The complete genome sequence of Propionibacterium acnes, a commensal of human skin

Propionibacterium acnes is a major inhabitant of adult human skin, where it resides within sebaceous follicles, usually as a harmless commensal although it has been implicated in acne vulgaris formation. The entire genome sequence of this Gram-positive bacterium encodes 2333 putative genes and revealed numerous gene products involved in degrading host molecules, including sialidases, neuraminidases, endoglycoceramidases, lipases, and pore-forming factors. Surface-associated and other immunogenic factors have been identified, which might be involved in triggering acne inflammation and other P. acnes-associated diseases.     

Experimental infection of pregnant ewes with bovine viral diarrhea virus type-2 (BVDV-2): effects on the pregnancy and fetus

The reproduction effects of bovine viral diarrhea virus type-2 (BVDV-2) infection were investigated in ewes inoculated with a non-cytopathic BVDV-2 isolate at three stages of gestation. Virus inoculation was followed by a transient viremia, accompanied by a transient and mild hyperthermia and nasal discharge in a few animals. Some ewes were sacrificed at different time-points after virus inoculation to study the kinetics of fetal infection. Infectivity and viral antigens were detected in placentomes from day 7 to 36 post-inoculation (pi) and in fetal fluids and tissues between days 10 and 28 pi. Cardiac petechial hemorrhages and hemoperitoneum accompanied by a severe fibrinous ulcerative placentitis were observed in fetuses examined at days 21, 28 and 36 pi. Inoculation of ewes at days 55-60 of gestation resulted in a prolonged virus replication in placentomes and fetal tissues; ewes that were allowed to proceed with pregnancy had 77% of abortions or fetal and perinatal deaths. Seven stillbirths, unviable and viable lambs born to these ewes were virus-positive at birth. Infectious virus was repeatedly isolated from leukocytes of two lambs up to 2 and 6 months of age, indicating they were persistently infected. Ewes inoculated at days 65-70 of gestation had 66.6% of fetal and perinatal losses. Three viable lambs born to these ewes were healthy, BVDV antibody-positive and virus-negative. A transient viral replication in placentomes and in a few fetal tissues, followed by the rise of fetal neutralizing antibodies and virus clearance was the result of inoculating ewes at days 120-125 of gestation. Lambs born to these ewes were healthy, antibody-positive and virus-negative. These results demonstrate that the biology of BVDV-2 infection in pregnant sheep is essentially similar to that of BVDV-1 in pregnant cattle and sheep. These features make this species an attractive animal model for studying the pathogenesis of congenital BVDV-2 infection.     

Occurrence and distribution of earthworms in agricultural landscapes across Europe with regard to testing for responses to plant protection products

Purpose

Within the regulatory framework for authorisation of plant protection products (PPPs) (EU Directive 91/414/1991/EEC replaced by Regulation (EC) 1107/2009), higher tier risk assessments and earthworm field tests are conducted in different countries across Europe. This paper describes dominant earthworm species for regulatory and biogeographical regions in agricultural landscapes across Europe and examines regional differences in earthworm communities and densities and their respective response to a toxic reference.

Materials and methods

For the assessment of earthworm abundance and species distribution, data of untreated control plots from 30 earthworm field studies were analysed; each conducted according to the ISO 11268–3 (1999) guideline by European Crop Protection Association member companies in the context of registration of PPPs. For the evaluation of the response to PPPs under different regional and climatic conditions, the effect on earthworm abundance was assessed by comparing plots treated with toxic references with untreated control plots. Additionally, a comparative literature review was included providing an overview of earthworm species composition and densities in agricultural crops from 14 European countries.

Results and discussion

The assessment of earthworm field studies from six different European countries revealed that common earthworm species of anecic and endogeic ecological groups are present at most field sites. Dominant species groups of endogeic and anecic earthworms can be defined that are abundant in all assessed countries. These are the endogeic species Aporrectodea caliginosa, Aporrectodea rosea and Allolobophora chlorotica, and the anecic species Lumbricus terrestris (Northern and Central Europe) and Lumbricus friendi (Southern Europe). Taking into account the high variability in total earthworm abundances, it can be concluded that the variability within regions was larger than the variability between regions.

Conclusions

Analysis of the earthworm community and data of toxic references lead to the conclusion that testing in different zones is not considered necessary.     

