鸭源NDV对SPF鸭免疫机能的影响

【目的】探讨鸭源新城疫病毒(NDV)对SPF鸭免疫机能的影响。【方法】选用120只已免疫H5N1禽流感油乳剂灭活疫苗的SPF鸭,随机分为静脉注射组、点眼滴鼻组和对照组,每组40只。攻毒(2个试验组接种鸭源NDV 0.2mL(含病毒106 ELD50),对照组点眼滴鼻等量生理盐水)后观测各组鸭的发病死亡情况,于感染后不同时间随机剖杀试验组和对照组鸭,采集脾脏、法氏囊,按常规方法制备石蜡切片,TUNEL法检测脾脏、法氏囊细胞凋亡情况,同时检测血液生化和血液常规指标,并测定鸭源NDV对SPF鸭外周血中淋巴细胞转化率和H5N1油乳剂灭活疫苗HI抗体效价的影响以及CD4+/CD8+的动态变化,分析不同处理组鸭源NDV对SPF鸭免疫机能的影响。【结果】攻毒后,试验组SPF鸭发病率为100%,死亡率为32.5%,并出现呼吸困难、肺脏出血、腺胃乳头出血等症状及剖检变化;血常规检测结果显示,鸭源NDV静脉注射组和点眼滴鼻组血液中红细胞总数、血红蛋白含量先降低后显著升高,血小板总数、白细胞总数降低且均与对照组差异显著(P<0.05)或极显著(P<0.01);血液生化检测结果显示,试验组鸭谷丙转氨酶、谷草转氨酶、乳酸脱氢酶、肌酸激酶、淀粉酶活性升高,总蛋白含量降低,与对照组相比差异显著(P<0.05)或极显著(P<0.01);静脉注射组和点眼滴鼻组的H5N1油乳剂灭活疫苗HI抗体效价比对照组低但差异不显著,淋巴细胞转化率与对照组相比降低且差异显著(P<0.05)或极显著(P<0.01);静脉注射组与点眼滴鼻组的CD4+/CD8+变化趋势基本一致,均为先升高后降至正常水平以下。TUNEL法检测脾脏、法氏囊均出现细胞凋亡,且凋亡率随着攻毒后时间的增加而升高。【结论】SPF鸭接种鸭源NDV后能引起免疫抑制。     

类蜘蛛丝丝素蛋白SPF198在毕赤酵母中的分泌表达

将人工合成的长度为594 bp的类蜘蛛丝丝素蛋白spf198基因克隆到表达载体pP iczαA并导入毕赤酵母(Pichia pastoris)GS115细胞内,利用筛选到的Mut+(m ethanol utilization p lus)重组酵母株进行了表达。初步的研究结果显示,spf198基因在GS115酵母里可以正确表达。     

微波在SPF实验动物饲料灭菌中的应用

本试验采用4因素3水平正交试验设计L(934),就微波处理前饲料的水分含量、微波功率、处理时间和料层厚度对饲料灭菌效果的影响进行了研究。结果表明:1)大肠杆菌、霉菌和酵母对微波比较敏感,经过3min的微波处理,都未检出。2)饲料水分含量、微波加热时间、微波功率和料层厚度对饲料中菌落总数有极显著影响(P<0.01),其影响程度为:微波加热时间>料层厚度>微波功率>饲料水分含量。3)最优工艺组合为饲料含水34%、微波加热9min、功率为700W、料层厚度为12mm,可以考虑适当减少微波时间。     

Enhancement of mucosal immune responses by intranasal co-delivery of Newcastle disease vaccine plus CpG oligonucleotide in SPF chickens in vivo

Immunostimulatory CpG oligodeoxynucleotides (ODN) have been tested as immunoadjuvants for various vaccines in mice and human. Findings from previous reports suggest that CpG ODN can be used to enhance magnitude and balance of an immune response while reducing undesirable side effects of commercial vaccine, when delivered by parenteral route. Recently, it has been showed that CpG ODN is a promising mucosal adjuvant in mice, but data on mucosal immune responses induced by CpG ODN in other animals, especially in chickens, are scarce. Herein, we evaluated intranasal (IN) delivery of CpG ODN with newcastle disease (ND) vaccine (NDV) to determine its potential as a mucosal adjuvant to a commercial vaccine. CpG ODN augmented systemic (IgG in serum, T cell proliferation) and mucosal (IgA in intestinal washings and feces) immune responses against antigen. CpG ODN stimulated effectively both systemic and mucosal immune responses when delivered intranasally. Results from this study indicate that stimulatory CpG ODN is a potential effective mucosal adjuvant for the NDV in SPF chickens and may be applicable to husbandry animals.     

Transmission of pathogenic respiratory bacteria to specific pathogen free pigs at slaughter

The purpose of this study was to evaluate the transmission of pathogenic respiratory bacteria to thirteen 5-month-old specific pathogen free (SPF) pigs, during the slaughtering process in a commercial slaughterhouse. Before transportation, the SPF pigs and the lorry were checked to confirm the absence of pathogenic respiratory bacteria.

