Association of wild bird density and farm management factors with the prevalence of E. coli O157 in dairy herds in Ohio (2007-2009)     

Cernicchiaro N  Pearl DL  McEwen SA  Harpster L  Homan HJ  Linz GM  Lejeune JT 《Zoonoses and public health》2012,59(5):320-329

Our objective was to determine the role that European starlings (Sturnus vulgaris) play in the epidemiology of Escherichia coli O157:H7 in dairy cattle. We visited 150 dairy farms in Ohio twice during summer and fall months from 2007 to 2009. Fresh faecal pats from 30 lactating cows were collected during each visit. Information on farm management and environmental variables was gathered through a questionnaire administered to the farm owner. The number of starlings observed on the farm was also recorded. Approximately 1% of dairy cattle and 24% of farms were positive for E. coli O157. Risk factors associated with the presence of E. coli O157 in faecal pats included contact between adult cattle and calves, types or number of ventilation and manure management systems and number of birds per milking cow.  相似文献   

欧洲山芥皂苷合成关键酶基因Bv-beta-AS 克隆及表达分析     

魏小春  张晓辉  吴青君  王海平  沈镝  邱杨  宋江萍  李锡香 《园艺学报》2012,39(5):923-930

 以能够产生抗虫皂苷的高抗小菜蛾资源G 型欧洲山芥（Barbarea vulgaris R. Br.）B44 为材料,利用RACE 技术克隆出皂苷合成关键酶beta–香树脂合成酶的基因（Barbarea vulgaris beta-amyrin synthase,Bv-beta-AS）。该基因编码区序列长为2 289 bp（GenBank 登录号JQ172795）,推导其编码762个氨基酸;在基因组水平上长度为4 107 bp （GenBank 登录号JQ172796）,含有15 个内含子。Bv-beta-AS编码的氨基酸具有beta–香树脂合成酶基因家族的保守序列,即DCTAE 序列和QW 特征序列,氨基酸多序列比对和进化树分析表明,该基因与拟南芥beta–香树脂合成酶基因的相似性最高,为74%。利用荧光定量PCR 对欧洲山芥在小菜蛾诱导下该基因的表达进行研究,结果表明,该基因受虫害诱导时上调表达,但是上升到12 h 达顶峰后随时间推移呈回归的趋势。从序列特征和表达模式上推测,Bv-beta-AS 可能是抗虫皂苷合成途径的一个关键酶的基因。  相似文献   

Moderate nitrogen retention in temperate heath ecosystem after elevated CO2, drought and warming through 7 years     

Louise C. Andresen  Per Ambus  Claus Beier  Anders Michelsen 《European Journal of Soil Science》2023,74(4):e13397

Nitrogen (N) dynamic is one of the main controlling factors of responses to climate change in N-limited terrestrial ecosystems, which rely on nutrient recycling and retention. In this study we investigate the N partitioning in ecosystem compartments of a grassland heath, and the impact of multiple climate change factors on long-term N retention after ¹⁵N pulse labelling. The impacts of elevated carbon dioxide (eCO₂), warming and drought and the treatments in combination on ecosystem N retention were investigated in a field scale manipulation experiment. A 6-year time-course was assessed by pulse-labelling with the stable N isotope ¹⁵N and by sampling after 1 day, 1 year and 6 years. After 6 years we observed that the total ecosystem retained 42% of the amended ¹⁵N across treatments (recovery of the amended ¹⁵N in the pool). The fate of the applied ¹⁵N was mainly stabilization in soil, with 36% ¹⁵N recovery in soil, while the plant compartment and microbial biomass each retained only 1%–2% of the added ¹⁵N. This suggests a moderate retention of N, for all treatments, as compared to similar long-term studies of forest ecosystems. A decreased ammonium and vegetation N pool combined with higher ¹⁵N retention in the soil under eCO₂ treatments suggests that eCO₂ promoted processes that immobilize N in soil, while warming counteracted this when combined with eCO₂. Drought treatments contrastingly increased the vegetation N pool. We conclude that as the organic soil layer has the main capacity for N storage in a temperate heathland-grassland, it is important for buffering nutrient availability and maintaining a resilient ecosystem. However, the full treatment combination of drought, warming and eCO₂ did not differ in ¹⁵N recovery from the control, suggesting unchanged long-term consequences of climate change on retention of pulse added N in this ecosystem.  相似文献   

