Effect of the route of administration on the mucosal and systemic immune responses to Lawsonia intracellularis vaccine in pigs

In an on‐farm study, 40 weaned piglets aged 3 weeks were vaccinated with Lawsonia intracellularis vaccine orally, IM or IP while a fourth group remained unvaccinated. All vaccinated animals showed increased serum levels of L. intracellularis‐specific IgG antibodies, but significantly elevated concentrations of specific IgG, IgA and cytokines were generated in ileal mucosal secretions from the orally and IP vaccinated pigs when examined at 17 days after vaccination.     

1株具有免疫增强功能的乳酸菌筛选及其免疫效果评价

为筛选出具有较强免疫功能的益生菌用于临床研究,对分离自健康鸡粪便样品中的20株乳酸菌进行耐酸、耐胆盐、体外抑菌、黏附、胞外多糖含量测定试验以及小鼠免疫功能检测,并结合上述试验结果进行综合性评价.结果:筛选出20号菌株为目的菌株,耐酸、耐胆盐试验表明,该菌株在pH=2时的存活率为72.7％,在胆盐浓度为1.0％的环境中存...     

沙棘芦荟三七复配物对小鼠免疫力的影响

研究沙棘果粉、库拉索芦荟提取物、三七提取物制成的复配物对小鼠免疫力的影响。实验设0.625 g/kg.bw、1.250 g/kg.bw、3.750 g/kg.bw三个剂量组和阴性对照组,经口灌胃30天后,考察样品对小鼠免疫脏器/体重比值、免疫细胞功能、体液免疫功能、单核-巨噬细胞功能和NK 细胞活性等的影响。结果表明,与对照组比较,中剂量和高剂量能显著提高小鼠迟发型变态反应能力、NK细胞活性、抗体生成细胞数(P<0.05),高剂量能显著提高小鼠半数溶血值(P<0.05),说明复配物能够增强小鼠的免疫力。本研究为相关产品开发提供了功能依据。     

茅苍术与内生菌互作信号对其活性成分的影响

为了了解内生菌对茅苍术道地性的影响,本文综述了各种内生菌引发的植物信号变化的异同,以及茅苍术内生菌在促进茅苍术生长以及多萜合成中的作用。内生菌可能被植物细胞表面受体所识别,通过活性氧、钙离子、一氧化氮3种第二信使以及多种植物激素信号引发植物代谢变化,进而累积次生代谢产物。受到影响的植物信号包括水杨酸、茉莉酸、脱落酸和乙烯。研究发现,内生菌的接种可能引起多种植物信号传递的变化,并且产生挥发油含量差异。     

灭活菌苗免疫的南方鲇外周血液细胞免疫指标的变化

以嗜水气单胞菌(Aeromonashydrophila)灭活菌苗为免疫原,以平均体重为86 20g人工饲养的健康南方(Silu rusmeridionalis)为实验对象,通过腹腔注射免疫原(浓度为1 0×108/mL)免疫,剂量为0 2mL/尾,并分别在免疫后的第1、2、4、7、14、21、28天对实验鱼尾静脉采血,进行血液生理指标和血液中吞噬细胞活性的测定。结果显示,嗜水气单胞菌灭活菌苗(FKC)可以增加南方外周血液白细胞数量并引起不同种类白细胞组成比例的变化,提高吞噬细胞的吞噬活性。在免疫后第1、2、4、7、14、21、28天,南方外周血中白细胞数量呈明显上升趋势,其中嗜中性粒细胞、单核细胞、淋巴细胞变化趋势更为明显;而且吞噬细胞活性大为提高,吞噬百分比较对照组平均升高了17 66%,吞噬指数比对照组平均升高了1 16,在免疫后第4天吞噬百分比和吞噬指数均达到最高值,吞噬百分比为48 40%,吞噬指数为4 82;免疫后第21天,吞噬百分比和吞噬指数开始下降,但仍高于对照组。由此表明,使用疫苗后,鱼类非特异细胞免疫在初期(尤其是在第2～7天)明显增强,这是鱼用疫苗在免疫早期保护作用的主要机制之一。     

