Geo-ecological soil features and the vegetation pattern in an arid dune area in the Northern Negev,Israel

Soils are suggested to be an important factor influencing the vegetation pattern. In order to prove this hypothesis in an arid and sandy Negev ecosystem of longitudinal dunes and interdune corridors near Nizzana, Israel, the distribution of soil units and plant communities were compared on a very small-distance level. The Nizzana site has a size of nearly 100 ha. 250 soil pits with 3–5 horizons were mapped and sampled within the soil geographical monitoring. Soil water capacity and cation exchange capacity were estimated from the field data. In addition 176 plots of 100 m² were established around the soil pits with emphasis on plants, coveting the environmental gradient across the dune ridges. Plant mapping plots were arranged into groups with the same dominating perennial species and a key for the vegetation mapping was developed. In the investigated desert site topography, soil surface crust, soil texture and salt content partly can explain the distribution of plant communities. A soil classification proposal is based on these parameters and is a useful tool to indicate correlations between soil units and the vegetation pattern. Nevertheless, dependent on topography and surface and/or subsurface water flow as well as the occurrence of “fertile islands” the moisture and nutrient regimes influence the vegetation pattern with respect to plant growth to a greater extent than the soils themselves.     

Monitoring of antibiotic consumption in livestock: a German feasibility study

Every application of antibacterial drugs in veterinary medicine may encourage selection for resistant bacteria. In Germany no valid data are available which would be suitable for a species specific estimation of drug consumption especially regarding food producing animals. Therefore, a representative monitoring of consumption of antibacterial drugs in food producing animals should be implemented. As a first step, a feasibility project was conducted to identify the technical preconditions and develop a concept for a regular monitoring system within Germany as a country with a non-central federal state system. The data were collected via the forms obligatory by German law concerning the treatment of animals and the delivery of animal drugs to the animal owners by the veterinarian. 24 veterinary practices and 65 farmers were visited, and all applications of antibiotics to farm animals during the course of one year (September 1, 2006 to August 31, 2007) were entered into a central database. A total of 95,584 records were collected and analysed statistically. Consumption of antibiotics was calculated in kg, but also the number of applications was analysed. The consumption of tetracyclines in kg reached 54.3% of all antimicrobial substances applied to pigs, but only 25.7% of all doses applied to pigs were tetracyclines. For the farms' data, the number of daily doses per animal year (DD(ay)) was estimated based on the number of daily doses recorded and on the number of animals kept in the farm. Correct and detailed data regarding the structures of the farms as well as of veterinary practices are necessary to estimate the consumption of antibiotics reliably. The proposed system is able to function as a monitoring system for antibiotic use in Germany, when the monitoring data are linked to the agricultural data (farm sizes) accounting for differences between German regional agricultural and animal husbandry structures. Furthermore, the results of the antibiotic use analyses may serve as basis to assess the results of the sales data of the pharmaceutical industry. Results are comparable to the outcome of respective systems in other European countries, e.g. the Netherlands and Denmark, and therefore it will contribute to a better understanding and development of strategies for the control of antimicrobial resistances on the European level.     

Performance of complement fixation test and confirmatory immunoblot as two-cascade testing approach for serodiagnosis of glanders in an endemic region of South East Asia

Various serological tests were used for the diagnosis of glanders in the past but still complement fixation test (CFT) is the internationally prescribed test for trading equines. A new immunoblot (IB) technique has recently been introduced to overcome the well known shortcomings of CFT i. e. a considerable number of false positive and negative results and anticomplementary effects of sera. The objective of this study was the comparative evaluation of two glanders CFT antigens commercially available at Central Veterinary Institute ofWageningen UR, Lelystad, NL (CIDC) and at c.c.pro GmbH, Oberdorla, DE (c.c.pro) in a glanders endemic area regarding specificity and sensitivity. A total of 1678 serum samples from the endemic region (Province Punjab, Pakistan) and a non-endemic area (Germany) were analysed. All sera tested positive or suspicious with CFT were analysed by the confirmatory IB to exclude CFT false positive results. Both CFT antigens showed 100% sensitivity. The use of CIDC or c.c.pro antigen resulted in specificities of 77.45% or 75.71% for sera from endemic area and 93.75% or 94.79% for sera from non-endemic areas, respectively. The results demonstrate the different performances of identical tests in different epidemiologically settings. Based on these results, the combined use of CFT and IB is highly suggestive for the serodiagnosis of glanders. Good agreement was calculated between CFT (using either c.c.pro or CIDC antigen) and immunoblot.     

Genetic diversity of <Emphasis Type="Italic">Patellifolia patellaris</Emphasis> from the Iberian Peninsula,a crop wild relative of cultivated beets

The genetic diversity of Patellifolia patellaris has been investigated to generate information required for the organisation of a systematic genetic resources conservation action combining the best elements of the ex situ and in situ conservation concept. To this end, ten occurrences of the species were sampled on the Iberian Peninsula in Portugal and Spain. A total of 271 individuals was analysed using 24 microsatellite markers. The factorial analysis separated the material into two occurrences from Portugal, two occurrences sampled east of Gibraltar and six occurrences from the eastern Spanish coast. The pairwise genetic distance between occurrences and the complementary compositional differentiation among occurrences were calculated. The genetic distance values were used to construct an Unweighted Pair Group Method with Arithmetic Mean tree, which can be separated into four equidistant clusters. Two clusters are located in Portugal and two further clusters in Spain. The factorial analysis as well as the genetic distance and differentiation analysis indicate that the two occurrences from Portugal are clearly genetically different from the Spanish group of occurrences. Both occurrences have low population sizes and are therefore highly endangered. In situ conservation actions are urgently required for both occurrences. Further investigations are needed to organise better informed conservation actions for P. patellaris, namely to study genetic relationships between occurrences on the Spanish mainland and occurrences distributed on the Canary Islands, Madeira and Cape Verde Islands as well as in Morocco.     

