Scoping review of approaches for improving antimicrobial stewardship in livestock farmers and veterinarians.

BACKGROUND: There has been an increased focus on antimicrobial stewardship (AMS) within the animal health domain (World Health Organization, 2015; O'Neill, 2016). Evidence of the effectiveness of interventions designed to enhance AMS is essential to support the development of this practice. This scoping review summarises for the first time the extent, range, and nature of global research activity on approaches for improving AMS in farmers and veterinarians involved in livestock farm animal management, health & well-being. METHODS: In November 2017 AGRICOLA, CAB Abstracts, EMBASE, MEDLINE, VetsRev and the Web of Science were searched. Studies were selected by two reviewers with 30 % of excluded and all included studies being independently reviewed by another reviewer. Inclusion criteria were primary studies or literature reviews focusing on antimicrobial use (AMU) in farming or veterinary practices for food-producing animals. Outcomes were changes in, or factors influencing farmers' or veterinarians' AMS. Exclusion criteria were studies on wild or companion animals or reports of the level of, rather influencing factors for AMS, or knowledge/awareness related to antimicrobial resistance (AMR). Study characteristics and relevant outcomes were extracted, identified facilitators and barriers grouped into categories, and a narrative synthesis was conducted. The PRISMA checklist extension for scoping reviews was used to guide the reporting of the review. RESULTS: 52 studies were included in the review; seven were intervention studies and 45 were studies of facilitators and barriers of AMU or antimicrobial prescribing (AMP). Studies were predominantly from high-income countries with only seven studies from low- or middle-income countries. Evidence for effective interventions was limited in terms of number of studies and robustness of evidence. There was some effect for an educational intervention in European cattle farmers and the Yellow Card scheme for Danish pig farmers. Significant facilitators to veterinarians' prudent AMP, in the cattle and pig livestock sector, included education, veterinarians' positive attitudes towards AMU reduction, and diagnostic. For farmers, significant facilitators to reduction of AMU were most frequently related to farming management practices. CONCLUSION: This review describes a scarcity of robust study designs and recommendations can be confidently made for better designed studies. Furthermore, greater consideration needs to be given to the outcome measures used in such studies. Nevertheless, the review summarises the evidence on the effectiveness of interventions and significant facilitators to farmers' and veterinarians' AMS, which can provide best currently available evidence to guide improvements in different livestock sectors.

Improving the identification of hydrologically sensitive areas using LiDAR DEMs for the delineation and mitigation of critical source areas of diffuse pollution.

Identifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants. A new GIS-based HSA Index is presented that improves the identification of HSAs at the sub-field scale by accounting for microtopographic controls. The Index is based on high resolution LiDAR data and a soil topographic index (STI) and also considers the hydrological disconnection of overland flow via topographic impediment from flow sinks. The HSA Index was applied to four intensive agricultural catchments (~7.5-12km(2)) with contrasting topography and soil types, and validated using rainfall-quickflow measurements during saturated winter storm events in 2009-2014. Total flow sink volume capacities ranged from 8298 to 59,584m(3) and caused 8.5-24.2% of overland-flow-generating-areas and 16.8-33.4% of catchment areas to become hydrologically disconnected from the open drainage channel network. HSA maps identified 'breakthrough points' and 'delivery points' along surface runoff pathways as vulnerable points where diffuse pollutants could be transported between fields or delivered to the open drainage network, respectively. Using these as proposed locations for targeting mitigation measures such as riparian buffer strips reduced potential costs compared to blanket implementation within an example agri-environment scheme by 66% and 91% over 1 and 5years respectively, which included LiDAR DEM acquisition costs. The HSA Index can be used as a hydrologically realistic transport component within a fully evolved sub-field scale CSA model, and can also be used to guide the implementation of 'treatment-train' mitigation strategies concurrent with sustainable agricultural intensification.

Inactivation and injury assessment of Escherichia coli during solar and photocatalytic disinfection in LDPE bags.

