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     

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。     

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。     

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。     

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.     

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.     

SPF莱航鸡种群的微卫星多态性分析

【研究目的】利用5个微卫星位点对两个SPF莱航鸡封闭群进行了遗传检测,探讨群体内的遗传多态性,以期为实验用鸡遗传质量监测提供理论依据。【方法】PCR扩增后用ABI-3100Avant全自动基因分析仪进行电泳检测,用Genemapper3.1软件进行片段大小分析,收集电泳结果并进行基因分型。【结果】5个微卫星标记在A、B两个鸡群中共检测到20个等位基因,平均为4个;两个鸡群的平均杂合度为0.6211,平均多态信息含量为0.6663,表明所选标记在SPF莱航鸡群中有较高的多态性;adl176位点的180峰仅出现在A群中,188、191两峰在两个群体中的频率相差极大,可作为品系鉴定的理想引物。【结论】大部分微卫星具有多态性,若进行大范围筛查,必能找到一些特异位点为遗传监测所用。     

鸭呼肠孤病毒人工感染SPF鸡胚的病理学研究

【目的】前人研究表明禽呼肠孤病毒可以经卵垂直传播, 禽呼肠孤病毒能引起雏禽的病毒性关节炎、呼吸道和肠道疾病、肝炎、心肌炎、免疫抑制等。以实验室分离的鸭呼肠孤病毒HP080421株为研究对象,该毒株引起病变主要以鸭软脚为主要临床特征,病鸭肝脏和脾脏表面有大量的白色坏死灶、肾脏肿大、出血为主要病变特点。研究了鸭呼肠孤病毒对鸡胚的致病性,通过雏鸡的病理变化特点,探讨所分离的HP080421鸭呼肠孤病毒株是否也可感染鸡群,旨在为鸡场鸭呼肠孤病毒感染的防控提供理论依据。【方法】运用华中农业大学兽医病理学实验室分离鉴定的HP080421株鸭呼肠孤病毒通过尿囊腔接种SPF鸡胚,建立SPF鸡胚鸭呼肠孤病毒感染模型,培养鸡胚至雏鸡出壳,运用临床观察、病理剖检、H.E染色和免疫组织化学染色等病理组织学检查方法,对鸭呼肠孤病毒感染SPF鸡胚进行病理学研究和致病性分析。【结果】研究发现病毒感染鸡胚孵化培养至22-23日龄均啄壳,但不能自主出壳,需人工剥壳。病理剖检可见雏鸡的肝脏、脾脏肿胀质脆,表面及实质分布有黄白色坏死灶;脑部组织肿胀,并可见出血点和出血斑。H.E染色的组织病理学观察可见接毒组雏鸡肝脏、脾脏的坏死灶周围有大量淋巴细胞浸润;法氏囊的滤泡髓质部和胸腺的髓质部淋巴细胞减少、缺失;脑、肺脏、肾脏存在不同程度的淤血、出血和水肿;免疫组织化学染色结果表明：病毒阳性信号主要分布于肝脏、脾脏、肺脏和法氏囊等器官,并且位于上皮细胞和巨噬细胞的细胞质和胞核内。【结论】鸭呼肠孤病毒株HP080421 能够在SPF鸡胚中复制增殖,并使雏鸡主要器官发生明显的病理变化,病理变化主要集中在肝脏和淋巴器官,因此鸭呼肠孤病毒可通过垂直传播感染鸡群,还可导致雏鸡免疫抑制。本研究通过SPF鸡胚鸭呼肠孤病毒感染模型,阐述了鸭呼肠孤病毒感染鸡群的可能性,因此在实际养殖过程中,养殖户要防止鸭呼肠孤病毒对鸡胚的污染,切断传播途径,以达到预防鸡群感染鸭呼肠孤病毒的目的。