Salmonella isolated from feeds and feed ingredients during the period 1982-1988: animal and public health implications

The prevalence of Salmonella in southern Africa in farm feeds and by-products of animal origin during 1982-1988 was determined. Salmonella occurred in 5.18% of the farm feed samples and in 9.54% of the by-product samples. Different serovars were isolated, some only once. The findings underestimate the true prevalence of Salmonella in farm feeds and by-products, and is representative of only the most severely contaminated products. The epidemiology of salmonellosis is discussed with special reference to the importance of multiple resistance to antibiotics, the increase in the number of cases of salmonellosis worldwide and "Salmonella free" feeds and foods. More detailed research on the role of farm feeds in the epidemiology of salmonellosis is required. Efforts should be made to increase awareness of the problem, to improve quality management at farm feed production plants and to develop efficient systems to monitor the hygienic safety of feeds and foods.     

Photodynamic therapy of feline cutaneous squamous cell carcinoma using a newly developed liposomal photosensitizer: preliminary results concerning drug safety and efficacy

BACKGROUND: Squamous cell carcinomas are common skin tumors in cats. We investigated photodynamic therapy (PDT) using a new liposomal photosensitizer as a minimally invasive, effective treatment that can be easily performed while achieving good cosmetic results. AIM: The goal of this study was to assess and describe possible toxicities using a liposomal formulation of the photosensitizer meta-(Tetrahydroxyphenyl)Chlorin (m-THPC) and investigate if favorable pharmacokinetics translate into favorable tumor response and control. ANIMALS: Eighteen client-owned cats with 20 spontaneous cutaneous squamous cell carcinomas were included in the study. METHODS: PDT was performed using a new, liposomal formulation of the photosensitizer. Toxicity, tumor response, and tumor control were evaluated retrospectively. RESULTS: No general adverse effects were observed in cats treated with the new liposomal formulation. Mild local toxicity such as erythema and edema were seen in 15% of the patients. All cats responded to therapy, with a complete response rate of 100%. The overall 1-year control rate was 75%. The tumor recurrence rate was 20% with a median time to recurrence of 172.25 +/-87.1) days. CONCLUSIONS AND CLINICAL IMPORTANCE: A new liposomal photosensitizer was successfully used for squamous cell carcinoma in cats and was well tolerated. There were no systemic adverse effects observed with the liposomal formulation. The favorable pharmacokinetics of the liposomal drug resulted in a favorable tumor response.     

Boots on the ground: construction management of urbanizing irrigated farm land

Since its inception, in 1885 the Buckeye Irrigation Canal has delivered irrigation water in the Buckeye Valley, southwest of Phoenix, Arizona. Throughout its tenure the owners of the canal have consulted design professionals for its engineering needs. Early engineering in 1885 established canal alignments, delivery points and channel capacity. Until recently, the Buckeye Valley was a rural area relying on agricultural revenues to drive the local economy. Now, due to the recent housing market boom new homes started springing up like corn in September driving the existing open-channel laterals below grade into a patch work redesigned pipeline system. Because of these changes, professional construction managers are an enormous benefit to the Buckeye Water Conservation and Drainage District (BWCDD), the owner of the canal.As a result of this urbanization, contractors working for home developers are installing irrigation pipelines and systems with the focus of completing the project as quickly and economically as possible. Irrigation providers, on the other hand, focus on meeting the agricultural needs of their clients with consistent and uninterrupted water delivery. The services of a professional construction manager help both entities achieve their respective goals, shield BWCDD from construction of sub-par systems and risk, maintain uninterrupted service to growers and providing the technical expertise to communicate with both BWCDD and contractors.Construction managers provide a number of services to rural irrigation districts under-going urbanization. They team with an irrigation district by:

• Understanding irrigation design concepts;
• Understanding agricultural demands;
• Providing a thorough knowledge of construction practices and standards;
• Creating long-term design functionality;
• Reducing stress on and increasing productivity of personnel;
• Coordinating construction activities with water deliveries;
• Verifying constructed facilities perform as designed, which reduces maintenance costs.

Construction managers represent an irrigation district in the field by:

• Reviewing development plans for adherence to current construction standards and practices and coordinates construction schedules with water delivery needs;
• Observing construction for proper installation;
• Clarifying installers understanding of plans and specifications;
• Coordinating interruptions in service;
• Tracking multiple construction projects;
• Explaining agricultural practices to contractor personnel;
• Providing a single point of contact for construction related correspondence.

These “boots on the ground” create a local presence with a focus on the specific needs unique to an irrigation district. They provide a liaison while minimizing the impact to its growers.This paper will discuss the strain of urbanization on an irrigation district and the benefits of an engineering consulting firm to manage construction projects. The benefits include expertise, technical resources, design capability, coordination and inspection. Construction managers can help protect an irrigation district from being overwhelmed by rapid urbanization.     