Solar disinfection (SODIS) of Escherichia coli suspensions in low-density polyethylene bag reactors was investigated as a low-cost disinfection method suitable for application in developing countries. The efficiency of a range of SODIS reactor configurations was examined (single skin (SS), double skin, black-backed single skin, silver-backed single skin (SBSS) and composite-backed single skin) using E. coli suspended in model and real surface water. Titanium dioxide was added to the reactors to improve the efficiency of the SODIS process. The effect of turbidity was also assessed. In addition to viable counts, E. coli injury was characterised through spread-plate analysis using selective and non-selective media. The optimal reactor configuration was determined to be the SBSS bag (t(50)=9.0min) demonstrating the importance of UVA photons, as opposed to infrared in the SODIS disinfection mechanism. Complete inactivation (6.5-log) was achieved in the presence of turbidity (50NTU) using the SBSS bag within 180min simulated solar exposure. The addition of titanium dioxide (0.025gL(-1)) significantly enhanced E. coli inactivation in the SS reactor, with 6-log inactivation observed within 90min simulated solar exposure. During the early stages of both SODIS and photocatalytic disinfection, injured E. coli were detected; however, irreversible injury was caused and re-growth was not observed. Experiments under solar conditions were undertaken with total inactivation (6.5-log) observed in the SS reactor within 240min, incomplete inactivation (4-log) was observed in SODIS bottles exposed to the same solar conditions.

Elimination of water pathogens with solar radiation using an automated sequential batch CPC reactor.

Solar disinfection (SODIS) of water is a well-known, effective treatment process which is practiced at household level in many developing countries. However, this process is limited by the small volume treated and there is no indication of treatment efficacy for the user. Low cost glass tube reactors, together with compound parabolic collector (CPC) technology, have been shown to significantly increase the efficiency of solar disinfection. However, these reactors still require user input to control each batch SODIS process and there is no feedback that the process is complete. Automatic operation of the batch SODIS process, controlled by UVA-radiation sensors, can provide information on the status of the process, can ensure the required UVA dose to achieve complete disinfection is received and reduces user work-load through automatic sequential batch processing. In this work, an enhanced CPC photo-reactor with a concentration factor of 1.89 was developed. The apparatus was automated to achieve exposure to a pre-determined UVA dose. Treated water was automatically dispensed into a reservoir tank. The reactor was tested using Escherichia coli as a model pathogen in natural well water. A 6-log inactivation of E. coli was achieved following exposure to the minimum uninterrupted lethal UVA dose. The enhanced reactor decreased the exposure time required to achieve the lethal UVA dose, in comparison to a CPC system with a concentration factor of 1.0. Doubling the lethal UVA dose prevented the need for a period of post-exposure dark inactivation and reduced the overall treatment time. Using this reactor, SODIS can be automatically carried out at an affordable cost, with reduced exposure time and minimal user input.

Comparative in vitro cytotoxicity study of carbon nanotubes and titania nanostructures on human lung epithelial cells.

The aim of this study is to assess in vitro cytotoxic effects of titania nanostructures and carbon nanotubes (CNTs) by exposing A549 lung epithelial cell line to these materials. Titania nanotubes (TiNTs) were grown by hydrothermal treatment of TiO(2) nanoparticles, followed by annealing them at 400°C. The titania nanostructures obtained on annealing (mixture of nanotubes and nanorods) were hollow and open ended, containing 3-5 layers of titania sheets, with an internal diameter ∼3-5 nm and external diameter ∼8-10 nm, and a specific surface area of 265 m(2)/g. As-supplied single walled (SWCNTs) and microwave plasma enhanced chemical vapour deposition (MPCVD) grown multi walled carbon nanotubes (MWCNTs) were used in this study. The lengths and diameters of the SWCNTs were 5-10nm and 0.5-3 nm respectively. The lengths and diameters of the MWCNTs were 25-30 µm and 10-30 nm respectively. The cell viability was evaluated using the MTT (3-(4,-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium) assay. No significant cytotoxic effects of titania nanostructures were observed over a period of a week of testing time, while the presence of CNTs in some cases demonstrated significant cytotoxic effects. Finally, possible reason of cytotoxicity is discussed in the light of microstructures of materials.