Fibroblast adhesion on unidirectional polymeric nanofilms

Nanotextured polymeric surfaces with inclined rods reveal highly anisotropic properties concerning wetting and adhesion. In this work, we report on the interaction of fibroblast cells with these highly anisotropic materials. The authors quantified removal of adherent cells from such surfaces by a laminar flow. The critical shear force needed for cell removal from the surface depends on the inclination direction. Based on electron microscopy cross sections we deduce that interactions of cellular filopodia extending into the nanotextured surface are causing the direction depending removal.     

Simulating the production potential and net energy yield of maize-ethanol in the southeastern USA

The interest in producing ethanol from maize has increased during recent years. However, the potential for maize-ethanol production is restricted to the extent of the feedstock production and the feedstock collection radius around an ethanol processing plant. The harvested acreage of maize in Alabama, Florida and Georgia has varied from 115,000 ha to 1.4 million ha during the last 50 years. One basic criterion for a sustainable production of renewable bio-ethanol is a positive net energy yield (NEY), i.e. more energy must be produced than the non-renewable energy that is used in the energy production chain, including the feedstock production and transportation and the biofuel processing. The goal of this study was to evaluate the potential to produce renewable energy the form of maize-ethanol in a region with typical southeastern USA maize cropping conditions. Two maize production acreages, which represent current and historical large acreages, and two feedstock collection radii of 100 and 200 km around an ethanol plant in southwest Georgia were evaluated. Maize growth and yield were simulated with the Cropping System Model (CSM)-CERES-Maize model to account for climate and soil variability. The simulations included weather data for 68 years. The potential ethanol production and NEY were calculated based on the simulated yields and energy requirements for the production. The ethanol production potential was 30–40 times greater for the large production acreage than for the small acreage. The average NEY across all simulated years was positive for all evaluated production acreages and collection radii. However, it was negative for the large production acreage under certain weather conditions. This study showed the potential to provide for an increase in renewable ethanol production from maize in the southeastern USA to meet the demand of the ethanol processing infrastructure.     

How does silviculture affect storm damage in forests of south-western Germany? Results from empirical modeling based on long-term observations

Storms represent the most important disturbance factor in forests of Central Europe. Using data from long-term growth and yield experiments in Baden-Wuerttemberg (south-western Germany), which permit separation of storm damage from other causes of mortality for individual trees, we investigated the influence of soil, site, forest stand, and tree parameters on storm damage, especially focusing on the influence of silvicultural interventions. For this purpose, a four-step modeling approach was applied in order to extract the main risk factors for (1) the general stand-level occurrence of storm damage, (2) the occurrence of total stand damage, and (3) partial storm damage within stands. The estimated stand-level probability of storm damage obtained in step 3 was then offset in order to describe the damage potential for the individual trees within each partially damaged stand (4). Generalized linear mixed models were applied. Our results indicate that tree species and stand height are the most important storm risk factors, also for characterizing the long-term storm risk. Additionally, data on past timber removals and selective thinnings appear more important for explaining storm damage predisposition than for example stand density, soil and site conditions or topographic variables. When quantified with a weighting method (summarizing the relative weight of single predictors or groups of predictors), removals could explain up to 20% of storm risk. The stepwise modeling approach proved an important methodological feature of the analysis, since it enabled consideration of the large number of observations without damage (“zero inflation”) in a statistically correct way. These results form a reliable basis for quantifying forest management’s direct impact on the risk of storm damage.     

A potential novel Brucella species isolated from mandibular lymph nodes of red foxes in Austria

The wild red fox (Vulpes vulpes) is a known indicator species for natural foci of brucellosis. Here, we describe phenotypic and molecular characteristics of two atypical Brucella strains isolated from two foxes hunted 2008 in Eastern Austria. Both strains agglutinated with monospecific anti-Brucella A serum and were positive in ELISA with monoclonal antibodies directed against various Brucella lipopolysaccharide epitopes. However, negative nitrate reductase- and negative oxidase-reaction were atypical traits. Affiliation to the genus Brucella was confirmed by 16S rRNA gene sequencing and by detection of the Brucella specific insertion element IS711 and gene bcsp31 using real-time PCR. Both fox strains showed identical IS711 Southern blot profiles but were distinct from known brucellae. The number of IS711 copies detected was as high as found in B. ovis or marine mammal Brucella strains. Molecular analyses of the recA and omp2a/b genes suggest that both strains possibly represent a novel Brucella species.