Development of a real time PCR for the detection of Taylorella equigenitalis directly from genital swabs and discrimination from Taylorella asinigenitalis

A discriminatory real time PCR for the detection of Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), and the related species T. asinigenitalis was developed for the direct examination of genital swabs. The 112bp amplicons produced from the two species were discriminated from each other using TaqMan probes labelled with different fluorophores. The TaqMan PCR was shown to be specific for the 16S ribosomal DNA of the two species of taylorella and did not cross-hybridise with the 16S ribosomal DNA of other bacteria tested. Direct amplification from genital swabs was shown to be equally sensitive to that of culture methods. Prevalence in a sample set from The Netherlands was shown to be equivalent to that demonstrated by culture. A companion real time PCR that amplified a fragment of the 16S rDNA gene of equine commensal bacteria was developed to ensure bacterial DNA was extracted from swab material supplied for testing. The use of a rapid and reliable real time PCR for the organism causing CEM should aid the control of this disease.     

A Bayesian meta-analysis of the effects of administering an intra-vaginal (CIDR) device in combination with other hormones on the reproductive performance of cycling,anoestrous and inseminated cows

AIMS: To evaluate the effectiveness of treatment programmes that included controlled internal drug-releasing (CIDR) devices containing progesterone (P4) in improving synchrony of oe- strus, and conception and pregnancy rates in cycling, anoestrous and inseminated dairy cows, using meta-analysis. To describe the difference in response between cycling and anoestrous cows to CIDR-based synchrony programmes.

METHODS: Scientific papers written in the English language between 1989 and 2002 that investigated the effects of treat- ment programmes including CIDR devices on reproductive per- formance in dairy heifers or lactating dairy cows were identified using a computerised literature search. The criteria for inclusion incorporated evidence that treatment allocation was completely randomised; the population studied was lactating dairy cows; and that data were available on submission, conception and pregnancy rates and their associated measures of variability. Re- productive outcomes from 25 synchrony trials (total n= 11,058 cows) were analysed. Summary measures of the effect of treat- ment on reproductive outcome were assessed using fixed- and random-effects Bayesian meta-analysis models.

RESULTS: Treatment programmes including a CIDR device increased the risk of submission in cycling cows (predicted Bayesian RR=2.86, 95% credible interval 1.46–5.67). Compared with controls, synchrony programmes including CIDR devices in cycling dairy cows had no effect on the risk of conception to first service post-treatment (predicted Bayesian RR=1.00, 95% credible interval=0.80-1.24). Compared with controls, synchrony programmes including CIDR devices had no effect on the risk of pregnancy throughout the mating period (pre- dicted Bayesian RR=1.02, 95% credible interval=0.89-1.17). In anoestrous cows, CIDR treatment had no effect on the risk of conception to first service post-treatment and no effect on the risk of pregnancy throughout the mating period, compared with anoestrous, untreated controls (predicted Bayesian RR=0.91 and 0.97, respectively; 95% credible interval=0.68–1.26 and 0.59-1.60, respectively).

CONCLUSION: The results of this meta-analysis showed that synchrony programmes using CIDR devices combined with other hormones reliably enhanced submission rates in lactat- ing dairy cows. The relatively small number of trials with data suitable for analysis and the heterogeneity of results at the indi- vidual trial level limited our ability to confirm either a beneficial or deleterious effect of treatment on conception or pregnancy rates. Further randomised, controlled trials to evaluate the ef- fectiveness of this form of reproductive therapy in commercial dairy farms are needed.     

Soil risk maps – Interpreting soils data for policy makers,agencies and industry

Surface runoff, erosion, compaction and the leaching of potential pollutants from land can degrade the soil resource and damage the water environment, reducing crop yields, causing loss of valuable nutrients and organic matter, together with increasing flood risk. Increasingly, it is recognized that scientific information must be translated into practical tools to change practices and protect the soil and water resource. Working alongside agencies in Scotland, we applied a suite of simple, transparent, rule-based models to identify areas most at risk of exporting sediment and pollutants that may degrade water quality based on field-scale (1:25,000) soil maps. The maps have been used by Scottish Environment Protection Agency, Scottish Water and Scottish Government to assess soil risks to waters from field to regional scale. The work brought scientists together with policy makers, agencies and the water industry to pool their knowledge to apply these practical tools for decision-making. It highlights the need to apply existing knowledge to answer salient questions. All three examples described show that providing the right type of information, which is based on fundamental soils data, can directly influence the implementation of policies, investment and monitoring decisions and provide evidence in support of government. However, this requires both researchers and agency scientists to develop skills as knowledge brokers and to normalize the use of soil data in everyday agency settings.     