Photocatalytic inactivation of Cryptosporidium parvum on nanostructured titanium dioxide films.

Control of waterborne gastrointestinal parasites represents a major concern to water industries worldwide. In developed countries, pathogens in drinking water supplies are normally removed by sand filtration followed by chemical disinfection. Cryptosporidium spp. are generally resistant to common disinfection techniques and alternative control strategies are being sought. In the current study, the photocatalytic inactivation of C. parvum oocysts was shown to occur in buffer solution (78.4% after 180 min) and surface water (73.7% after 180 min). Viability was assessed by dye exclusion, excystation, direct examination of oocysts and a novel gene expression assay based on lactate dehydrogenase 1 (LDH1) expression levels. Collectively, this confirmed the inactivation of oocysts and scanning electron microscopy (SEM) confirmed cleavage at the suture line of oocyst cell walls, revealing large numbers of empty (ghost) cells after exposure to photocatalytic treatment.

Electrochemical growth of titanium oxide nanotubes: the effect of surface roughness and applied potential.

Aligned titanium dioxide nanotubes may be grown on the surface of titanium metal by electrochemical oxidation in the presence of fluoride ion. There are a number of salient parameters that have been reported to affect the nanotube growth i.e., the nature, pH and concentration of the fluoride electrolyte, the cell potential and process time for anodisation. Furthermore, it has been reported that the nanotubes as grown are amorphous and can be converted to a mixture of anatase and rutile crystalline phases by heat treatment at elevated temperatures. There have been no studies reported investigating the effect of surface roughness of the parent titanium metal on nanotube growth. In this work the electrochemical growth of titanium oxide nanotubes on titanium foil was investigated using an ammonium fluoride/ammonium sulphate electrolyte. The results confirm that the anodisation potential controls pore diameter. The surface coverage of nanotubes was dependent on the surface roughness of the parent titanium metal. AFM measurements on untreated titanium foil showed relatively high microscale roughness and low nanoscale roughness. SEM analysis of these samples showed nanotube growth to be confined to depressions or valleys on the surface and the nanotubes were of uniform pore diameter. Mechanically polishing the surface of the parent titanium decreased the microscale roughness and increased the nanoscale roughness which, resulted in more uniform surface coverage. However, this led to an increased variation in pore diameter and shape of the nanotubes. XRD was used to determine crystal structure before and after annealing at 460 degrees C.

Injury to the axillary artery, a complication of fixation using a locking plate.

The proximal humerus internal locking system is an internal fixation device consisting of a low-profile plate and locking screws, which is used for the fixation of three- and four-part fractures of the proximal humerus. We describe a case in which the screws cut out of the humeral head causing injury to the axillary artery necessitating urgent removal of the implant.

An impedimetric sensor for monitoring the growth of Staphylococcus epidermidis.

There is a need for accurate, reliable methods of detecting bacteria for a range of applications. One organism that is commonly found in urinary catheter infections is Staphylococcus epidermidis. Current methods to determine the presence of an infection require the removal of catheters. An alternative approach may be the use of in vivo sensing for bacterial/biofilm detection. This work investigates electrical impedance spectroscopy to detect the growth of Staphylococcus epidermidis RP62A on gold electrodes fabricated on a flexible substrate. Impedance spectra measured during biofilm formation on the electrode surface showed an increase in charge transfer resistance (RCT) with time.

The foot-and-mouth disease epidemic in Dumfries and Galloway, 2001. 2: Serosurveillance, and efficiency and effectiveness of control procedures after the national ban on animal movements.

