Effects of an S6 strain of Mycoplasma gallisepticum inoculation before beginning of lay on the leukocytic characteristics of commercial layers

A clinical study was conducted on commercial layers housed in biological isolation units, within which exogenous stress factors potentially affecting bird performance were minimized. This set-up was devised in order to assess how a pre-lay inoculation of S6 strain Mycoplasma gallisepticum affects the leukocytic properties of laying chickens. Previous studies have demonstrated relative decreases in lymphocyte and relative increases in heterophil percentages in birds infected with other strains of Mycoplasma gallisepticum. However, current results showed that the differential percentages of lymphocytes were decreased, whereas those of heterophils were increased, in both sham-inoculated control birds and birds inoculated with S6 Mycoplasma gallisepticum between 19 and 26 wk of age. This study clearly shows that a pre-lay inoculation of S6 Mycoplasma gallisepticum alone had no apparent effect on the leukocyte profile of commercial layers housed in biological isolation units.     

产气荚膜梭菌型特异性多重PCR的研究

建立了一种简单且具有型特异性的产气荚膜梭菌的多重PCR诊断方法.结果表明,该PCR特异性好,只有产气荚膜梭菌呈现阳性,被检验的其他7种梭菌以及大肠杆菌、葡萄球菌和多杀性巴氏杆菌均为阴性.该PCR具有较高的敏感性,最小检测量为4.2×105 CFU/mL,单个菌落稀释10倍后也能被检测出,适用于医院、防疫和兽医诊断等部门,具有重要的公共卫生意义.     

Characterization of the in vitro adhesion of Actinobacillus pleuropneumoniae to swine alveolar epithelial cells

Actinobacillus pleuropneumoniae biovar 1 serotypes 2, 5a, 9 and 10 strains were tested for their ability to adhere to alveolar epithelial cells in culture. For the serotypes 5a, 9 and 10 strains, optimal adherence was observed after growth of bacterial cells in a NAD-restricted medium (0.001% NAD). This condition was also associated with the expression of a 55 kDa outer membrane protein (OMP) and of fimbriae. For the serotype 2 strain, adherence and expression of fimbriae and a 55 kDa OMP was less influenced by the growth conditions. The N-terminal amino acid sequence of the 55 kDa OMP had no homology with any known sequence, suggesting that it is an as yet unknown protein. Adherence capabilities were significantly reduced following treatment of the bacteria with proteolytic enzymes or heat. These findings suggest that proteins are involved in adhesion. The hydrophobic bond-breaking agent tetramethylurea was unable to inhibit the adherence of A. pleuropneumoniae to alveolar epithelial cells. Treatment of the bacteria with sodium metaperiodate resulted in lower adhesion scores for the serotypes 2 and 9 strains but the inhibition of adhesion was clearly lower than after treatment with proteolytic enzymes. This indicates that, besides proteins, carbohydrates might also be involved in adhesion of A. pleuropneumoniae to alveolar epithelial cells. The finding that inhibition of adhesion was very high when bacteria were treated with a combination of sodium metaperiodate and pronase also suggests that more than one adhesin is involved.     

Relation between Habitual Diet and Canine Mammary Tumors in a Case-Control Study

In the present case-control study several dietary and nutritional factors were investigated to determine if a relationship exists between diet and development of mammary tumors in female dogs. Control female dogs (n = 86) were compared with a case group of dogs (n = 102) with dysplasias or tumors of the mammary gland. A questionnaire providing information on the dog's body conformation and dietary and reproductive histories was answered by the owners. Serum selenium and retinol concentrations and the fatty acid profile in subcutaneous adipose tissue were analyzed as indicators of nutritional status. Obesity at 1 year of age and 1 year before the diagnosis of mammary nodules was found to be significantly related to a higher prevalence of mammary tumors and dysplasias. The intake of homemade meals (compared to that of commercial foods) was also significantly related to a higher incidence of tumors and dysplasias. Other significant risk factors were a high intake of red meat, especially beef and pork, and a low intake of chicken. The subcutaneous fatty acid profile and the serum selenium concentration were not significantly different in the cases and the controls, with the exception of C18:1 fatty acid (oleic acid) content, which was significantly higher in the cases than in healthy controls. Serum retinol concentration was significantly lower in the cases than in the controls. In the multivariate analysis, older age, obesity at 1 year of age, and a high red meat intake were independently and significantly associated with the risk of developing mammary tumor and dysplasias.     