Antibacterial Activity of Long-Chain Polyunsaturated Fatty Acids against Propionibacterium acnes and Staphylococcus aureus     

Andrew P. Desbois  Keelan C. Lawlor 《Marine drugs》2013,11(11):4544-4557

New compounds are needed to treat acne and superficial infections caused by Propionibacterium acnes and Staphylococcus aureus due to the reduced effectiveness of agents used at present. Long-chain polyunsaturated fatty acids (LC-PUFAs) are attracting attention as potential new topical treatments for Gram-positive infections due to their antimicrobial potency and anti-inflammatory properties. This present study aimed to investigate the antimicrobial effects of six LC-PUFAs against P. acnes and S. aureus to evaluate their potential to treat infections caused by these pathogens. Minimum inhibitory concentrations were determined against P. acnes and S. aureus, and the LC-PUFAs were found to inhibit bacterial growth at 32–1024 mg/L. Generally, P. acnes was more susceptible to the growth inhibitory actions of LC-PUFAs, but these compounds were bactericidal only for S. aureus. This is the first report of antibacterial activity attributed to 15-hydroxyeicosapentaenoic acid (15-OHEPA) and 15-hydroxyeicosatrienoic acid (HETrE), while the anti-P. acnes effects of the six LC-PUFAs used herein are novel observations. During exposure to the LC-PUFAs, S. aureus cells were killed within 15–30 min. Checkerboard assays demonstrated that the LC-PUFAs did not antagonise the antimicrobial potency of clinical agents used presently against P. acnes and S. aureus. However, importantly, synergistic interactions against S. aureus were detected for combinations of benzoyl peroxide with 15-OHEPA, dihomo-γ-linolenic acid (DGLA) and HETrE; and neomycin with 15-OHEPA, DGLA, eicosapentaenoic acid, γ-linolenic acid and HETrE. In conclusion, LC-PUFAs warrant further evaluation as possible new agents to treat skin infections caused by P. acnes and S. aureus, especially in synergistic combinations with antimicrobial agents already used clinically.  相似文献   

Skeletal deformities associated with nutritional congenital rickets in newborn lambs     

KE Dittmer  RE Morley  RL Smith 《New Zealand veterinary journal》2013,61(1):51-55

Abstract

CASE HISTORY: A group of 545 pregnant rising 2-year-old Coopdale ewes on a Southland sheep farm were grazed over winter on a fodder beet (Beta vulgaris) crop. Subsequently, 45 out of approximately 750 lambs were born with a variety of skeletal deformities, including shortened limbs, varus and valgus angular limb deformities, palmar grade stance and cranial bowing of the carpus. Analysis of the crop showed the fodder beet contained a low percentage of phosphorus. In addition, 60 out of 460 rising 2-year-old ewes that had been grazed on the fodder beet crop as 1-year-olds had incisor abnormalities and malocclusion.

PATHOLOGICAL FINDINGS: Two affected lambs (1-day-old and 3-days-old) with representative clinical signs examined postmortem were found to have markedly enlarged costochondral junctions, and noticeably enlarged long bone metaphyses. In addition, one lamb had a dense band of metaphyseal sclerosis beneath the physes of all long bones examined. Histopathological findings included small islands and columns of chondrocytes and eosinophilic cartilage matrix present in the metaphysis. Metaphyseal trabeculae were disorganised and often lined by accumulations of pale pink osteoid; similar pale pink osteoid was also present in the cortices. Unerupted molar teeth in the affected lambs lacked a layer of enamel, and the dentine was irregular with globular basophilia.

DIAGNOSIS: The gross and histopathological lesions were consistent with a diagnosis of rickets.