After the foot-and-mouth disease (FMD) epidemic in Dumfries and Galloway in south-west Scotland in 2001, serosurveillance of sheep remaining in the 3 km radius Protection Zones around Infected Premises (IPS), and within a 10 km radius of IPS, revealed no evidence of infection. The epidemic was brought under control by a range of traditional techniques: slaughter of all animals on IPS and of veterinary-assessed Dangerous Contacts (DCS), movement restrictions, biosecurity, tracing of potential sources and spread of virus, and surveillance of At-Risk premises. Novel pre-emptive slaughter of FMD-susceptible animals on premises contiguous to IPS, and small ruminants and pigs on premises within 3 km of IPSs, commenced after the epidemic had peaked. Most of the traditional control procedures were undertaken quickly and with appropriate priority. Animals on IPS were usually slaughtered within one day of confirmation, and veterinary-assessed DCS within two days of confirmation of relevant IPS (a median of two days). The pre-emptive contiguous and 3 km culls took somewhat longer (medians of five and 17 days, respectively). IPS were most commonly identified as a result of reporting by farmers or their veterinarians (72 per cent of IPS); veterinary clinical patrols identified 16 per cent, while veterinary assessment of DCS and tracing each identified 5 per cent. No evidence of infection was found on any pre-emptively contiguously culled premises, and IPS were declared only on three 3 km cull premises. The time from estimated first lesion to end of slaughter on an IP was found, by regression analysis, to be a key component in effective control, manifested by a reduction in the estimated dissemination rate (EDR); there was little evidence that the intensity of contiguous culling affected the EDR. Patrols and serological surveillance of residual animals within 10 km of IPS, supported by more extensive evidence from elsewhere in the UK, suggested that cryptic infection in sheep was not widespread. Ultimately, there was insufficient evidence to support the effectiveness of 3 km pre-emptive culling as a control procedure.

The foot-and-mouth disease epidemic in Dumfries and Galloway, 2001. 1: Characteristics and control.

The foot-and-mouth disease epidemic in Dumfries and Galloway in south-west Scotland comprised 177 infected premises (IPS) in 24 geographical clusters, and ran from March 1 until May 23, 2001. Initial seeding of infection was by livestock (predominantly sheep) that had passed through Longtown Market in adjacent Cumbria. Thereafter, spread within existing, and to new, clusters was associated with the movement of personnel and vehicles, with further transmission by Longtown Market contacts and across common boundaries. Sheep and cattle premises were equally affected. After the peak of the epidemic at the beginning of the third week of March, the upper possible limit of attack rates for premises contiguous to IPS, and premises within 3 km, remained around 10 per cent, with new clusters emerging more distantly. Control procedures included traditional methods of slaughter of all animals on IPS and, elsewhere, of animals considered by veterinary assessment to be Dangerous Contacts; movement restrictions; enhanced biosecurity; tracing of potential sources and spread of virus; and surveillance of premises subsequently considered at risk. These methods were supplemented by the novel pre-emptive slaughter, without veterinary assessment, of all susceptible livestock on all premises contiguous to IPS, and of small ruminants and pigs within a 3 km radius (known as the Protection Zone) around IPS. In total, approximately 80,000 cattle, 564,000 sheep, 2600 pigs and 500 goats were slaughtered, the novel methods accounting for 29 per cent of all cattle and 75 per cent of all sheep killed. Limitations of existing national databases necessitated the development of local databases to administer control procedures.

Monitoring genotoxicity during the photocatalytic degradation of p-nitrophenol.

p-Nitrophenol is a common structural unit of many pesticides and was chosen as a model compound to monitor genotoxicity during photocatalytic degradation. The genotoxicity of p-nitrophenol (PNP) and its breakdown products was measured using a bioluminescent bacterial bioassay, Vitotox. The genotoxic potential decreased with the concomitant photocatalytic degradation of the parent PNP concentration. The rate of genotoxicity reduction was slower than the rate of removal of the parent PNP, due to the formation of genotoxic by-products. After 6 h of photocatalytic treatment the total genotoxicity was removed. These results indicate that bioassays can be used as a simple and highly sensitive method for monitoring the general toxicity of chemical pollutants before, during and after photocatalytic treatment or other destructive processes.

The effect of the anorectic agent, d-fenfluramine, and its primary metabolite, d-norfenfluramine, on intact human platelet serotonin uptake and efflux.

