Urban Prevalence of Listeria spp. and Listeria monocytogenes in Public Lavatories and on Shoe Soles of Facility Patrons in the European Capital City Vienna

The aim of this study was to determine the prevalence of Listeria spp. and Listeria monocytogenes (L. monocytogenes) in urban public lavatories and on shoe soles of facility patrons in a European capital city. More than 91% of all municipal public lavatories in Vienna close to public hubs were included in this study. Overall, 373 swab samples of public lavatories and shoes of facility patrons were enriched, according to ISO 11290‐1. Listeria monocytogenes isolates were subtyped using pulsed‐field gel electrophoresis. A total of 24 samples were positive for Listeria spp., yielding an overall prevalence of 6.4% (24/373). Listeria monocytogenes was found in 2.1% (8/373) of all samples. Swabs from lavatories in parks, container lavatories and lavatories at markets had the highest prevalences of 20.7% (6/29), 20% (2/10) and 12.5% (1/8) Listeria spp., respectively. These detection rates were statistically significantly higher than those associated with lavatories in shopping centres (P = 0.003, P = 0.002, P = 0.02) and at public transport locations (P = 0.0004, P = 0.005, P = 0.02). Shoes sampled at Christmas markets showed the highest Listeria spp. and L. monocytogenes prevalences of 80% (4/5) and 40% (2/5), respectively. With regard to shoe type, Listeria spp. detection rates were 14.3% (3/21; winter boots), 13.3% (2/15; hiking boots), sport shoes (5.9%; 2/34) and brogues (5.1%; 4/79). No Listeria spp. were found on shoe soles that had smooth treads (0/76), while Listeria spp. were detected on 19.5% (8/41) of medium depth tread shoe types and on 9.4% (3/32) of deep tread shoes. These data suggest that soil environment is still one of the most important reservoirs for the foodborne pathogen L. monocytogenes.     

The genetic landscape of the childhood cancer medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor of children. To identify the genetic alterations in this tumor type, we searched for copy number alterations using high-density microarrays and sequenced all known protein-coding genes and microRNA genes using Sanger sequencing in a set of 22 MBs. We found that, on average, each tumor had 11 gene alterations, fewer by a factor of 5 to 10 than in the adult solid tumors that have been sequenced to date. In addition to alterations in the Hedgehog and Wnt pathways, our analysis led to the discovery of genes not previously known to be altered in MBs. Most notably, inactivating mutations of the histone-lysine N-methyltransferase genes MLL2 or MLL3 were identified in 16% of MB patients. These results demonstrate key differences between the genetic landscapes of adult and childhood cancers, highlight dysregulation of developmental pathways as an important mechanism underlying MBs, and identify a role for a specific type of histone methylation in human tumorigenesis.     

Linuron sorption-desorption in field-moist soils

Pesticide sorption or binding to soil is traditionally characterized using batch slurry techniques. The objective of this study was to determine linuron sorption in field-moist or unsaturated soils. Experiments were performed using low-density (i.e., 0.25 g mL(-)(1)) supercritical carbon dioxide to remove linuron from the soil water phase, thus allowing calculation of sorption coefficients (K(d)) at low water contents. Both soil water content and temperature influenced sorption. K(d) values increased with increased water content, if less than saturated. K(d) values decreased with increased temperature. K(d) values for linuron sorption on silty clay and sandy loam soils at 12% water content and 40 degrees C were 3.9 and 7.0 mL g(-)(1), respectively. Isosteric heats of sorption (DeltaH(i)) were -41 and -35 kJ mol(-)(1) for the silty clay and sandy loam soils, respectively. The sorption coefficient obtained using the batch method was comparable (K(f) for sandy loam soil = 7. 9 microg(1)(-)(1/)(n)() mL(1/)(n)() g(-)(1)) to that obtained using the SFE technique. On the basis of these results, pesticide sorption as a function of water content must be known to more accurately predict pesticide transport through soils.     

DHPLC scoring of a SNP between promoter sequences of HMW glutenin x-type alleles at the Glu-D1 locus in wheat

The promoter regions of HMW glutenin x-type genes at the Glu-D1 locus were surveyed for SNPs within a subpopulation of German bread wheat cultivars. On the basis of the promoter sequences of HMW glutenin subunit genes Glu-A1-x1, Glu-A1-x2, Glu-B1-x1, Glu-B1-x7, Glu-D1-x2, and Glu-D1-x5, an amplification refractory mutation system assay was designed to selectively amplify Dx-specific PCR fragments. Comparative sequence analysis among seven Glu-D1-x2 and seven Glu-D1-x5 wheat cultivars only confirmed a G-A transition in the promoter sequence to be a true polymorphism. SNP scoring by DHPLC of 95 German bread wheat cultivars, with the exception of cv. Anemos, showed that the transition completely agreed with the presence of HMW glutenin subunits 1Dx5 + 1Dy10 in SDS-PAGE. Therefore, the developed DHPLC assay is suitable for high-throughput genotyping to assist the selection of HMW glutenin genes in wheat quality breeding programs.     

