Novel form of collective movement by soil bacteria.

Although migrations are essential for soil microorganisms to exploit scarce and heterogeneously distributed resources, bacterial mobility in soil remains poorly studied due to experimental limitations. In this study, time-lapse images collected using live microscopy techniques captured collective and coordinated groups of B. subtilis cells exhibiting "crowd movement". Groups of B. subtilis cells moved through transparent soil (nafion polymer with particle size resembling sand) toward plant roots and re-arranged dynamically around root tips in the form of elongating and retracting "flocks" resembling collective behaviour usually associated with higher organisms (e.g., bird flocks or fish schools). Genetic analysis reveals B. subtilis flocks are likely driven by the diffusion of extracellular signalling molecules (e.g., chemotaxis, quorum sensing) and may be impacted by the physical obstacles and hydrodynamics encountered in the soil like environment. Our findings advance understanding of bacterial migration through soil matrices and expand known behaviours for coordinated bacterial movement.

Access time to pasture under wet soil conditions: Effects on productivity and profitability of pasture-based dairying.

A long grazing season improves the profitability of pasture-based dairy production. It can entail grazing under wet soil conditions and the risk of damaging swards. Housing cows either temporarily or completely while soil moisture is high can avoid damaging swards. An experiment with 4 grazing systems was conducted over 3 yr (Sep. 1, 2013, to Aug. 31, 2016). The purpose was to evaluate whether soil moisture measurements are an effective decision support to assess the risk of treading damage and effects on pasture productivity and dairy cow performance during wet soil conditions. Access time to pasture between February and December of each grazing season was dependent on volumetric soil moisture content (VSMC, m3/m3) measured each morning: Control = cows were housed at VSMC >0.5 and otherwise allowed 22 h/d access to pasture; S<7 = cows were housed on days with VSMC >0.7 and otherwise allowed 22 h/d access to pasture; S7-6 = cows were housed at VSMC >0.7 and allowed 8 h/d access to pasture at VSMC between 0.7 and 0.6 and 22 h/d access at VSMC ≤0.6; S7-5 = cows were housed at VSMC >0.7 and allowed 8 h/d access to pasture at VSMC between 0.7 and 0.5 and 22 h/d access at VSMC ≤0.5. Cows with 8-h access per day received no other feeding when housed. All herds were compact spring-calving, with a mean calving date of Feb. 19. Mean stocking rate was 2.57 cows/ha. Measurements of VSMC provided an objective indicator for the risk of treading damage. Less time spent at pasture under wet soil conditions lowered treading damage but had no effect on annual pasture production (mean 14.8 t of organic matter/ha). Annual milk solids production per cow was lowest for the control herd (485 kg) and not different between the other systems (503 kg). Reducing treading damage to swards did not improve productivity or profitability of the grazing systems. Nevertheless, measuring soil moisture was a useful decision support for assessing the risk of treading damage when turning cows out to pasture.

A management framework for phosphorus use on agricultural soils using sorption criteria and soil test P.

The variation in sorption and desorption of phosphorus (P) among soil types is not captured in current agronomic advice for agri-environmentally sustainable use of P. Phosphorus use is typically based on soil test P (STP) and soils are assumed to have the same rate of response to added P, regardless of sorption properties. The development of P sorption categories, coupled with STP information could improve fertiliser decision making, by making it more site specific and soil type specific. A framework for P sorption specific advice is proposed here integrating soil P sorption dynamics with STP for agronomic and environmental management, at farm and catchment scale. Using a national population of agricultural soils, laboratory measurement of Langmuir sorption maximum (Smax50, mg kg-1) and binding energy (k50, l mg-1), were coupled with STP (Morgan P) to derive novel categories for P management advice, specifically addressing the build-up and draw-down phases of P in soils. In addition to measured values, Smax50 and k50 were predicted from MIR spectroscopy and pedotransfer functions and used to allocate soils into these new sorption categories. The allocation of soils into a P management category using predicted values indicated that pedotransfer functions offered greater reliability (90% allocation accuracy using an independent test set), however MIR spectroscopy is faster and less resource intensive (67% allocation accuracy using an independent test set). Phosphorus sorption dynamics should be interpreted alongside soil test P and P Index information so that water quality policy can consider the difference between high and very high STP soils based on sorption information. In the absence of laboratory data on P sorption, soils can be classified into P management classes using predicted values from spectroscopy (rapid and cheap) or pedotransfer functions (greater reliability). Further development of the MIR methodology is recommended along with field validation.

