绵羊肺炎支原体人工感染SPF鸡胚的研究

为探索SPF鸡胚作为绵羊肺炎支原体实验室感染模型的可行性,本试验用不同浓度绵羊肺炎支原体（10⁸、10⁹、10¹⁰ ccu/mL）经由卵黄囊和尿囊腔两个部位接种7日龄SPF鸡胚,通过统计鸡胚死亡情况和不同鸡胚组织样品中绵羊肺炎支原体检测阳性率（PCR检测和支原体分离鉴定）,确定绵羊肺炎支原体鸡胚感染方式、感染剂量和最佳分离部位,再用3株不同来源的绵羊肺炎支原体分离株感染鸡胚,观察其对鸡胚的致病力。结果表明,绵羊肺炎支原体感染鸡胚最佳接种途径为卵黄囊接种,感染剂量为10⁹ ccu/mL、0.2 mL/只,最佳分离部位为卵黄液。3株支原体均能感染和致死鸡胚,并均能从卵黄液中分离到绵羊肺炎支原体,但对鸡胚的致病性存在一定差异：FL3株致鸡胚死亡率为45%,略高于MoGH3-3株（40%）,二者均高于A3株（25%）,但差异均不显著（P>0.05）;FL3株鸡胚检测阳率为100%,高于MoGH3-3株（85%）及A3株（90%）,但差异也不显著（P>0.05）。本试验初步确定了绵羊肺炎支原体可感染和致死SPF鸡胚,不同分离株对SPF鸡胚致病力有差异,表明SPF鸡胚可作为下一步建立绵羊肺炎支原体实验室感染模型的候选,为绵羊肺炎支原体致病性研究和疫苗研制奠定基础。     

Development of a specific pathogen free population of the Chinese fleshy prawn, Fenneropenaeus chinensis: Part II. Secondary quarantine

The Oceanic Institute (OI), in collaboration with researchers from the University of Arizona (UAZ), established a population of specific pathogen free (SPF) Fenneropenaeus chinensis through Secondary Quarantine (SQ) in Kona, Hawaii. Shrimp were 0.38 g (S.D. ± 0.13 g) when they entered the nursery/growout module of the SQ facility. Juveniles from five maternal families were stocked in separate 230-L nursery tanks, as was a sixth family comprised of shrimp from two of the seven original spawns. After tagging, representative shrimp from all six families were stocked in a 50-m² concrete raceway that was enclosed in a biosecure greenhouse. After 155 days in the growout module, mean shrimp weight was 23.4 g (S.D. ± 7.25 g) and females (29.1 ± 4.61 g) were 74% larger than males (16.7 ± 2.44 g). A Sprung Structure™ was erected to enclose the biosecure maturation and hatchery module of the SQ facility. Broodstock were subjected to an acclimation process where they were kept in seawater at 22 °C, followed by a reduction in water temperature of 1 °C/day until the temperature reached 17 °C. At this time, unilateral eyestalk ablation was performed on female broodstock and water temperature was further reduced at the same rate until it reached 12 °C. After 2 weeks, water temperature was raised to 17 °C at a rate of 1 °C/day to induce ovarian development. Production of an F₁ generation of Fe. chinensis was successfully accomplished using artificial insemination, and representative shrimp from this generation have tested negative for all specifically listed pathogens using histology and PCR/RT-PCR. Of particular interest with Fe. chinensis is their cold tolerance. This species may represent a valuable resource for shrimp farmers in temperate and sub-tropical climates to grow a second “winter” crop, thereby increasing production and profitability for the shrimp farmer.     

H5N1亚型禽流感病毒感染SPF雏鸡的外周血液免疫病理变化

以7日龄SPF雏鸡为试验动物,应用细胞培养和免疫酶技术,通过对外周血液免疫球蛋白含量、T和B淋巴细胞数量及其功能的检测,较全面系统地研究了鹅源H5N1亚型中强毒禽流感病毒(AIV)感染SPF雏鸡后,其外周血液上述指标的动态变化。结果发现,SPF雏鸡感染鹅源H5N1亚型AIV后,血清IgG和IgA含量在1~4d显著或极显著低于对照雏鸡(P<0.05或P<0.01),而IgM在病毒感染早期未见显著性差异,随后3种免疫球蛋白含量逐渐回升;血液T淋巴细胞数量显著低于对照雏鸡(P<0.05或P<0.01),而B淋巴细胞在1~5d明显降低(P<0.05或P<0.01);T、B淋巴细胞对ConA或PMA的增殖反应分别于1~8d、1~4d明显低于对照雏鸡(P<0.05或P<0.01)。上述结果表明,AIV感染SPF雏鸡外周血液无论是细胞免疫还是体液免疫功能均呈现一定抑制。     

禽脑脊髓炎琼扩抗原的研制与应用

利用禽脑脊髓炎病毒Ｖａｎ Ｒｏｅｋｅｌ株和山东野外分离株，分别脑内接种１日龄ＳＰＦ雏鸡，在隔离器中饲养，以典型发病鸡脑，胃肠和胰腺等制备琼扩抗原。通过特异性检查，效价测定，与进口抗原及血清对比，田间试验等证实，该方法所制备的抗原性能稳定，效价高，特异性强。可广泛用于ＡＥ抗体的普查，适合于评价免疫鸡群抗体的水平。     