CLINICAL RELEVANCE: Nutritional congenital rickets has not been previously diagnosed in sheep, but is a recognised disease of human infants with vitamin D deficient mothers. The rickets in affected lambs was most likely associated with phosphorus deficiency as a result of the pregnant ewes grazing fodder beet during gestation. While vitamin D deficiency was not definitively ruled out in these cases, practitioners are alerted to the possible effects of feeding phosphorus-deficient fodder beet to ewes for long periods during gestation and to 1-year-old sheep during important growth periods.  相似文献   

松鼠贮食时对红松松塔的选择特征     

梁振玲  戎可 《安徽农业科学》2013,41(10):4431-4432,4435

[目的]揭示松鼠贮食时对红松松塔的选择特征。[方法]通过样线调查的方法收集松鼠贮食时丢弃的松塔核,测量其长宽数据。根据已经建立的松塔质量评价标准进行分析。[结果]无论在哪个贮食阶段,松鼠都倾向于选择较大的松塔贮藏,且将最大的松塔贮藏在距离母树林150～300 m的范围内。[结论]松鼠选择较大的松塔贮藏以降低贮藏能耗,获得最大的能量收益。  相似文献   

小球藻自养、异养和混养特性的研究     

杨素玲  孟佑婷  刘桂君  王平  尚宏忠 《安徽农业科学》2013,(18):7748-7749,7863

[目的]为小球藻的高密度培养及开发高附加值代谢产物提供基础参数。[方法]从细胞生长、营养物质吸收、细胞生理生化特性等方面,研究小球藻自养、异养和混养特性。[结果]在异养和混养条件下小球藻生物量显著提高,最大生物量分别是自养时的3.2、4.0倍,对葡萄糖的吸收与生长状态相对应;在不同营养方式下细胞组分存在差别,在异养和混养条件下蛋白质和碳水化合物含量降低,但总脂含量增加;与自养相比,异养和混养时叶绿素含量降低,激发能在2个光合系统间的分配比PSII/PSI降低。[结论]混合培养在高密度高油脂含率小球藻培养方面具重要的应用前景。  相似文献   

Effects of Different Irrigation Levels and Arbuscular Mycorrhizal Fungi (AMF), Photosynthesis Activator,Traditional Fertilizer on Yield and Growth Parameters of Dry Bean (Phaseolus Vulgaris L.) in Arid Climatic Conditions     

M. Cüneyt Bağdatli  Oktay Erdoğan 《Communications in Soil Science and Plant Analysis》2019,50(5):527-537

A field experiment has been conducted to determine the effects of different irrigation water and AMF (Arbuscular Mycorrhizal Fungi) biofertilizer, photosynthesis activator and traditional fertilizer dry bean (Phaseolus vulgaris L.) on yield and growth parameters in Nevsehir Province of Turkey in 2015. The experiment has been carried out using three replications in a split plot design with three different irrigation types as main plots and AMF biofertilizer (ERS), photosynthesis activator (Multigreen-Mg), traditional fertilization (TF-Control), ERS + Mg, ERS + TF and TF + Mg applied as subplots. The number of pods per plant, the length of pods, the number of grains per pod, the weight of grains per plant, the yield of grains, 1000 seed weight, the number of grains per plant, protein yield, arbuscular mycorrhizal fungi rate have been evaluated as yield and growth criteria in the study. In the experiment, as well as the treatment x irrigation interaction, the plant height, pod number per plant, pod lenght, grain number per pod, grain weight per plant, grain yield, 1000 seed weight, grain number per plant, protein rate/grain, protein yield, root weight and AMF colonization parameters, were the other studied properties that were found to be significant. The results obtained were 877.6 mm for I₁₀₀ irrigation treatment, 512.2 mm for I₅₀ irrigation treatment and 40.19 mm water for I₃₀ irrigation treatment. Regarding the growth parameters of dry bean, the highest PH was in ERS + Mg (67.66 cm), the lowest PH was in ERS (54.33 cm); In I₅₀, the highest Plant Height (PH) was in ERS + Mg (65.66 cm), the lowest PH was in TF-Control (53.00 cm); and in I₃₀, the highest PH was in TF-Control (50.66 cm), and the lowest PH was again in ERS + Mg (44.33 cm). For protein yield (PY) value, ERS + Mg, ERS + TF, TF + Mg have been placed in the same group, in I₁₀₀ and I₅₀ irrigation treatment. The highest value was ERS + TF (34.90 kg da^?1) in I₁₀₀, The lowest value was TF-control (19.90 kg da^?1) in I₃₀ irrigation treatment. In terms of mycorrhiza colonization ratio, ERS has been ranked first in all irrigation treatments, while the highest mycorrhiza colonization has been observed in I₃₀ irrigation treatment (26.30%). ERS was followed by ERS + Mg (23.33%). As expected, the lowest mycorrhiza colonization ratio in all irrigation treatments have been observed in TF-control treatment, while the highest mycorrhiza colonization ratio has been respectively observed in I₃₀ and I₅₀ irrigation topics. The highest root weight (RW) in I₁₀₀ irrigation treatment was observed in ERS (15.06 g plant^?1) and it was observed in ERS (19.05 g plant^?1; 26.30 g plant^?1) in I₅₀ and I₃₀ irrigation treatments. The lowest RW in all irrigation treatments has been observed in TF + Mg (4.43 g plant^?1, 6.40 g plant^?1, 10.26 g plant^?1), respectively.  相似文献   