Water use efficiency of Irish dairy processing.

Dairy processing uses a significant amount of water for processing and cleaning. Withdrawing and distributing water and treating wastewater represent significant costs to the Irish dairy processing industry. Stringent discharge limits also add pressure for water use efficiency, particularly during peak production months. Improving water use efficiency is therefore critical for Irish dairy processing. We conducted a detailed analysis of water use efficiency in 4 Irish dairy processing plants. Using farm gate to processor gate (gate-to-gate) life cycle assessment, we assessed on-site water data quality and investigated gate-to-gate volumetric water use and eutrophication potential (EP) for 3 common dairy products. We also benchmarked the on-site water use and water balance, characterized wastewater nutrient load, analyzed the influencers of on-site water use, and identified scope for increased water use efficiency. We found that condensate from evaporation represented a significant input at the site level (0.51 to 1.14 L/L of fresh water purchased or extracted from nature). In terms of gate-to-gate volumetric water use, butter used 1,326 to 1,843 m3/t of solids, with electricity being the largest contributor, whereas milk powders used 3,006 to 3,754 m3/t of solids, with electricity and ingredients being the largest contributors. Eutrophication of butter was found to be 0.51 to 0.77 kg of PO4 equivalents (eq)/t of solids, with transportation and nutrient emissions from wastewater treatment being the largest contributors. Eutrophication of milk powder was found to be 0.96 to 3.35 kg of PO4 eq/t of solids, and contributions varied depending on powder specifications. Milk intake water use and various leakages were found to be hotspots that could be managed to reduce water use on site. Comprehensive metering is urgently needed to improve water use efficiency in light of the ongoing expansion of dairy production and hence processing in Ireland. Significant opportunities exist to optimize operator behavior, water reuse, and off-site transportation and energy. This study represents the first attempt to define water efficiency opportunities both at the site level and along the supply chain. Processors need to be aware of off-site contributors that significantly affect both volumetric water use and environmental impacts of processed dairy products.

Water footprinting of pasture-based farms; beef and sheep.

In the context of water use for agricultural production, water footprints (WFs) have become an important sustainability indicator. To understand better the water demand for beef and sheep meat produced on pasture-based systems, a WF of individual farms is required. The main objective of this study was to determine the primary contributors to freshwater consumption up to the farm gate expressed as a volumetric WF and associated impacts for the production of 1 kg of beef and 1 kg of sheep meat from a selection of pasture-based farms for 2 consecutive years, 2014 and 2015. The WF included green water, from the consumption of soil moisture due to evapotranspiration, and blue water, from the consumption of ground and surface waters. The impact of freshwater consumption on global water stress from the production of beef and sheep meat in Ireland was also computed. The average WF of the beef farms was 8391 l/kg carcass weight (CW) of which 8222 l/kg CW was green water and 169 l/kg CW was blue water; water for the production of pasture (including silage and grass) contributed 88% to the WF, concentrate production - 10% and on-farm water use - 1%. The average stress-weighted WF of beef was 91 l H2O eq/kg CW, implying that each kg of beef produced in Ireland contributed to freshwater scarcity equivalent to the consumption of 91 l of freshwater by an average world citizen. The average WF of the sheep farms was 7672 l/kg CW of which 7635 l/kg CW was green water and 37 l/kg CW was blue water; water for the production of pasture contributed 87% to the WF, concentrate production - 12% and on-farm water use - 1%. The average stress-weighted WF was 2 l H2O eq/kg CW for sheep. This study also evaluated the sustainability of recent intensification initiatives in Ireland and found that increases in productivity were supported through an increase in green water use and higher grass yields per hectare on both beef and sheep farms.

Evaluation of allocation methods for calculation of carbon footprint of grass-based dairy production.