Hematologic and biochemical reference intervals for specific pathogen free 6-week-old Hampshire-Yorkshire crossbred pigs

Background： Hematologic and biochemical reference intervals depend on many factors, including age. A review of the literature highlights the lack of reference intervals for 6-wk-old specific pathogen free （SPF） Hampshire-Yorkshire crossbred pigs. For translational research, 6-wk-old pigs represent an important animal model for both human juvenile colitis and diabetes mellitus type 2 given the similarities between the porcine and human gastrointestinal maturation process. The aim of this study was to determine reference intervals for hematological and biochemical parameters in healthy 6-wk-old crossbred pigs. Blood samples were collected from 66 clinically healthy Hampshire-Yorkshire pigs. The pigs were 6 wks old, represented both sexes, and were housed in a SPF facility. Automated hematological and biochemical analysis were performed using an ADVIA 120 Hematology System and a Cobas 6000 C501 Clinical Chemistry Analyzer. Results： Reference intervals were calculated using both parametric and nonparametric methods. The mean, median, minimum, and maximum values were calculated. Conclusion： As pigs are used more frequently as medical models of human disease, having reference intervals for commonly measured hematological and biochemical parameters in 6-wk-old pigs will be useful. The reference intervals calculated in this study will aid in the diagnosis and monitoring of both naturally occurring and experimentally induced disease. In comparison to published reference intervals for older non SPF pigs, notable differences in leukocyte populations, and in levels of sodium, potassium, glucose, protein, and alkaline phosphatase were observed.     

Pseudorabies virus is transmitted among vaccinated conventional pigs, but not among vaccinated SPF pigs

Whereas the reproduction ratio (R) of pseudorabies virus (PRV) in vaccinated specific pathogen free (SPF) pigs without maternally derived antibodies under experimental conditions has repeatedly been shown to be significantly below 1, R in vaccinated conventional pigs in the field with maternally derived antibodies was significantly above 1. To exclude the difference in husbandry conditions as a cause for this discrepancy, we quantified and compared the transmission of PRV in both groups under identical experimental conditions. Whereas none of the SPF sentinel pigs became infected (R=0, significantly<1), all conventional sentinel pigs did become infected (R=2.5, significantly>1). Moreover, only one SPF pigs shed virus in saliva, the mean cumulative titre being almost a 100-fold less than in conventional pigs (17 pigs, P=0.003). In addition, the mean proliferation of peripheral blood lymphocytes in response to PRV antigens was significantly higher in SPF pigs than in conventional pigs at all points studied (P<0.0001). Moreover, the virus-neutralising antibody titre after vaccination was significantly higher in SPF pigs than in conventional pigs. We conclude that the discrepancy in transmission between vaccinated SPF pigs and vaccinated conventional pigs cannot be attributed to the experimental conditions.     

我国SPF鸡胚生产与质量控制现状分析

从生产能力、饲养方式、微生物质量监测等方面介绍了我国SPF鸡胚发展概况,对我国SPF鸡胚生产与质量控制现状进行了调查与分析,并对存在的问题提出建议.经调查,2012年我国有20家SPF鸡生产企业生产SPF鸡胚年产量约5050万枚,其中年产600万枚以上的企业有3家,300万～600万枚的企业有4家,10家企业年产量在100万～200万枚之间,其他3家企业年产量少于100万枚.从供需情况可以看出,目前我国SPF鸡胚生产数已供大于求略有结余.     

SPF鸡的饲养管理与隔离器的安装使用

SPF鸡是一种无特定病原的实验动物。SPF鸡对各种病原微生物有敏锐的感受性,且重复性好,能够保证实验结果的精确性。SPF鸡饲养环境监测主要是对噪声、照明、空气中细菌及粉尘、温度、湿度、气流速度、换气次数、系统压力梯度和过滤器的过滤效率等进行测定,实施良好的监控机制是确保SPF鸡质量的重要措施,因此应特别注意饲养SPF鸡隔离器的安装使用,并加强对SPF鸡的饲养管理。     

Ⅰ型鸭肝炎病毒（DHV-Ⅰ）在鸡胚中的增殖及感染力的测定

摘要：将Ⅰ型鸭肝炎病毒（DHV-Ⅰ）接种9日龄SPF鸡胚尿囊腔（0.2 mL/胚）进行增殖,制备鸡胚成纤维细胞（CEF）,并分别运用CELD50法和TCID50法测定DHV的感染力。结果表明,DHV-Ⅰ在SPF鸡胚内成功增殖,致死鸡胚具有典型临床症状和体表特征,所增殖病毒的CELD50和TCID50分别为10-5.6/0.2 mL和10-5.12/0.1 mL。     

SPF理论及其在捕捞能力计算中的应用

随机生产边界法是一种基于Cobb-Douglas生产函数的线性规划方法。在得到待定系数的估计值后,可求得理论产出,进而可以求得各投入单元的技术效率。以年渔获产量为产出,海洋捕捞专业劳动力和渔船数为投入,应用该方法计算浙江省1996—2004年的海洋捕捞能力。结果表明2000年浙江省捕捞技术效率最高,达到99．9％。在与DEA法进行比较后得出结论：两者计算结果相近,都能较准确的反映捕捞能力水平;在使用SPF法分析捕捞能力时,要注意技术无效率投入的剔除。此外,在用SPF法计算捕捞能力时,应将除去劳动力外的投入因子全部货币化,以提高计算的准确性。