Dexfenfluramine, a drug formerly prescribed for treatment of obesity, caused heart valve damage and pulmonary hypertension in some people. The cause of the toxicity has not been defined, but 5-HT has been implicated. The objective of this study was to evaluate the effect of the anorectic agent, d-fenfluramine, and its major metabolite, d-norfenfluramine, on intact human platelet serotonin (5-HT) transport in vitro. The effects of d-fenfluramine and d-norfenfluramine on platelet uptake and efflux of 3H-5-HT were measured in buffer at pH 6.7, to optimize serotonin transporter (SERT) function, and at pH 7.4. Uptake of 3H-5-HT at pH 6.7 and 7.4 was inhibited by both agents at micro m concentrations (IC50, d-fenfluramine approximately 3 microM; d-norfenfluramine approximately 10 microM). However, no efflux of 3H-5-HT from labeled platelets at either pH 6.7 or 7.4 occurred at similar concentrations of d-fenfluramine or d-norfenfluramine. With inhibition of platelet dense granule 3H-5-HT uptake by reserpine, efflux of 3H-5-HT was observed at pH 6, but not at pH 7.4. Fluoxetine, a SERT inhibitor, was a more potent inhibitor of uptake (IC50 0.05 microM) than d-fenfluramine, but the anorectic agent, phentermine, had no effect. Therefore, d-fenfluramine and d-norfenfluramine inhibit human platelet uptake of 5-HT in vitro at tissue concentrations attainable in vivo, but they do not stimulate 5-HT efflux due to dense granule sequestration. Inhibition of platelet 5-HT uptake may play a role in the cardiopulmonary toxicity of d-fenfluramine, but other factors probably contribute, since similar toxicity has not been observed with fluoxetine.

Early dissemination of foot-and-mouth disease virus through sheep marketing in February 2001.

The results of epidemiological investigations suggest that livestock on up to 79 premises, spread widely throughout the British Isles, may have been exposed to infection by foot-and-mouth disease (FMD) virus by the movement of infected sheep before the first case of the disease was confirmed at an abattoir in Essex on February 20, 2001. A further 36 premises may have been infected by this route before the national livestock movement ban was imposed on February 23.

Percutaneous ablation of an internal iliac aneurysm using tissue adhesive.

We report the percutaneous injection of tissue adhesive (Tisseal, Immuno, Vienna, Austria) to ablate a 12-cm internal iliac aneurysm. The complex history of this lesion included previous surgery for a ruptured aortic aneurysm, attempted repair of the internal iliac aneurysm, and several embolization procedures. These factors precluded further open repair or transcatheter techniques and dictated the choice of a more direct approach.

Epinephrine correction of impaired platelet thromboxane receptor signaling.

This study evaluated the mechanism of epinephrine potentiation of platelet secretion induced by thromboxane A(2) (TXA(2)). Dog platelets that do not secrete in response to TXA(2) alone (TXA(2)-) were compared with dog platelets that do secrete (TXA(2)+) and with human platelets. TXA(2)- platelets had impaired TXA(2) receptor (TP receptor)-G protein coupling, indicated by 1) impaired stimulated GTPase activity, 2) elevated basal guanosine 5'-O-(3-thiotriphosphate) binding, and 3) elevated Galpha(q) palmitate turnover that was corrected by preexposure to epinephrine. Kinetic agonist binding studies revealed biphasic dog and human platelet TP receptor association and dissociation. TXA(2)- and TP receptor-desensitized TXA(2)+ dog and human platelets had altered ligand binding parameters compared with untreated TXA(2)+ or human platelets. These parameters were reversed, along with impaired secretion, by epinephrine. Basal phosphorylation of TXA(2)- platelet TP receptors was elevated 60% and was normalized by epinephrine. Epinephrine potentiates platelet secretion stimulated by TXA(2) by reducing basal TP receptor phosphorylation and facilitating TP receptor-G protein coupling in TXA(2)- platelets and, probably, in normal platelets as well.

Merkel cell carcinoma of the abdominal wall.

Merkel cell carcinoma is a rare highly malignant tumour. There have been previous descriptions of the CT appearances of this tumour, but to our knowledge this is the first MRI description. MRI may be a more sensitive method of initial evaluation of the local extension of the primary tumour.