A major methodological issue for life cycle assessment, commonly used to quantify greenhouse gas emissions from livestock systems, is allocation from multifunctional processes. When a process produces more than one output, the environmental burden has to be assigned between the outputs, such as milk and meat from a dairy cow. In the absence of an objective function for choosing an allocation method, a decision must be made considering a range of factors, one of which is the availability and quality of necessary data. The objective of this study was to evaluate allocation methods to calculate the climate change impact of the economically average (€/ha) dairy farm in Ireland considering both milk and meat outputs, focusing specifically on the pedigree of the available data for each method. The methods were: economic, energy, protein, emergy, mass of liveweight, mass of carcass weight and physical causality. The data quality for each method was expressed using a pedigree score based on reliability of the source, completeness, temporal applicability, geographical alignment and technological appropriateness. Scenario analysis was used to compare the normalised impact per functional unit (FU) from the different allocation methods, between the best and worst third of farms (in economic terms, €/ha) in the national farm survey. For the average farm, the allocation factors for milk ranged from 75% (physical causality) to 89% (mass of carcass weight), which in turn resulted in an impact per FU, from 1.04 to 1.22 kg CO2-eq/kg (fat and protein corrected milk). Pedigree scores ranged from 6.0 to 17.1 with protein and economic allocation having the best pedigree. It was concluded that when making the choice of allocation method, the quality of the data available (pedigree) should be given greater emphasis during the decision making process because the effect of allocation on the results. A range of allocation methods could be deployed to understand the uncertainty associated with the decision.

Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

BACKGROUND: Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. RESULTS: The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. CONCLUSIONS: The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from "wetlands drainage and rewetting". The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

Validation of the use of exogenous gonadotropins (PG600) to increase the efficiency of gilt development programs without affecting lifetime productivity in the breeding herd.

The objective of this study was to validate the use of exogenous gonadotropin (PG600) treatment for stimulating estrus in noncyclic gilts and to compare lifetime productivity of gilts recorded as having natural (NAT) versus PG600-induced (PG600) first estrus in a commercial setting. Prepubertal Camborough gilts ( = 4,489) were delivered to a gilt development unit (GDU) with the goal of delivering known cyclic breeding-eligible females to the sow farm (SF). A boar exposure area (BEAR) was designed to facilitate stimulation and detection of puberty by providing fence line and direct contact (15 min daily) with mature boars over an intensive 28-d period, starting at approximately d 160 (d 0). At d 14, nonpubertal gilts were mixed in new pen groups. At d 23, noncyclic "opportunity" gilts with no record of vulval development and required to meet breeding targets, were eligible for treatment with PG600 to induce puberty. Overall, 77.6% ( = 3,475) of gilts exhibited standing estrus (NAT = 2,654; PG600 = 821) and were eligible for shipping to the SF at approximately 35 d, and 76.6% of gilts that were administered PG600 exhibited the standing reflex within 13 d of treatment. Ultimately, 72.0% of gilts entering the GDU were delivered to the SF as breeding-eligible females. Considering the gilts delivered, a greater proportion of NAT than PG600 gilts were successfully bred ( < 0.001) and had better farrowing rates to first service, and overall farrowing rates (including gilts that returned to estrus and were rebred) were greater for NAT compared to PG600 gilts ( < 0.001) . Farrowing rates at second and third parity were similar between NAT and PG600 gilts; however, at fourth parity, a greater proportion of NAT gilts farrowed. In comparison, considering only gilts served, there was no difference ( > 0.05) in the proportion of NAT and PG600 gilts farrowing a third litter, but a greater proportion of NAT than PG600 gilts farrowed their fourth litter ( < 0.001). There was no difference between NAT and PG600 gilts for litter size at parity 1 through 4 or total pigs born over 4 parities ( > 0.05). A negative correlation ( < 0.0001) was detected between age at puberty and lifetime growth rate at puberty, and growth rate classification affected age and weight at puberty. However, retention rates and total sow productivity to parity 4 were not affected by growth rate classification at puberty.

The effects of treading by two breeds of dairy cow with different live weights on soil physical properties, poaching damage and herbage production on a poorly drained clay-loam soil.

