Simultane Messung der Chlorophyll Fluoreszenz-Kinetik bei verschiedenen Wellenlángen als rasches Verfahren zur Frühdiagnose von Immissionsbelastungen an Waldbäumen: Ozoneinwirkungen auf Buchen und Pappeln

Simultaneous measurement of chlorophyll fluorescence-kinetics at two different wavelengths as a rapid and an early detection method of air pollution damage on trees: Ozone effects on beech and poplar . A newly defined light adaption index A_P shows the stress influence already before the comparable and known vitality index R_fd and the appearance of visible ozone symptoms on foliage.     

Isolation, structure determination, and sensory activity of mouth-drying and astringent nitrogen-containing phytochemicals isolated from red currants (Ribes rubrum)

Application of chromatographic separation and taste dilution analyses recently revealed, besides a series of flavon-3-ol glycosides and (E)/(Z)-aconitic acid, four nitrogen-containing phytochemicals as the key astringent and mouth-drying compounds in red currants (Ribes rubrum). The isolation and structure determination of the astringent indoles 3-carboxymethyl-indole-1-N-beta-D-glucopyranoside (1) and 3-methylcarboxymethyl-indole-1-N-beta-D-glucopyranoside (2), as well as the astringent, noncyanogenic nitriles 2-(4-hydroxybenzoyloxymethyl)-4-beta-D-glucopyranosyloxy-2(E)-butenenitrile (3) and 2-(4-hydroxy-3-methoxybenzoyloxymethyl)-4-beta-D-glucopyranosyloxy-2(E)-butenenitrile (4) by means of 1D/2D NMR, LC-MS/MS, and UV-vis spectroscopy are reported. The structures of compounds 1 and 2 were confirmed by synthesis. Using the recently developed half-tongue test, human recognition thresholds for the astringent and mouth-drying nitrogen compounds were determined to be between 0.0003 and 5.9 micromol/L (water). In particular, the extraordinarily low threshold of 0.0003 micromol/L evaluated for the indole 1 represents the lowest recognition threshold of any astringent phytochemical reported to date.     

Validation of the tetrasensor honey test kit for the screening of tetracyclines in honey

Regarding anti-infectious agents, no maximum residue limits are fixed for honey in the European legislation. Discussions are being conducted in order to set working limits at the European level; for example, for tetracyclines, 20 microg/kg was proposed. The Tetrasensor Honey test kit is a receptor-based assay using dipsticks for a rapid screening (30 min) of honey on the presence of tetracyclines. The test was validated according to Commission Decision 2002/657/EC. The test detects tetracycline, oxytetracycline, chlortetracycline, and doxycycline in honey in a specific and sensitive way. Depending on the type of tetracycline, detection capabilities (CCbeta) between 6 and 12 microg/kg were obtained (4-7 microg/kg for dried dipsticks). The test is rugged and participation with the test in an international ring trial gave compliant results. It can be concluded that the Tetrasensor Honey test kit is a simple and reliable test that can even be used at the production site.     

Molecular analysis of Salmonella enterica subsp. enterica serovar Agona isolated from slaughter pigs

Salmonella enterica subsp. enterica (S.) serovar Agona plays an important role in Brazil as causative agent of salmonellosis in food-producing animals - in particular, pigs and poultry - as well as in humans. A total of 45 S. Agona isolates collected from slaughter pigs at three different slaughterhouses in Southern Brazil was investigated in this study for their phenotypic and genotypic relatedness. For this, the antimicrobial susceptibility patterns and the phage types were determined. Molecular analysis included the determination of plasmid profiles as well as the analysis of XbaI- and BlnI-generated macro-restriction patterns. Moreover, a novel typing method called subtracted restriction fingerprinting (SRF) was successfully applied to the S. Agona isolates. Based on all properties determined, a dominant clonal group comprising 33 of the 45 isolates was identified. Members of this group were susceptible to all antimicrobials tested, did not carry plasmids, shared the same phage type and were closely related or even indistinguishable by their EcoRI-PauI SRF patterns as well as their XbaI and BlnI macro-restriction patterns. Members of this clonal group were identified at all 3 slaughterhouses at variable frequencies and originated from pig herds raised in 15 different cities in Southern Brazil which were located up to 450 km apart from each other. Since the S. Agona-carrying slaughter pigs were from various integrated production lines, the results of this study suggest that a specific clonal group of S. Agona had entered numerous pig production lines. This observation supports the requirement for the establishment of monitoring and control programmes in Brazil which should also include molecular techniques to better trace the dissemination of S. Agona and other Salmonella serovars in pigs and other food-producing animals.     

