Sampling and repeatability of radiometric faecal culture in bovine Johne's disease

The repeatability of detection of Mycobacterium avium subsp. paratuberculosis (Map) within and between samplings from 16 paratuberculous dairy cows (13 subclinical; 3 clinical) was investigated by radiometric culture of quadrants of faecal dung pats collected on four to seven occasions over a 10-16-day period. Results were compared to serological status and to pathological and bacteriological findings in multiple tissues obtained at slaughter from 15 of the animals 2-6 weeks after the faecal samplings. From faecal samples taken on 77 occasions over the 2-week period, 296/308 (96%) quadrants were culture positive, with samples from all cattle showing evidence of faecal shedding of Map. Histological lesions typical of paratuberculosis were present in 14 of the 15 cows examined at slaughter, varying in severity from mild (two animals) to moderate (4) and advanced (8), and all predilection tissue sites yielded Map. The negative faecal samples were derived from a single animal that was culture positive in two quadrants on each of the first two (of four) sampling occasions (i.e. culture positive in only 4 of 16 collected quadrants). This animal was found to be histologically negative at slaughter, and culture positive from three of five predilection tissue sites. Faecal samples from cows with subclinical and clinical paratuberculosis, with lesion severity ranging from mild to severe at multiple predilection sites, produced faeces with relatively consistent concentrations of Map within samples. There was significant variation in concentrations of Map between samples in individual animals over a period of 2 weeks, but this did not affect the dichotomous positive-negative culture status for 15 of the 16 cattle. A faecal sample collected non-randomly per rectum thus provides a representative specimen for detection of Map by radiometric culture on a single sampling occasion.     

Thermal antinociception following oral administration of tapentadol in conscious cats

Objective

To evaluate the onset, magnitude and duration of thermal antinociception after oral administration of two doses of tapentadol in cats.

Immunohistochemical detection of canine distemper virus in haired skin, nasal mucosa, and footpad epithelium: a method for antemortem diagnosis of infection.

A reliable antemortem diagnostic method is needed for determining infection with canine distemper virus (CDV). The utility of immunohistochemical detection of CDV antigen was examined was examined for samples of nasal and footpad epithelium and haired skin in dogs with and without detectable CDV antigen in the lung and/or brain. Tissues from 57 dogs at risk of CDV infection were tested. Viral antigen was found in the lung and/or brain of 28 dogs. Among these dogs, viral antigen was demonstrated in the epithelial cells of the nasal mucosa in 24 of 27 dogs, in the footpad epithelium in 24 of 26 dogs, and in the haired skin of the dorsal neck in 26 of 27 dogs. Among the 29 dogs without CDV antigen in either the lung or brain, 1 dog had positive staining for viral antigen in the skin and nasal mucosa. Biopsies of haired skin of the dorsal neck, which is relatively simple to sample, can be used for immunohistochemical testing for acute and subacute infection with CDV.     

A retrospective study of non-suppurative encephalitis in beef cattle from western Canada

Non-suppurative encephalitis occurs sporadically in beef cattle in western Canada, leading to loss of animals. This retrospective study investigated the presence of viral, bacterial, and protozoal antigens or DNA in 37 western Canadian feedlot cattle with non-suppurative encephalitis for which a cause had not been identified. Cases were selected based on the age of the animal (> 7 months), and clinical history of recumbency and depression. The identification of rabies in 1 case stresses the importance of including this viral disease in the list of differential diagnoses. Because there was variation in the severity, distribution, and type of lesions, it is possible that there may be more than 1 cause, but failure to identify an infectious agent might also suggest that non-infectious agents could play a role.     