Nine SPF pigs (group 1) were in contact in a conventional slaughterhouse with finishing pigs, during 4 h before slaughtering. Four SPF pigs (group 2) were slaughtered immediately at arrival in the slaughterhouse.

Five bacterial pathogens (Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Pasteurella multocida, Haemophilus parasuis and Streptococcus suis) were detected by PCR, after slaughtering, from nasal cavities, tonsils and trachea in the two groups of pigs. Lung samples were PCR negative. Three and four bacterial species were isolated from the pigs of group 2 and group 1, respectively. Cultures were negative from the lungs.

All the bacterial species present in the SPF pigs were detected by PCR. P. multocida was isolated, from three samples of scalding water before the onset of slaughtering.

Our results suggest that the SPF pigs became contaminated mainly by the slaughterhouse environment and the scalding water. Histological examinations revealed that during scalding, contaminated water could reach the trachea and the lungs of pigs. Checks conducted at slaughter for respiratory disorders have to be carried on, but nasal cavities and tonsils are not appropriate for bacteriological investigations. Moreover, bacteriological results obtained from the lungs of slaughtered pigs have to be used with carefulness.     

感染网状内皮组织增殖病病毒SPF雏鸡中枢和外周免疫器官的免疫学变化

实验研究了１日龄ＳＰＦ雏鸡感染网状内皮组织增殖病病毒（Ｒｅｔｉｃｕｌｏｅｎｄｏｔｈｅｌｉｏｓｉｓｖｉｒｕｓ,ＲＥＶ）后免疫器官匀浆涂片的免疫学变化。结果发现,雏鸡感染ＲＥＶ后其免疫器官法氏囊、胸腺、脾脏中淋巴细胞数、酯酶阳性（ＡＮＡＥ＋）Ｔ细胞数以及颗粒型和弥散型ＡＮＡＥ＋Ｔ淋巴细胞数显著降低（Ｐ＜０．０５,Ｐ＜０．０１）。表明１日龄ＳＰＦ雏鸡感染ＲＥＶ后,其中枢免疫器官和外周免疫器官的细胞免疫呈现抑制。     

SPF鸡人工感染鸡败血霉形体后血液生物化学变化

用鸡败血霉形体（ＭＧ）国际标准强毒Ｒ株人工感染１５日龄ＳＰＦ鸡,在感染后１５ｄ采血作血液生物化学检验。结果：ＴＢｉｌ、ＧＯＴ、ＧＰＴ、ＡＬＰ、ＬＤｈ、ＣＯ２－ＣＰ、ＣＲＥ、ＢｕＮ、ＣＲＥ－Ｕ、无机磷、Ｍｇ＾２＋明显升高,而ＴＰ、ＡＬＢ、Ａ／Ｇ、Ｃｈｏ、Ｇｌｕ、Ｃａ＾２＋等明显下降,ＲＢＣ和Ｈｂ下降,ＷＢＣ上升,其中ＬＣ和嗜酸性白细胞明显上升。说明ＭＧ不仅造成呼吸系统障碍,也对肝功能和功能产生较大影     

某复方中药抗禽流感病毒的免疫机制

通过SPF鸡服用某复方中药后,了解免疫器官指数、外周血液中CD 3、CD 4、CD 8及TCR 1T淋巴细胞百分比含量及IgG的变化,探索某复方中药对禽流感病毒作用的免疫机理.结果表明:给药组免疫器官指数、外周血液中CD 3、CD 4、CD 8及TCR 1 T淋巴细胞百分比含量及IgG均比对照组高.所以,该复方中药可促进SPF雏鸡免疫器官的发育和迅速成熟,提高SPF鸡的细胞免疫及体液免疫功能.     

重组禽流感灭活苗和禽流感灭活苗对鸡免疫效果的观察

用重组禽流感灭活苗接种10日龄、14日龄和21日龄的SPF鸡,接种后HI抗体效价无显著差异。将H5N1和H5N2疫苗分别接种21日龄SPF鸡,结果表明,H5N1和H5N2均能刺激SPF鸡产生较高的HI抗体;分别接种三黄鸡,接种后21 d,H5N1能刺激三黄鸡产生较高的HI抗体;而H5N2不能刺激三黄鸡产生合格的HI抗体,与SPF鸡免疫组相比差异显著。经过二次接种,HI抗体平均为8.9 log2,与SPF鸡组接种后42 d的各组相比差异不显著,而与一免后21 d的各组HI抗体效价相比差异显著。表明应用禽流感灭活苗对三黄鸡免疫接种,必须进行二免方可达到理想免疫效果,而应用重组禽流感灭活苗对三黄鸡进行免疫接种,一次免疫即可获得较高的HI抗体效价。