Ultrathin films of a polyelectrolyte with layered architecture

Posttransfer modification of preformed Langmuir-Blodgett films of poly(tert-butyl methacrylate) and poly(tert-butyl acrylate) by gaseous hydrochloric acid yields films with layered architecture of poly(methacrylic acid) and poly(acrylic acid), respectively. X-ray reflectivity and infrared spectroscopy confirm monolayer by monolayer transfer of the source polymers and their transformation to acid multilayer assemblies with retention of low surface roughnesses. The incorporation of cross-linking groups into the system offers the possibility for further chemical modification to produce ultrathin films of model networks desirable for bioadsorption studies and as hydrophilic spacing layers for tethered membranes.     

Antibiotic residues in milk samples obtained from cows after treatment for papillomatous digital dermatitis.

OBJECTIVE: To determine whether there would be detectable antibiotic residues in milk obtained from dairy cattle with papillomatous digital dermatitis (PDD) after topical treatment with oxytetracycline. DESIGN: Randomized controlled clinical trial. ANIMALS: 28 lactating Holstein cows with PDD. PROCEDURE: Cows were assigned to 2 treatment groups. Treatment 1 (n = 16) consisted of spraying of PDD lesions with 15 ml of a solution containing 100 mg of oxytetracycline/ml; lesions were sprayed twice daily for 7 days, using a garden sprayer. Treatment 2 (n = 12) consisted of a one-time application of a bandage that consisted of cotton soaked with 20 ml of a solution containing 100 mg of oxytetracycline/ml. Milk samples were obtained before and after treatment and assayed for tetracycline content by use of high-performance liquid chromatography and a commercially available tetracycline screening test. RESULTS: None of the cows in either treatment group had violative residues of oxytetracycline in milk samples. CONCLUSIONS AND CLINICAL RELEVANCE: Producers treating lactating cows that have PDD, via topical application of oxytetracycline solution at the concentrations reported in this study, have a low risk of causing violative antibiotic residues in milk.     

An In Vitro Biomechanical Comparison of Two Fixation Methods for Transverse Osteotomies of the Medial Proximal Forelimb Sesamoid Bones in Horses

OBJECTIVE: This study compared the mechanical properties of the normal intact suspensory apparatus and two methods of fixation for repair of transverse, midbody fractures of the proximal sesamoid bones of adult horses: transfixation wiring (TW) and screws placed in lag fashion (LS). STUDY DESIGN: An in vitro, paired study using equine cadaver limbs mounted in a loading apparatus was used to test the mechanical properties of TW and LS. ANIMAL OR SAMPLE POPULATION: Seventeen paired (13 repaired, 4 normal) equine cadaver limbs consisting of the suspensory apparatus third metacarpal bone, and first and second phalanges. METHOD: The two methods of repair and normal intact specimens were evaluated in single cycle-to-failure loading. Yield failure was defined to occur at the first notable discontinuity (>50 N) in the load-displacement curve, the first visible failure as evident on the videotape, or a change in the slope of the moment-fetlock angle curve. Ultimate failure was defined to occur at the highest load resisted by the specimen. Corresponding resultant force and force per kg of body weight on the suspensory apparatus, fetlock joint moment, and angle of fetlock dorsiflexion were calculated by use of specimen dimensions and applied load. These were compared along with specimen stiffness, and ram displacement. RESULTS: Load on the suspensory apparatus, load on the suspensory apparatus per kg of body weight, moment, applied load, and angle of fetlock dorsiflexion at yield failure were significantly greater for the TW-repaired than for the LS-repaired specimens. A 3 to 5 mm gap was observed before yield failure in most TW-repaired osteotomies. CONCLUSIONS: Transfixation wiring provided greater strength to yield failure than screws placed in lag fashion in single cycle load-to-failure mechanical testing of repaired transverse osteotomized specimens of the medial proximal forelimb sesamoid bone.     