嗜水气单胞菌ompA、flaA基因重组干酪乳杆菌对鲤生长及免疫效果分析

为构建嗜水气单胞菌ompA和flaA基因重组干酪乳杆菌并分别检测其表达产物对鲤生长及免疫效果的影响,实验将目的基因克隆至乳酸菌穿梭表达质粒pPG612中,并电转至干酪乳杆菌中,经诱导后包被饲料对鲤进行饲养56 d,称重并采集血清及组织,分析生长指标及免疫指标变化。在56 d饲养免疫结束后结果显示,生长指标显示重组干酪乳杆菌组与对照组无显著差异,表明重组干酪乳杆菌对生长无影响;免疫效果分析显示,血清中IgM表达水平显著上升。血清中AKP、LZM、SOD、CAT、C3和C4也均显著升高。荧光定量PCR检测发现,免疫后肝脏、脾脏、头肾及肠组织中的细胞免疫因子基因IL-1β、IL-8、TNF-α、 NF-κB、 TLR5及MYD88的表达水平有不同程度的显著提升;其中TLR5及MYD88表达量在Lc-mcs-flaA组高于Lc-mcs-ompA组。攻毒后Lc-mcs-ompA与Lc-mcs-flaA组免疫保护率分别为59%与54%,显著高于对照组。研究表明,本实验构建的重组干酪乳杆菌Lc-mcs-ompA与Lc-mcs-flaA免疫鲤能刺激机体产生免疫应答反应,进而提高自身存活率,为预防鱼类嗜...     

高植物蛋白饲料中添加蛋白酶对克氏原螯虾生长、免疫力及消化力的影响

为探讨低鱼粉高植物蛋白饲料中蛋白酶的适宜添加范围,在克氏原螯虾基础饲料中分别添加0、0.1、0.2、0.4、0.8、1.6 g/kg蛋白酶,制作成6组饲料。选择初始体质量为(8.18±0.11) g的克氏原螯虾,随机分为6组,每组3个重复,每个重复15尾虾,在室内养殖桶中饲养8周。结果显示,随饲料蛋白酶添加量的增加：(1)各组间存活率、肝体比、腹部含肉率均无显著差异;增重率和特定生长率均先升高后降低,且在蛋白酶添加量为0.2 g/kg时达到最大值。当蛋白酶添加量为0.4 g/kg时饲料系数最低;蛋白质效率和蛋白质沉积率分别在添加量为0.4和0.2 g/kg时达到最高值。经折线回归分析,增重率、饲料系数、蛋白质效率分别在蛋白酶添加量为0.16、0.24、0.23 g/kg时有最佳值。(2)腹部肌肉和全虾粗蛋白质含量先升高后降低最终趋于平稳,均在0.2 g/kg组有最大值。(3)肠道及肝胰腺蛋白酶、脂肪酶、淀粉酶活性均先增加后缓慢降低,均在0.2 g/kg组出现最大值,且显著高于对照组。(4)血清总蛋白含量在0.4 g/kg组出现最大值;谷草转氨酶及谷丙转氨酶活性先降低后增加,均在0.4 ...     

Structure and function of antimicrobial peptide penaeidin-5 from the black tiger shrimp Penaeus monodon

The gene for penaeidin-5, an antimicrobial peptide comprising 55 amino acids, was isolated from the hemocyte of black tiger shrimp (Penaeus monodon). RT-PCR expression tests revealed that penaeidin-5 was produced in hemocytes, gills, the intestine and muscle. Western blot analysis confirmed the panaeidin-5 was aboundantin hemocytes, the intestine and hemolymph. Immunohistochemistry revealedpenaeidin-5 in the cuticle and gills that are considered primary defense barriers. The deduced amino acid sequence of penaeidin-5 included a proline-rich N-terminal domain and a carboxyl-domain that contained six cysteine residues. Circular dichrosim analysis revealed an -helix in its secondary structure and the predicted 3D structure indicated two-disulfide bridges in the -helix. Based on the sequence of penaeidin-5 peptide cDNA, synthetic penaeidin-5 was prepared to carry out functional tests. The synthetic peptide had efficient bacteriostatic and bactericidal activity against Aerococcus viridans, and also inhibited the growth of two filamentous fungi, Fusarium pisi and Fusarium oxysporum. To measure penaeidin-5 in vivo, black tiger shrimp were challenged with Vibrio alginolyticus and A. viridans. At 3 h post-challenge, penaeidin-5 was induced and bacterial numbers decreased significantly by 12 h and 24 h.     