Characterization of a novel type of MLSB resistance plasmid from Staphylococcus saprophyticus carrying a constitutively expressed erm(C) gene

An erm(C)-carrying plasmid of unusual size and restriction map, designated pSES22, was identified in a Staphylococcus saprophyticus strain and sequenced completely. Constitutive expression of the erm(C) gene from pSES22 is based on a novel 22-bp tandem duplication in the erm(C) translational attenuator. Comparative analysis of the deduced Erm(C) amino acid sequence revealed that Erm(C) from pSES22 - together with an Erm(C) methylase from S. hyicus - represented a separate branch in the homology tree of Erm(C) methylases. Structural comparisons showed that plasmid pSES22 differed distinctly from all other completely sequenced erm(C)-carrying resistance plasmids. However, pSES22 was similar to several members of a diverse group of small plasmids, all of which carried closely related plasmid backbones consisting of the genes repU and pre/mob, but differed in their resistance genes.     

Impacts of chemical crop protection applications on related CO2 emissions and CO2 assimilation of crops

BACKGROUND: A major global challenge is to provide agricultural production systems that are able to sustain growing demands for food, feed, fibre and renewable raw materials without exacerbating climate change. Detailed and reliable data on the CO₂ balance of different agricultural management activities and inputs as a basis to quantify carbon footprints of agriculture are still lacking. This study aims to fill this gap further by quantifying the net balance of emitted and assimilated CO₂ due to the application of crop protection treatments on the farm, and by assessing their partial contribution to GHG emissions and mitigation in agriculture. The study focuses on key agricultural crops including wheat, corn, oilseeds and sugar crops. RESULTS: The final CO₂ balance, considering GHG emissions due to on‐farm CPP treatment in comparison with CO₂ storage in additional biomass, CO₂ protected with respect to agrotechnical inputs and land inputs and CO₂ saved with respect to associated global land use changes, is positive and may reach multiples of up to nearly 2000. CONCLUSION: The results highlight the importance of the positive yield effects of the CPP programme applications on the farm, resulting in additional assimilated biomass at the farm level and less land use changes at the global level, and thus lower pressure on environmentally important indicators of overall agricultural sustainability. Copyright © 2012 Society of Chemical Industry     

In vitro antimicrobial activity of miconazole and polymyxin B against canine meticillin-resistant Staphylococcus aureus and meticillin-resistant Staphylococcus pseudintermedius isolates

Background – Meticillin‐resistant Staphylococcus aureus (MRSA) and meticillin‐resistant Staphylococcus pseudintermedius (MRSP) infections are increasingly reported in dogs, and these bacteria may be isolated from ear infections. Hypothesis/Objectives – The main aim of the present study was to investigate the in vitro antimicrobial activity of miconazole, polymyxin B and a combination of both against 24 canine MRSA and 50 canine MRSP isolates. The minimal inhibitory concentration (MIC) values of 12 other antimicrobial agents were also determined. Methods – All MIC values were determined according to a broth microdilution assay. Results – Acquired resistance was found to all tested agents, except for linezolid, miconazole and polymyxin B. The MIC values for miconazole and polymyxin B against MRSA were in the range of 4–8 and 8–64 μg/mL, respectively, while the MIC values for miconazole and polymyxin B against MRSP were in the range of 1–2 and 0.25–4 μg/mL, respectively. Using a combination of miconazole and polymyxin B, there was no evidence for enhanced in vitro activity of the combination (i.e. synergy) of both products. Nevertheless, MIC₉₀ values of the combination of these antimicrobial agents and of a commercial product containing both agents were at least 1000 times lower than the concentration present in the commercial product. Conclusions and clinical importance – These results indicate that the topical use of a combination of miconazole and polymyxin B in a 43.5:1 ratio may have potential for the treatment of MRSA‐mediated and MRSP‐associated otitis externa in dogs.