There is little empirical evidence to indicate that dairy cow live weight affects the extent of soil damage at the hoof-soil interface during grazing on poorly drained permanent grassland. In the present study the impact of Holstein-Friesian (HF) dairy cows with a mean (±standard deviation) live weight of 570 (±61) kg were compared with Jersey × Holstein-Friesian (JX) with a mean live weight of 499 (±52) kg each at two stocking densities: mean 2·42 ± (0·062) and 2·66 (±0·079) cows/ha. Soil physical properties (bulk density, macroporosity, gravimetric water content, air-filled porosity, penetration resistance and shear strength), poaching damage (post-grazing soil surface deformation and hoof-print depth), herbage yield and milk production were measured throughout 2011 and 2012. Soil physical properties, post-grazing soil surface deformation and herbage production were not affected by dairy cow breed or by interactions between breed and stocking density. Hoof-print depth was higher in the HF treatments (39 v. 37 mm, s.e. 0·5 mm). Loading pressure imposed at the soil surface was the same for both breeds due to a direct correlation between live weight and hoof size. Poaching damage was greater at higher stocking density. Using the lighter JX cow offered little advantage in terms of lowering the negative impact of treading on soil physical properties or reducing poaching damage and no advantage in terms of herbage or milk production compared with the heavier HF cow.

Prevalence and diversity of Escherichia coli isolated from a barley trial supplemented with bulky organic soil amendments: green compost and bovine slurry.

UNLABELLED: A barley field trial supplemented with bulky organic soil amendments, municipal compost or bovine slurry was sampled for Escherichia coli to test the hypothesis that E. coli isolated from the soil or from barley plants were derived from bovine slurry. A qualitative analysis showed that a total of 12% of the bulk soil cores and 16% of harvested grain samples yielded E. coli. The strongest association for positive detection of E. coli from soil was with time of year and for slurry-treated plots, with irrigation. However, E. coli were detected in plots from all treatment types and not exclusively associated with bovine slurry. Phylogroup, plasmid profiling and population genetics analysis (multilocus sequence typing) revealed extensive genetic diversity. Identical sequence types for slurry and soil isolates were detected, indicative of direct transfer into the soil, although not frequently. Host interaction assays with selected isolates showed a variation in the ability to colonize barley roots, but not in interactions with bovine cells. The work has implications in appropriate use of E. coli as a faecal indicator as isolates were widespread and diverse, reinforcing the view that some are a natural part of the microflora in agricultural systems. SIGNIFICANCE AND IMPACT OF THE STUDY: Faecal deposition is considered to be the main process that introduces Escherichia coli into soil, giving rise to their use as a faecal indication species and the potential for cycling pathogens in agricultural systems. We found that bovine slurry was not the main source of E. coli in a barley trial and a high degree of diversity was present in the collection. The findings support the hypothesis that the population structure of E. coli in secondary habitats is shaped by the environment and highlight the drawbacks of its use as a faecal indicator species.

Life cycle assessment of milk production from commercial dairy farms: the influence of management tactics.

Little consideration has been given to how farm management, specifically tactics used to implement the management strategy, may influence the carbon footprint (CF) and land use for milk produced on commercial farms. In this study, the CF and land use of milk production from 18 Irish commercial dairy farms were analyzed based on foreground data from a 12-mo survey capturing management tactics and background data from the literature. Large variation was found in farm attributes and management tactics; for example, up to a 1.5-fold difference in fertilizer nitrogen input was used to support the same stocking density, and up to a 3.5-fold difference in concentrate fed for similar milk output per cow. However, the coefficient of variation for milk CF between farms only varied by 13% and for land use by 18%. The overall CF and overall land use of the milk production from the 18 dairy farms was 1.23±0.04kg of CO2 Eq and 1.22±0.05 m(2) per kilogram of energy-corrected milk. Milk output per cow, economic allocation between exports of milk and liveweight, and on-farm diesel use per ha were found to be influential factors on milk CF, whereas the fertilizer N rate, milk output per cow, and economic allocation between exports of milk and liveweight were influential on land use. Effective sward management of white clover within a few farms appeared to lower the CF but increased on-farm land use. It was concluded that a combination of multiple tactics determines CF and land use for milk production on commercial dairy farms and, although these 2 measures of environmental impact are correlated, a farm with a low CF did not always have low land use and vice versa.

The carbon footprint of pasture-based milk production: can white clover make a difference?

