不同禽流感病毒含量的新-流二联灭活疫苗免疫SPF鸡后抗体水平的监测

将未浓缩的新城疫抗原分别与未浓缩的、浓缩3倍、浓缩6倍的禽流感抗原混合,并制备成三组鸡新城疫、禽流感（H9N2 HP株）二联灭活疫苗（简称新-流二联灭活疫苗）,分别免疫21日龄SPF鸡,每羽0.3 mL,同时设置未免疫的空白对照组,免疫组与对照组均在免疫前及免疫后7、14、21、28、35 d进行采血,检测新城疫和禽流感抗体。结果发现,各免疫组在免后不同日龄的新城疫抗体基本一致,禽流感病毒抗原浓缩倍数越高（即禽流感病毒含量越高）的新-流二联灭活疫苗,免后14、21 d的抗体也越高;从免后21 d开始,各免疫组的禽流感抗体水平差异逐渐减小,免疫后禽流感抗体水平的高低可以反映该疫苗的免疫效果。试验结果表明,该疫苗可以通过浓缩提高抗原病毒含量的方法来提高免后早期抗体水平,取得良好的早期免疫效果。     

网状内皮增殖病病毒(REV)感染SPF雏鸡后局部免疫组织抗体生成细胞的变化

对 SPF雏鸡人工感染 REV后局部免疫组织盲肠扁桃体和哈德氏腺的 Ig A、Ig G和 Ig M抗体生成细胞数量动态变化进行了检测。结果发现 ,REV感染 SPF雏鸡后 7～ 4 9天消化道局部免疫组织盲肠扁桃体和呼吸道相关局部免疫组织哈德氏腺的 Ig A、Ig G和 Ig M抗体生成细胞数量明显低于未感染对照雏鸡。表明雏鸡感染 REV后消化道局部组织盲肠扁桃体和呼吸道相关免疫组织哈德氏腺体液免疫机能均显著下降。     

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。     

核酸探针技术在鼠金黄色葡萄球菌流行病学调查中的应用

用金黄色葡萄球菌耐热核酸酶nuc基因特异性核酸探针 ,对江苏和上海 5个实验动物中心送检的 4 2 1份SPF鼠样品进行了检测。有 11份样品为阳性反应结果 ,阳性率 2 6 % ( 11/4 2 1)。结果表明 ,在我国一些实验动物中心SPF鼠群中还存在着金黄色葡萄球菌感染     

The effects of the supplementation of multi‐strain probiotics on intestinal microbiota,metabolites and inflammation of young SPF chickens challenged with Salmonella enterica subsp. enterica

This study assessed the effect of probiotics on cecal microbiota, cecal short‐chain fatty acids (SCFAs), and the gene expression of cytokines in young specific‐pathogen‐free (SPF) chickens infected with S. enterica subsp. enterica. One‐day‐old SPF chickens (n = 105) were randomly assigned to one of the three treatment groups: control (Cont) group, Salmonella‐infected (Sal) group, and a Salmonella‐infected group treated with multi‐strain probiotics (ProSal group). All chickens except those in the Cont group were challenged orally with 1 × 10⁸ cfu/ml of Salmonella 4 days after hatching. Chickens in the Sal group exhibited more abundance of Proteobacteria than those in the Cont and ProSal groups. At the genus level, chickens in ProSal group exhibited increased numbers of Lactobacillus and Oscillospira compared with those in the other groups. Chickens in the ProSal group exhibited a significant increase of cecal SCFAs compared with chickens in the Sal group. Chickens in the ProSal group exhibited increased gene expression of anti‐inflammatory cytokines, IL‐10 and TGF‐β4, and decreased expression of the proinflammatory cytokine, IFN‐γ, in the cecal tonsil compared with those in the Sal group. The results of this study indicated that the administration of probiotics can modulate microbiota, SCFAs, and immunomodulatory activity in SPF chickens.     

Dietary Bacillus subtilis C-3102 Supplementation Enhances the Exclusion of Salmonella enterica from Chickens

Among the reported probiotic Bacillus strains, B. subtilis C-3102 has the unique potential to improve feed uptake under stress conditions in the broilers, piglets, and cows. In this study, we sought to evaluate the protective effect of feed additive probiotic Bacillus subtilis C-3102 against Salmonella enterica infection of specific pathogen-free (SPF) chicks in floor pens in two experiments. In the experiment-1, the chicks in the control group (n=32) were fed a basal diet and those in the C-3102 group (n=32) were fed a basal diet supplemented with 1×10⁶ CFU/g of feed for 28 days. On day 7 post-challenge with S. enterica, there was no significant change in the body weight between both the groups throughout the test period, whereas detection rates of S. enterica in the C-3102 group were significantly lower in the cecum and liver on days 21 and 14 post-challenge, respectively. In the experiment-2, minimum dosage of C-3102 cells required to protect Salmonella infection was evaluated using 3 dosages. Chicks were divided into four groups, fed with different dosages of C-3102 (1×10⁶, 5×10⁵, 3×10⁵, and 0 CFU/g of feed), and challenged with S. enterica (2.8×10⁸ CFU/chicken). S. enterica infection was completed within 7 days post- challenge and was almost excluded from the liver and spleen on day 21 post- challenge in the control group. Average values showed a trend for higher infection rates in the control group >3×10⁵>5×10⁵>1×10⁶ CFU/g on days 14 and 21 post-challenge. These results suggest that B. subtilis C-3102 supplementation has the potential to reduce S. enterica infection rates and/or to accelerate the exclusion of S. enterica from the chicks.     

SPF仔猪肠道菌群结构的分子分析

目的：对SPF（Specific Pathogen Free）仔猪断奶前后的肠道菌群组成进行动态监测,并以普通饲养仔猪（自然分娩）为对照作相关分子微生物生态学分析.方法：利用剖腹取胎的方式将仔猪从母体子宫中取出放于屏障系统中饲养,于7日龄时转移至消毒的开放式环境中,14日龄断奶,分别于10日龄、16日龄和22日龄以及32日龄采集仔猪新鲜粪便样品.提取粪便样品中细菌总DNA,获得其ERIC-PCR指纹图谱,再将其中一个样品的ERIC-PCR产物以地高辛标记为混合探针通过杂交对指纹图谱上DNA条带序列的异同进一步比较.结果：SPF仔猪和普通仔猪在断奶后肠道菌群的组成发生较大变化,而且SPF仔猪的肠道菌群和普通仔猪有显著差异.     

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.     

猪链球菌2型感染SPF小型猪模型的构建

构建了致病性猪链球菌2型(SS2)感染模型。通过典型临床症状观察、剖检病变和组织学观察及病原分离鉴定,证实该模型能成功模拟自然感染状态下SS2引起的典型临床症状和病理变化特点,稳定性好,可进一步用于致病性SS2在动物体内动态分布规律、致病机制和机体免疫应答以及疫苗的效果评价和相关药物筛选等方面的研究,对于猪链球菌2型感染的防控具有重要意义。