Rate of desorption of eight heavy metals from goethite and its implications for understanding the pathways for penetration

We compared rates of desorption of heavy metals from goethite, an important soil constituent, in order to understand the mechanisms of sorption and desorption better. Samples of goethite were reacted with salt solutions of heavy metals for 2 hours or for 8 weeks. The metals were Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb. Desorption was then induced by successive treatments with 0.7 m HNO₃ for up to 360 hours followed by complete dissolution of the goethite particles. After brief sorption (2 hours), a large proportion of the sorbed metals was desorbed by brief treatment (15 minutes) with HNO₃. This suggests that the metals were mainly sorbed on, or close to, external goethite surfaces. After longer sorption (8 weeks), even 360 hours of extraction with 0.7 m HNO₃ did not recover all of the sorbed metals. Complete dissolution of the goethite particles was necessary. This suggests that the eight heavy metals had penetrated the goethite particles deeply. When desorption was summarized using a pragmatic equation, it was only for brief sorption followed by brief desorption that indices of the rate of desorption were well correlated with measures of the rate of sorption as obtained in an earlier work. When desorption was described with a mechanistic model, observed desorption was often faster than predicted and the discrepancy was greatest with the shorter periods of desorption. The discrepancy was marked for Ni, Cr and Co. We think this was because large portions of these metals were incorporated into the goethite structure by lattice diffusion and were therefore held close to the surface. When the acid dissolved some of the goethite these metals were released. For long‐term desorption and for most metals, the ratio of observed to predicted desorption decreased with increasing ionic radius. We think that this reflects a changing balance between lattice and pore diffusion, with lattice diffusion more important for metals with radii near that of Fe (Cr, Co, Ni), and pore diffusion more important for the larger cations of Cd and Pb. Manganese was an exception. Desorption was at first faster than predicted but then declined to be close to predicted values. This suggests that Mn mostly penetrated more deeply by pore diffusion.     

Mikrosondenuntersuchungen an unterschiedlich stark mit Schwermetallen belasteten Böden. 1. Methodische Grundlagen und Elementanalysen an pedogenen Oxiden

Electron microprobe studies on soil samples with varying heavy metal contamination. 1. Methods and analysis of elements in pedogenic oxides EMA point analysis, line scan profiles and microprobe photos were performed on thin sections from 19 soil samples with variing heavy metal content to show the distribution of elements in soil particles on a microscopic level. The investigations showed that the detection limits generally have a range of 110-830 mg/kg in anorganic soil matrix respectively 80-320 mg/kg in organic soil matrix. The element specific heavy metal accumulation capacities on the pedogen oxides compared to the average content of the soil samples can be described for Co, Ni, Cu, Zn, Cd and Pb. The maximum trace element accumulations in concretions related to their element total content in the soil samples were by Co 3.170 times, Ni 6.635 times, Cu 323 times, Zn 112 times, Cd 2.000 times and by Pb 745 times. The accumulation and immobilization of heavy metals by iron oxides suggests that additions of Fe oxides could be used to reduce heavy metal availability and leaching to the subsoil on highly contaminated soils.     

Responses of deciduous forest trees to severe drought in Central Europe

In 2003, Central Europe experienced the warmest summer on record combined with unusually low precipitation. We studied plant water relations and phenology in a 100-year- old mixed deciduous forest on a slope (no ground water table) near Basel using the Swiss Canopy Crane (SCC). The drought lasted from early June to mid September. We studied five deciduous tree species; half of the individuals were exposed to elevated CO(2) concentration ([CO(2)]) (530 ppm) using a free-air, atmospheric CO(2)-enrichment system. In late July, after the first eight weeks of drought, mean predawn leaf water potential about 30 m above ground was -0.9 MPa across all trees, dropping to a mean of -1.5 MPa in mid-August when the top 1 m of the soil profile had no plant accessible moisture. Mean stomatal conductance and rates of maximum net photosynthesis decreased considerably in mid-August across all species. However, daily peak values of sap flow remained surprisingly constant over the whole period in Quercus petraea (Matt.) Liebl., and decreased to only about half of the early summer maxima in Fagus sylvatica L. and Carpinus betulus L. (stomatal down- regulation of flux). Although we detected no differences in most parameters between CO(2)-treated and control trees, predawn leaf water potential tended to be less negative in trees exposed to elevated [CO(2)]. Leaf longevity was greater in 2003 compared with the previous years, but the seasonal increase in stem basal area reached only about 75% of that in previous years. Our data suggest that the investigated tree species, particularly Q. petraea, did not experience severe water stress. However, an increased frequency of such exceptionally dry summers may have a more serious impact than a single event and would give Q. petraea a competitive advantage in the long run.