Extended summaries pesticides group symposium natural products as a source for new agricultural chemicals

The following are extended abstracts of six of the papers presented at the above meeting and, as so presented, they are entirely the responsibility of the authors and do not reflect the views of the Editorial Board of Pesticide Science.     

Antimicrobial susceptibility of coagulase-positive and coagulase-variable Staphylococci from various indications of swine, dogs and cats as determined in the BfT-GermVet monitoring program 2004-2006

A total of 248 coagulase-positive and coagulase-variable staphylococci from two indications of swine (infections of the urinary/genital tract including strains from the mastitis metritis agalactia syndrome as well as infections of the skin) as well as two indications of dogs/cats (respiratory tract infections and infections of skin/ear/mouth) were investigated for their susceptibility to numerous antimicrobial agents. Regardless of the animal origin and indication, the most frequently detected resistance properties were resistances against penicillin G (53-77%) and ampicillin (42-75%), tetracycline (33-52%) as well as erythromycin (13-27%). Oxacillin-resistant staphylococci were rarely detected.     

Bacillus cereus var. toyoi enhanced systemic immune response in piglets

Probiotic bacteria have been suggested to stimulate the host immune system. In this study we evaluated the immunomodulatory effects of probiotic Bacillus cereus var. toyoi on the systemic immunity of piglets. A pool of 70 piglets was divided into a probiotic or control group. We determined the ratios of peripheral blood mononuclear cell (PBMC) subsets and measured proliferative responses and cytokine production of PBMCs and effects on vaccination responses. Blood samples of probiotic-treated piglets showed a significantly lower frequency of CD8(high)/CD3+ T cells and CD8(low)/CD3+ T cells and a significant higher CD4+/CD8+ ratio. IL-4 and IFN-gamma production of polyclonally stimulated PBMCs was on average higher in the probiotic group. Specific proliferative responses of PBMCs to Influenza vaccination antigens were significantly higher and antibody titers against H3N2 Influenza and Mycoplasma vaccination antigens were on average higher in the probiotic group. In conclusion, B. cereus var. toyoi therefore alters the immune status of piglets as indicated by changes in the ratios as well as functionalities of systemic immune cell populations.     

Investigations on the identification of risk factors for seroprevalences of Salmonella infections in breeding gilt rearing herds

The aim of this study in breeding gilt rearing herds was to identify production-specific risk factors for an increased Salmonella seroprevalence. The statistical analysis for determining risk factors based on 10,429 animals from 40 herds. Blood samples were taken regularly between 2001 and 2003 from gilts five and six months of age. Only those herds from which at least 60 samples per year and 10 per quarter were available were included in the statistical analysis of risk factors. For this, the results of the serological examinations were combined with data obtained from a questionnaire and subsequent visual examination of the herds and their environment. Different kinds of categories were validated using sensitivity analysis. Finally, all herds with a Salmonella seroprevalence < 0.15 were classified as "Salmonella low risk", and those with a Salmonella seroprevalence > or = 0.15 were classified as "Salmonella high risk". Four of the sixteen variables could be ascertained as risk factors for enhanced Salmonella seroprevalences: the use of pelleted or granulated feed, the use of purchased feed, partially or not slatted floors in the pens, a floor space of 0.85m2/pig and the freedom of PRRSV-infection in a herd. Some of these variables were identified as risk factors in earlier studies, too. The identification of these risk factors in pig herds of a breeding company with a low Salmonella seroprevalence, emphasises the importance of these factors for controlling Salmonella infections in pig herds.     

Silikate im Pflanzenschutz: Elektrostatische Applikation und Abhängigkeit der Wirksamkeit von der Schichtdicke

Natural occurring amorphous silica is ubiquitous on the earth in soils and sediments. Both, natural derived silica and synthetically produced amorphous silica are used against stored product pests and parasites in animal houses. New formulations, active even under higher relative humidity's can be possible used against horticultural arthropod pests. Since many horticultural pests hide on the undersides of leaves and silica is a physical contact insecticide, an appropriate application method is needed. This paper reviews electrostatic application of natural derived amorphous silica to Brassica chinensis leaves. Due to the inherent high volume resistivity of silica powder, induction charging was ineffective for electrostatic powder coating. Corona charging involves a reliable current source, but typically is inefficient in charging the powder particles and creates a high density of free ions between the gun and grounded substrate as well as within the coating layer. These factors resulted in poor coating quality and inefficient particle deposition. The best leave coating was archived using tribo charging. Here we have been able to apply coatings with different thickness. While a silica coating of 25–50?μm in petri dish experiments resulted in a reduced mortality of the granary weevil, Sitophilus granarius (L.), there was no difference between mortality with coatings of 50–100?μm and 100–125?μm. Silica applications on B. chinensis leaves resulted within two hours in a 45% reduction of the CO₂-absorption. Absorption level stayed reduced over a period of seven days and was between 45 and 73% compared to the control. Even after removing silica dust using pressurized air CO₂-absorption was between 19 and 28% reduced. This might be the case because silica particles where so small that they could possible clog the stomata opening resulting in a reduced transpiration and photosynthesis rate.