银屑胶囊联合阿维A胶囊治疗寻常性银屑病临床疗效和安全性的Meta分析          下载免费PDF全文

黄树宏  李可欣  查旭山 《勤云标准版测试》2019,39(4):495-502

目的 系统评价银屑胶囊联合阿维A胶囊治疗寻常性银屑病的临床疗效和安全性。方法 检索数据库包括：PubMed、Embase、Cochrane图书馆、中国生物医学文献数据库、中国知网、维普、万方数据库等,关键词采用"疗效"银屑胶囊"和"银屑病",定年限为2000年1月至2018年12月,由两位研究者按照纳入排除标准独立筛选文献,进行文献质量评估和数据提取,结果采用Rev Man 5.3软件进行Meta分析。结果 共纳入7篇文献,共涉及660例患者。Meta分析结果显示,在有效性方面,银屑胶囊联合阿维A胶囊治疗寻常性银屑病的临床疗效优于单用阿维A胶囊,其60 d治愈率和60 d有效率的OR值分别为：2.21（95% CI：1.53~3.17）和2.66（95% CI：1.86~3.79）;在PASI评分方面,银屑胶囊联合阿维A胶囊治疗寻常性银屑病的PASI评分低于单用阿维A胶囊（SMD=-0.93,95% CI：-1.23~-0.62）;在血清炎症因子指标方面,银屑胶囊联合阿维A胶囊治疗寻常性银屑病的血清炎症因子IL-4、IL-10水平均高于单用阿维A胶囊：IL-4（SMD=0.83,95% CI：0.01,1.66）,IL-10（SMD=0.56,95% CI：0.28,0.84）;在安全性方面,除了鼻出血外,银屑胶囊联合阿维A胶囊治疗寻常性银屑病的眼干、皮肤干燥、毛囊炎、转氨酶升高、高脂血症等不良反应发生率均显著低于单用阿维A胶囊的情况。结论 银屑胶囊联合阿维A胶囊治疗寻常性银屑病安全有效,然而,确切结论有待于更多的高质量、多中心、大规模的随机对照研究证实。  相似文献   

甜菜BvMTP11基因的克隆及序列分析   总被引：1，自引：0，他引：1  

王锦霞  李硕  代春艳  马龙彪  刘大丽 《中国糖料》2019,(3):7-11

在植物中,金属耐受蛋白(Metal tolerant proteins,MTPs)是阳离子转运家族(Cation effluxtransporters)重要的成员之一,其在细胞重金属逆境耐受性及离子平衡代谢中发挥着重要的作用。本研究通过RT-PCR方法,在甜菜体内克隆获得了Beta vulgaris metal tolerantce protein 11(BvMTP11)基因的全长序列。该基因CDS全长为1 227 bp,编码了408个氨基酸,分子量(Mw)和等电点(pI)分别为45.935 kDa和4.89,属于相对不稳定蛋白。该基因编码的蛋白有5个跨膜螺旋区,是一种具有阳离子排出域(Cation efflux domain)的膜蛋白,并且有80%的可能性定位于过氧化物酶体膜上。因此可以推测,BvMTP11可能作为甜菜体内重要的转运蛋白参与到重金属逆境胁迫应答网络中,同时,该基因的克隆也为进一步研究其在重金属逆境下的分子机制奠定基础。  相似文献