosa Using the ERACE-PA Global Surveillance Program

Background: Carbapenemase-producing, carbapenem-resistant Pseudomonas aeruginosa (CP-CRPA) is a global challenge. However, detection efforts can be laborious because numerous mechanisms produce carbapenem resistance. A minimum inhibitory concentration-based algorithm (imipenem- or meropenem-resistant plus ceftazidime-nonsusceptible plus cefepime-nonsusceptible) was proposed to identify the isolates most likely to harbor a carbapenemase; however, prospective validation in geographies displaying genotypic diversity and varied carbapenemase prevalence is warranted. Methods: CRPA isolates were collected during the Enhancing Rational Antimicrobials for P. aeruginosa (ERACE-PA) global surveillance program from 17 sites in 12 countries. Isolates underwent susceptibility testing following local standards to ceftazidime, cefepime, and ceftolozane/tazobactam. Isolates underwent initial phenotypic carbapenemase screening followed by molecular testing if positive. The primary algorithm criteria were applied, and results were compared with phenotypic carbapenemase results to assess the performance of the algorithm. A secondary criterion, the algorithm criterion or imipenem- or meropenem-resistant plus ceftolozane/tazobactam-nonsusceptible, was assessed. Results: A total of 807 CRPA were assessed, and 464 isolates met the algorithm criteria described above. Overall, testing was reduced by 43% compared with testing all CRPA. Carbapenemase-positive isolates missed by the algorithm were largely driven by Guiana extended spectrum (GES). Addition of the criterion of imipenem- or meropenem-resistant plus ceftolozane/tazobactam-nonsusceptible decreased the number of CP-CRPA missed by the algorithm (21 vs 40 isolates, respectively), reducing number of isolates tested by 39%. Conclusions: Application of the initial algorithm (imipenem- or meropenem-resistant plus ceftazidime-nonsusceptible plus cefepime-nonsusceptible) performed well in a global cohort, with 33% phenotypically carbapenemase-positive isolates. The addition of imipenem- or meropenem-resistant plus ceftolozane/tazobactam-nonsusceptible reduced the number of phenotypically carbapenemase-positive isolates missed and may be useful in areas with a prominence of GES