How lambs control infection with Ostertagia circumcincta

Two of the most important questions for immunologists studying nematode infections are what effect does the host response have on the parasite and which components of the host response are responsible for these effects. The number of nematodes and the mean length of adult female Ostertagia circumcincta was measured in over 500 6-7 month old lambs of the Scottish Blackface breed. Quantitative genetic analyses indicated that there was substantial genetic variation among lambs in faecal egg counts and in worm length but the analyses provided no evidence for genetic variation in worm numbers. Separate analyses have shown a strong relationship between decreased worm length and decreased worm fecundity. Therefore, genetic resistance in lambs appears to be due to control of worm growth and not to control of worm numbers. The only immune response that is consistently associated with reduced worm length is the IgA response to fourth-stage larvae. The association is remarkably strong. After allowing for the influence of worm number on worm length (density-dependence) essentially all of the variation among deliberately infected lambs in worm length can be accounted for, in a statistical sense, by variation in the strength and specificity of the local IgA response. Therefore, the IgA mediated suppression of worm growth and fecundity appears to be the major mechanism of resistance to O. circumcincta in lambs.     

Effect of hyperbaric oxygen treatment on incorporation of an autogenous cancellous bone graft in a nonunion diaphyseal ulnar defect in cats

OBJECTIVE: To determine whether hyperbaric oxygen treatment (HBOT) would affect incorporation of an autogenous cancellous bone graft in diaphyseal ulnar defects in cats. ANIMALS: 12 mature cats. PROCEDURE: Bilateral nonunion diaphyseal ulnar defects were created in each cat. An autogenous cancellous bone graft was implanted in 1 ulnar defect in each cat, with the contralateral ulnar defect serving as a nongrafted specimen. Six cats were treated by use of hyperbaric oxygen at 2 atmospheres absolute for 90 minutes once daily for 14 days, and 6 cats were not treated (control group). Bone labeling was performed, using fluorochrome markers. Cats were euthanatized 5 weeks after implanting, and barium sulfate was infused to evaluate vascularization of grafts. Ulnas were evaluated by use of radiography, microangiography, histologic examination, and histomorphometric examination. RESULTS: Radiographic scores did not differ between treatment groups. Microangiographic appearance of grafted defects was similar between groups, with all having adequate vascularization. Differences were not observed between treated and nontreated groups in the overall histologic appearance of decalcified samples of tissue in grafted defects. Mean distance between fluorescent labels was significantly greater in cats given HBOT than in nontreated cats. Median percentage of bone formation in grafted defects was significantly greater in cats given HBOT. CONCLUSIONS: Hyperbaric oxygen treatment increased the distance between fluorescent labels and percentage of bone formation when incorporating autogenous cancellous bone grafts in induced nonunion diaphyseal ulnar defects in cats, but HBOT did not affect revascularization, radiographic appearance, or qualitative histologic appearance of the grafts.     

Immunity,safety and protection of an Adenovirus 5 prime - Modified Vaccinia virus Ankara boost subunit vaccine against Mycobacterium avium subspecies paratuberculosis infection in calves

Vaccination is the most cost effective control measure for Johne’s disease caused by Mycobacterium avium subspecies paratuberculosis (MAP) but currently available whole cell killed formulations have limited efficacy and are incompatible with the diagnosis of bovine tuberculosis by tuberculin skin test. We have evaluated the utility of a viral delivery regimen of non-replicative human Adenovirus 5 and Modified Vaccinia virus Ankara recombinant for early entry MAP specific antigens (HAV) to show protection against challenge in a calf model and extensively screened for differential immunological markers associated with protection. We have shown that HAV vaccination was well tolerated, could be detected using a differentiation of infected and vaccinated animals (DIVA) test, showed no cross-reactivity with tuberculin and provided a degree of protection against challenge evidenced by a lack of faecal shedding in vaccinated animals that persisted throughout the 7 month infection period. Calves given HAV vaccination had significant priming and boosting of MAP derived antigen (PPD-J) specific CD4⁺, CD8⁺ IFN-γ producing T-cell populations and, upon challenge, developed early specific Th17 related immune responses, enhanced IFN-γ responses and retained a high MAP killing capacity in blood. During later phases post MAP challenge, PPD-J antigen specific IFN-γ and Th17 responses in HAV vaccinated animals corresponded with improvements in peripheral bacteraemia. By contrast a lack of IFN-γ, induction of FoxP3+ T cells and increased IL-1β and IL-10 secretion were indicative of progressive infection in Sham vaccinated animals. We conclude that HAV vaccination shows excellent promise as a new tool for improving control of MAP infection in cattle.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0112-9) contains supplementary material, which is available to authorized users.     

A comparison of haemodynamic and vasoconstrictory responses in sheep with a toxic fraction from Pachystigma pygmaeum and with the plant material

ST-segment changes in the ECG, which are an indication of acute myocardial ischaemia, are obtained when a small quantity of an extract from dried Pachystigma pygmaeum is injected intravenously in sheep. When the fraction was injected subcutaneously, animals reached a crisis after about 5 h, with low values of stroke volumes and high values for pulmonary arterial pressures, pulmonary vascular resistances and heart rates. The haemodynamic changes are an indication of the development of pump failure of the heart. In sheep, injected subcutaneously with the toxic fraction, as well as for sheep dosed with plant material through rumen fistula, increased serum levels for thromboxane and increased or decreased levels for prostacycline were observed. The experimental results are interpreted as being an indication that these prostaglandines may be involved in the development of gousiekte by impeding cardiopulmonary function as a result of coronary and pulmonary vasoconstriction. The sudden death observed in some gousiekte sheep may be due to myocardial ischaemia and associated arrhythmias.