SPIKE and D-PIKE: innovative experiences that engage students early and position them to succeed in food-supply veterinary medicine

Recent trends in urbanization of the population, increased need for bio-security on large farms, and more food-animal or mixed-animal practitioners approaching retirement age are forcing a renewed focus on recruiting and training veterinary students with an interest in production-animal medicine. The increasing number of veterinary students coming from urban backgrounds has led to a need to expose these students to standard animal-production practices and to interest them in a career involving food animals. This article describes one such program developed at Iowa State University, in which 14 students obtained hands-on experience in all aspects of swine and dairy production across a wide sampling of herd size, housing style, bio-security levels, and production phases. The participating students, ranging from senior undergraduates to third-year veterinary students, gained valuable insight not only into daily farming practices but also the knowledge and skills necessary to provide quality veterinary care to these clients. The first year of this program has yielded positive feedback from all participants, including the veterinary practices, private producers, corporate sponsors, and students. Current applicants cite positive comments from past participants as motivating their interest in the program. This program has the potential to expand as an opportunity to educate selected students in the field of food-supply veterinary medicine and to help fill the anticipated void in this area.     

Facing Rose rosette virus: A risk to European rose cultivation

Roses (Rosa) are one of the most valuable ornamental flowering shrubs around the globe. They are susceptible to numerous pathogens that require management, increasing the cost of cultivation. Rose rosette virus (RRV; genus Emaravirus) is a devastating virus that has been spreading since the 1940s in the United States and Canada. It is an emerging risk to European and worldwide rose cultivation, causing symptoms such as witches' broom, malformations, excessive thorn production, and eventually plant death. RRV is transmitted by the eriophyid mite Phyllocoptes fructiphilus and by grafting. Research is being undertaken to understand RRV and to find control measures and resistant cultivars, as they are not currently available. Early detection of the disease is the key to prevent the establishment and spread of RRV and its vector. Different molecular and serological diagnostic methods have been designed and implemented, including ELISA, RT-PCR, RT-qPCR, LAMP, and high-throughput sequencing. RRV infected plants can remain symptomless for long periods, so these diagnostic assays are necessary in conjunction with visual assessment to facilitate early detection. Significant social, economic, and environmental impacts are expected if RRV and its vector establish and spread in Europe. Rose trade between countries is the most likely pathway of introduction of RRV into Europe. In this review we describe current knowledge about RRV, the molecular and serological methods available for the detection of this virus, pathways to entry, and the possible impact if it establishes and spreads in Europe.     

Environmental associations of Pacific bluefin tuna (Thunnus orientalis) catch in the California Current system

We investigate the impact of oceanographic variability on Pacific bluefin tuna (Thunnus orientalis: PBF) distributions in the California Current system using remotely sensed environmental data, and fishery‐dependent data from multiple fisheries in a habitat‐modeling framework. We examined the effects of local oceanic conditions (sea surface temperature, surface chlorophyll, sea surface height, eddy kinetic energy), as well as large‐scale oceanographic phenomena, such as El Niño, on PBF availability to commercial and recreational fishing fleets. Results from generalized additive models showed that warmer temperatures of around 17–21°C with low surface chlorophyll concentrations (<0.5 mg/m³) increased probability of occurrence of PBF in the Commercial Passenger Fishing Vessel and purse seine fisheries. These associations were particularly evident during a recent marine heatwave (the “Blob”). In contrast, PBF were most likely to be encountered on drift gillnet gear in somewhat cooler waters (13–18°C), with moderate chlorophyll concentrations (0.5–1.0 mg/m³). This discrepancy was likely a result of differing spatiotemporal distribution of fishing effort among fleets, as well as the different vertical depths fished by each gear, demonstrating the importance of understanding selectivity when building correlative habitat models. In the future, monitoring and understanding environmentally driven changes in the availability of PBF to commercial and recreational fisheries can contribute to the implementation of ecosystem approaches to fishery management.     

The Global Ocean Biodiversity Initiative: Promoting scientific support for global ocean governance

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