Carbon footprint (CF) calculated by life cycle assessment (LCA) was used to compare greenhouse gas emissions from pasture-based milk production relying mainly on (1) fertilizer N (FN), or (2) white clover (WC). Data were sourced from studies conducted at Solohead Research Farm in Ireland between 2001 and 2006. Ten FN pastures stocked between 2.0 and 2.5 livestock units (LU)/ha with fertilizer N input between 180 and 353 kg/ha were compared with 6 WC pastures stocked between 1.75 and 2.2 LU/ha with fertilizer N input between 80 and 99 kg/ha. The WC-based system had 11 to 23% lower CF compared with FN (average CF was 0.86 to 0.87 and 0.97 to 1.13 kg of CO(2)-eq/kg of energy-corrected milk, respectively, 91% economic allocation). Emissions of both N(2)O and CO(2) were lower in WC, whereas emissions of CH(4) (per kg of energy-corrected milk) were similar in both systems. Ratio sensitivity analysis indicated that the difference was not caused by error due to modeling assumptions. Replacing fertilizer N by biological nitrogen fixation could lower the CF of pasture-based milk production.

The prevalence and distribution of Alaria alata, a potential zoonotic parasite, in foxes in Ireland.

The digenean trematode Alaria alata, an intestinal parasite of wild canids is widely distributed in Europe. The recent finding of the mesocercarial life cycle stage in the paratenic wild boar host suggests that it may potentially infect humans Mohl et al. (Parasitol Res 105:1-15, 2009). Over 500 foxes were examined during a wildlife survey for zoonotic diseases in 2009 and 2010. The prevalence of A. alata ranged from 21% to 26% in 2009 and 2010, and the intensity of infection varied, with the majority of foxes having between one and ten trematodes, but a small number of animals had parasitic burdens greater than 500. The location of foxes was geo-referenced and mapped using a geographic information system. The results of the spatial analysis suggest that A. alata may have a limited distribution being confined mainly to areas of pasture especially in the central plain and north Munster. Hot spot analysis indicated a clustering and that the level of parasitism was greatest in foxes from those areas where the prevalence of infection was highest.

Corticosteroid-induced gene expression in allergen-challenged asthmatic subjects taking inhaled budesonide.

BACKGROUND AND PURPOSE: Inhaled corticosteroids (ICS) are the cornerstone of asthma pharmacotherapy and, acting via the glucocorticoid receptor (GR), reduce inflammatory gene expression. While this is often attributed to a direct inhibitory effect of the GR on inflammatory gene transcription, corticosteroids also induce the expression of anti-inflammatory genes in vitro. As there are no data to support this effect in asthmatic subjects taking ICS, we have assessed whether ICS induce anti-inflammatory gene expression in subjects with atopic asthma. EXPERIMENTAL APPROACH: Bronchial biopsies from allergen-challenged atopic asthmatic subjects taking inhaled budesonide or placebo were subjected to gene expression analysis using real-time reverse transcriptase-PCR for the corticosteroid-inducible genes (official gene symbols with aliases in parentheses): TSC22D3 [glucocorticoid-induced leucine zipper (GILZ)], dual-specificity phosphatase-1 (MAPK phosphatase-1), both anti-inflammatory effectors, and FKBP5 [FK506-binding protein 51 (FKBP51)], a regulator of GR function. Cultured pulmonary epithelial and smooth muscle cells were also treated with corticosteroids before gene expression analysis. KEY RESULTS: Compared with placebo, GILZ and FKBP51 mRNA expression was significantly elevated in budesonide-treated subjects. Budesonide also increased GILZ expression in human epithelial and smooth muscle cells in culture. Immunostaining of bronchial biopsies revealed GILZ expression in the airways epithelium and smooth muscle of asthmatic subjects. CONCLUSIONS AND IMPLICATIONS: Expression of the corticosteroid-induced genes, GILZ and FKBP51, is up-regulated in the airways of allergen-challenged asthmatic subjects taking inhaled budesonide. Consequently, the biological effects of corticosteroid-induced genes should be considered when assessing the actions of ICS. Treatment modalities that increase or decrease GR-dependent transcription may correspondingly affect corticosteroid efficacy.

ANCA-stimulated neutrophils release BLyS and promote B cell survival: a clinically relevant cellular process.