The lipid compositions of two isolates of Cladosporium cucumerinum do not explain their differences in sensitivity to fungicides which inhibit sterol biosynthesis

Isolate 840905 of Cladosporium cucumerinum, when grown on agar or in liqiud medium, was sensitive to triadimenol, HWG 1608 (tebuconazole), fenpropimorph and pimaricin but relatively resistant to terbinafine. Conversely, isolate 49628 was sensitive to terbinafine but relatively resistant to the other fungicides. Changes in sterol composition following treatment with the fungicides reflected the known modes of action of each fungicide. When individual enantiomers of triadimenol were tested against isolate 840905 the order of activity in reducing mycelial growth was 1 S, 2R > 1R, 2R > 1R, 2S ≈? 1S, 2S, and this was paralleled by the depletion of ergosterol and the appearance of 14α-methyl sterols. Isolate 49628 had a greater saturated:unsaturated fatty acid ratio than did isolate 840905 but no major changes in fatty acid composition of either isolate were induced by fungicide treatment. There appears to be no obvious explanation for the differences in fungicide sensitivity of the isolates in terms of their lipid compositions.     

Co‐infection by Botryosphaeriaceae and Ilyonectria spp. fungi during propagation causes decline of young grafted grapevines

Decline of newly planted, grafted grapevines is a serious viticultural problem worldwide. In the Riverina (New South Wales, Australia), characteristic symptoms include low fruit yields, very short shoots and severely stunted roots with black, sunken, necrotic lesions. To determine the cause, roots and wood tissue from affected plants in 20 vineyards (Vitis vinifera cv. Chardonnay grafted to V. champini cv. Ramsey rootstock) were assayed for microbial pathogens. Ilyonectria spp. (I. macrodidyma or I. liriodendra, producers of phytotoxin brefeldin A, BFA, and cause of black foot disease of grapevines) and Botryosphaeriaceae spp. (predominantly Diplodia seriata) were isolated from rootstocks of 100 and 95% of the plants, respectively. Togninia minima and Phaeomoniella chlamydospora (cause of grapevine Petri disease) were isolated from 13 and 7% of affected plants, respectively. All Ramsey rootstock stems of grafted plants sampled from a supplier nursery were infected with Ilyonectria spp. and D. seriata. Diplodia seriata, but not Ilyonectria spp., was also isolated from 25% of canes sampled from the rootstock source block. Root inoculation of potted, disease‐free Chardonnay plants with Ilyonectria isolates from diseased vineyards caused typical disease symptoms, while co‐inoculation with Botryosphaeriaceae spp. increased disease severity. This is the first study to show that a major cause of young grapevine decline can be sequential infection by Botryosphaeriaceae from rootstock cuttings and Ilyonectria spp. from nursery soil. Although the Petri disease fungi were less common in young declining grafted grapevines in the Riverina, they are likely to contribute to the decline of surviving plants as they mature.     

A perspective on the role of quantitative structure-activity and structure-property relationships in herbicide discovery

BACKGROUND: For the last 15 years the agrochemical industry has focused on using genetic modification to put genes that confer resistance to existing commercial herbicides into crop plants rather than on discovering new herbicides with novel modes of action. The widespread appearance of weeds resistant to those herbicides is now causing the industry to revive their herbicide discovery programs. RESULTS: Elucidation of quantitative structure–activity relationships (QSARs) played a major role in the discovery and development of existing commercial herbicides, but the advent of genetically modified crops has caused published work (at least) in the area to drift from the industrial arena into academic studies. The focus has also turned inward, to refining models for established herbicide targets instead of elucidating new ones. CONCLUSION: This perspective highlights the importance of QSARs and quantitative structure–property relationships (QSPRs) to herbicide discovery in an historical context and provides some guidance as to how they might profitably be applied going forward. Copyright © 2011 Society of Chemical Industry     

Traumatic luxation of the cubital joint (elbow) in dogs: 44 cases (1978-1988).

The medical records from 44 dogs with traumatic luxation of the cubital joint were reviewed. Closed reduction was performed in 35 dogs, and open reduction in 9 dogs. Excellent or good results were achieved in 31 of 35 dogs (88.6%) treated by closed reduction and in 5 of 9 dogs (55.6%) treated by open reduction. Collateral ligament repair, performed in 5 dogs, did not appear to affect the prognosis. Factors such as body weight and type and duration of external coaptation also did not appear to influence the outcome. Increased dysfunction associated with open reduction most likely was caused by the chronic nature of the dislocation, iatrogenic damage to the articular cartilage during reduction, or both. A good prognosis for return to normal function with minimal gait abnormality can be expected in most cases of traumatic luxation of the cubital joint treated by early closed reduction.