实验动物房消毒试验研究

选用５种常用消毒药物进行消毒试验,抑菌试验。结果表明实验动物房选择消毒药物的顺序为：乳酸、醋酸钠、百毒杀、卫康、过氧乙酸,消毒间隔以３个月为宜。     

Seroprevalence of Antibodies to Chlamydophila psittaci in Zoo Workers in Brazil

To evaluate the prevalence of antibodies to Chlamydophila psittaci 364 serum samples were collected from veterinarians, biologists, animal scientists, veterinary students, animal keepers and others employees in 20 zoos, and from veterinary practitioners in 10 Brazilian states. Subjects ranged from 15 to 64 years of age, with 268 (74%) males and 96 (26%) females. Chlamydial antibodies were determined by the complement fixation test (CFT) and specific anti‐C. psittaci IgG antibodies were determined by the microimmunoflurescence (MIF) test. Complement fixation test showed 23.9% (87/364) and MIF test showed 4.7% (17/364) positive serum samples. Titres ranged from 16 to 256 in both assays, demonstrating evidence of recent or current infection. Although chlamydial antibodies were detected in workers of seventeen zoos, MIF test only detected specific C. psittaci antibodies in seven of them. Previous psittacosis infection was suspected in eight workers of two zoos, five of whom reported having pneumonia, while employed at the zoos. However, diagnosis was not established in any of these cases in the past. Results indicated the occurrence of infection and previous contact of Brazilian zoo workers with C. psittaci, as well as the zoonotic potential of psittacosis in this risk population. Other studies are necessary to evaluate the risk factors of infection in this population. This seroepidemiological survey confirmed the need to adopt preventive measures to control avian chlamydiosis and protect the health of zoo workers in the country.     

硫酸链霉素细菌内毒素定量测定法的研究

应用鲎试剂动态浊度法，将硫酸链霉素制备成4、2、1、0．5mg／mL溶液，定量添加标准内毒素进行干扰预试验，计算回收率，确定不干扰浓度为0．5—2mg／mL。从中选出1mg／mL为最佳浓度，然后进行3个批次硫酸链霉素正式干扰试验。在供试品中定量添加标准内毒素，其回收率分别为125．8％、126．1％、127．3％，均在50％-200％之间，说明此浓度的供试品对鲎试剂反应无干扰作用。因此，内毒素含量在0．015—1EU／mL范围内，将硫酸链霉素制备成浓度为1．0mg／mL的溶液，可用于细菌内毒素的定量检测。     

用大肠杆菌K99和F41菌毛抗原检测牛血清抗体的琼脂扩散试验的研究

用含２ｍｏｌ／Ｌ尿素的磷酸盐缓冲液以热处理方法提取的Ｋ９９和Ｆ４１菌毛作为抗原,对琼脂扩散试验方法进行研究。结果表明本试验方法简便,特异性强,敏感性高,可用于血清抗体检测;所制备的抗原稳定、重复性好。     

基于近红外光谱法的紫花苜蓿品质综合评价

探索近红外光谱法测定紫花苜蓿品质的可行性,采用近红外光谱法与常规方法对8个紫花苜蓿品种(系)的粗蛋白、粗脂肪、粗灰分、酸性洗涤纤维、中性洗涤纤维、钙、磷和干物质等8项指标进行测定.利用配对T检验、多重比较和回归分析等方法检验近红外光谱法测定结果的可行性,运用灰色关联度分析对苜蓿品质进行综合评价.结果 表明,粗蛋白、粗灰...     

通过雏鸡MDV攻毒试验选择抗马立克氏病亲本

对F0、F1、F2亲本经继代No.614血型基因选择后繁殖的F2、F3雏鸡,10日龄以马立克氏病强毒（MDV）攻击至60日龄的死亡率,其父母亲对No.614抗血清呈阳性反应的试验组显著低于其父母亲对此抗血清呈阴性反应的对照组。试验组25个家系中,有14个家系的F2雏鸡死亡率显著低于对照组;F3雏鸡有21个家系的死亡率低于对照组,其中8个家系具有统计意义。肿瘤发生率,以肾脏和腺胃最高,肺脏和神经组织最低。综合血型抗原检测和MDV攻毒结果,从试验组25个家系中选留强MDV抗性家系留种繁殖,继代选育。     