T lymphocyte responses during early enteric Mycobacterium avium subspecies paratuberculosis infection in cattle

Johne's disease (JD) is a costly intestinal disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (Map), which is transmitted to perinatal calves by the fecal-oral route. Disease control efforts focus on identification and culling of infected cattle from herds; therefore failure to identify animals early is a major obstacle to reducing transmission. Development of host immunity during early JD remain incompletely characterized so detecting subclinical JD using immunologic techniques is a substantial challenge in the field. Development of a test with high sensitivity and specificity is a major research goal with significant implications for the cattle industry. The objectives of this study were to compare early Map-specific T lymphocyte responses in naive, experimentally Map infected and Map vaccinated calves using a subcutaneous matrigel biopolymer-based assay. We examined the phenotype of recruited lymphocytes and local interferon gamma (IFNγ) production within subcutaneously placed matrigel containing Map antigen 30 days after experimentally induced intestinal Map infection or Map vaccination. We show that IFNγ-secreting CD4+ T cells are recruited to matrigel sites in vaccinated but not infected or naïve calves. γδ T cells recruited to matrigel sites of Map-infected calves were mostly WC1-, while γδ T cells recruited to matrigel sites of Map-vaccinated calves were predominantly WC1+. IFNγ at matrigel sites was a discriminating factor between infected calves, naïve calves and vaccinated calves. These data contribute to our understanding of early anti-Map immunity, and may be useful for detecting early intestinal Map infections in calves or for enhancing our ability to discriminate between Map-infected and Map-vaccinated calves.     

Factors associated with morbidity,mortality, and growth of dairy heifer calves up to 3 months of age

Calfhood disease is an important problem on many dairy operations that can have substantial effects on heifer survival and productivity, and has economic and welfare impacts. Neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) are the most common causes of morbidity and mortality in young dairy cattle. The objective of this observational study was to investigate factors associated with the risks of morbidity and mortality, and with growth, in commercial dairy heifers calves. A total of 2874 heifer calves from 19 commercial dairy farms in Minnesota and Ontario were enrolled at 1–7 days of age and followed for approximately 3 months. Using cut-points of serum total protein of 5.2 and 5.7 g/dl, the incidences of failure of transfer of passive immunity (FTPI) were 11 and 32%, respectively. A cut-point of 5.7 g/dl was the most predictive of BRD before 5 weeks of age (sensitivity = 40%, specificity = 69%). The positive predictive value was poor (PPV = 18%), but the negative predictive value was good (NPV = 87%). A cut-point of 5.2 g/dl was most predictive of death before 5 weeks of age (sensitivity = 27%, specificity = 89%, PPV = 5%, NPV = 98%). Serum total protein during the first week of life was a poor predictor of NCD. Over 23% of calves were treated for diarrhea. Risk factors were weight at enrollment, other diseases before 2 weeks of age, and an interaction between season of birth and herd-level incidence of NCD. Almost 22% of calves were treated at least once for BRD. Factors associated with an increased risk of BRD included herd-level incidence of BRD, season of birth, navel dipping, other diseases before 2 weeks of age, failure of transfer of passive immunity, and manual control of temperature in pre-weaning housing. Administration of supplemental antibody products at birth was associated with a reduced incidence of BRD. Overall mortality was 3.5%. Risk of mortality was increased by treatment for BRD and other diseases. The mean average weight gain was 0.95 kg/day (range: 0.11–1.62 kg/day; SD = 0.2). Twinning status, FTP, treatment for NCD or other diseases, and month of birth influenced body weight. This study illustrated relationships among various diseases, mortality, and growth. Furthermore, it demonstrated the importance of colostrum for protection against BRD and improved growth performance, while bringing into question the optimal method of determining failure of transfer of passive immunity.