OBJECTIVES: To determine a role for antineutrophil cytoplasmic antibody (ANCA)-activated neutrophils in promoting B cell survival through the release of B lymphocyte stimulator (BLyS). METHODS: Neutrophil BLyS expression was measured by flow cytometry. Concentrations of BLyS in cell supernatants and donor serum samples were measured by ELISA. Cell survival assays were carried out using an L3055 cell line and viability measured by flow cytometry. RESULTS: Tumour necrosis factor α and formyl-Met-Leu-Phe (fMLP) treatment of non-primed neutrophils and treatment of primed neutrophils with anti-PR3 ANCA IgG resulted in a significant increase in surface expression of BLyS within 30 min which returned to basal levels by 2 h. Supernatants from ANCA-stimulated neutrophils were shown to contain increased levels of BLyS and to promote the survival of the centroblast cell line L3055. Serum BLyS concentrations are increased in patients with active ANCA-associated systemic vasculitis and these levels are increased further following 1-3 months of treatment with rituximab. CONCLUSIONS: ANCA specifically causes the release of BLyS from activated neutrophils which can support B cell survival in vitro. The presence of serum BLyS in active disease and its increase following B cell depletion suggest it is an important factor in disease pathogenesis and may facilitate disease relapse.

Spatial distribution of risk factors for Cryptosporidium spp. transport in an Irish catchment.

Cryptosporidium spp. has become a major public health concern in many parts of the globe, including Ireland, as a result of recent reported waterborne outbreaks of Cryptosporidiosis. Continuous monitoring of Cryptosporidium spp. in water supplies is not feasible, so a risk-forecasting approach is required. This study reports a globally applicable approach for evaluating the spatial variation in relative risk of contaminating surface water by Cryptosporidium spp. based on a risk potential index (RPI) as an indicator of the potential pollution of surface water. The RPI is predicted by readily available data on land use, rainfall, soil type, slope, soil moisture deficit, and distance from water course. A small catchment in County Meath, Ireland, was chosen to illustrate the analysis of the approach. Data for the study area were digitized and rectified using surveyed ground control points to capture each of the RPI factors, field boundaries, and land use. The six parameters were classified and assigned a relative risk score out of 5. A Geographic Information Systems overlay analysis then was used to calculate a cumulative relative risk score for each month of the year. The analysis indicated that April and June experienced a relatively low risk of Cryptosporidium spp. transport compared with other months of the year. June had the least risk, because more than 98% of the catchment was estimated to be of low or moderate risk (RPI ranges = 0 to 2). December had the highest risk of Cryptosporidium spp. transport, because approximately 20% of the catchment area had a moderately high to very high risk (RPI ranges = 2 to 5). The study also made an attempt to reduce the risk of contaminating surface water by alternative land-use practice and relocating the field boundaries. The study demonstrated a semi-quantitative and readily implemented method for using spatial risk assessment for planning land management to reduce the risk of surface water contamination by Cryptosporidium spp. from agricultural sources. The approach could be used in any catchment with similar hydrological characteristics subject to a surface water pathogen contamination risk from grazing livestock.

Enhancement of inflammatory mediator release by beta(2)-adrenoceptor agonists in airway epithelial cells is reversed by glucocorticoid action.

BACKGROUND AND PURPOSE: Due to their potent bronchodilator properties, beta(2)-adrenoceptor agonists are a mainstay of therapy in asthma. However, the effects of beta(2)-adrenoceptor agonists on inflammation are less clear. Accordingly, we have investigated the effects of beta(2)-adrenoceptor agonists on inflammatory mediator release. EXPERIMENTAL APPROACH: Transcription factor activation, and both release and mRNA expression of IL-6 and IL-8 were examined by luciferase reporter assay, elisa and real-time RT-PCR in bronchial human epithelial BEAS-2B cells or primary human bronchial epithelial cells grown at an air-liquid interface. KEY RESULTS: Pre-incubation with beta(2)-adrenoceptor agonists (salbutamol, salmeterol, formoterol) augmented the release and mRNA expression of IL-6 and IL-8 induced by IL-1beta and IL-1beta plus histamine, whereas NF-kappaB-dependent transcription was significantly repressed, and AP-1-dependent transcription was unaffected. These effects were mimicked by other cAMP-elevating agents (PGE(2), forskolin). Enhancement of cytokine release by beta(2)-adrenoceptor agonists also occurred in primary bronchial epithelial cells. Addition of dexamethasone with salmeterol repressed IL-6 and IL-8 release to levels that were similar to the repression achieved in the absence of salmeterol. IL-6 release was enhanced when salmeterol was added before, concurrently or after IL-1beta plus histamine stimulation, whereas IL-8 release was only enhanced by salmeterol addition prior to stimulation. CONCLUSIONS AND IMPLICATIONS: Enhancement of IL-6 and IL-8 release may contribute to the deleterious effects of beta(2)-adrenoceptor agonists in asthma. As increased inflammatory mediator expression is prevented by the addition of glucocorticoid to the beta(2)-adrenoceptor, our data provide further mechanistic support for the use of combination therapies in asthma management.