Development and application of molecular methods (PCR) for detection of Tasmanian Atlantic salmon reovirus

Molecular (PCR) diagnostic tests for the detection and identification of aquareovirus in general, and Tasmanian Atlantic salmon reovirus (TSRV) specifically, were developed, and their diagnostic sensitivity and specificity were determined and compared with virus isolation in cell culture. Intralaboratory and interlaboratory comparison of PCR (conventional hemi‐nested RT‐PCR & RT‐qPCR) and virus isolation in cell culture using finfish cell lines, CHSE‐214 and EPC, was carried out for the detection and identification of TSRV using field samples of farmed Atlantic salmon Salmo salar, L. from various aquaculture sites around Tasmania. The interlaboratory comparison of diagnostic methods was carried out between two laboratories, AAHL‐CSIRO and DPIPWE‐Tasmania. A total of 144 fish from nine sites (12–33 fish per site) were sampled from two regions of Tasmania (Tamar River estuary in the north and Huon River estuary in the south‐east) during late spring to early summer of 2009, and the data were analysed using different statistical approaches. The prevalence of TSRV ranged from 6% to 22% in both regions. All the diagnostic methods (data from both laboratories) had high specificity, while the estimated sensitivity varied between tests with RT‐qPCR being the most sensitive (95.2%) method followed by virus isolation and then conventional hemi‐nested RT‐PCR.     

Expression of MHC-I and -II in Uterine Tissue from Early Pregnant Bitches

The aim of the study was to investigate the expression of major histocompatibility complex (MHC)-I and -II in uterine tissues from pregnant and non-pregnant bitches, taken at different time periods after mating. The pregnant bitches were ovariohysterectomized during the pre-implantation (group 1, n = 4), implantation (group 2, n = 7) and placentation stage (group 3, n = 7). Non-pregnant animals in diestrus served as controls (group 4, n = 7). The expression of MHC- I and -II in salpinx, apex, middle horn, corpus uteri and at implantation sites was investigated by immunohistochemistry as well as qualitative and quantitative RT-PCR; MHC-I mRNA was detected in all tissues and with quantitative RT-PCR, and no significant changes were detected until placentation. Immunohistologically, at the apex and corpus site, the average number of MHC-II positive cells increased from the pre-implantation to the post-implantation stage (apex: 1.54 ± 1.21 to 3.82 ± 2.93; corpus: 1.62 ± 1.9 to 5.04 ± 4.95; p < 0.05). The greatest numbers of MHC-II positive cells were observed at placentation sites (6.64 ± 5.9). In parallel, a marked increase in the relative mRNA expression of MHC-II in uterine tissues was assessed from the pre-implantation to the placentation stage (relative to Glycerinaldehyd-3-phosphate-Dehydrogenase (GAPDH): 6.9 ± 9.5, 8.4 ± 5.8, p > 0.05). Immunohistologically, in the salpinx, significantly greater numbers of MHC-II positive cells were found in the tissues of pregnant animals than in the control group (p < 0.05). It is proposed that the increase in MHC-II is pregnancy-related, even though the impact on maintenance of canine pregnancy is still unclear.     

Morphological Examination of the Corpora Lutea from Pregnant Bitches Treated with Different Abortifacient Regimes

Different abortifacient regimes in dogs were analysed for their effect on the pregnancy corpora lutea (CL), namely, prostaglandin F2a analogue cloprostenol (CLO) combined with dopamine agonist cabergoline (CAB), or progesterone (P4) receptor antagonist aglepristone (AGL). Ovaries were collected after 6-10 days of treatment during first trimester. The CL of the control-group showed strong expression of relaxin (RLX), its receptor RXFP1 and enzymes of steroid biosynthesis (HSD) with high peripheral P4-levels. Whereas RXL, RXFP1 and HSD were lowest expressed in the CLO/CAB-group with a massive degeneration of CL and their blood vessels combined with low peripheral P4-level. The AGL-group showed less extensive CL degeneration and more intensive staining of the examined factors than CLO/CAB. In summary, all examined factors are associated with normal luteal function and are useful tools to stage luteolysis. Although both treatments have the same abortive action, their sequence of events on the CL is different.