PRRSV重组N蛋白表达、纯化及间接ELISA检测试剂盒的研制

采用RT-PCR扩增出大小409bp猪繁殖与呼吸综合征病毒核衣壳蛋白基因（PRRSV N gene）,将该基因克隆到表达载体pGEX-KG,构建重组表达载体pGEX-KG-N,转化表达菌株BL21（DM3）诱导表达,经SDS-PAGE和Western blot分析表明,重组N蛋白获得了高效表达,融合蛋白相对分子质量为41 000,并具有良好的免疫学活性。扩大诱导培养,收集菌体,提取包涵体,用GST-Protein Purtification Kit亲和层析纯化目的蛋白,SDS-PAGE电泳检测纯度达到90%以上,可满足诊断抗原质量要求。用纯化PRRSV重组核衣壳蛋白GST-N为包被抗原,建立检测PRRSV血清的间接ELISA诊断方法,并组装ELISA试剂盒。优化后抗原最适包被质量浓度为2.5mg/L;血清最适稀释度为1∶100;对血清样本检测临界值为0.224;与美国IDEXX公司的HerdChek ELISA试剂盒符合率为92%,特异性为95%,敏感性为90%;与猪细小病毒、猪伪狂犬病病毒、猪乙型脑炎病毒、猪圆环病毒、猪瘟病毒等常见猪繁殖障碍病标准阳性血清无交叉反应。ELISA试剂盒批内和批间变异系数分别为3.44%～6.34%和5.04%～7.64%。置4℃条件保存12个月,试剂盒稳定性无明显改变。该试剂盒对350份临床疑似血清检出率为88.6%。研制的ELISA试剂盒为PRRSV临床血清抗体检测及流行病学调查提供了技术手段。     

某猪场支气管败血波氏杆菌和化脓隐秘杆菌混合感染的病原分离鉴定及药敏试验

支气管败血波氏杆菌是引起猪萎缩性鼻炎的病原之一,化脓隐秘杆菌是一种感染牛、羊、猪等动物的机会致病菌.国内目前没有关于二者混合感染猪的报道.本研究从陕西省某猪场发病仔猪肺脏中分离出两株病原菌,经染色镜检、生化试验和16S rDNA测序鉴定,确定病原菌为支气管败血波氏杆菌和化脓隐秘杆菌.采用K-B纸片扩散法进行药敏试验,发...     

Precision of estimated QTL positions in granddaughter designs using combined haplotype sharing TDT and linkage analysis

The aim of this study was to develop the linear haplotype sharing transmission disequilibrium test (LHS-TDT) method and combine this method with the simple regression method to estimate the precision of QTL positions in granddaughter designs. This precision was determined by Monte Carlo simulation in granddaughter designs. A single bi-allelic QTL at the midpoint of a linkage group and 26 markers with 1 cM intervals and with two alleles each were simulated. Three linear models, (i.e. the simple regression model, the linear haplotype sharing TDT method and the combination of these two models) were compared. The mean of absolute differences (A) between the estimated and true QTL position of each method was considered for six different scenarios consisting of combinations of a number of markers and the most frequent haplotypes. The mean of A, using the simple regression method, was 4.38 centimorgan (cM). The means of A using the LHS-TDT method were less than the simple regression method in all scenarios and ranged from 1.86 to 3.82 cM depending on the scenario. The mean of A using the combined method was more than the LHS-TDT method and less than the simple regression method. The means of A using the combined method ranged from 2.32 to 4.36 cM. Therefore, for populations similar to those population simulated in this study, the LHS-TDT was better than the simple regression method and the combined method for precision of estimated QTL position in granddaughter designs.     

Investigation of the Effects of a Dietary Supplement on Insulin and Adipokine Concentrations in Equine Metabolic Syndrome/Insulin Dysregulation

High insulin concentrations are a common clinical feature of equine metabolic syndrome (EMS) and insulin dysregulation. Hyperinsulinemia can induce laminitis, so reduction of insulin concentrations in response to an oral challenge should decrease risk. In human studies, diets containing a polyphenol (resveratrol) led to improvements in insulin sensitivity. In rodents, the addition of leucine to a resveratrol supplement caused a decrease in the amount of resveratrol needed to achieve a clinical effect. We hypothesize a supplementation with a low dose of a synergistic polyphenol and amino acid blend including leucine (SPB+L) would improve metabolic health in EMS/insulin dysregulated horses. Fifteen EMS/ID horses received a high or low dose of SPB+ L daily for 6 weeks. Insulin during an oral sugar test (OST), body condition score, weight, baseline high-molecular-weight (HMW) adiponectin, triglycerides, nonesterified fatty acids, and tumor necrosis factor alpha were assessed before supplementation (PRE) and after supplementation (POST) via paired Student’s t-tests and a repeated-measures mixed-model analysis of variance (significant at P < .05). There were no differences between doses. Horses in the POST group weighed significantly less, had significantly higher baseline HMW adiponectin concentrations, and had significantly lower insulin concentrations at 60- and 75-minute time points (P < .05). Insulin concentrations of the horsesin the POST group, but not in the PRE group, were lower and similar to results from the study conducted three years before the present study (PRIOR) for 0- and 60-minute time points (P < .002). An increased HMW adiponectin level supports increasing insulin sensitivity after supplementation. These results suggest that SPB + L supplementation at either dose leads to improvements in the clinical manifestations of EMS/insulin dysregulation, potentially reducing laminitis risk.