A study of matrix metalloproteinase expression and activity in atopic dermatitis using a novel skin wash sampling assay for functional biomarker analysis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin condition that is characterized by a defective skin barrier. Despite the well-recognized role of proteases in skin barrier maintenance, relatively little is known of the contribution made by matrix metalloproteinases (MMPs) to the inflammatory process in AD. OBJECTIVES: To test a simple, novel ex vivo bioassay technique in an analysis of the MMPs present in wash samples taken from the skin surface of patients with AD. METHODS: Saline wash samples were collected from eczematous and unaffected areas of the skin of patients with AD and from the skin of normal controls. Wash samples were analysed for their MMP content using a functional peptide cleavage assay, gelatin zymography and an antibody array. RESULTS: Using a functional substrate cleavage assay, skin wash samples from AD lesions were shown to contain 10- to 24-fold more MMP activity than those from normal control skin (P < 0.02) and fivefold more than those from unaffected AD skin (P < 0.05); this activity was inhibited by a broad-spectrum MMP inhibitor Ro 31-9790. Gelatin zymography and antibody array analysis revealed substantial levels of MMP-8 (neutrophil collagenase) and MMP-9 (92-kDa gelatinase) in AD skin wash samples as well as lower levels of MMP-10 (stromelysin 2) and tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2; low levels of MMP-1 (fibroblast collagenase), MMP-3 (stromelysin 1) and TIMP-4 were also detected. CONCLUSIONS: A simple skin wash technique suitable for the quantitative and functional analysis of biomolecules in AD is described. Using this method we show that MMPs, and in particular MMP-8 and MMP-9, represent an important potential component of the pathology of AD. The method is expected to prove useful in advancing our understanding of AD and in identifying biomarkers for the evaluation of new therapies.

Dendritic cells from control but not atopic donors respond to contact and respiratory sensitizer treatment in vitro with differential cytokine production and altered stimulatory capacity.

BACKGROUND: Chemical haptens induce both contact and allergic respiratory disease with dendritic cells (DCs) controlling and directing immune responses in vivo. Contact and respiratory haptens may promote differential cytokine production yet distinguishing these effects in vitro remains difficult due to human donor variability. Objective We sought to determine the effect of atopic status on the ability of DC to respond to contact and respiratory sensitizer treatment in vitro as DC from atopic donors are believed to promote Th2-type responses. METHODS: Enriched DC from control or atopic donors were treated for 4 h with levels of the contact sensitizer 2,4-dinitrochlorobenzene (DNCB) or the respiratory sensitizer trimellitic anhydride (TMA) that did not reduce cell viability. A sensitive intracellular detection technique was used to measure cytokine production, while T cell responses were assessed in a mixed leucocyte reaction. RESULTS: DC from control, non-atopic, donors produced cytokines differentially in response to sensitizer treatment; DNCB treatment significantly increased the production of Th1 cytokines IL-12 and IFN-gamma while TMA induced the production of IL-13. Control donor DC treated with TMA stimulated less in a mixed leucocyte reaction than untreated cells with any response reduced further by blocking IL-13 in culture. However, DC from atopic donors showed no significant alteration in either cytokine production or T cell stimulatory capacity after sensitizer treatment. CONCLUSION: Haptens modulate DC by changing the production of cytokines that may play a role in T cell stimulation and subsequent polarization of the immune response. DC from atopic donors were unresponsive to chemical sensitizer treatment, and may be deficient in inducing divergent T cell responses.